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Shilovsky GA, Putyatina TS, Markov AV. Evolution of Longevity in Tetrapods: Safety Is More Important than Metabolism Level. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:322-340. [PMID: 38622099 DOI: 10.1134/s0006297924020111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 12/04/2023] [Accepted: 12/29/2023] [Indexed: 04/17/2024]
Abstract
Various environmental morphological and behavioral factors can determine the longevity of representatives of various taxa. Long-lived species develop systems aimed at increasing organism stability, defense, and, ultimately, lifespan. Long-lived species to a different extent manifest the factors favoring longevity (gerontological success), such as body size, slow metabolism, activity of body's repair and antioxidant defense systems, resistance to toxic substances and tumorigenesis, and presence of neotenic features. In continuation of our studies of mammals, we investigated the characteristics that distinguish long-lived ectotherms (crocodiles and turtles) and compared them with those of other ectotherms (squamates and amphibians) and endotherms (birds and mammals). We also discussed mathematical indicators used to assess the predisposition to longevity in different species, including standard indicators (mortality rate, maximum lifespan, coefficient of variation of lifespan) and their derivatives. Evolutionary patterns of aging are further explained by the protective phenotypes and life history strategies. We assessed the relationship between the lifespan and various studied factors, such as body size and temperature, encephalization, protection of occupied ecological niches, presence of protective structures (for example, shells and osteoderms), and environmental temperature, and the influence of these factors on the variation of the lifespan as a statistical parameter. Our studies did not confirm the hypothesis on the metabolism level and temperature as the most decisive factors of longevity. It was found that animals protected by shells (e.g., turtles with their exceptional longevity) live longer than species that have poison or lack such protective adaptations. The improvement of defense against external threats in long-lived ectotherms is consistent with the characteristics of long-lived endotherms (for example, naked mole-rats that live in underground tunnels, or bats and birds, whose ability to fly is one of the best defense mechanisms).
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Affiliation(s)
- Gregory A Shilovsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
- Institute for Information Transmission Problems (Kharkevich Institute), Russian Academy of Sciences, Moscow, 127051, Russia
| | - Tatyana S Putyatina
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Alexander V Markov
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
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2
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Chu PC, Wierucka K, Murphy D, Tilley HB, Mumby HS. Human interventions in a behavioural experiment for Asian Elephants (Elephas maximus). Anim Cogn 2023; 26:393-404. [PMID: 35987800 PMCID: PMC9392510 DOI: 10.1007/s10071-022-01668-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 07/21/2022] [Accepted: 08/01/2022] [Indexed: 11/30/2022]
Abstract
Experiments are widely used to investigate the behaviour and cognition of animals. While the automation of experiments to avoid potential experimenter bias is sometimes possible, not all experiments can be conducted without human presence. This is particularly true for large animals in captivity, which are often managed by professional handlers. For the safety of the animals and experimenters, a handler must be present during behavioural studies with certain species. It is not always clear to what extent cues provided by handlers affect the animals, and therefore the experimental results. In this study, we investigate handler interventions during the training process for a behavioural experiment with Asian elephants (Elephas maximus) in Nepal. We show that elephant handlers (mahouts) intervened to guide elephants in performing the learning task using vocal and behavioural cues, despite experimenters requesting minimal intervention. We found that although the frequency of mahout interventions did not decrease as the training progressed, the nature of their interventions changed. We also found more non-verbal than verbal cues across the training. Our results suggest that guidance from handlers may be common in behavioural studies, and continued consideration should be put into experimental design to reduce or account for cues that animals may receive from humans. This study also emphasises the need to take into account the presence of humans in interpreting the results of animal behavioural experiments, which not only presents challenges to behavioural research, but also represents opportunities for further study.
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Affiliation(s)
- Pui Ching Chu
- Area of Ecology and Biodiversity, School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Kaja Wierucka
- Area of Ecology and Biodiversity, School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong
- Department of Anthropology, University of Zurich, Zurich, Switzerland
| | - Derek Murphy
- Area of Ecology and Biodiversity, School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong
- Cognitive Ethology Laboratory, German Primate Centre, Göttingen, Germany
| | - Hannah Bethany Tilley
- Area of Ecology and Biodiversity, School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Hannah Sue Mumby
- Area of Ecology and Biodiversity, School of Biological Sciences, University of Hong Kong, Pok Fu Lam, Hong Kong.
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3
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Gingerich PD, Amane A, Zouhri S. Skull and partial skeleton of a new pachycetine genus (Cetacea, Basilosauridae) from the Aridal Formation, Bartonian middle Eocene, of southwestern Morocco. PLoS One 2022; 17:e0276110. [PMID: 36288346 PMCID: PMC9604876 DOI: 10.1371/journal.pone.0276110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 09/22/2022] [Indexed: 11/18/2022] Open
Abstract
Pachycetus paulsonii, Pachycetus wardii, and Antaecetus aithai are middle Eocene archaeocete whales found in Europe, North America, and Africa, respectively. The three are placed in the new basilosaurid subfamily Pachycetinae. Antaecetus is a new genus known from Egypt and Morocco, and the only pachycetine known from a substantial postcranial skeleton. The skull of A. aithai described here resembles that of Saghacetus osiris in size, but lacks the narrowly constricted rostrum of Saghacetus. Antaecetus is smaller than Pachycetus and its teeth are more gracile. Upper premolars differ in having two rather than three accessory cusps flanking the principal cusp. Pachycetines differ from dorudontines in having elongated posterior thoracic and lumbar vertebrae like those of Basilosaurus, but differ from basilosaurines and from dorudontines in having conspicuously pachyosteosclerotic vertebrae with dense and thickly laminated cortical bone surrounding a cancellous core. Pachycetinae are also distinctive in having transverse processes on lumbar vertebrae nearly as long anteroposteriorly as the corresponding centrum. We infer from their pachyosteosclerotic vertebrae that pachycetines were probably sirenian-like slow swimmers living in shallow coastal seas and feeding on passing fish and mobile invertebrates.
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Affiliation(s)
- Philip D. Gingerich
- Museum of Paleontology, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
| | - Ayoub Amane
- Department of Geology and Health and Environment Laboratory, Faculty of Sciences Aïn Chock, Hassan II University of Casablanca, Casablanca, Morocco
| | - Samir Zouhri
- Department of Geology and Health and Environment Laboratory, Faculty of Sciences Aïn Chock, Hassan II University of Casablanca, Casablanca, Morocco
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4
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Retallack GJ. Damaged Dickinsonia specimens provide clues to Ediacaran vendobiont biology. PLoS One 2022; 17:e0269638. [PMID: 35709144 PMCID: PMC9202952 DOI: 10.1371/journal.pone.0269638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 05/19/2022] [Indexed: 12/14/2022] Open
Abstract
Recently reported specimens of the enigmatic Ediacaran fossil Dickinsonia from Russia show damage and repair that provides evidence of how they grew, and of their biological affinities. Marginal and terminal areas of wilting deformation are necrotic zones separating regenerated growth, sometimes on two divergent axes, rather than a single axis. Necrotic zones of damage to Dickinsonia are not a thick scar or callus, like a wound or amputation. Nor are they smooth transitions to a regenerated tail or arm. The wilted necrotic zone is most like damage by freezing, salt, or sunburn of leaves and lichens, compatible with evidence of terrestrial habitat from associated frigid and gypsic paleosols. Dickinsonia did not regrow by postembryonic addition of modules from a subterminal or patterned growth zone as in earthworms, myriapods, trilobites, crustaceans, and lizards. Rather Dickinsonia postembryonic regrowth from sublethal damage was from microscopic apical and lateral meristems, as in plants and lichens. Considered as fungal, Dickinsonia, and perhaps others of Class Vendobionta, were more likely Glomeromycota or Mucoromycotina, rather than Ascomycota or Basidiomycota.
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Affiliation(s)
- Gregory J. Retallack
- Department of Earth Sciences, University of Oregon, Eugene, Oregon, United States of America
- * E-mail:
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5
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Social Behavior and Group Formation in Male Asian Elephants (Elephas maximus): The Effects of Age and Musth in Wild and Zoo-Housed Animals. Animals (Basel) 2022; 12:ani12091215. [PMID: 35565641 PMCID: PMC9100748 DOI: 10.3390/ani12091215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/03/2022] [Accepted: 05/06/2022] [Indexed: 12/10/2022] Open
Abstract
Simple Summary The conservation of wild and zoo-housed Asian elephants partly depends on developing our understanding of male elephant social behavior. Once thought to be solitary, we now know that male elephants can display rich social exchanges with both males and females. However, these interactions are expected to change with age and around the sexually active state of “musth.” We used behavioral data from wild and zoo-housed elephant populations to investigate how age, musth, and environmental factors influence how male elephants socialize and associate with group members. In Sri Lanka, only male elephants of older age (>20 years) exhibited signs of musth, but even some of the youngest zoo-housed elephants underwent musth (as young as 11 years). Additionally, we found that age and musth status predicted whether a wild male elephant associated with females, other males or was alone, as well as the number of conspecifics (males and females) in the same group with which a male was observed. Finally, rates of aggression, prosocial behavior (affiliative behaviors that promote positive social bonds between elephants), and submissive behavior exhibited by wild and zoo-housed male elephants were associated with age, musth status, the number of elephants presented, and group type (all-male or mixed sex). These results provide motivation for future studies of social behavior in male Asian elephants, as they will contribute to the reproduction and conservation of this endangered species. Abstract Asian elephants are endangered, and the long-term viability of the species depends on integrative approaches to address the sustainability of in-situ and ex-situ populations. Growing evidence shows that male elephants exhibit extensive and flexible social behavior that rivals the complexity of that of females. Male elephant sociality is expected to change dramatically around the unique sexual state of musth. However, data related to male Asian elephant sociality is lacking. Here, we conducted complementary observations in Wasgamuwa National Park, Sri Lanka, and North American zoos of male Asian elephant social behavior. Age and musth status, along with other factors, were associated with variation in social behavior and group formation of males. In wild male elephants, both musth status and age impacted elephant associations within all-male and mixed-sex groups: non-musth elephants were generally sighted less often in mixed-sex groups as they aged, while the inverse occurred with musth elephants. Musth status interacted with age to predict the number of conspecifics with which a wild male elephant associated: younger males were observed with more females during non-musth (but the opposite was true during musth), and male elephants between 20 and 30 years were observed with the highest number of male conspecifics except during musth. Finally, we found variation in aggression, prosocial behavior, and submissive behavior was influenced by intrinsic (age and musth status) and extrinsic factors (group size and type) in similar ways in both populations; prosocial behavior was most common and was influenced by the number of conspecifics present (both populations), and age, group type, and musth status (zoo population), while aggression was rare, especially among older elephants. We suggest that longitudinal studies of this threatened species will be particularly helpful to promote the reproduction and conservation of Asian elephants in in-situ and ex-situ environments.
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Lalande LD, Lummaa V, Aung HH, Htut W, Nyein UK, Berger V, Briga M. Sex-specific body mass ageing trajectories in adult Asian elephants. J Evol Biol 2022; 35:752-762. [PMID: 35470907 DOI: 10.1111/jeb.14008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 03/17/2022] [Accepted: 03/28/2022] [Indexed: 11/29/2022]
Abstract
In species with marked sexual dimorphism, the classic prediction is that the sex which undergoes stronger intrasexual competition ages earlier or quicker. However, more recently, alternative hypotheses have been put forward, showing that this association can be disrupted. Here, we utilize a unique, longitudinal data set of a semi-captive population of Asian elephants (Elephas maximus), a species with marked male-biased intrasexual competition, with males being larger and having shorter lifespans, and investigate whether males show earlier and/or faster body mass ageing than females. We found evidence of sex-specific body mass ageing trajectories: adult males gained weight up to the age of 48 years old, followed by a decrease in body mass until natural death. In contrast, adult females gained body mass with age until a body mass decline in the last year of life. Our study shows sex-specific ageing patterns, with an earlier onset of body mass declines in males than females, which is consistent with the predictions of the classical theory of ageing.
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Affiliation(s)
- Lucas D Lalande
- Department of Biology, University of Turku, Turku, Finland.,Université Bourgogne Franche-Comté, Dijon, France.,Université de Lyon, Université Claude Bernard Lyon 1, Laboratoire de Biométrie et Biologie Evolutive, UMR 5558, Villeurbanne CEDEX, France
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku, Finland
| | - Htoo H Aung
- Myanma Timber Enterprise, Ministry of Natural Resources and Environmental Conservation, West Gyogone Forest Compound, Yangon, Myanmar
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environmental Conservation, West Gyogone Forest Compound, Yangon, Myanmar
| | - U Kyaw Nyein
- Myanma Timber Enterprise, Ministry of Natural Resources and Environmental Conservation, West Gyogone Forest Compound, Yangon, Myanmar
| | - Vérane Berger
- Department of Biology, University of Turku, Turku, Finland
| | - Michael Briga
- Department of Biology, University of Turku, Turku, Finland.,Infectious Disease Epidemiology Group, Max Planck Institute for Infection Biology, Berlin, Germany
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7
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Mumby HS, Chapman SN, Crawley JAH, Mar KU, Htut W, Soe AT, Aung HH, Lummaa V. Correction to: Distinguishing between determinate and indeterminate growth in a long-lived mammal. BMC Ecol Evol 2021; 21:217. [PMID: 34872496 PMCID: PMC8647441 DOI: 10.1186/s12862-021-01951-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Hannah S Mumby
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
| | - Simon N Chapman
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Jennie A H Crawley
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Khyne U Mar
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Win Htut
- Ministry of Environmental Conservation and Forestry, Myanmar Timber Enterprise, Yangon, Myanmar
| | - Aung Thura Soe
- Ministry of Environmental Conservation and Forestry, Myanmar Timber Enterprise, Yangon, Myanmar
| | - Htoo Htoo Aung
- Ministry of Environmental Conservation and Forestry, Myanmar Timber Enterprise, Yangon, Myanmar
| | - Virpi Lummaa
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
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8
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Köhler M, Herridge V, Nacarino-Meneses C, Fortuny J, Moncunill-Solé B, Rosso A, Sanfilippo R, Palombo MR, Moyà-Solà S. Palaeohistology reveals a slow pace of life for the dwarfed Sicilian elephant. Sci Rep 2021; 11:22862. [PMID: 34819557 PMCID: PMC8613187 DOI: 10.1038/s41598-021-02192-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/11/2021] [Indexed: 11/17/2022] Open
Abstract
The 1-m-tall dwarf elephant Palaeoloxodon falconeri from the Pleistocene of Sicily (Italy) is an extreme example of insular dwarfism and epitomizes the Island Rule. Based on scaling of life-history (LH) traits with body mass, P. falconeri is widely considered to be ‘r-selected’ by truncation of the growth period, associated with an early onset of reproduction and an abbreviated lifespan. These conjectures are, however, at odds with predictions from LH models for adaptive shifts in body size on islands. To settle the LH strategy of P. falconeri, we used bone, molar, and tusk histology to infer growth rates, age at first reproduction, and longevity. Our results from all approaches are congruent and provide evidence that the insular dwarf elephant grew at very slow rates over an extended period; attained maturity at the age of 15 years; and had a minimum lifespan of 68 years. This surpasses not only the values predicted from body mass but even those of both its giant sister taxon (P. antiquus) and its large mainland cousin (L. africana). The suite of LH traits of P. falconeri is consistent with the LH data hitherto inferred for other dwarfed insular mammals. P. falconeri, thus, not only epitomizes the Island Rule but it can also be viewed as a paradigm of evolutionary change towards a slow LH that accompanies the process of dwarfing in insular mammals.
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Affiliation(s)
- Meike Köhler
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain. .,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain.
| | | | - Carmen Nacarino-Meneses
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain.,Department of Biological Sciences, University of Cape Town, Rondebosch, Cape Town, South Africa
| | - Josep Fortuny
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain
| | - Blanca Moncunill-Solé
- Dipartimento di Scienze, Università degli Studi Roma Tre, Roma, Italy.,Centro de Investigacións Científicas Avanzadas, Universidade da Coruña, A Coruña, Spain
| | - Antonietta Rosso
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Catania, Catania, Italy
| | - Rossana Sanfilippo
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Catania, Catania, Italy
| | - Maria Rita Palombo
- c7o Earth Science Department, IGAG-CNR, Sapienza University of Rome, Rome, Italy
| | - Salvador Moyà-Solà
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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9
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Fuchs E, Beeck VC, Baotic A, Stoeger AS. Acoustic structure and information content of trumpets in female Asian elephants (Elephas maximus). PLoS One 2021; 16:e0260284. [PMID: 34813615 PMCID: PMC8610244 DOI: 10.1371/journal.pone.0260284] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 11/05/2021] [Indexed: 12/02/2022] Open
Abstract
Most studies on elephant vocal communication have focused on the low-frequency rumble, with less effort on other vocalization types such as the most characteristic elephant call, the trumpet. Yet, a better and more complete understanding of the elephant vocal system requires investigating other vocalization types and their functioning in more detail as well. We recorded adult female Asian elephants (Elephas maximus) at a private facility in Nepal and analyzed 206 trumpets from six individuals regarding their frequency, temporal and contour shape, and related acoustic parameters of the fundamental frequency. We also tested for information content regarding individuality and context. Finally, we recorded the occurrence of non-linear phenomena such as bifurcation, biphonation, subharmonics and deterministic chaos. We documented a mean fundamental frequency ± SD of 474 ± 70 Hz and a mean duration ± SD of 1.38 ± 1.46 s (Nindiv. = 6, Ncalls = 206). Our study reveals that the contour of the fundamental frequency of trumpets encodes information about individuality, but we found no evidence for trumpet subtypes in greeting versus disturbance contexts. Non-linear phenomena prevailed and varied in abundance among individuals, suggesting that irregularities in trumpets might enhance the potential for individual recognition. We propose that trumpets in adult female Asian elephants serve to convey an individual's identity as well as to signal arousal and excitement to conspecifics.
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Affiliation(s)
- Evelyn Fuchs
- Mammal Communication Lab, Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Veronika C. Beeck
- Mammal Communication Lab, Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Anton Baotic
- Mammal Communication Lab, Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Angela S. Stoeger
- Mammal Communication Lab, Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
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Reichert S, Berger V, Dos Santos DJF, Lahdenperä M, Nyein UK, Htut W, Lummaa V. Age related variation of health markers in Asian elephants. Exp Gerontol 2021; 157:111629. [PMID: 34800624 DOI: 10.1016/j.exger.2021.111629] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 11/12/2021] [Indexed: 11/15/2022]
Abstract
Although senescence is often observed in the wild, its underlying mechanistic causes can rarely be studied alongside its consequences, because data on health, molecular and physiological measures of senescence are rare. Documenting how different age-related changes in health accelerate ageing at a mechanistic level is key if we are to better understand the ageing process. Nevertheless, very few studies, particularly on natural populations of long-lived animals, have investigated age-related variation in biological markers of health and sex differences therein. Using blood samples collected from semi-captive Asian elephants, we show that pronounced differences in haematology, blood chemistry, immune, and liver functions among age classes are also evident under natural conditions in this extremely long-lived mammal. We provide strong support that overall health declined with age, with progressive declines in immune and liver functions similarly in both males and females. These changes parallel those mainly observed to-date in humans and laboratory mammals, and suggest a certain ubiquity in the ageing patterns.
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Affiliation(s)
- Sophie Reichert
- Department of Biology, University of Turku, Turku, Finland; Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, UK.
| | - Vérane Berger
- Department of Biology, University of Turku, Turku, Finland.
| | | | - Mirkka Lahdenperä
- Department of Public Health, University of Turku and Turku University Hospital, 20014 Turku, Finland; Centre for Population Health Research, University of Turku and Turku University Hospital, 20014 Turku, Finland
| | - U Kyaw Nyein
- Myanma Timber Enterprise, Ministry of Natural Resources and Environmental Conservation, Yangon, Myanmar
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environmental Conservation, Yangon, Myanmar
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku, Finland
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11
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Berger V, Reichert S, Lahdenperä M, Jackson J, Htut W, Lummaa V. The elephant in the family: Costs and benefits of elder siblings on younger offspring life-history trajectory in a matrilineal mammal. J Anim Ecol 2021; 90:2663-2677. [PMID: 34545574 DOI: 10.1111/1365-2656.13573] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 07/21/2021] [Indexed: 11/30/2022]
Abstract
Many mammals grow up with siblings, and interactions between them can influence offspring phenotype and fitness. Among these interactions, sibling competition between different-age offspring should lead to reproductive and survival costs on the younger sibling, while sibling cooperation should improve younger sibling's reproductive potential and survival. However, little is known about the consequences of sibling effects on younger offspring life-history trajectory, especially in long-lived mammals. We take advantage of a large, multigenerational demographic dataset from semi-captive Asian elephants to investigate how the presence and sex of elder siblings influence the sex, survival until 5 years old, body condition, reproductive success (i.e. age at first reproduction and lifetime reproductive success) and long-term survival of subsequent offspring. We find that elder siblings have heterogeneous effects on subsequent offspring life-history traits depending on their presence, their sex and the sex of the subsequent offspring (named focal calf). Overall, the presence of an elder sibling (either sex) strongly increased focal calf long-term survival (either sex) compared to sibling absence. However, elder sisters had higher impact on the focal sibling than elder brothers. Focal females born after a female display higher long-term survival, and decreased age at first reproduction when raised together with an elder sister rather than a brother. Focal males born after a female rather than a male showed lower survival but higher body weight when both were raised together. We did not detect any sibling effects on the sex of the focal calf sex, survival until 5 years old and lifetime reproductive success. Our results highlight the general complexity of sibling effects, but broadly that elder siblings can influence the life-history trajectory of subsequent offspring. We also stress the importance of considering all life stages when evaluating sibling effects on life trajectories.
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Affiliation(s)
- Vérane Berger
- Department of Biology, University of Turku, Turku, Finland
| | - Sophie Reichert
- Department of Biology, University of Turku, Turku, Finland.,Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Mirkka Lahdenperä
- Department of Public Health, University of Turku and Turku University Hospital, Turku, Finland.,Centre for Population Health Research, University of Turku and Turku University Hospital, Turku, Finland
| | - John Jackson
- Department of Zoology, University of Oxford, Oxford, UK
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environmental Conservation, Yangon, Myanmar
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku, Finland
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12
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Abstract
Relationships between the complexity of the cranial sutures and the inferred ecology of dicynodont synapsids are explored. Simple complexity indices based on degree of sutural interdigitation were calculated for 70 anomodont species and indicate that the naso-frontal sutures of Cistecephalidae, a clade inferred to be dedicated fossors based on aspects of postcranial morphology, are substantially more complex than those of other dicynodonts. The elevated complexity of the naso-frontal suture in this clade is interpreted as being related to compressive forces sustained during burrowing, paralleling the condition in some other fossorial vertebrate groups (e.g., amphisbaenians). The most highly interdigitated sutures in the cistecephalid skull are those oriented transversely to its long axis, which would experience the greatest longitudinal stresses from contact with the substrate. Although it is uncertain to what degree cistecephalid burrowing was based on scratch vs. head-lift digging, it is argued that the head played an important role during locomotion in this group. Increased sutural complexity, rather than cranial fusion, as an adaptation to resisting compressive forces during burrowing may be related to indeterminate growth in dicynodonts.
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13
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Beeck VC, Heilmann G, Kerscher M, Stoeger AS. A novel theory of Asian elephant high-frequency squeak production. BMC Biol 2021; 19:121. [PMID: 34134675 PMCID: PMC8210382 DOI: 10.1186/s12915-021-01026-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/14/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Anatomical and cognitive adaptations to overcome morpho-mechanical limitations of laryngeal sound production, where body size and the related vocal apparatus dimensions determine the fundamental frequency, increase vocal diversity across taxa. Elephants flexibly use laryngeal and trunk-based vocalizations to form a repertoire ranging from infrasonic rumbles to higher-pitched trumpets. Moreover, they are among the few evolutionarily distantly related animals (humans, pinnipeds, cetaceans, birds) capable of imitating species-atypical sounds. Yet, their vocal plasticity has so far not been related to functions within their natural communicative system, in part because not all call types have been systematically studied. Here, we reveal how Asian elephants (Elephas maximus) produce species-specific squeaks (F0 300-2300 Hz) by using acoustic camera recordings to visualize sound emission and examining this alongside acoustic, behavioral, and morphological data across seven captive groups. RESULTS We found that squeaks were emitted through the closed mouth in synchrony with cheek depression and retraction of the labial angles. The simultaneous emission of squeaks with nasal snorts (biphonation) in one individual confirmed that squeak production was independent of nasal passage involvement and this implicated oral sound production. The squeaks' spectral structure is incongruent with laryngeal sound production and aerodynamic whistles, pointing to tissue vibration as the sound source. Anatomical considerations suggest that the longitudinal closed lips function as the vibrators. Acoustic and temporal parameters exhibit high intra- and inter-individual variability that enables individual but no call-subtype classification. Only 19 of 56 study subjects were recorded to squeak, mostly during alarming contexts and social arousal but some also on command. CONCLUSION Our results strongly suggest that Asian elephants force air from the small oral cavity through the tensed lips, inducing self-sustained lip vibration. Besides human brass players, lip buzzing is not described elsewhere in the animal kingdom. Given the complexity of the proposed mechanism, the surprising absence of squeaking in most of the unrelated subjects and the indication for volitional control, we hypothesize that squeak production involves social learning. Our study offers new insights into how vocal and cognitive flexibility enables mammals to overcome size-related limitations of laryngeal sound production. This flexibility enables Asian elephants to exploit a frequency range spanning seven octaves within their communicative system.
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Affiliation(s)
- Veronika C Beeck
- Department of Behavioural and Cognitive Biology, Mammal Communication Lab, University of Vienna, Vienna, Austria.
| | | | | | - Angela S Stoeger
- Department of Behavioural and Cognitive Biology, Mammal Communication Lab, University of Vienna, Vienna, Austria.
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14
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Słowiak J, Szczygielski T, Rothschild BM, Surmik D. Dinosaur senescence: a hadrosauroid with age-related diseases brings a new perspective of "old" dinosaurs. Sci Rep 2021; 11:11947. [PMID: 34117305 PMCID: PMC8196189 DOI: 10.1038/s41598-021-91366-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/26/2021] [Indexed: 02/05/2023] Open
Abstract
Senile vertebrates are extremely rare in the fossil record, making their recognition difficult. Here we present the largest known representative of the Late Cretaceous hadrosauriform Gobihadros mongoliensis showing features of cessation of growth indicating attainment of the terminal size. Moreover, this is the first non-avian dinosaur with an age-related pathology recognized as primary calcium pyrophosphate deposition disease indicating its advanced age. Because senile dinosaurs are so rare and thus "senescence" in dinosaurs is unclear, we also propose a new unified definition of a senile dinosaur: an individual which achieved the terminal size as revealed by the presence of the external fundamental system and closed transcortical channels, has completely secondary remodeled weight-bearing bones and possesses non-traumatic, non-contagious bone pathologies correlated with advanced age.
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Affiliation(s)
- Justyna Słowiak
- Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, 00-818, Warsaw, Poland
| | - Tomasz Szczygielski
- Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, 00-818, Warsaw, Poland.
| | - Bruce M Rothschild
- Carnegie Museum of Natural History, 4400 Forbes Ave, Pittsburgh, PA, 15213, USA
| | - Dawid Surmik
- Institute of Earth Sciences, Faculty of Natural Sciences, University of Silesia, Będzińska 60, 41-200, Sosnowiec, Poland
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15
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Keerthipriya P, Nandini S, Vidya TNC. Effects of Male Age and Female Presence on Male Associations in a Large, Polygynous Mammal in Southern India: The Asian Elephant. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.616666] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We present a detailed study of male associations in the Asian elephant, using 6 years of data on identified, non-musth males. Adult males spent greater proportions of their time solitarily than in mixed-sex or in all-male groups. Old (over 30 years) males were sighted more frequently with their age-peers and less frequently with young (15–30 years) males than expected at random in all-male groups. Young males were not sighted more frequently with old males than with young males, and did not disproportionately initiate associations with old males. These results suggest that male associations, in the absence of females, may allow for old non-musth males to test strengths against age-peers. Social learning from older individuals did not seem to be important in male associations, unlike that observed in the African savannah elephant. We also found a constraint on the sizes of all-male groups, similar to that seen in female groups in our study population, and all-male groups were rarer and smaller than those in African savannah elephant. Although male associations were weak, most males had a significant top associate, with whom their association was the strongest, in female absence. In mixed-sex groups, male associations occurred at random, suggesting that males were tracking female groups independently. Differences in male social organization from that of the related African savannah elephant that occupies a similar niche possibly arise from differences in ecology.
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16
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Frýdlová P, Mrzílková J, Šeremeta M, Křemen J, Dudák J, Žemlička J, Minnich B, Kverková K, Němec P, Zach P, Frynta D. Determinate growth is predominant and likely ancestral in squamate reptiles. Proc Biol Sci 2020; 287:20202737. [PMID: 33352069 PMCID: PMC7779497 DOI: 10.1098/rspb.2020.2737] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Body growth is typically thought to be indeterminate in ectothermic vertebrates. Indeed, until recently, this growth pattern was considered to be ubiquitous in ectotherms. Our recent observations of a complete growth plate cartilage (GPC) resorption, a reliable indicator of arrested skeletal growth, in many species of lizards clearly reject the ubiquity of indeterminate growth in reptiles and raise the question about the ancestral state of the growth pattern. Using X-ray micro-computed tomography (µCT), here we examined GPCs of long bones in three basally branching clades of squamate reptiles, namely in Gekkota, Scincoidea and Lacertoidea. A complete loss of GPC, indicating skeletal growth arrest, was the predominant finding. Using a dataset of 164 species representing all major clades of lizards and the tuataras, we traced the evolution of determinate growth on the phylogenetic tree of Lepidosauria. The reconstruction of character states suggests that determinate growth is ancestral for the squamate reptiles (Squamata) and remains common in the majority of lizard lineages, while extended (potentially indeterminate) adult growth evolved several times within squamates. Although traditionally associated with endotherms, determinate growth is coupled with ectothermy in this lineage. These findings combined with existing literature suggest that determinate growth predominates in both extant and extinct amniotes.
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Affiliation(s)
- Petra Frýdlová
- Department of Zoology, Faculty of Science, Charles University, Prague 12844, Czech Republic.,Department of Anatomy, Third Faculty of Medicine, Charles University, Prague 100 00, Czech Republic
| | - Jana Mrzílková
- Specialized Laboratory of Experimental Imaging, Third Faculty of Medicine of Charles University, Institute of Technical and Applied Physics and Faculty of Bioengineering, Prague 100 00, Czech Republic.,Department of Anatomy, Third Faculty of Medicine, Charles University, Prague 100 00, Czech Republic
| | - Martin Šeremeta
- Specialized Laboratory of Experimental Imaging, Third Faculty of Medicine of Charles University, Institute of Technical and Applied Physics and Faculty of Bioengineering, Prague 100 00, Czech Republic.,Department of Anatomy, Third Faculty of Medicine, Charles University, Prague 100 00, Czech Republic
| | - Jan Křemen
- Specialized Laboratory of Experimental Imaging, Third Faculty of Medicine of Charles University, Institute of Technical and Applied Physics and Faculty of Bioengineering, Prague 100 00, Czech Republic.,Department of Anatomy, Third Faculty of Medicine, Charles University, Prague 100 00, Czech Republic
| | - Jan Dudák
- Institute of Experimental and Applied Physics, Czech Technical University in Prague, Prague 110 00, Czech Republic
| | - Jan Žemlička
- Institute of Experimental and Applied Physics, Czech Technical University in Prague, Prague 110 00, Czech Republic
| | - Bernd Minnich
- Department of Biosciences, University of Salzburg, Hellbrunnerstrasse 34, Salzburg 5020, Austria
| | - Kristina Kverková
- Department of Zoology, Faculty of Science, Charles University, Prague 12844, Czech Republic
| | - Pavel Němec
- Department of Zoology, Faculty of Science, Charles University, Prague 12844, Czech Republic
| | - Petr Zach
- Specialized Laboratory of Experimental Imaging, Third Faculty of Medicine of Charles University, Institute of Technical and Applied Physics and Faculty of Bioengineering, Prague 100 00, Czech Republic.,Department of Anatomy, Third Faculty of Medicine, Charles University, Prague 100 00, Czech Republic
| | - Daniel Frynta
- Department of Zoology, Faculty of Science, Charles University, Prague 12844, Czech Republic
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Chevallier D, Mourrain B, Girondot M. Modelling leatherback biphasic indeterminate growth using a modified Gompertz equation. Ecol Modell 2020. [DOI: 10.1016/j.ecolmodel.2020.109037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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18
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Reichert S, Berger V, Jackson J, Chapman SN, Htut W, Mar KU, Lummaa V. Maternal age at birth shapes offspring life-history trajectory across generations in long-lived Asian elephants. J Anim Ecol 2020; 89:996-1007. [PMID: 31222736 DOI: 10.1111/1365-2656.13049] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 04/14/2019] [Indexed: 11/30/2022]
Abstract
Advanced maternal age at birth can have pronounced consequences for offspring health, survival and reproduction. If carried over to the next generation, such fitness effects could have important implications for population dynamics and the evolution of ageing, but these remain poorly understood. While many laboratory studies have investigated maternal age effects, relatively few studies have been conducted in natural populations, and they usually only present a "snapshot" of an offspring's lifetime. In the present study, we focus on how maternal age influences offspring life-history trajectories and performance in a long-lived mammal. We use a multigenerational demographic dataset of semi-captive Asian elephants to investigate maternal age effects on several offspring life-history traits: condition, reproductive success and overall survival. We show that offspring born to older mothers display reduced overall survival but higher reproductive success, and reduced survival of their own progeny. Our results show evidence of a persistent effect of maternal age on fitness across generations in a long-lived mammal. By highlighting transgenerational effects on the fitness of the next generation associated with maternal age, the present study helps increase our understanding of factors contributing to individual variation in ageing rates and fitness.
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Affiliation(s)
- Sophie Reichert
- Department of Biology, University of Turku, Turku, Finland
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Vérane Berger
- Department of Biology, University of Turku, Turku, Finland
| | - John Jackson
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | | | - Win Htut
- Ministry of Natural Resources and Environmental Conservation, Myanma Timber Enterprise, Yangon, Myanmar
| | - Khyne U Mar
- Department of Biology, University of Turku, Turku, Finland
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku, Finland
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19
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Abstract
Understanding factors preventing populations of endangered species from being self-sustaining is vital for successful conservation, but we often lack sufficient data to understand dynamics. The global Asian elephant population has halved since the 1950s, however >25% currently live in captivity and effective management is essential to maintain viable populations. Here, we study the largest semi-captive Asian elephant population, those of the Myanma timber industry (~20% global captive population), whose population growth is heavily limited by juvenile mortality. We assess factors associated with increased mortality of calves aged 4.0–5.5 years, the taming age in Myanmar, a process affecting ~15,000 captive elephants to varying degrees worldwide. Using longitudinal survival data of 1,947 taming-aged calves spanning 43 years, we showed that calf mortality risk increased by >50% at the taming age of four, a peak not seen in previous studies on wild African elephants. Calves tamed at younger ages experienced higher mortality risk, as did calves with less experienced mothers. Taming-age survival greatly improved after 2000, tripling since the 1970’s. Management should focus on reducing risks faced by vulnerable individuals such as young and first-born calves to further improve survival. Changes associated with reduced mortality here are important targets for improving the sustainability of captive populations.
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20
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Seltmann MW, Ukonaho S, Reichert S, Dos Santos D, Nyein UK, Htut W, Lummaa V. Faecal Glucocorticoid Metabolites and H/L Ratio are Related Markers of Stress in Semi-Captive Asian Timber Elephants. Animals (Basel) 2020; 10:ani10010094. [PMID: 31935980 PMCID: PMC7023510 DOI: 10.3390/ani10010094] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/21/2019] [Accepted: 01/03/2020] [Indexed: 11/19/2022] Open
Abstract
Simple Summary Animals are kept in captivity for various reasons worldwide. Throughout its range countries, the Asian elephant is used for various purposes, with a significant proportion of the remaining population working as draft and transport animals in the timber industry. However, captivity can also lead to compromises in welfare that need to be quantified for successful intervention. A key way of assessing an animal’s well-being in wildlife and zoo biology is to measure its stress. Previous studies have found positive, negative, or no relationship between two commonly used measures of stress: stress hormones and the ratio of two types of white blood cells—heterophils to lymphocytes. Our study is one of the first to show a positive and consistent link between these two measures in semi-captive Asian elephants from Myanmar, irrespective of sex, age, or environmental context. Our results show that using the heterophil/lymphocyte ratio from blood smears on-site may offer a potentially cheaper and faster way to determine stress than measuring faecal glucocorticoid metabolite concentrations in the laboratory. Abstract Animals are kept in captivity for various reasons, but species with a slower pace of life may adapt to captive environments less easily, leading to welfare concerns and the need to assess stress reliably in order to develop effective interventions. Our aim was to assess welfare of semi-captive timber elephants from Myanmar by investigating the relationship between two physiological markers of stress commonly used as proxies for welfare, faecal glucocorticoid metabolite concentrations (FGM) and heterophil/lymphocyte ratios (H/L), and link these measures to changes in body condition (determined by body weight). We further assessed how robustly these two markers of stress performed in animals of different age or sex, or in different ecological contexts. We measured FGM concentrations and H/L ratios between 2016 and 2018 from 316 samples of 75 females and 49 males ranging in age from 4 to 68. We found a positive and consistent link between FGMs and H/L ratios in Asian elephants, irrespective of their sex, age, or ecological context. Our results will help to inform managers of (semi-) captive elephants about using heterophil/lymphocyte ratio data from blood smears on site as a potentially cheaper and faster alternative to determining stress than measuring faecal glucocorticoid metabolite concentrations in the laboratory.
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Affiliation(s)
- Martin W. Seltmann
- Department of Biology, University of Turku, FIN-20014 Turku, Finland; (S.U.); (S.R.); (D.D.S.); (V.L.)
- Correspondence:
| | - Susanna Ukonaho
- Department of Biology, University of Turku, FIN-20014 Turku, Finland; (S.U.); (S.R.); (D.D.S.); (V.L.)
| | - Sophie Reichert
- Department of Biology, University of Turku, FIN-20014 Turku, Finland; (S.U.); (S.R.); (D.D.S.); (V.L.)
| | - Diogo Dos Santos
- Department of Biology, University of Turku, FIN-20014 Turku, Finland; (S.U.); (S.R.); (D.D.S.); (V.L.)
| | - U Kyaw Nyein
- Myanma Timber Enterprise, Ministry of Natural Resources and Environmental Conservation, Gyogone Forest Compound, Bayint Naung Road, Insein Township, Yangon, Myanmar; (U.K.N.); (W.H.)
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environmental Conservation, Gyogone Forest Compound, Bayint Naung Road, Insein Township, Yangon, Myanmar; (U.K.N.); (W.H.)
| | - Virpi Lummaa
- Department of Biology, University of Turku, FIN-20014 Turku, Finland; (S.U.); (S.R.); (D.D.S.); (V.L.)
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21
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Hoekstra LA, Schwartz TS, Sparkman AM, Miller DAW, Bronikowski AM. The untapped potential of reptile biodiversity for understanding how and why animals age. Funct Ecol 2020; 34:38-54. [PMID: 32921868 PMCID: PMC7480806 DOI: 10.1111/1365-2435.13450] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 09/03/2019] [Indexed: 12/12/2022]
Abstract
1. The field of comparative aging biology has greatly expanded in the past 20 years. Longitudinal studies of populations of reptiles with a range of maximum lifespans have accumulated and been analyzed for evidence of mortality senescence and reproductive decline. While not as well represented in studies of amniote senescence, reptiles have been the subjects of many recent demographic and mechanistic studies of the biology of aging. 2. We review recent literature on reptile demographic senescence, mechanisms of senescence, and identify unanswered questions. Given the ecophysiological and demographic diversity of reptiles, what is the expected range of reptile senescence rates? Are known mechanisms of aging in reptiles consistent with canonical hallmarks of aging in model systems? What are the knowledge gaps in our understanding of reptile aging? 3. We find ample evidence of increasing mortality with advancing age in many reptiles. Testudines stand out as slower aging than other orders, but data on crocodilians and tuatara are sparse. Sex-specific analyses are generally not available. Studies of female reproduction suggest that reptiles are less likely to have reproductive decline with advancing age than mammals. 4. Reptiles share many physiological and molecular pathways of aging with mammals, birds, and laboratory model organisms. Adaptations related to stress physiology coupled with reptilian ectothermy suggest novel comparisons and contrasts that can be made with canonical aging phenotypes in mammals. These include stem cell and regeneration biology, homeostatic mechanisms, IIS/TOR signaling, and DNA repair. 5. To overcome challenges to the study of reptile aging, we recommend extending and expanding long-term monitoring of reptile populations, developing reptile cell lines to aid cellular biology, conducting more comparative studies of reptile morphology and physiology sampled along relevant life-history axes, and sequencing more reptile genomes for comparative genomics. Given the diversity of reptile life histories and adaptations, achieving these directives will likely greatly benefit all aging biology.
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Affiliation(s)
- Luke A Hoekstra
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, 50010, USA
| | - Tonia S Schwartz
- Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA
| | - Amanda M Sparkman
- Department of Biology, Westmont College, Santa Barbara, California, 93108, USA
| | - David A W Miller
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA 16802, USA
| | - Anne M Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, 50010, USA
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22
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Mahout Perspectives on Asian Elephants and Their Living Conditions. Animals (Basel) 2019; 9:ani9110879. [PMID: 31671818 PMCID: PMC6912500 DOI: 10.3390/ani9110879] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 10/18/2019] [Accepted: 10/18/2019] [Indexed: 12/02/2022] Open
Abstract
Simple Summary Mahouts, often known as elephant handlers, or by other terms, such as oozie in Myanmar, work closely with captive Asian elephants in elephant range countries. This work usually involves taking responsibility for just one elephant. The daily tasks of mahouts can include feeding, cleaning or bathing elephants, treating minor medical conditions, participating in training, and riding elephants in order for them to achieve specific tasks, such as transportation of materials, religious functions, or tourism activities. Because of their close interactions with elephants, mahouts have knowledge of elephants that stretches from the cultural to the behavioral and ecological. In this study, I interviewed mahouts in their own languages with a translator, using a mix of short and open-ended questions. The second kind of questions allowed mahouts to elaborate in as much detail as they wanted on their experience. The methods allowed me to collect perspectives on welfare and the associations with elephants in Nepal. I also asked questions about how long they had worked with elephants and how many elephants they worked with. The mahouts were not a uniform group, with differences in age, experience, and perspectives. The mahouts gave their most extensive comments when discussing elephant welfare, particularly on the use of fenced enclosures versus chains, elephant diet, and interactions with domestic animals. The input of mahouts could be useful for proposing and implementing plans for elephant welfare in range countries. Abstract The skills, knowledge, and expertise of mahouts have been recognized by organizations and individual managers who are responsible for captive elephants and by academics, where they have been a source of studies from the ethnographic to animal behavior research. In this study, I used semi-structured interviews in local languages to explore individual experiences of mahouts in Nepal. I also investigated perspectives on elephant welfare, including the use of corral (fenced) enclosures. I undertook a further key informant interview in English to gain more discursive perspectives on the topics. Our results revealed that mahouts at the study site are unlikely to come from multi-generational families of mahouts. All mahouts referenced the religious significance of elephants in their country when describing broader local perspectives. Many mahouts explained both positive and negative implications for differing strategies in housing captive elephants, often balanced the competing interests of elephant welfare with their own need for elephants to follow verbal communication, and their responsibility for the safety of the elephants, other staff, and tourists. The fine-balancing perspectives of mahouts, taking both humans and elephants into account, underlines their role as an important source of knowledge of captive Asian elephants in range countries, and their potential role as co-producers of research linked to welfare. This approach could also be of relevance to the welfare of ex-situ Asian elephants.
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Chapman SN, Jackson J, Htut W, Lummaa V, Lahdenperä M. Asian elephants exhibit post-reproductive lifespans. BMC Evol Biol 2019; 19:193. [PMID: 31638893 PMCID: PMC6805341 DOI: 10.1186/s12862-019-1513-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 09/16/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The existence of extended post-reproductive lifespan is an evolutionary puzzle, and its taxonomic prevalence is debated. One way of measuring post-reproductive life is with post-reproductive representation, the proportion of adult years lived by females after cessation of reproduction. Analyses of post-reproductive representation in mammals have claimed that only humans and some toothed whale species exhibit extended post-reproductive life, but there are suggestions of a post-reproductive stage for false killer whales and Asian elephants. Here, we investigate the presence of post-reproductive lifespan in Asian elephants using an extended demographic dataset collected from semi-captive timber elephants in Myanmar. Furthermore, we investigate the sensitivity of post-reproductive representation values to availability of long-term data over 50 years. RESULTS We find support for the presence of an extended post-reproductive stage in Asian elephants, and that post-reproductive representation and its underlying demographic rates depend on the length of study period in a long-lived animal. CONCLUSIONS The extended post-reproductive lifespan is unlikely due to physiological reproductive cessation, and may instead be driven by mating preferences or condition-dependent fertility. Our results also show that it is crucial to revisit such population measures in long-lived species as more data is collected, and if the typical lifespan of the species exceeds the initial study period.
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Affiliation(s)
| | - John Jackson
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environment Conservation, Yangon, Myanmar
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku, Finland
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Lahdenperä M, Jackson J, Htut W, Lummaa V. Capture from the wild has long-term costs on reproductive success in Asian elephants. Proc Biol Sci 2019; 286:20191584. [PMID: 31594514 DOI: 10.1098/rspb.2019.1584] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Capturing wild animals is common for conservation, economic or research purposes. Understanding how capture itself affects lifetime fitness measures is often difficult because wild and captive populations live in very different environments and there is a need for long-term life-history data. Here, we show how wild capture influences reproduction in 2685 female Asian elephants (Elephas maximus) used in the timber industry in Myanmar. Wild-caught females demonstrated a consistent reduction in breeding success relative to captive-born females, with significantly lower lifetime reproduction probabilities, lower breeding probabilities at peak reproductive ages and a later age of first reproduction. Furthermore, these negative effects lasted for over a decade, and there was a significant influence on the next generation: wild-caught females had calves with reduced survival to age 5. Our results suggest that wild capture has long-term consequences for reproduction, which is important not only for elephants, but also for other species in captivity.
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Affiliation(s)
| | - John Jackson
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environment Conservation, Yangon, Myanmar
| | - Virpi Lummaa
- Department of Biology, University of Turku, 20014 Turku, Finland
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Lynch EC, Lummaa V, Htut W, Lahdenperä M. Evolutionary significance of maternal kinship in a long-lived mammal. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180067. [PMID: 31303162 PMCID: PMC6664136 DOI: 10.1098/rstb.2018.0067] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2018] [Indexed: 11/12/2022] Open
Abstract
Preferential treatment of kin is widespread across social species and is considered a central prerequisite to the evolution of cooperation through kin selection. Though it is well known that, among most social mammals, females will remain within their natal group and often bias social behaviour towards female maternal kin, less is known about the fitness consequences of these relationships. We test the fitness benefits of living with maternal sisters, measured by age-specific female reproduction, using an unusually large database of a semi-captive Asian elephant ( Elephas maximus) population. This study system is particularly valuable to an exploration of reproductive trends in a long-lived mammal, because it includes life-history data that span multiple generations, enabling a study of the effects of kinship across a female's lifespan. We find that living near a sister significantly increased the likelihood of annual reproduction among young female elephants, and this effect was strongest when living near a sister 0-5 years younger. Our results show that fitness benefits gained from relationships with kin are age-specific, establish the basis necessary for the formation and maintenance of close social relationships with female kin, and highlight the adaptive importance of matriliny in a long-lived mammal. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.
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Affiliation(s)
- Emily C. Lynch
- Department of Biology, University of Turku, Turku 20014, Finland
| | - Virpi Lummaa
- Department of Biology, University of Turku, Turku 20014, Finland
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environment Conservation, Yangon, Myanmar
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Jackson J, Childs DZ, Mar KU, Htut W, Lummaa V. Long-term trends in wild-capture and population dynamics point to an uncertain future for captive elephants. Proc Biol Sci 2019; 286:20182810. [PMID: 30900534 PMCID: PMC6452069 DOI: 10.1098/rspb.2018.2810] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 02/28/2019] [Indexed: 11/12/2022] Open
Abstract
Maintaining sustainable populations in captivity without supplementation through wild-capture is a major challenge in conservation that zoos and aquaria are working towards. However, the capture of wild animals continues for many purposes where conservation is not the primary focus. Wild-capture hinders long-term conservation goals by reducing remaining wild populations, but the direct and long-term indirect consequences of wild-capture for captive population viability are rarely addressed using longitudinal data. We explored the implications of changes in wild-capture on population dynamics in captivity over 54 years using a multi-generational studbook of working Asian elephants ( Elephas maximus) from Myanmar, the largest remaining captive elephant population. Here we show that population growth and birth rates declined between 1960 and 2014 with declines in wild-capture. Importantly, wild-caught females had reduced birth rates and a higher mortality risk. However, despite the disadvantages of wild-capture, the population may not be sustainable without it, with immediate declines owing to an unstable age-structure that may last for 50 years. Our results highlight the need to assess the long-term demographic consequences of wild-capture to ensure the sustainability of captive and wild populations as species are increasingly managed and conserved in altered or novel environments.
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Affiliation(s)
- John Jackson
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Dylan Z. Childs
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Khyne U. Mar
- Department of Biology, University of Turku, 20500 Turku, Finland
| | - Win Htut
- Myanma Timber Enterprise, Ministry of Natural Resources and Environment Conservation, Gyogone Forest Compound, Bayint Naung Road, Insein Township, Yangon, Myanmar
| | - Virpi Lummaa
- Department of Biology, University of Turku, 20500 Turku, Finland
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Seltmann MW, Helle S, Htut W, Lahdenperä M. Males have more aggressive and less sociable personalities than females in semi-captive Asian elephants. Sci Rep 2019; 9:2668. [PMID: 30804421 PMCID: PMC6390182 DOI: 10.1038/s41598-019-39915-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/01/2019] [Indexed: 12/03/2022] Open
Abstract
Personality, i.e. consistent between-individual differences in behaviour, has been documented in many species. Yet little is known about how males and females of long-lived, highly social species differ in their measures of personality structure. We investigated sex differences in the mean, variance, and covariance of three previously reported personality traits (Attentiveness, Sociability, Aggressiveness) in 150 female and 107 male Asian elephants (Elephas maximus) from a semi-captive population in Myanmar. These three personality traits were obtained by performing exploratory factor analysis on 28 behavioural items that had been rated by experienced elephant handlers. We found that males scored significantly higher on Aggressiveness and tended to score lower on Sociability than females. However, no sex difference was found in the mean scores of Attentiveness. Variances for the three personality traits did not differ between the sexes, suggesting that male and female elephants share the same range of personality variation. Likewise, trait covariances were similar between the sexes. While both sexes show complex sociality in the wild, female Asian elephants typically live in highly social family units, whereas male elephants' social bonds are weaker. Males usually form dominance ranks by aggressive interactions, especially during musth. Our results on a large sample of individuals living in their natural environment are thus in agreement with elephant life-histories and parallel the findings of sex differences in other long-lived highly social species with similar life-histories.
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Affiliation(s)
| | - Samuli Helle
- Department of Biology, University of Turku, Turku, Finland
| | - Win Htut
- Myanma Timber Enterprise, Department of Timber Extraction, MOECAF, Yangoon, Myanmar
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28
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Are female camels capital breeders? Influence of seasons, age, and body condition on reproduction in an extremely arid region. Mamm Biol 2018. [DOI: 10.1016/j.mambio.2018.10.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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29
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Lynsdale CL, Mumby HS, Hayward AD, Mar KU, Lummaa V. Parasite-associated mortality in a long-lived mammal: Variation with host age, sex, and reproduction. Ecol Evol 2017; 7:10904-10915. [PMID: 29299268 PMCID: PMC5743535 DOI: 10.1002/ece3.3559] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/23/2017] [Accepted: 09/28/2017] [Indexed: 01/03/2023] Open
Abstract
Parasites can cause severe host morbidity and threaten survival. As parasites are generally aggregated within certain host demographics, they are likely to affect a small proportion of the entire population, with specific hosts being at particular risk. However, little is known as to whether increased host mortality from parasitic causes is experienced by specific host demographics. Outside of theoretical studies, there is a paucity of literature concerning dynamics of parasite-associated host mortality. Empirical evidence mainly focuses on short-lived hosts or model systems, with data lacking from long-lived wild or semi-wild vertebrate populations. We investigated parasite-associated mortality utilizing a multigenerational database of mortality, health, and reproductive data for over 4,000 semi-captive timber elephants (Elephas maximus), with known causes of death for mortality events. We determined variation in mortality according to a number of host traits that are commonly associated with variation in parasitism within mammals: age, sex, and reproductive investment in females. We found that potentially parasite-associated mortality varied significantly across elephant ages, with individuals at extremes of lifespan (young and old) at highest risk. Mortality probability was significantly higher for males across all ages. Female reproducers experienced a lower probability of potentially parasite-associated mortality than females who did not reproduce at any investigated time frame. Our results demonstrate increased potentially parasite-associated mortality within particular demographic groups. These groups (males, juveniles, elderly adults) have been identified in other studies as susceptible to parasitism, stressing the need for further work investigating links between infection and mortality. Furthermore, we show variation between reproductive and non-reproductive females, with mothers being less at risk of potentially parasite mortality than nonreproducers.
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Affiliation(s)
- Carly L. Lynsdale
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
| | - Hannah S. Mumby
- Department of ZoologyUniversity of CambridgeCambridgeUK
- Department of Environmental SciencesApplied Behavioural Ecology and Ecosystem Research UnitUniversity of South AfricaJohannesburgSouth Africa
| | - Adam D. Hayward
- Department of Biological and Environmental SciencesUniversity of StirlingStirlingUK
| | - Khyne U. Mar
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
| | - Virpi Lummaa
- Department of BiologyUniversity of TurkuTurkuFinland
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30
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Crawley JAH, Mumby HS, Chapman SN, Lahdenperä M, Mar KU, Htut W, Thura Soe A, Aung HH, Lummaa V. Is bigger better? The relationship between size and reproduction in female Asian elephants. J Evol Biol 2017; 30:1836-1845. [DOI: 10.1111/jeb.13143] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 06/30/2017] [Accepted: 07/07/2017] [Indexed: 12/01/2022]
Affiliation(s)
| | - H. S. Mumby
- Department of Zoology; University of Cambridge; Cambridge UK
| | - S. N. Chapman
- Department of Biology; University of Turku; Turku Finland
| | - M. Lahdenperä
- Department of Biology; University of Turku; Turku Finland
| | - K. U. Mar
- Department of Animal and Plant Sciences; University of Sheffield; Sheffield UK
| | - W. Htut
- Myanma Timber Enterprise; Ministry of Environmental Conservation and Forestry; Yangon Myanmar
| | - A. Thura Soe
- Myanma Timber Enterprise; Ministry of Environmental Conservation and Forestry; Yangon Myanmar
| | - H. H. Aung
- Myanma Timber Enterprise; Ministry of Environmental Conservation and Forestry; Yangon Myanmar
| | - V. Lummaa
- Department of Biology; University of Turku; Turku Finland
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31
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Patterns of growth in monitor lizards (Varanidae) as revealed by computed tomography of femoral growth plates. ZOOMORPHOLOGY 2016. [DOI: 10.1007/s00435-016-0338-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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32
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Prondvai E. Medullary bone in fossils: function, evolution and significance in growth curve reconstructions of extinct vertebrates. J Evol Biol 2016; 30:440-460. [DOI: 10.1111/jeb.13019] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/12/2016] [Accepted: 11/15/2016] [Indexed: 02/02/2023]
Affiliation(s)
- E. Prondvai
- Evolutionary Morphology of Vertebrates; Ghent University; Gent Belgium
- MTA - ELTE Lendület Dinosaur Research Group; Eötvös Loránd University; Budapest Hungary
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33
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Selonen V, Wistbacka R, Santangeli A. Sex-specific patterns in body mass and mating system in the Siberian flying squirrel. BMC ZOOL 2016. [DOI: 10.1186/s40850-016-0009-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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34
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Chapman SN, Mumby HS, Crawley JAH, Mar KU, Htut W, Thura Soe A, Aung HH, Lummaa V. How Big Is It Really? Assessing the Efficacy of Indirect Estimates of Body Size in Asian Elephants. PLoS One 2016; 11:e0150533. [PMID: 26938085 PMCID: PMC4777392 DOI: 10.1371/journal.pone.0150533] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 02/15/2016] [Indexed: 12/03/2022] Open
Abstract
Information on an organism’s body size is pivotal in understanding its life history and fitness, as well as helping inform conservation measures. However, for many species, particularly large-bodied wild animals, taking accurate body size measurements can be a challenge. Various means to estimate body size have been employed, from more direct methods such as using photogrammetry to obtain height or length measurements, to indirect prediction of weight using other body morphometrics or even the size of dung boli. It is often unclear how accurate these measures are because they cannot be compared to objective measures. Here, we investigate how well existing estimation equations predict the actual body weight of Asian elephants Elephas maximus, using body measurements (height, chest girth, length, foot circumference and neck circumference) taken directly from a large population of semi-captive animals in Myanmar (n = 404). We then define new and better fitting formulas to predict body weight in Myanmar elephants from these readily available measures. We also investigate whether the important parameters height and chest girth can be estimated from photographs (n = 151). Our results show considerable variation in the ability of existing estimation equations to predict weight, and that the equations proposed in this paper predict weight better in almost all circumstances. We also find that measurements from standardised photographs reflect body height and chest girth after applying minor adjustments. Our results have implications for size estimation of large wild animals in the field, as well as for management in captive settings.
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Affiliation(s)
- Simon N. Chapman
- Department of Animal and Plant Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, United Kingdom
| | - Hannah S. Mumby
- Department of Animal and Plant Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, United Kingdom
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom
- * E-mail:
| | - Jennie A. H. Crawley
- Department of Animal and Plant Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, United Kingdom
| | - Khyne U. Mar
- Department of Animal and Plant Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, United Kingdom
| | - Win Htut
- Myanma Timber Enterprise, Extraction Department, Ministry for Environmental Conservation and Forestry, Yangon, Myanmar
| | - Aung Thura Soe
- Myanma Timber Enterprise, Extraction Department, Ministry for Environmental Conservation and Forestry, Yangon, Myanmar
| | - Htoo Htoo Aung
- Myanma Timber Enterprise, Extraction Department, Ministry for Environmental Conservation and Forestry, Yangon, Myanmar
| | - Virpi Lummaa
- Department of Biology, University of Turku, FIN-20014, Turku, Finland
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