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1.
Mol Biol Rep ; 51(1): 136, 2024 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-38236328

RESUMEN

BACKGROUND: Captive breeding programs play a vital role in conservation of threatened species, necessitating an understanding of genetic diversity among captive individuals to ensure long-term genetic viability, appropriate mate selection, and successful reintroduction to native habitats. METHODS AND RESULTS: We did not observe any recent genetic bottleneck, and population showed moderate genetic diversity. The estimated effective population size, representing individuals capable of contributing genetically to future generations, was estimated as 18.6 individuals (11.4-35.1 at 95% CI). Based on the genetic make-up and allelic diversity, we found seventeen pangolins (11 females and 6 males) were genetically unrelated and relatively more potent than others. CONCLUSION: In this study, we evaluated the captive breeding program of the Indian pangolin population at the Pangolin Conservation Breeding Centre in Nandankanan Zoological Park, Bhubaneswar, Odisha. We highlight the significance of genetic monitoring within the captive population of Indian pangolin for preserving genetic diversity and ensuring the long-term survival of the species. We established the genetic profiles of all 29 pangolins and identified 17 pangolins to be prioritized for enhanced breeding and future zoo exchange programs. We appreciate the zoo authorities for promoting genetic assessment of pangolin for better and more effective monitoring of the captive breeding of the endangered Indian pangolin.


Asunto(s)
Cruzamiento , Pangolines , Humanos , Femenino , Masculino , Animales , Alelos , Especies en Peligro de Extinción , Perfil Genético
2.
J Fish Biol ; 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38830639

RESUMEN

Dystocia, or obstructed labor, is a well-documented phenomenon in various captive vertebrates, including fish. However, despite the documentation of dystocia in several viviparous (live-bearing) Chondrichthyan species (i.e., sharks, rays, skates, and chimaeras), there are no reports to date of dystocia in any oviparous (egg-laying) species. Here we present a case of a captive female epaulette shark (Hemiscyllium ocellatum) that demonstrated symptoms of dystocia in a research-related captive breeding programme. This communication serves as documentation that dystocia can occur in oviparous Chondrichthyans, and this information can help inform researchers and veterinary practitioners for improved care.

3.
J Environ Manage ; 354: 120240, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38340671

RESUMEN

Captive breeding is often seen as a solution to sustainably increasing the supply of individuals in the wildlife trade. To be an effective conservation measure this requires robust systems to verify the authenticity of captive-bred species. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) monitors the international trade in Listed species-which for many taxa is dominated by captive-bred individuals-using the Review of Captive Trade (RCT) process. A key question is how best to identify laundered or inauthentic captive-bred trade and how has this changed over time and space. We develop targeted assessments based on multiple RCT criteria to identify probable instances of laundering and misuse of source and purpose codes in international trade records, and apply this to 39,167 records of captive trade from 2000 to 2020 spanning 53,674,762 individuals. We find a very low proportion of trade volume (1.8%, 37,835 individuals) misreported as originating from non-existent, registered Appendix I-breeding facilities, and low instances of exporter-reported captive trade being recorded by importers as wild-sourced (<4%) or ranched (1%). We also find that <2% of species-year-exporter records have abrupt shifts from wild to captive sources, potentially indicating laundering. Conversely, we find high incidences of exporter- and importer-reported trade differing in whether the trade was commercial or not - a phenomenon we attribute to differing definitions, not illegal activity. Our results indicate a low incidence of concerning international trade being reported, but we suggest this likely stems from reporting requirements that limit our assessments. We highlight additional trade data that, if embedded into Party's annual reports, would vastly improve inferential potential, greatly increasing the number of records (Appendix II and III species) that could be verified with minimal effort for management authorities.


Asunto(s)
Comercio , Conservación de los Recursos Naturales , Animales , Especies en Peligro de Extinción
4.
Zoo Biol ; 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38837463

RESUMEN

Fruit bats (genus Pteropus) are typically island-endemic species important in seed dispersal and reforestation that are vulnerable to increased extinction risk. An effective method of reducing extinction risk in vulnerable species that cannot be conserved in their native habitat is establishing an ex-situ captive breeding programme. Due to anthropogenic threats and low population numbers, in the early 1990s, a captive breeding programme was established at Jersey Zoo, British Isles, for Critically Endangered Livingstone's fruit bats (Pteropus livingstonii). Here we use six polymorphic microsatellite loci to assess genetic diversity in the captive breeding population of Livingstone's fruit bats (P. livingstonii), 30 years after the programme's establishment, investigating change over generations and comparing our findings with published data from the wild population. We found no significant difference between the genetic diversity in the captive and wild populations of Livingstone's fruit bats (P. livingstonii), in both expected heterozygosity and allelic richness. The captive population has retained a comparable level of genetic diversity to that documented in the wild, and there has been no significant decline in genetic diversity over the last 30 years. We advise that a full pedigree of the paternal lineage is created to improve the management of the captive breeding programme and further reduce the possibility of inbreeding. However, it appears that the captive breeding programme is currently effective at maintaining genetic diversity at levels comparable to those seen in the wild population, which suggests reintroductions could be viable if genetic diversity remains stable in captivity.

5.
Zoo Biol ; 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38900371

RESUMEN

Boreal chorus frogs (Pseudacris maculata Agassiz 1850) are a widespread amphibian in North America, but several populations are in decline. Specifically, we are developing captive breeding and reintroduction methods for the Great Lakes/St. Lawrence-Canadian Shield population. Here we present the effects of tadpole density, food variety, and addition of supplemental minerals to rearing water on the growth, development, and survival during the larval and metamorph/juvenile stages. We conducted two experiments using a factorial design. We found that low tadpole density (1 vs. 2 tadpoles/L) and high food variety (five food items vs. three food items) significantly increased tadpole body length and Gosner stage after 2 weeks (p < .001), increased survival to metamorphosis (p < .001), decreased time to metamorphosis (p < .001), and increased weight after metamorphosis (p < .001). On average, tadpoles in the high density/low food treatment, compared to the low density/high food, were 25% smaller after 2 weeks, had 3.9× lower survival to metamorphosis, took 1.25× longer to reach metamorphosis, and weighed 1.5× less after metamorphosis. In contrast, neither density (0.5 vs. 1 tadpole/L) nor mineral supplemented water affected growth and development, but tadpole survival was higher at 1 tadpole/L. Our findings demonstrate the feasibility of rearing boreal chorus frogs in captivity and provide guidelines for rearing this and similar species in a laboratory environment.

6.
Zoo Biol ; 43(2): 178-182, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38234153

RESUMEN

The Louisiana pinesnake (Pituophis ruthveni) is considered one of the rarest snakes in North America and was federally listed under the Endangered Species Act in 2018. Captive breeding and reintroduction of zoo-bred hatchlings has been successful, however, limited founders in the captive population and the inability to bring new, wild genes into the captive colony presents a major concern for the conservation of this species. The use of artificial insemination (AI) was first applied to snakes in the 1980s but further development of the technique has since received little attention. Our goal was to develop a method of AI for use in breeding Louisiana pinesnakes to facilitate gene flow from wild to captive populations. We inseminated two captive Louisiana pinesnakes with semen collected from one donor male, novel to both females. Timing of AI occurred following the emergence of females from brumation, and when large, distinct follicles were detected using digital palpation. Females were inseminated four and five times over a period of 14 and 19 days, respectively, using fresh and 2-day refrigerator stored semen. One female laid seven eggs, which resulted in four fertile eggs and two viable hatchlings, while the second female produced three fertile of seven eggs laid but no viable hatchlings. Genetic analyses confirmed the donor male was the sire of hatchlings. This is the first successful AI of an endangered snake species and provides a framework for the use and optimization of assisted reproductive technologies for use in conservation breeding programs.


Asunto(s)
Animales de Zoológico , Preservación de Semen , Animales , Femenino , Masculino , Inseminación Artificial/veterinaria , Preservación de Semen/métodos , Especies en Peligro de Extinción , Semen
7.
Ecol Lett ; 26(5): 789-796, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36929598

RESUMEN

Captive breeding and release to the wild is a globally important conservation tool. However, captivity can result in phenotypic changes that incur post-release fitness costs, especially if they affect strenuous or risky behaviours. Bird wing shape is critical for migration success and suboptimal phenotypes are strongly selected against. In this study, I demonstrate surprising plasticity of bird wing phenotypes in captivity for 4/16 studied species. In a model species, captive-born juveniles with wild wing phenotypes (a 1-mm longer distal primary flight feather) survived post-release at 2.7 times the rate of those with captive phenotypes (i.e. a shorter distal feather). Subtle phenotypic changes and their fitness impacts are more common than widely realised because they are easily overlooked. To improve captive breeding for conservation, practitioners must surveil phenotypic changes and find ways to mitigate them.


Asunto(s)
Conservación de los Recursos Naturales , Animales , Fenotipo
8.
Mol Ecol ; 32(19): 5228-5240, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37610278

RESUMEN

The accelerating pace of global biodiversity loss is exacerbated by habitat fragmentation and subsequent inbreeding in small populations. To address this problem, conservation practitioners often turn to assisted breeding programmes with the aim of enhancing genetic diversity in declining populations. Although genomic information is infrequently included in these efforts, it has the potential to significantly enhance the success of such programmes. In this study, we showcase the value of genomic approaches for increasing genetic diversity in assisted breeding efforts, specifically focusing on a highly inbred population of Western burrowing owls. To maximize genetic diversity in the resulting offspring, we begin by creating an optimal pairing decision tree based on sex, kinship and patterns of homozygosity across the genome. To evaluate the effectiveness of our strategy, we compare genetic diversity, brood size and nestling success rates between optimized and non-optimized pairs. Additionally, we leverage recently discovered correlations between telomere length and fitness across species to investigate whether genomic optimization could have long-term fitness benefits. Our results indicate that pairing individuals with contrasting patterns of homozygosity across the genome is an effective way to increase genetic diversity in offspring. Although short-term field-based metrics of success did not differ significantly between optimized and non-optimized pairs, offspring from optimized pairs had significantly longer telomeres, suggesting that genetic optimization can help reduce the risk of inbreeding depression. These findings underscore the importance of genomic tools for informing efforts to preserve the adaptive potential of small, inbred populations at risk of further decline.


Asunto(s)
Variación Genética , Endogamia , Humanos , Animales , Variación Genética/genética , Cruzamiento , Genoma , Genómica
9.
Conserv Biol ; 37(4): e14076, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37144474

RESUMEN

The wildlife trade is a billion-dollar global business, involving millions of people, thousands of species, and hundreds of millions of individual organisms. Unravelling whether trade targets reproductively distinct species and whether this preference varies between captive- and wild-sourced species is a crucial question. We used a comprehensive list of all bird species traded, trade listings and records kept in compliance with the Convention on International Trade in Endangered Species (CITES), and a suite of avian reproductive parameters to examine whether wildlife trade is associated with particular facets of life history and to examine the association between life-history traits and captive- and wild-sourced traded volumes over time. Across all trade, CITES listing, and CITES trade, large birds were more likely to be traded and listed, but their longevity and age at maturity were not associated with CITES listing or trade. We found species across almost the full range of trait values in both captive and wild trade between 2000 and 2020. Captive trade volumes clearly associated with relatively longer lived and early-maturing species; these associations remained stable and largely unchanged over time. Trait-volume associations in wild-sourced trade were more uncertain. Only body mass had a clear association, and it varied from negative to positive over time. Although reproductive traits were important in captive-sourced trade, species-level variation dominated trade, with even congeneric species varying greatly in volume despite similar traits. The collection and incorporation of trait data into sustainability assessments of captive breeding facilities are crucial to ensure accurate quotas and guard against laundering.


Asociación entre los rasgos reproductivos de aves en cautiverio versus las de origen silvestre comercializadas Resumen El mercado de fauna es un negocio mundial de miles de millones de dólares que involucra a millares de personas, miles de especies y cientos de millones de organismos individuales. Por ello es necesario resolver la cuestión de si el mercado se enfoca en especies con distinciones reproductivas y si esta preferencia varía entre las especies de origen silvestre y en cautiverio. Usamos una lista completa de todas las especies de aves comercializadas, listados y registros comerciales conforme a la Convención sobre el Comercio Internacional de Especies Amenazadas (CITES) y un conjunto de parámetros de reproducción de aves para analizar si el mercado de fauna está asociado con facetas particulares de la historia de vida. También analizamos la asociación entre los rasgos de la historia de vida y el volumen comercializado de origen silvestre y de cautiverio a lo largo del tiempo. En todos los mercados, listas de CITES y mercados CITES, las aves de mayor tamaño tuvieron mayor probabilidad de ser comercializadas y estar enlistadas, pero su longevidad y edad a la madurez no se asoció con el mercado o la lista e CITES. Detectamos especies en casi toda la gama de rasgos tanto en el comercio de cautiverio como el silvestre entre 2000 y 2020. El volumen comercial de cautiverio mostró una asociación clara con las especies relativamente más longevas y de madurez temprana; esta relación fue estable y casi no cambió con el tiempo. La asociación del volumen en las especies de origen silvestre fue más incierta; sólo la masa corporal tuvo una relación clara y ésta varió entre positiva y negativa con el tiempo. Aunque los rasgos reproductivos fueron importantes para el mercado con origen en cautiverio, la variación a nivel de especies dominó el mercado, incluso mostrando una enorme variación del volumen entre las especies congéneres a pesar de tener rasgos similares. La recolección e incorporación de datos sobre los rasgos dentro de los análisis de sustentabilidad de las instalaciones para la cría en cautiverio es crucial para asegurar las cuotas adecuadas y prevenir blanqueo de capitales.


Asunto(s)
Comercio , Conservación de los Recursos Naturales , Humanos , Animales , Internacionalidad , Animales Salvajes , Especies en Peligro de Extinción , Aves
10.
Gen Comp Endocrinol ; 330: 114142, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36243057

RESUMEN

This study demonstrates the utility of the analysis of fecal hormone metabolites as a reproductive management tool for captive short-beaked echidnas. Over three breeding seasons daily fecal samples were collected from female echidnas (n = 8) that were monitored continuously by video surveillance to confirm key reproductive events. Fecal progesterone metabolite concentrations were elevated above baseline values (448.0 ± 156.3 ng/g) during pregnancy and the luteal phase. However, compared to plasma progesterone the rise in fecal progesterone metabolite concentrations after copulation was delayed (3.3 ± 0.4 versus 8.3 ± 0.6 days, respectively), such that pregnancy was more reliably detected in its latter half when using fecal samples. Mating and oviposition were observed for 14 of the 19 pregnancies resulting in an estimated gestation of 16.7 ± 0.2 days (range 16.0-18.1 d). The estrogen enzyme-immunoassays tested (n = 3) in this study were not suitable for the fecal samples of the echidna. Fecal progesterone metabolites are an effective tool for confirming the timing and occurrence of estrous cycles in captive echidna colonies and can assist zookeepers in identifying possible causes of sub-optimal reproductive success without the unnecessary stress of repeated capture and anaesthesia for blood collection.


Asunto(s)
Monotremata , Tachyglossidae , Embarazo , Animales , Femenino , Progesterona/metabolismo , Reproducción , Heces , Estrógenos/metabolismo
11.
Zygote ; 31(2): 201-206, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36793131

RESUMEN

Brazilian basslet Gramma brasiliensis is a fish highly appreciated by the marine ornamental industry. There is an increasing interest in the development of a breeding protocol for this species. However, descriptions of the reproductive biology, eggs and larval development are scarce. This study was the first to describe the spawning, eggs and larvae of G. brasiliensis in captivity, including mouth size information. Six spawning events produced egg masses with 27, 127, 600, 750, 850, and 950 eggs. Larger egg masses showed embryos with at least two different developmental stages. Eggs are spherical (∼1.0 mm diameter), held together by filaments entangling chorionic projections. Larvae with fewer than 12 hph (hours post-hatch) presented 3.55 mm standard-length, well developed eyes, fully absorbed yolk sac, an inflated swim bladder and mouth opened. Exogenous feeding on rotifers began within 12 hph. The average mouth width at first feeding was 0.38 mm. The first settled larva was noted by day 21. This information should help to determine appropriate diets and prey-shift time during the larviculture of the species.


Asunto(s)
Peces , Saco Vitelino , Animales , Larva , Brasil
12.
Reprod Domest Anim ; 58(6): 769-777, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36964983

RESUMEN

Sperm quality is a very important population survival factor, which can be influenced by the level of male's genetic diversity and can influence reproduction effectiveness, what may be crucial in terms of decision about local, endangered population protection plans. Thus, we analysed if heterozygosity and age influence sperm quality in the engendered European capercaillie (Tetrao urogallus) population in Polish breeding stations. Obtained results showed no relationship between normal sperm morphology and heterozygosity, as well as age and sperm morphology, but it was shown that both high and low level of heterozygosity significantly influenced the percentage of abnormal sperm. Thus, heterozygosity level can be a useful tool for population reproduction potential prediction, however, further research on how those abnormalities influence fertilization process are needed.


Asunto(s)
Galliformes , Análisis de Semen , Masculino , Animales , Análisis de Semen/veterinaria , Semen , Galliformes/genética , Especies en Peligro de Extinción , Codorniz , Espermatozoides
13.
J Fish Biol ; 102(1): 119-127, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36217919

RESUMEN

Endemic to the south-west Atlantic Ocean, the shortnose guitarfish (Zapteryx brevirostris) is a small species, classified as endangered by the IUCN. Although reproduction in captivity has been successful for some species, a range of factors can limit the success of captive breeding programmes for elasmobranchs. In Brazil, the Ubatuba Aquarium was the first public aquarium to reproduce small-sized elasmobranchs. Since 2018, at least five parturition events have been recorded for Z. brevirostris at the institution. From a total of 13 live neonates that rearing was attempted, the mean ± standard error of weight, total length (TL) and disc width at birth were 17.47 ± 1.6 g, 13.25 ± 0.7 cm and 6.53 ± 0.2 cm, respectively. The mean weight as well as mean TL were higher for females at all births, with 26.15 g and 15.07 cm for females in comparison with 17.09 g and 13.94 cm for males. Considering the increasing risk of extinction that the species is facing, age and growth studies are fundamental for the success of conservation, improving the knowledge of Z. brevirostris life cycle so that a more efficient and sustainable management can be carried out. This study provides important data, as well as directions for captive breeding of the species.


Asunto(s)
Elasmobranquios , Rajidae , Femenino , Masculino , Animales , Embarazo , Reproducción , Parto , Brasil
14.
Zoo Biol ; 42(1): 162-170, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35723495

RESUMEN

The Raggiana Bird-of-paradise (Paradisaea raggiana) has been held by the San Diego Zoo for more than 50 years, but the population remained in low numbers until the mid-1990s. A previous article published in 1997 documented the beginning of the rise in the population; however, no new information has been published since that time. Over the past 25 years, behavioral observations by animal staff have led to improvements in husbandry techniques, which includes artificial incubation of eggs and hand-rearing of chicks. The ability to simulate a lek with various housing arrangements, in which the males can display with each other, be given access to a female for copulation, and then be separated again has proven paramount for breeding success. Additionally, females are allowed mate choice, further mimicking natural behaviors observed by this species. The refinement of these methods has led to a greater number of fertile eggs as well as higher hatchability and survivability, which in turn has resulted in a significant increase in the captive population.


Asunto(s)
Animales de Zoológico , Passeriformes , Reproducción , Animales , Femenino , Masculino , Crianza de Animales Domésticos/métodos
15.
Zoo Biol ; 42(4): 577-581, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36959717

RESUMEN

The golden lancehead (Bothrops insularis) is a critically endangered snake endemic to Queimada Grande Island, southeastern Brazil. Captive breeding programs are vital for the conservation of this species. This study evaluates the gestation of two females golden lanceheads using radiography and ultrasonography. The first female was collected on the island while reproductively active (late vitellogenesis or early pregnancy) and kept in captivity. This female gave birth to five neonates after an 8-month gestation period, which is longer than estimates based on specimens preserved in museums. The second female copulated in captivity in July and probably ovulated in October. In this case, no embryonic development was detected, and the female deposited 14 undeveloped eggs approximately 6 months after ovulation.


Asunto(s)
Bothrops , Femenino , Animales , Embarazo , Animales de Zoológico , Brasil
16.
Zoo Biol ; 42(5): 675-682, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37171149

RESUMEN

There are only a few studies that describe the larval development of Echinaster or aspects on culture systems for the genus. For starfishes, the choice of suitable substrates has received special attention since it could influence the acid-base balance of the water, movement capacity and predation rate. The objective of this study was to evaluate the ideal food-related substrate for the rearing of juvenile Echinaster brasiliensis. A batch of fertilized eggs released in spontaneous spawning was collected and kept in a plankton-kreisel until metamorphosis. Data on preference of food-related substrate was recorded for 10 weeks from day 58 post-release. From release to 132 days old, arm length increased from 0.81 mm to 1.31 ± 0.03 mm. Considering the sudden increase in arm length (AL), it was estimated that feeding started around 40 days of age. Regarding food-related substrate preferences, biofilm grown on "rocks" showed a significant difference among other treatments, adding up to 50% of preference (p < .05). For sponge and biofilm from bio media, there was no statistical difference for the whole period. In this study, sponges showed to be the least preferred food-related substrate for post-settlement juveniles. Considering that Echinaster and other starfish are commonly maintained on a diet of collected or cultured sponges, difficulties in sourcing a ready supply throughout the year represent limitations to their sole use within commercial or laboratory-scale production. In this sense, the use of biofilm from biological media for the feeding of juvenile starfish is not yet reported in the literature and showed to be an easy and promising option.


Asunto(s)
Animales de Zoológico , Estrellas de Mar , Animales , Preferencias Alimentarias , Dieta/veterinaria
17.
Zoo Biol ; 42(4): 490-508, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36967628

RESUMEN

An investigation was conducted on the phenotypic results of mouse hybridization and seven generations of backcrossing, observing reciprocal F1 hybrids and backcrosses of Mus spretus and a laboratory strain of Mus domesticus C57BL/6J. F1 hybrids, backcrosses, and pure control specimens were measured for 6 body characteristics, 4 pelage coloration characteristics, 14 behaviors, and reproduction as reflected in litter size. Backcrossing was pursued for seven generations to FBC7 (i.e., "Backcross 7" or seven generations from commencement of backcrossing from an F1 hybrid female) where species restoration is mathematically calculated to be at 99.7%. Except for a minority of FBC7 M. spretus specimens failing to conform completely to one pelage characteristic, FBC7 specimens were indistinguishable from controls both subjectively and in all areas of measurement. The M. spretus backcross line was followed generation by generation and was largely conforming to controls by FBC4 at latest. The same effect was observed in the reciprocal M. domesticus backcross line. Fertility was negatively affected in F1 hybrids but restored or improved in backcross generations. Discussion is offered on hybridization and backcrossing as it occurs in nature and how it has been used or could be used as an additional ex situ tool in wildlife conservation efforts. It is concluded that conservation-oriented backcrossing is a practical species/subspecies restoration technique and has the potential to make genetic rescue feasible with minimal gene flow at the binomial level. Backcrossing is most applicable in closely monitored ex situ settings (1) where only one sex remains of a given taxon; and (2) where inbreeding depression seriously threatens a remnant taxon's ability to recover, and the only gene flow option is from another distinct species.


Asunto(s)
Animales de Zoológico , Muridae , Ratones , Femenino , Animales , Muridae/genética , Cruzamientos Genéticos , Ratones Endogámicos C57BL , Animales de Zoológico/genética , Hibridación Genética
18.
Conserv Biol ; 36(4): e13918, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35554972

RESUMEN

The pink pigeon (Nesoenas mayeri) is an endemic species of Mauritius that has made a remarkable recovery after a severe population bottleneck in the 1970s to early 1990s. Prior to this bottleneck, an ex situ population was established from which captive-bred individuals were released into free-living subpopulations to increase population size and genetic variation. This conservation rescue led to rapid population recovery to 400-480 individuals, and the species was twice downlisted on the International Union for the Conservation of Nature (IUCN) Red List. We analyzed the impacts of the bottleneck and genetic rescue on neutral genetic variation during and after population recovery (1993-2008) with restriction site-associated sequencing, microsatellite analyses, and quantitative genetic analysis of studbook data of 1112 birds from zoos in Europe and the United States. We used computer simulations to study the predicted changes in genetic variation and population viability from the past into the future. Genetic variation declined rapidly, despite the population rebound, and the effective population size was approximately an order of magnitude smaller than census size. The species carried a high genetic load of circa 15 lethal equivalents for longevity. Our computer simulations predicted continued inbreeding will likely result in increased expression of deleterious mutations (i.e., a high realized load) and severe inbreeding depression. Without continued conservation actions, it is likely that the pink pigeon will go extinct in the wild within 100 years. Conservation rescue of the pink pigeon has been instrumental in the recovery of the free-living population. However, further genetic rescue with captive-bred birds from zoos is required to recover lost variation, reduce expression of harmful deleterious variation, and prevent extinction. The use of genomics and modeling data can inform IUCN assessments of the viability and extinction risk of species, and it helps in assessments of the conservation dependency of populations.


La paloma rosada (Nesoenas mayeri) es una especie endémica de Mauricio que se ha recuperado impresionantemente después de un grave cuello de botella poblacional a principios de la década de 1970 que duró hasta inicios de la década de 1990. Antes de este cuello de botella se había establecido una población ex situ de la cual se liberaban individuos reproducidos en cautiverio a las subpoblaciones en libertad para incrementar la variación genética y el tamaño poblacional. Este rescate de conservación derivó en una recuperación rápida de la población (400-480 individuos) y la especie cambió positivamente de categoría dos veces en la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza (UICN). Analizamos los impactos del cuello de botella y el rescate genético sobre la variación genética neutral durante y después de la recuperación poblacional (de 1993 a 2008) mediante secuenciación RAD, análisis de microsatélites y análisis genéticos cuantitativos de los datos del libro genealógico de 1112 aves ubicadas en zoológicos de Europa y los Estados Unidos. Usamos simulaciones por computadora para estudiar los cambios pronosticados en la variación genética y en la viabilidad poblacional del pasado hacia el futuro. La variación genética declinó rápidamente, a pesar de la recuperación poblacional, y el tamaño efectivo de la población fue aproximadamente un orden de magnitud más pequeño que el tamaño del censo. La especie contó con una carga genética elevada de casi 15 equivalentes letales para la longevidad. Nuestras simulaciones pronostican que la endogamia continua probablemente resultará en un incremento en la expresión de mutaciones deletéreas (es decir, una carga realizada elevada) y en una depresión endogámica severa. Sin acciones continuas para la conservación, es probable que la paloma rosada esté extinta en vida libre dentro de cien años. El rescate de conservación de la paloma rosada ha sido fundamental en la recuperación de la población silvestre; sin embargo, se requiere de un rescate genético adicional con las aves de reproducción en cautiverio de los zoológicos para recuperar la variación perdida, reducir la expresión de la variación deletérea dañina y prevenir la extinción. El uso de la genómica y los datos modelados puede orientar las valoraciones de la UICN sobre la viabilidad y el riesgo de extinción de las especies, además de que ayuda en la evaluación de la dependencia que tienen las poblaciones de la conservación.


Asunto(s)
Aves , Conservación de los Recursos Naturales , Animales , Aves/genética , Especies en Peligro de Extinción , Europa (Continente) , Variación Genética , Genómica , Densidad de Población
19.
Mol Biol Rep ; 49(5): 4107-4114, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35359235

RESUMEN

BACKGROUND: Genetics driven interventions if adopted in conservation breeding projects may enhance the overall success by prioritizing breeding among genetically most competent individuals and delaying or completely diminishing the ill effects of inbreeding. METHODS AND RESULTS: In the present study, we investigated genetic make-up of 15 tigers housed at five different captive facilities of West Bengal in India and report the moderate level of genetic variation. We identified five tigers based on individual genetic attributes that may be prioritized for future breeding or animal exchange programmes. The occurrence of first and second order related individuals in captivity require management attention and they should be paired considering their immediate genetic background. CONCLUSION: Considering tiger as a case study, we highlight the use of genetic assessment and necessity to validate the studbook records in formulating adaptive management strategies for long-term conservation and management of species of interest.


Asunto(s)
Tigres , Animales , Conservación de los Recursos Naturales/métodos , ADN , Antecedentes Genéticos , Variación Genética , Endogamia , Tigres/genética
20.
Conserv Genet ; 23(2): 417-428, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35401067

RESUMEN

Captive breeding is often a last resort management option in the conservation of endangered species which can in turn lead to increased risk of inbreeding depression and loss of genetic diversity. Thus, recording breeding events via studbook for the purpose of estimating relatedness, and facilitating mating pair selection to minimize inbreeding, is common practice. However, as founder relatedness is often unknown, loss of genetic variation and inbreeding cannot be entirely avoided. Molecular genotyping is slowly being adopted in captive breeding programs, however achieving sufficient resolution can be challenging in small, low diversity, populations. Here, we evaluate the success of the Vancouver Island marmot (Marmota vancouverensis; VIM; among the worlds most endangered mammals) captive breeding program in preventing inbreeding and maintaining genetic diversity. We explored the use of high-throughput amplicon sequencing of microsatellite regions to assay greater genetic variation in both captive and wild populations than traditional length-based fragment analysis. Contrary to other studies, this method did not considerably increase diversity estimates, suggesting: (1) that the technique does not universally improve resolution, and (2) VIM have exceedingly low diversity. Studbook estimates of pairwise relatedness and inbreeding in the current population were weakly, but positively, correlated to molecular estimates. Thus, current studbooks are moderately effective at predicting genetic similarity when founder relatedness is known. Finally, we found that captive and wild populations did not differ in allelic frequencies, and conservation efforts to maintain diversity have been successful with no significant decrease in diversity over the last three generations. Supplementary Information: The online version contains supplementary material available at 10.1007/s10592-022-01429-7.

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