1
|
Avedik A, Clauss M. Chewing, dentition and tooth wear in Hippopotamidae (Hippopotamus amphibius and Choeropsis liberiensis). PLoS One 2023; 18:e0291825. [PMID: 37792716 PMCID: PMC10550173 DOI: 10.1371/journal.pone.0291825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 09/06/2023] [Indexed: 10/06/2023] Open
Abstract
Among mammals, hippopotamids ('hippos') have been described as the species with the lowest chewing efficacy despite elaborate enamel folds on the occlusal surface or their cheek teeth, which was hypothesized to result from the lack of a grinding chewing motion. We investigated the chewing and dentition of the two extant hippo species, the common hippo (Hippopotamus amphibius) and the pygmy hippo (Choeropsis liberiensis), making (video) observations of live animals and gathering data on museum specimens (n = 86 H. amphibius and 26 C. liberiensis skulls). Hippos have a low degree of anisodonty (differences in width between maxillary and mandibular cheek teeth) and anisognathy (difference in width between the upper and the lower jaw), corresponding to a mainly orthal (up-and-down) chewing motion. The two hippo species differ slightly, but distinctively, in their anterior dental morphology and chewing mode. In both species, the canines do not completely prevent a lateral jaw movement but would, in theory, permit this movement until the mandibular canines get into contact with the maxillary protruding snout. This movement is only realized, to a small extent, in pygmy hippos, leaving distinct wear traces on their incisors and creating relatively wider wear facets on the maxillary canines. In common hippos, the interlocking upper and lower incisors prevent lateral jaw movement. Corresponding contact wear facets are evident on the medial aspect of the upper, and on the lateral aspect of the lower incisors-unless museal reconstructions mispositioned these teeth. If these facets are interpreted as an indication for a relic of a lateral jaw movement that was probably more prominent in hippo ancestors, i.e. if we assume that hippos evolved orthal chewing secondarily, several other characteristics of hippos can be explained, such as a low degree of hypsodonty (in the absence of distinct attrition due to a grinding chewing movement), a secondary loss of complexity in their enamel schmelzmuster, a secondary evolution of a wide mouth gape, a reduction in anisodonty compared to their ancestors, and the evolution of a bilaterally symmetrical ('trifoliate') enamel folding pattern on the molar occlusal surface from an ancestral bunoselenodont condition. As an underlying driving force, selection for intraspecific combat with canines and incisors, necessitating a wide gape and a rigid jaw, has been suggested.
Collapse
Affiliation(s)
- Annika Avedik
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Marcus Clauss
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| |
Collapse
|
2
|
Voysey MD, de Bruyn PJN, Davies AB. Are hippos Africa's most influential megaherbivore? A review of ecosystem engineering by the semi-aquatic common hippopotamus. Biol Rev Camb Philos Soc 2023; 98:1509-1529. [PMID: 37095627 DOI: 10.1111/brv.12960] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 03/30/2023] [Accepted: 04/03/2023] [Indexed: 04/26/2023]
Abstract
Megaherbivores perform vital ecosystem engineering roles, and have their last remaining stronghold in Africa. Of Africa's remaining megaherbivores, the common hippopotamus (Hippopotamus amphibius) has received the least scientific and conservation attention, despite how influential their ecosystem engineering activities appear to be. Given the potentially crucial ecosystem engineering influence of hippos, as well as mounting conservation concerns threatening their long-term persistence, a review of the evidence for hippos being ecosystem engineers, and the effects of their engineering, is both timely and necessary. In this review, we assess, (i) aspects of hippo biology that underlie their unique ecosystem engineering potential; (ii) evaluate hippo ecological impacts in terrestrial and aquatic environments; (iii) compare the ecosystem engineering influence of hippos to other extant African megaherbivores; (iv) evaluate factors most critical to hippo conservation and ecosystem engineering; and (v) highlight future research directions and challenges that may yield new insights into the ecological role of hippos, and of megaherbivores more broadly. We find that a variety of key life-history traits determine the hippo's unique influence, including their semi-aquatic lifestyle, large body size, specialised gut anatomy, muzzle structure, small and partially webbed feet, and highly gregarious nature. On land, hippos create grazing lawns that contain distinct plant communities and alter fire spatial extent, which shapes woody plant demographics and might assist in maintaining fire-sensitive riverine vegetation. In water, hippos deposit nutrient-rich dung, stimulating aquatic food chains and altering water chemistry and quality, impacting a host of different organisms. Hippo trampling and wallowing alters geomorphological processes, widening riverbanks, creating new river channels, and forming gullies along well-utilised hippo paths. Taken together, we propose that these myriad impacts combine to make hippos Africa's most influential megaherbivore, specifically because of the high diversity and intensity of their ecological impacts compared with other megaherbivores, and because of their unique capacity to transfer nutrients across ecosystem boundaries, enriching both terrestrial and aquatic ecosystems. Nonetheless, water pollution and extraction for agriculture and industry, erratic rainfall patterns and human-hippo conflict, threaten hippo ecosystem engineering and persistence. Therefore, we encourage greater consideration of the unique role of hippos as ecosystem engineers when considering the functional importance of megafauna in African ecosystems, and increased attention to declining hippo habitat and populations, which if unchecked could change the way in which many African ecosystems function.
Collapse
Affiliation(s)
- Michael D Voysey
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, MA, 02138, USA
| | - P J Nico de Bruyn
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Private Bag X20, Hatfield, 0028, South Africa
| | - Andrew B Davies
- Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity Avenue, Cambridge, MA, 02138, USA
| |
Collapse
|
3
|
Richard OK, Codron D, Hagen KB, Südekum KH, Clauss M. Little differences in digestive efficiency for protein and fat in mammals of different trophic guilds and digestive strategies: data constraints or fundamental functional similarity? J Anim Physiol Anim Nutr (Berl) 2017. [DOI: 10.1111/jpn.12657] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- O. K. Richard
- Clinic for Zoo Animals, Exotic Pets and Wildlife; Vetsuisse Faculty; University of Zurich; Zurich Switzerland
| | - D. Codron
- Florisbad Quaternary Research; National Museum; Bloemfontein South Africa
- Centre for Environmental Management; University of the Free State; Bloemfontein South Africa, and
| | - K. B. Hagen
- Clinic for Zoo Animals, Exotic Pets and Wildlife; Vetsuisse Faculty; University of Zurich; Zurich Switzerland
- Zoological Garden of Halle; Halle Germany
| | - K.-H. Südekum
- Institute of Animal Science; University of Bonn; Bonn Germany
| | - M. Clauss
- Clinic for Zoo Animals, Exotic Pets and Wildlife; Vetsuisse Faculty; University of Zurich; Zurich Switzerland
| |
Collapse
|
4
|
Stillfried M, Gras P, Busch M, Börner K, Kramer-Schadt S, Ortmann S. Wild inside: Urban wild boar select natural, not anthropogenic food resources. PLoS One 2017; 12:e0175127. [PMID: 28403244 PMCID: PMC5389637 DOI: 10.1371/journal.pone.0175127] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/21/2017] [Indexed: 12/02/2022] Open
Abstract
Most wildlife species are urban avoiders, but some became urban utilizers and dwellers successfully living in cities. Often, they are assumed to be attracted into urban areas by easily accessible and highly energetic anthropogenic food sources. We macroscopically analysed stomachs of 247 wild boar (Sus scrofa, hereafter WB) from urban areas of Berlin and from the surrounding rural areas. From the stomach contents we determined as predictors of food quality modulus of fineness (MOF,), percentage of acid insoluble ash (AIA) and macronutrients such as amount of energy and percentage of protein, fat, fibre and starch. We run linear mixed models to test: (1) differences in the proportion of landscape variables, (2) differences of nutrients consumed in urban vs. rural WB and (3) the impact of landscape variables on gathered nutrients. We found only few cases of anthropogenic food in the qualitative macroscopic analysis. We categorized the WB into five stomach content categories but found no significant difference in the frequency of those categories between urban and rural WB. The amount of energy was higher in stomachs of urban WB than in rural WB. The analysis of landscape variables revealed that the energy of urban WB increased with increasing percentage of sealing, while an increased human density resulted in poor food quality for urban and rural WB. Although the percentage of protein decreased in areas with a high percentage of coniferous forests, the food quality increased. High percentage of grassland decreased the percentage of consumed fat and starch and increased the percentage of fibre, while a high percentage of agricultural areas increased the percentage of consumed starch. Anthropogenic food such as garbage might serve as fallback food when access to natural resources is limited. We infer that urban WB forage abundant, natural resources in urban areas. Urban WB might use anthropogenic resources (e.g. garbage) if those are easier to exploit and more abundant than natural resources. This study shows that access to natural resources still is mandatory and drives the amount of protein, starch, fat or fibre in wild boar stomachs in urban as well as rural environments.
Collapse
Affiliation(s)
- Milena Stillfried
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research IZW, Alfred-Kowalke-Strasse 17, Berlin, Germany
| | - Pierre Gras
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research IZW, Alfred-Kowalke-Strasse 17, Berlin, Germany
| | - Matthias Busch
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research IZW, Alfred-Kowalke-Strasse 17, Berlin, Germany.,Department of Animal Ecology and Tropical Biology, Julius Maximilians Universität Würzburg, Am Hubland, Wuerzburg, Germany
| | - Konstantin Börner
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research IZW, Alfred-Kowalke-Strasse 17, Berlin, Germany
| | - Stephanie Kramer-Schadt
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research IZW, Alfred-Kowalke-Strasse 17, Berlin, Germany
| | - Sylvia Ortmann
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research IZW, Alfred-Kowalke-Strasse 17, Berlin, Germany
| |
Collapse
|
5
|
Methane production by two non-ruminant foregut-fermenting herbivores: The collared peccary ( Pecari tajacu ) and the pygmy hippopotamus ( Hexaprotodon liberiensis ). Comp Biochem Physiol A Mol Integr Physiol 2016; 191:107-114. [DOI: 10.1016/j.cbpa.2015.09.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 09/28/2015] [Accepted: 09/29/2015] [Indexed: 11/24/2022]
|
6
|
Dudley JP, Hang'Ombe BM, Leendertz FH, Dorward LJ, Castro J, Subalusky AL, Clauss M. Carnivory in the common hippopotamus
H
ippopotamus amphibius
: implications for the ecology and epidemiology of anthrax in
A
frican landscapes. Mamm Rev 2015. [DOI: 10.1111/mam.12056] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joseph P. Dudley
- Leidos Inc. 20201 Century Boulevard Germantown MD 20874 USA
- Institute of Arctic Biology University of Alaska Fairbanks Fairbanks AK 99775‐7000 USA
| | | | | | | | - Julio Castro
- Departamento de Colonia Zorrilla 348 Carmelo Uruguay
| | - Amanda L. Subalusky
- Department of Ecology and Evolutionary Biology Yale University 165 Prospect St. New Haven CT 06511 USA
| | - Marcus Clauss
- Clinic for Zoo Animals Exotic Pets and Wildlife Vetsuisse Faculty University of Zurich Winterthurerstr. 260 8057 Zurich Switzerland
| |
Collapse
|
7
|
Hagen KB, Besselmann D, Cyrus-Eulenberger U, Vendl C, Ortmann S, Zingg R, Kienzle E, Kreuzer M, Hatt JM, Clauss M. Digestive physiology of the plains viscacha (Lagostomus maximus): A large herbivorous hystricomorph rodent. Zoo Biol 2015; 34:345-59. [DOI: 10.1002/zoo.21216] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Katharina B. Hagen
- Clinic for Zoo Animals, Exotic Pets and Wildlife; Vetsuisse Faculty; University of Zurich; Zurich Switzerland
| | - Dorothea Besselmann
- Clinic for Zoo Animals, Exotic Pets and Wildlife; Vetsuisse Faculty; University of Zurich; Zurich Switzerland
| | - Ulrike Cyrus-Eulenberger
- Clinic for Zoo Animals, Exotic Pets and Wildlife; Vetsuisse Faculty; University of Zurich; Zurich Switzerland
| | - Catharina Vendl
- Clinic for Zoo Animals, Exotic Pets and Wildlife; Vetsuisse Faculty; University of Zurich; Zurich Switzerland
| | - Sylvia Ortmann
- Leibniz Institute for Zoo and Wildlife Research (IZW); Berlin Germany
| | | | - Ellen Kienzle
- Chair of Animal Nutrition and Dietetics; Ludwig-Maximilians-University of Munich; Munich Germany
| | - Michael Kreuzer
- Institute of Agricultural Sciences; ETH Zurich; Zurich Switzerland
| | - Jean-Michel Hatt
- Clinic for Zoo Animals, Exotic Pets and Wildlife; Vetsuisse Faculty; University of Zurich; Zurich Switzerland
| | - Marcus Clauss
- Clinic for Zoo Animals, Exotic Pets and Wildlife; Vetsuisse Faculty; University of Zurich; Zurich Switzerland
| |
Collapse
|
8
|
Flacke GL, Chambers BK, Martin GB, Paris MC. The Pygmy Hippopotamus Choeropsis liberiensis (Morton, 1849): Bringing to Light Research Priorities for the Largely Forgotten, Smaller Hippo Species. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.zoolgart.2015.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
9
|
Clauss M, Steuer P, Müller DWH, Codron D, Hummel J. Herbivory and body size: allometries of diet quality and gastrointestinal physiology, and implications for herbivore ecology and dinosaur gigantism. PLoS One 2013; 8:e68714. [PMID: 24204552 PMCID: PMC3812987 DOI: 10.1371/journal.pone.0068714] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Digestive physiology has played a prominent role in explanations for terrestrial herbivore body size evolution and size-driven diversification and niche differentiation. This is based on the association of increasing body mass (BM) with diets of lower quality, and with putative mechanisms by which a higher BM could translate into a higher digestive efficiency. Such concepts, however, often do not match empirical data. Here, we review concepts and data on terrestrial herbivore BM, diet quality, digestive physiology and metabolism, and in doing so give examples for problems in using allometric analyses and extrapolations. A digestive advantage of larger BM is not corroborated by conceptual or empirical approaches. We suggest that explanatory models should shift from physiological to ecological scenarios based on the association of forage quality and biomass availability, and the association between BM and feeding selectivity. These associations mostly (but not exclusively) allow large herbivores to use low quality forage only, whereas they allow small herbivores the use of any forage they can physically manage. Examples of small herbivores able to subsist on lower quality diets are rare but exist. We speculate that this could be explained by evolutionary adaptations to the ecological opportunity of selective feeding in smaller animals, rather than by a physiologic or metabolic necessity linked to BM. For gigantic herbivores such as sauropod dinosaurs, other factors than digestive physiology appear more promising candidates to explain evolutionary drives towards extreme BM.
Collapse
Affiliation(s)
- Marcus Clauss
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
- * E-mail:
| | - Patrick Steuer
- Institute of Animal Science, University of Bonn, Bonn, Germany
| | | | - Daryl Codron
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
- Florisbad Quaternary Research, National Museum, Bloemfontein, South Africa
| | - Jürgen Hummel
- Institute of Animal Science, University of Bonn, Bonn, Germany
- Ruminant Nutrition, Department of Animal Sciences, University of Göttingen, Göttingen, Germany
| |
Collapse
|
10
|
Stahl M, Osmann C, Ortmann S, Kreuzer M, Hatt JM, Clauss M. Energy intake for maintenance in a mammal with a low basal metabolism, the giant anteater (Myrmecophaga tridactyla). J Anim Physiol Anim Nutr (Berl) 2011; 96:818-24. [DOI: 10.1111/j.1439-0396.2011.01226.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
11
|
Resource partitioning among African savanna herbivores in North Cameroon: the importance of diet composition, food quality and body mass. JOURNAL OF TROPICAL ECOLOGY 2011. [DOI: 10.1017/s0266467411000307] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Abstract:The relationship between herbivore diet quality, and diet composition (the range of food plants consumed) and body mass on resource partitioning of herbivores remains the subject of an ongoing scientific debate. In this study we investigated the importance of diet composition and diet quality on resource partitioning among eight species of savanna herbivore in north Cameroon, with different body mass. Dung samples of four to seven wild herbivore and one domesticated species were collected in the field during the dry and wet period. Diet composition was based on microhistological examination of herbivore droppings, epidermis fragments were identified to genus or family level. In addition, the quality of the faecal droppings was determined in terms of phosphorus, nitrogen and fibre concentrations. The results showed that there was no significant correlation between body mass and (differences in) diet composition for wet and dry season. When all species are considered, only significant relationships are found by the Spearman rank correlation analyses during the wet season between body mass and phosphorus and nitrogen, but this relationship did not exist during the dry season. When the analyses focuses on ruminants only (thus leaving out hippo), none of the relationships between body mass and diet quality was significant in either season. During the dry season the proportion of graminoids ranged between 10% (small unidentified herbivore species) to 90% (hippopotamus), during the wet season this proportion ranged from 60% (zebu) to 90% (hippopotamus). All species but zebu had more graminoids in their dung during wet season compared with dry season. However all species but hartebeest had more graminoids old stems in their dung during the dry season, compared with the wet season. The niche breadth for food categories consumed by kob (0.300), hippo (0.090), hartebeest (0.350), roan (0.510) and zebu (0.300) was much greater in the dry season than in the wet season for kob (0.120), hippo (0.020), hartebeest (0.190), roan (0.090) and zebu (0.200). When looking at grass taxa consumed, the niche breadth of kob (0.220), hartebeest (0.140), and roan (0.250) was also greater in the dry season when compared with the wet season for kob (0.050), hartebeest (0.120) and roan (0.120). The opposite was found for zebu and hippo. Comparison of the species’ diet compositions with randomized data showed that dietary overlap between different herbivore species was much higher than what would be expected on the basis of chance, demonstrating surprisingly limited niche separation between species. This offers potential for competition, but it is more likely that the high niche overlap indicates absence of competition, due to low herbivore densities and abundant food resources, permitting species to share non-limiting resources. With increasing herbivore densities and subsequent increasing scarcity of resources, the relationship between diet quality and body mass in combination with increased niche separation is expected to become more visible.
Collapse
|
12
|
Sander PM, Christian A, Clauss M, Fechner R, Gee CT, Griebeler EM, Gunga HC, Hummel J, Mallison H, Perry SF, Preuschoft H, Rauhut OWM, Remes K, Tütken T, Wings O, Witzel U. Biology of the sauropod dinosaurs: the evolution of gigantism. Biol Rev Camb Philos Soc 2011; 86:117-55. [PMID: 21251189 PMCID: PMC3045712 DOI: 10.1111/j.1469-185x.2010.00137.x] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 03/13/2010] [Accepted: 03/16/2010] [Indexed: 11/28/2022]
Abstract
The herbivorous sauropod dinosaurs of the Jurassic and Cretaceous periods were the largest terrestrial animals ever, surpassing the largest herbivorous mammals by an order of magnitude in body mass. Several evolutionary lineages among Sauropoda produced giants with body masses in excess of 50 metric tonnes by conservative estimates. With body mass increase driven by the selective advantages of large body size, animal lineages will increase in body size until they reach the limit determined by the interplay of bauplan, biology, and resource availability. There is no evidence, however, that resource availability and global physicochemical parameters were different enough in the Mesozoic to have led to sauropod gigantism. We review the biology of sauropod dinosaurs in detail and posit that sauropod gigantism was made possible by a specific combination of plesiomorphic characters (phylogenetic heritage) and evolutionary innovations at different levels which triggered a remarkable evolutionary cascade. Of these key innovations, the most important probably was the very long neck, the most conspicuous feature of the sauropod bauplan. Compared to other herbivores, the long neck allowed more efficient food uptake than in other large herbivores by covering a much larger feeding envelope and making food accessible that was out of the reach of other herbivores. Sauropods thus must have been able to take up more energy from their environment than other herbivores. The long neck, in turn, could only evolve because of the small head and the extensive pneumatization of the sauropod axial skeleton, lightening the neck. The small head was possible because food was ingested without mastication. Both mastication and a gastric mill would have limited food uptake rate. Scaling relationships between gastrointestinal tract size and basal metabolic rate (BMR) suggest that sauropods compensated for the lack of particle reduction with long retention times, even at high uptake rates. The extensive pneumatization of the axial skeleton resulted from the evolution of an avian-style respiratory system, presumably at the base of Saurischia. An avian-style respiratory system would also have lowered the cost of breathing, reduced specific gravity, and may have been important in removing excess body heat. Another crucial innovation inherited from basal dinosaurs was a high BMR. This is required for fueling the high growth rate necessary for a multi-tonne animal to survive to reproductive maturity. The retention of the plesiomorphic oviparous mode of reproduction appears to have been critical as well, allowing much faster population recovery than in megaherbivore mammals. Sauropods produced numerous but small offspring each season while land mammals show a negative correlation of reproductive output to body size. This permitted lower population densities in sauropods than in megaherbivore mammals but larger individuals. Our work on sauropod dinosaurs thus informs us about evolutionary limits to body size in other groups of herbivorous terrestrial tetrapods. Ectothermic reptiles are strongly limited by their low BMR, remaining small. Mammals are limited by their extensive mastication and their vivipary, while ornithsichian dinosaurs were only limited by their extensive mastication, having greater average body sizes than mammals.
Collapse
|
13
|
Franz R, Hummel J, Müller DW, Bauert M, Hatt JM, Clauss M. Herbivorous reptiles and body mass: Effects on food intake, digesta retention, digestibility and gut capacity, and a comparison with mammals. Comp Biochem Physiol A Mol Integr Physiol 2011; 158:94-101. [DOI: 10.1016/j.cbpa.2010.09.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 09/10/2010] [Accepted: 09/12/2010] [Indexed: 12/01/2022]
|
14
|
Clauss M, Kleffner H, Kienzle E. Carnivorous mammals: nutrient digestibility and energy evaluation. Zoo Biol 2010; 29:687-704. [DOI: 10.1002/zoo.20302] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
15
|
Retention of fluid and particles in captive tapirs (Tapirus sp.). Comp Biochem Physiol A Mol Integr Physiol 2010; 157:95-101. [DOI: 10.1016/j.cbpa.2010.03.029] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 03/24/2010] [Accepted: 03/27/2010] [Indexed: 11/23/2022]
|
16
|
MEYER K, HUMMEL J, CLAUSS M. The relationship between forage cell wall content and voluntary food intake in mammalian herbivores. Mamm Rev 2010. [DOI: 10.1111/j.1365-2907.2010.00161.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
17
|
Schwarm A, Ortmann S, Wolf C, Streich WJ, Clauss M. Passage marker excretion in red kangaroo (Macropus rufus), collared peccary (Pecari tajacu) and colobine monkeys (Colobus angolensis,C. polykomos,Trachypithecus johnii). ACTA ACUST UNITED AC 2009; 311:647-61. [DOI: 10.1002/jez.552] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
18
|
Schwarm A, Schweigert M, Ortmann S, Hummel J, Janssens GPJ, Streich WJ, Clauss M. No easy solution for the fractionation of faecal nitrogen in captive wild herbivores: results of a pilot study. J Anim Physiol Anim Nutr (Berl) 2009; 93:596-605. [DOI: 10.1111/j.1439-0396.2008.00842.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
19
|
Polycystic Kidney Disease in the Pygmy Hippopotamus (Hexaprotodon liberiensis). J Zoo Wildl Med 2009; 40:529-35. [DOI: 10.1638/2007-0175.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
20
|
Clauss M, Nunn C, Fritz J, Hummel J. Evidence for a tradeoff between retention time and chewing efficiency in large mammalian herbivores. Comp Biochem Physiol A Mol Integr Physiol 2009; 154:376-82. [PMID: 19651229 DOI: 10.1016/j.cbpa.2009.07.016] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2009] [Revised: 07/13/2009] [Accepted: 07/14/2009] [Indexed: 10/20/2022]
Abstract
Large body size is thought to produce a digestive advantage through different scaling effects of gut capacity and food intake, with supposedly longer digesta retention times in larger animals. However, empirical tests of this framework have remained equivocal, which we hypothesize is because previous comparative studies have not included digesta particle size. Larger particles require more time for digestion, and if digesta particle size increases with body mass, it could explain the lack of digestive advantage in larger herbivores. We combine data on body mass, food intake, digesta retention and digestibility with data on faecal particle size (as a proxy for digesta particle size) in 21 mammalian herbivore species. Multiple regression shows that fibre digestibility is independent of body mass but dependent on digesta retention and particle size; the resulting equation indicates that retention time and particle size can compensate for each other. Similarly, digestible food intake is independent of body mass, but dependent on food intake, digesta retention, and particle size. For mammalian herbivores, increasing digesta retention and decreasing digesta particle size are viable strategies to enhance digestive performance and energy intake. Because the strategy of increased digesta retention is usually linked to reduced food intake, the high selective pressure to evolve a more efficient dentition or a physiological particle separation mechanism that facilitates repeated mastication of digesta (rumination) becomes understandable.
Collapse
Affiliation(s)
- Marcus Clauss
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Winterthurerstr. 260, 8057 Zurich, Switzerland.
| | | | | | | |
Collapse
|
21
|
Schwarm A, Ortmann S, Wolf C, Streich WJ, Clauss M. More efficient mastication allows increasing intake without compromising digestibility or necessitating a larger gut: Comparative feeding trials in banteng (Bos javanicus) and pygmy hippopotamus (Hexaprotodon liberiensis). Comp Biochem Physiol A Mol Integr Physiol 2009; 152:504-12. [DOI: 10.1016/j.cbpa.2008.12.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 12/08/2008] [Accepted: 12/08/2008] [Indexed: 10/21/2022]
|
22
|
Clauss M, Nijboer J, Loermans JHM, Roth T, Van der Kuilen J, Beynen AC. Comparative digestion studies in wild suids at Rotterdam Zoo. Zoo Biol 2008; 27:305-19. [DOI: 10.1002/zoo.20191] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
23
|
Schwarm A, Ortmann S, Wolf C, Jürgen Streich W, Clauss M. Excretion patterns of fluid and different sized particle passage markers in banteng (Bos javanicus) and pygmy hippopotamus (Hexaprotodon liberiensis): Two functionally different foregut fermenters. Comp Biochem Physiol A Mol Integr Physiol 2008; 150:32-9. [DOI: 10.1016/j.cbpa.2008.02.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Revised: 02/22/2008] [Accepted: 02/22/2008] [Indexed: 11/26/2022]
|
24
|
Clauss M, Schwarm A, Ortmann S, Streich WJ, Hummel J. A case of non-scaling in mammalian physiology? Body size, digestive capacity, food intake, and ingesta passage in mammalian herbivores. Comp Biochem Physiol A Mol Integr Physiol 2007; 148:249-65. [PMID: 17643330 DOI: 10.1016/j.cbpa.2007.05.024] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2007] [Revised: 05/18/2007] [Accepted: 05/19/2007] [Indexed: 10/23/2022]
Abstract
As gut capacity is assumed to scale linearly to body mass (BM), and dry matter intake (DMI) to metabolic body weight (BM(0.75)), it has been proposed that ingesta mean retention time (MRT) should scale to BM(0.25) in herbivorous mammals. We test these assumptions with the most comprehensive literature data collations (n=74 species for gut capacity, n=93 species for DMI and MRT) to date. For MRT, only data from studies was used during which DMI was also recorded. Gut capacity scaled to BM(1.06). In spite of large differences in feeding regimes, absolute DMI (kg/d) scaled to BM(0.76) across all species tested. Regardless of this allometry inherent in the dataset, there was only a very low allometric scaling of MRT with BM(0.14) across all species. If species were divided according to the morphophysiological design of their digestive tract, there was non-significant scaling of MRT with BM(0.04) in colon fermenters, BM(0.08) in non-ruminant foregut fermenters, BM(0.06) in browsing and BM(0.04) in grazing ruminants. In contrast, MRT significantly scaled to BM(0.24) (CI 0.16-0.33) in the caecum fermenters. The results suggest that below a certain body size, long MRTs cannot be achieved even though coprophagy is performed; this supports the assumption of a potential body size limitation for herbivory on the lower end of the body size range. However, above a 500 g-threshold, there is no indication of a substantial general increase of MRT with BM. We therefore consider ingesta retention in mammalian herbivores an example of a biological, time-dependent variable that can, on an interspecific level, be dissociated from a supposed obligatory allometric scaling by the morphophysiological design of the digestive tract. We propose that very large body size does not automatically imply a digestive advantage, because long MRTs do not seem to be a characteristic of very large species only. A comparison of the relative DMI (g/kg(0.75)) with MRT indicates that, on an interspecific level, higher intakes are correlated to shorter MRTs in caecum, colon and non-ruminant foregut fermenters; in contrast, no significant correlation between relative DMI and MRT is evident in ruminants.
Collapse
Affiliation(s)
- Marcus Clauss
- Division of Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Switzerland, Winterthurerstr. 260, 8057 Zurich, Switzerland
| | | | | | | | | |
Collapse
|
25
|
Clauss M, Jürgen Streich W, Schwarm A, Ortmann S, Hummel J. The relationship of food intake and ingesta passage predicts feeding ecology in two different megaherbivore groups. OIKOS 2007. [DOI: 10.1111/j.0030-1299.2007.15461.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|