Captive management and the maintenance of genetic diversity in a vulnerable marsupial, the greater bilby

2015 ◽  
Vol 37 (2) ◽  
pp. 170 ◽  
Author(s):  
Emily J. Miller ◽  
Mark D. B. Eldridge ◽  
Keith Morris ◽  
Neil Thomas ◽  
Catherine A. Herbert

The endemic Australian greater bilby (Macrotis lagotis) is a vulnerable and iconic species. It has declined significantly due to habitat loss, as well as competition and predation from introduced species. Conservation measures include a National Recovery Plan that incorporates several captive breeding programs. Two of these programs were established within 12 months of one another (1997/98), with the same number and sex ratio of founding individuals, but executed different breeding strategies: (1) unmanipulated mating in semi–free range natural habitat versus (2) minimising mean kinship in large enclosures, with the supplementation of new individuals into both populations. This study evaluates the long-term genetic impact of these programs and examines the congruency between the pedigree studbook estimates of diversity and molecular data. Our data demonstrate that genetic diversity was maintained in both populations, with the supplementation of new individuals contributing to the gene pool. The studbook estimates of diversity and inbreeding are not consistent with the microsatellite data and should not solely be relied upon to evaluate the genetic health of captive populations. Our analyses suggest that captive breeding programs may not require costly and intensive management to effectively maintain long-term genetic diversity in a promiscuous species.

2017 ◽  
Author(s):  
Parice A Brandies ◽  
Catherine E Grueber ◽  
Jamie A Ivy ◽  
Carolyn J Hogg ◽  
Professor K Belov

Successful captive breeding programs are crucial to the long-term survival of threatened species. However, pair incompatibility limits sustainability of many captive populations. Understanding whether the drivers of this incompatibility are behavioural or genetic, or a combination of both, is crucial to improving breeding programs. We used twenty-eight years of pairing data from the San Diego Zoo koala colony, plus genetic analyses using both MHC-linked and non-MHC-linked microsatellite markers, to show that both behavioural and genetic determinants can influence mating success. Male age was reconfirmed to be a contributing factor to the likelihood of a pair copulating. Familiarity was also reconfirmed to increase the probability of a successful copulation. Our data provided evidence that females select mates based on MHC and genome-wide similarity. Male heterozygosity at class II MHC loci influenced both pre- and post-copulatory female choice. Genome-wide similarity and similarity at the MHCII DAB locus were also found to influence female choice at the post-copulatory level. Finally, certain MHC-linked alleles were associated with increased or decreased mating success. We predict that utilising a variety of behavioural and MHC-dependent mate choice mechanisms improves female fitness through increased reproductive success. This study highlights the complexity of mate choice mechanisms within a species and the importance of ascertaining mate choice mechanisms to improve the success of captive breeding programs.


2021 ◽  
Author(s):  
Pauline ML van Leeuwen ◽  
Albrecht I. Schulte-Hostedde ◽  
Christine Fournier-Chambrillon ◽  
Carmen M. Aranda ◽  
Laurie Berthomieu ◽  
...  

Abstract Host’s fitness can be affected by its genotype and gut microbiota, defined as the microbes living in the host’s intestinal tract. This study explored how the genetic diversity of the host influences its bacterial communities in the context of captive breeding programs, for the critically endangered European mink (Mustela lutreola). As stated by the ecosystem on a leash model, loss of host genetic diversity may lead to changes in immunomodulation and will therefore induce modifications of the gut microbiota. We investigated variation in the gut bacteria through 16S rRNA metabarcoding, related to the genetic diversity of European mink held in captivity in two breeding centers representing separate breeding stocks originating from the western and eastern populations. The genetic diversity of the host was assessed through diversity analysis of the adaptive MHC class I and II genes as well as neutral microsatellite markers. Results indicate lower diversity in neutral and MHC class I genes for the western population, and the opposite for MHC class II. A lower MHC class II gene variability led to an increase in microbial phylogenetic diversity and in abundance depending on the presence of specific MHC-II motifs. Those results seem to be linked to management practices that differs between the two programs, especially the number of generations in captivity. Long term Ex situ conservation practices can thus modulate gut microbial communities, that might potentially have consequences on the survival of reintroduced animals. We suggest strategies to foster genetic diversity in captive breeding program to mitigate the effects of genetic drift on those small, isolated populations.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12212
Author(s):  
Deepanwita Purohit ◽  
Shivakumara Manu ◽  
Muthuvarmadam Subramanian Ram ◽  
Shradha Sharma ◽  
Harika Chinchilam Patnaik ◽  
...  

Long-term captive populations often accumulate genetic changes that are detrimental to their survival in the wild. Periodic genetic evaluation of captive populations is thus necessary to identify deleterious changes and minimize their impact through planned breeding. Pygmy hog (Porcula salvania) is an endangered species with a small population inhabiting the tall sub-Himalayan grasslands of Assam, India. A conservation breeding program of pygmy hog from six founders has produced a multi-generational captive population destined for reintroduction into the wild. However, the impact of conservation breeding on its genetic diversity remained undocumented. Here, we evaluate temporal genetic changes in 39 pygmy hogs from eight consecutive generations of a captive population using genome-wide SNPs, mitochondrial genomes, and MHC sequences, and explore the relationship between genetic diversity and reproductive success. We find that pygmy hog harbors a very low genome-wide heterozygosity (H) compared to other members of the Suidae family. However, within the captive population we find excess heterozygosity and a significant increase in H from the wild-caught founders to the individuals in subsequent generations due to the selective pairing strategy. The MHC and mitochondrial nucleotide diversities were lower in captive generations compared to the founders with a high prevalence of low-frequency MHC haplotypes and more unique mitochondrial genomes. Further, even though no signs of genetic inbreeding were observed from the estimates of individual inbreeding coefficient F and between individuals (FIS) in each generation, the kinship coefficient showed a slightly increasing trend in the recent generations, due to a relatively smaller non-random sample size compared to the entire captive population. Surprisingly, male pygmy hogs that had higher heterozygosity also showed lower breeding success. We briefly discuss the implications of our findings in the context of breeding management and recommend steps to minimize the genetic effects of long-term captive breeding.


Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 617
Author(s):  
Brian Ramos-Güivas ◽  
Jodie M. Jawor ◽  
Timothy F. Wright

Many species are threatened with extinction, and captive breeding programs are becoming more common to avoid this outcome. These programs serve to prevent extinction and produce individuals for eventual reintroduction to natural populations in historical habitat. Captive animals experience different energetic demands than those in the wild, however, and as a result may have different levels of glucocorticoid hormones. Glucocorticoids help with responses to energetically expensive and potentially stressful situations. Elevated glucocorticoid levels can also potentially alter reproduction and other key behaviors, thus complicating successful captive breeding. The Puerto Rican parrot (Amazona vittata) is a critically endangered parrot that currently exists in only two wild and two captive populations. Its recovery program provides a good platform to better understand how glucocorticoid levels may relate to reproductive success under captive conditions. We validated a corticosterone assay in this species and used non-invasive techniques of measuring fecal glucocorticoid metabolites of males and females from two captive populations (Rio Abajo and El Yunque) of Puerto Rican parrots over two consecutive breeding seasons, 2017 and 2018, and the pre-breeding season of 2018, which occurred just after Hurricane Maria struck Puerto Rico. Our results show that levels of fecal glucocorticoid metabolites of males measured during the breeding season of 2018 negatively correlated to the number of total eggs and fertile eggs laid by pairs. In contrast, there was a positive relationship of female fecal glucocorticoid metabolite levels during the pre-breeding season of 2018 with total eggs laid. In males from the Rio Abajo population, we found seasonal differences in fecal glucocorticoid metabolite levels, with higher levels during the pre-breeding season of 2018 compared to both 2017 and 2018 breeding seasons. There was no difference in the mean value of male fecal glucocorticoid metabolites between the 2017 breeding season and 2018 breeding season which started four months after Hurricane Maria struck Puerto Rico. We did find sex differences during the pre-breeding season of 2018 in birds from the Rio Abajo population. Adjustments in the care routine of both populations that could reduce circulating baseline glucocorticoids and avoid frequent, sudden elevations of glucocorticoids should be considered. These results provide a baseline for future comparison with reintroduced populations of this endangered species and other species with captive breeding programs.


2017 ◽  
Author(s):  
Parice A Brandies ◽  
Catherine E Grueber ◽  
Jamie A Ivy ◽  
Carolyn J Hogg ◽  
Professor K Belov

Successful captive breeding programs are crucial to the long-term survival of threatened species. However, pair incompatibility limits sustainability of many captive populations. Understanding whether the drivers of this incompatibility are behavioural or genetic, or a combination of both, is crucial to improving breeding programs. We used twenty-eight years of pairing data from the San Diego Zoo koala colony, plus genetic analyses using both MHC-linked and non-MHC-linked microsatellite markers, to show that both behavioural and genetic determinants can influence mating success. Male age was reconfirmed to be a contributing factor to the likelihood of a pair copulating. Familiarity was also reconfirmed to increase the probability of a successful copulation. Our data provided evidence that females select mates based on MHC and genome-wide similarity. Male heterozygosity at class II MHC loci influenced both pre- and post-copulatory female choice. Genome-wide similarity and similarity at the MHCII DAB locus were also found to influence female choice at the post-copulatory level. Finally, certain MHC-linked alleles were associated with increased or decreased mating success. We predict that utilising a variety of behavioural and MHC-dependent mate choice mechanisms improves female fitness through increased reproductive success. This study highlights the complexity of mate choice mechanisms within a species and the importance of ascertaining mate choice mechanisms to improve the success of captive breeding programs.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3447 ◽  
Author(s):  
Emilio Valbuena-Ureña ◽  
Anna Soler-Membrives ◽  
Sebastian Steinfartz ◽  
Mònica Alonso ◽  
Francesc Carbonell ◽  
...  

Ex situ management strategies play an important role in the conservation of threatened species when the wild survival of the species cannot be ensured. Molecular markers have become an outstanding tool for the evaluation and management of captive breeding programs. Two main genetic objectives should be prioritized when planning breeding programs: the maintenance of maximum neutral genetic diversity, and to obtain “self-sustaining” captive populations. In this study, we use 24 microsatellite loci to analyze and evaluate the genetic representativity of the initial phases of the captive breeding program of the Montseny brook newt, Calotriton arnoldi, an Iberian endemic listed as Critically Endangered. The results show that the initial captive stock has 74–78% of the alleles present in the wild populations, and captures roughly 93–95% of their total genetic diversity as observed in a previous study on wild newts, although it does not reach the desired 97.5%. Moreover, the percentage of unrelatedness among individuals does not exceed 95%. Therefore, we conclude that the genetic diversity of the captive stock should be improved by incorporating genetic material from unrelated wild newts. In recognition of the previously described significant genetic and morphological differentiation between eastern and western wild populations of C. arnoldi, we suggest maintaining two distinct breeding lines, and we do not recommend outbreeding between these lines. Our comparisons of genetic diversity estimates between real and distinct sample-sized simulated populations corroborated that a minimum of 20 individuals are needed for each captive population, in order to match the level of genetic diversity present in the wild populations. Thus, the current initial stock should be reinforced by adding wild specimens. The captive stock and subsequent cohorts should be monitored in order to preserve genetic variation. In order to avoid genetic adaptation to captivity, occasionally incorporating previously genotyped individuals from the wild into the captive populations is recommended.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1515
Author(s):  
Marissa L. Parrott ◽  
Leanne V. Wicker ◽  
Amanda Lamont ◽  
Chris Banks ◽  
Michelle Lang ◽  
...  

Modern zoos are increasingly taking a leading role in emergency management and wildlife recovery. In the face of climate change and the predicted increase in frequency and magnitude of catastrophic events, zoos provide specialised expertise to assist wildlife welfare and endangered species recovery. In the 2019–2020 Australian bushfire season, now called Australia’s Black Summer, a state government-directed response was developed, assembling specialised individuals and organisations from government, non-government organisations, research institutions, and others. Here, we detail the role of Zoos Victoria staff in wildlife triage and welfare, threatened species evacuation and recovery, media and communications, and fundraising during and after the fires. We share strategies for future resilience, readiness, and the ability to mobilise quickly in catastrophic events. The development of triage protocols, emergency response kits, emergency enclosures, and expanded and new captive breeding programs is underway, as are programs for care of staff mental health and nature-based community healing for people directly affected by the fires. We hope this account of our response to one of the greatest recent threats to Australia’s biodiversity, and steps to prepare for the future will assist other zoos and wildlife organisations around the world in preparations to help wildlife before, during, and after catastrophic events.


Biologia ◽  
2016 ◽  
Vol 71 (4) ◽  
Author(s):  
Somaye Vaissi ◽  
Mozafar Sharifi

AbstractThe effects of temperature and food levels on body size, growth rate, time to metamorphosis and survival were studied in larval and post-metamorphic juvenile endangered yellow spotted mountain newts


Sign in / Sign up

Export Citation Format

Share Document