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von Seth J, van der Valk T, Lord E, Sigeman H, Olsen RA, Knapp M, Kardailsky O, Robertson F, Hale M, Houston D, Kennedy E, Dalén L, Norén K, Massaro M, Robertson BC, Dussex N. Genomic trajectories of a near-extinction event in the Chatham Island black robin. BMC Genomics 2022; 23:747. [DOI: 10.1186/s12864-022-08963-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 10/23/2022] [Indexed: 11/11/2022] Open
Abstract
Abstract
Background
Understanding the micro-evolutionary response of populations to demographic declines is a major goal in evolutionary and conservation biology. In small populations, genetic drift can lead to an accumulation of deleterious mutations, which will increase the risk of extinction. However, demographic recovery can still occur after extreme declines, suggesting that natural selection may purge deleterious mutations, even in extremely small populations. The Chatham Island black robin (Petroica traversi) is arguably the most inbred bird species in the world. It avoided imminent extinction in the early 1980s and after a remarkable recovery from a single pair, a second population was established and the two extant populations have evolved in complete isolation since then. Here, we analysed 52 modern and historical genomes to examine the genomic consequences of this extreme bottleneck and the subsequent translocation.
Results
We found evidence for two-fold decline in heterozygosity and three- to four-fold increase in inbreeding in modern genomes. Moreover, there was partial support for temporal reduction in total load for detrimental variation. In contrast, compared to historical genomes, modern genomes showed a significantly higher realised load, reflecting the temporal increase in inbreeding. Furthermore, the translocation induced only small changes in the frequency of deleterious alleles, with the majority of detrimental variation being shared between the two populations.
Conclusion
Our results highlight the dynamics of mutational load in a species that recovered from the brink of extinction, and show rather limited temporal changes in mutational load. We hypothesise that ancestral purging may have been facilitated by population fragmentation and isolation on several islands for thousands of generations and may have already reduced much of the highly deleterious load well before human arrival and introduction of pests to the archipelago. The majority of fixed deleterious variation was shared between the modern populations, but translocation of individuals with low mutational load could possibly mitigate further fixation of high-frequency deleterious variation.
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Bernátková A, Oyunsaikhan G, Šimek J, Komárková M, Bobek M, Ceacero F. Influence of weather on the behaviour of reintroduced Przewalski’s horses in the Great Gobi B Strictly Protected Area (Mongolia): implications for conservation. BMC ZOOL 2022; 7:32. [PMID: 37170378 PMCID: PMC10127430 DOI: 10.1186/s40850-022-00130-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 05/11/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Reintroduction is a common technique for re-establishing threatened species. However, the adaptation to novel habitats with distinct conditions poses a risk of failure. Weather conditions affect the behaviour of animals, and thus, their adaptation to new conditions and survival. Reintroduced Przewalski’s horses living in Mongolia’s continental arid climate with extreme temperature and precipitation variability, serve as an ideal model species for studying the behavioural response of selected groups to these harsh conditions.
Methods
The research was conducted in The Great Gobi B Strictly Protected Area, Mongolia. In summer 2018, three groups were recorded (Azaa, Tsetsen and Mares18) involving 29 individuals. In Spring 2019, 4 groups were recorded (Azaa, Tsetsen, Hustai1 and Mares19) involving 34 individuals. In Autumn 2019, 4 groups were recorded (Azaa, Tsetsen, Hustai2 and Tanan) involving 35 individuals. Thirteen weather variables were recorded in 10-min intervals, together with the percentage representation of selected behavioural categories (feeding, locomotion, resting, and social). The effect of weather on behaviour was analysed through GLMM. Influence of the group-history factors (recently reintroduced, long-term reintroduced and wild-born) was also analysed.
Results
Feeding significantly increased with cloudy and windy conditions and was more frequent in autumn than spring and summer. Locomotion was positively explained by temperature and cloudiness and was higher in summer than spring and autumn. Resting behaviour decreased with altitude and cloudiness, and the dispersion of the group was lower when resting. Increased social interactions were observed with higher temperatures and were more frequent in summer compared to spring and autumn. Differences were found in the display of the behaviours among the selected harems, showing interesting patterns when grouping them according to their origin and experience.
Conclusions
Weather patterns seem to influence the behaviour of Przewalski’s horse. These results might assist in further management plans for the species, especially in the view of intensifying climate change and alteration of weather patterns. As previously suggested, after approximately 1 year, horses adapt to novel conditions and display the typical behavioural pattern of wild-born Przewalski’s horses.
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Hunter-Ayad J, Jarvie S, Greaves G, Digby A, Ohlemüller R, Recio MR, Seddon PJ. Novel Conditions in Conservation Translocations: A Conservative-Extrapolative Strategic Framework. FRONTIERS IN CONSERVATION SCIENCE 2021. [DOI: 10.3389/fcosc.2021.691714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In response to anthropogenic threats, conservation translocations are increasingly used to combat species' population and range declines. However, moving animals outside of their current distribution can mean introducing them to novel conditions, even in the case of reintroductions to formerly inhabited areas due to ecosystem changes following extirpation. This exposure to novel conditions introduces uncertainty that can undermine decision making for species conservation. Here we propose two strategies, which we define as conservative and extrapolative, for approaching and managing novelty and the resulting uncertainty in conservation translocations. Conservative strategies are characterised by the avoidance and removal of novel conditions as much as possible, whereas extrapolative strategies are more experimental, allowing exposure to novel conditions and monitoring outcomes to increase understanding of a species' ecology. As each strategy carries specific risks and opportunities, they will be applicable in different scenarios. Extrapolative strategies suit species in recovery which can afford some experimental management, or species facing novel and emerging threats which require less traditional translocations, such as assisted colonisations. We provide examples, applying our framework to two endemic New Zealand species with long histories of translocation management: tuatara (Sphenodon punctatus), a reptile and takahē (Porphyrio hochstetteri), a flightless bird.
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Segal RD, Massaro M, Carlile N, Whitsed R. Small‐scale species distribution model identifies restricted breeding habitat for an endemic island bird. Anim Conserv 2021. [DOI: 10.1111/acv.12698] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. D. Segal
- School of Environmental Sciences Charles Sturt University Albury NSW Australia
- Institute for Land, Water and Society Charles Sturt University Albury NSW Australia
| | - M. Massaro
- School of Environmental Sciences Charles Sturt University Albury NSW Australia
- Institute for Land, Water and Society Charles Sturt University Albury NSW Australia
| | - N. Carlile
- Department of Planning, Industry and Environment NSW Parramatta NSW Australia
| | - R. Whitsed
- School of Environmental Sciences Charles Sturt University Albury NSW Australia
- Institute for Land, Water and Society Charles Sturt University Albury NSW Australia
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McNicol CM, Bavin D, Bearhop S, Bridges J, Croose E, Gill R, Goodwin CED, Lewis J, MacPherson J, Padfield D, Schofield H, Silk MJ, Tomlinson AJ, McDonald RA. Postrelease movement and habitat selection of translocated pine martens Martes martes. Ecol Evol 2020; 10:5106-5118. [PMID: 32551086 PMCID: PMC7297779 DOI: 10.1002/ece3.6265] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 12/20/2019] [Accepted: 02/13/2020] [Indexed: 11/26/2022] Open
Abstract
Monitoring postrelease establishment and movement of animals is important in evaluating conservation translocations. We translocated 39 wild pine martens Martes martes (19 females, 20 males) from Scotland to Wales. We released them into forested areas with no conspecifics in 2015, followed by a second release in 2016, alongside the previously released animals. We used radio-tracking to describe postrelease movement and habitat selection. Six martens (15%) were not re-encountered during the tracking period, of which four undertook long-distance dispersal. For the remaining individuals, we characterized two phases of movement, "exploration" followed by "settlement," that differed between releases. In the first release, martens remained in exploration phase for a mean of 14.5 days (SE = 3.9 days) and settled at a mean distance of 8.7 km (SE = 1.8 km) from release sites, whereas martens released in year two, alongside resident conspecifics, traveled away from release sites at a faster rate, settling sooner, at a mean of 6.6 days (SE = 1.8 days), but further, at a mean distance of 14.0 km (SE = 1.7 km) from release sites. Animals released in year one did not exhibit habitat preferences overall but within forests they favored recently felled areas, whereas animals released in year two showed strong selection for forested habitat but did not discriminate between forest types. The presence of conspecifics appeared influential for settlement and site fidelity of translocated martens and was associated with more rapid but more distant dispersal of the later cohort. Releases of animals in close proximity appeared to promote site fidelity and rapid establishment of ranges in the recipient environment.
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Affiliation(s)
| | - David Bavin
- Environment and Sustainability InstituteUniversity of ExeterPenrynUK
- Vincent Wildlife TrustEastnorLedburyUK
| | - Stuart Bearhop
- Centre for Ecology and ConservationUniversity of ExeterPenrynUK
| | | | | | - Robin Gill
- Forest ResearchAlice Holt LodgeFarnhamUK
| | | | | | | | - Daniel Padfield
- Environment and Sustainability InstituteUniversity of ExeterPenrynUK
| | | | - Matthew J. Silk
- Environment and Sustainability InstituteUniversity of ExeterPenrynUK
- Centre for Ecology and ConservationUniversity of ExeterPenrynUK
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Davison AC, Hautphenne S, Kraus A. Parameter estimation for discretely observed linear birth-and-death processes. Biometrics 2020; 77:186-196. [PMID: 32306397 DOI: 10.1111/biom.13282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 03/21/2020] [Accepted: 03/30/2020] [Indexed: 11/29/2022]
Abstract
Birth-and-death processes are widely used to model the development of biological populations. Although they are relatively simple models, their parameters can be challenging to estimate, as the likelihood can become numerically unstable when data arise from the most common sampling schemes, such as annual population censuses. A further difficulty arises when the discrete observations are not equi-spaced, for example, when census data are unavailable for some years. We present two approaches to estimating the birth, death, and growth rates of a discretely observed linear birth-and-death process: via an embedded Galton-Watson process and by maximizing a saddlepoint approximation to the likelihood. We study asymptotic properties of the estimators, compare them on numerical examples, and apply the methodology to data on monitored populations.
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Affiliation(s)
- A C Davison
- Institute of Mathematics, Ecole Polytechnique Fédérale de Lausanne, EPFL-FSB-MATH-STAT, Lausanne, Switzerland
| | - S Hautphenne
- Institute of Mathematics, Ecole Polytechnique Fédérale de Lausanne, EPFL-FSB-MATH-STAT, Lausanne, Switzerland.,School of Mathematics and Statistics, The University of Melbourne, Melbourne, Australia
| | - A Kraus
- Department of Mathematics and Statistics, Masaryk University, Brno, Czech Republic
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Kongsurakan P, Chaiyarat R, Nakbun S, Thongthip N, Anuracpreeda P. Monitoring body condition score of reintroduced banteng ( Bos javanicus D'Alton, 1923) into Salakphra Wildlife Sanctuary, Thailand. PeerJ 2020; 8:e9041. [PMID: 32351790 PMCID: PMC7183756 DOI: 10.7717/peerj.9041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 04/01/2020] [Indexed: 11/20/2022] Open
Abstract
Background Banteng (Bos javanicus d’Alton 1823) are an endangered species, highly sensitive to habitat structure and quality. In many areas, banteng were extinct and needed to be reintroduced to restore their population. Thus, understanding the responses of body condition of reintroduced banteng to their habitat was important for ensuring the sustainability of a reintroduction program. The aim of the present study was to evaluate the body condition of banteng after reintroduction into the Salakphra Wildlife Sanctuary in Thailand based on photographs from camera-traps carried out between July 2016 and November 2018. Methods Seven banteng were bred at the Khao Nampu Nature and Wildlife Education Center and systematically reintroduced into the Salakphra Wildlife Sanctuary in December 2015 (four) and July 2016 (three). The seven reintroduced adults and two newborns (from the 2015 group) were captured via camera traps in 2018. The body condition scoring (BCS) obtained from these photographs was used to identify the individual performance of all seven adults after their reintroduction. Results The BCS scores in reintroduced adult banteng, both males and females, (between 5 and 7 years old) increased significantly over time after reintroduction into a natural habitat (p < 0.05), although the BCS scores in females were not significantly different between the second and third years (p > 0.05). Conclusions The results from the present study suggest that camera traps are a practical tool to assess the BCS of reintroduced banteng, and can be used to monitor their condition post-release. These techniques may be appropriate for translocation programs elsewhere.
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Affiliation(s)
- Praeploy Kongsurakan
- Wildlife and Plants Research Center, Faculty of Environment and Resource Studies, Mahidol University, Phuttamonthon, Nakhon Pathom, Thailand
| | - Rattanawat Chaiyarat
- Wildlife and Plants Research Center, Faculty of Environment and Resource Studies, Mahidol University, Phuttamonthon, Nakhon Pathom, Thailand
| | - Seree Nakbun
- Khao Nampu Nature and Wildlife Education Center, Department of National Parks, Wildlife and Plant Conservation, Kanchanaburi, Thailand
| | - Nikorn Thongthip
- Faculty of Veterinary Medicine, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom, Thailand.,Center for Agricultural Biotechnology, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom, Thailand.,Center of Excellence on Agricultural Biotechnology, Science and Technology Postgraduate Education and Research Department Commission on Higher Education, Ministry of Education (AG-BIO/PERDO-CHE), Bangkok, Thailand
| | - Panat Anuracpreeda
- Institute of Molecular Biosciences, Mahidol University, Phuttamonthon, Nakhon Pathom, Thailand
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Hautphenne S, Massaro M, Turner K. Fitting Markovian binary trees using global and individual demographic data. Theor Popul Biol 2019; 128:39-50. [PMID: 31059720 DOI: 10.1016/j.tpb.2019.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 04/19/2019] [Accepted: 04/22/2019] [Indexed: 10/26/2022]
Abstract
We consider a class of continuous-time branching processes called Markovian binary trees (MBTs), in which the individuals lifetime and reproduction epochs are modelled using a transient Markovian arrival process (TMAP). We develop methods for estimating the parameters of the TMAP by using either age-specific averages of reproduction and mortality rates, or age-specific individual demographic data. Depending on the degree of detail of the available information, we follow a weighted non-linear regression or a maximum likelihood approach. We discuss several criteria to determine the optimal number of states in the underlying TMAP. Our results improve the fit of an existing MBT model for human demography, and provide insights for the future conservation management of the threatened Chatham Island black robin population.
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Affiliation(s)
- Sophie Hautphenne
- The University of Melbourne, School of Mathematics and Statistics, 3010 Melbourne, Victoria, Australia; Ecole polythechnique fédérale de Lausanne, Switzerland.
| | - Melanie Massaro
- Charles Sturt University, Institute for Land, Water and Society and School of Environmental Sciences, Australia.
| | - Katharine Turner
- Ecole polythechnique fédérale de Lausanne, Switzerland; Australian National University, Australia.
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Chaiyarat R, Youngpoy N, Kongsurakan P, Nakbun S. Habitat preferences of reintroduced banteng (Bos javanicus) into the Salakphra Wildlife Sanctuary, Thailand. WILDLIFE RESEARCH 2019. [DOI: 10.1071/wr18184] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract
ContextLarge forest-dwelling mammals are highly sensitive to habitat structure. Thus, understanding the responses of reintroduced banteng (Bos javanicus d’Alton 1823) to their habitat is important for ensuring the sustainability of a reintroduction program.
AimsThe aim of the present study was to evaluate the habitat preferences of banteng after reintroduction into the Salakphra Wildlife Sanctuary in Thailand on the basis of fieldwork conducted between January 2015 and November 2017.
MethodsSeven banteng individuals bred at the Khao Nampu Nature and Wildlife Education Center were systematically reintroduced into the Salakphra Wildlife Sanctuary in 2015 (four individuals) and 2016 (three individuals). The banteng individuals were tracked via radio-collars and camera-traps. The maximum-entropy method (MaxEnt) and multiple logistic regressions (MLR) were used to identify habitat preferences. Kernel-density estimates (KDE) and a minimum convex polygon (MCP) were used to estimate the area of the habitat used.
Key resultsIn total, 407 radio-signal locations showed that the MaxEnt habitat-preference models classified the banteng as associated with distance from villages and salt licks (regularised training gain of >1.0). Multiple logistic regressions form 32 camera-trap locations classified the banteng as associated with low elevations far from villages, guard stations and roads in a flat area (no aspect). The two methods for estimating habitat use provided similar results and showed that the reintroduced banteng used a wider range of habitat in the dry than in the wet season.
ConclusionsThe results from the present study suggest that the reintroduced banteng individuals prefer low elevations and flat areas without human activity.
ImplicationsThese findings are important for possible translocations elsewhere.
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