Water monitors (Varanus salvator macromaculatus) are large lizards that inhabit wetlands. However, populations seem to be declining due to habitat fragmentation resulting from urban development. To develop an effective strategic conservation plan, the genetic diversity and population structure of water monitors at Bang Kachao Peninsula, a rich urban ecosystem in Bangkok, were analyzed using mitochondrial (mt) D‐loop II sequences and microsatellite genotyping. Both genetic markers indicated a high degree of population‐level genetic diversity. The consistency of the star‐shaped haplotype network and results of neutrality tests strongly suggest the occurrence of a recent expansion in the population, possibly driven by anthropogenic urbanization. Subpopulations at Bang Kachao Peninsula are unlikely but gene flow between water monitors has occurred, which is suggestive of female‐based dispersal. The large population of water monitors at Bang Kachao Peninsula creates conflict with local residents. Long‐term population management through translocation has been conducted by captive management at Varanus Farm Kamphaeng Saen. The results of genetic monitoring indicate that the captive research population was soundly established. Comparison of allelic profiles between the two populations is necessary before translocation of water monitor groups from Bang Kachao Peninsula to Varanus Farm Kamphaeng Saen to reduce human‐wildlife conflict. This work is the first step toward establishment of long‐term ecological monitoring and an in situ/ex‐situ conservation program, which are part of attempts to promote biodiversity in Thailand, following scientific principles.
The fragmentation of habitats and hunting have impacted the Asian woolly-necked stork (Ciconia episcopus), leading to a serious risk of extinction in Thailand. Programs of active captive breeding, together with careful genetic monitoring, can play an important role in facilitating the creation of source populations with genetic variability to aid the recovery of endangered species. Here, the genetic diversity and population structure of 86 Asian woolly-necked storks from three captive breeding programs [Khao Kheow Open Zoo (KKOZ) comprising 68 individuals, Nakhon Ratchasima Zoo (NRZ) comprising 16 individuals, and Dusit Zoo (DSZ) comprising 2 individuals] were analyzed using 13 microsatellite loci, to aid effective conservation management. Inbreeding and an extremely low effective population size (Ne) were found in the KKOZ population, suggesting that deleterious genetic issues had resulted from multiple generations held in captivity. By contrast, a recent demographic bottleneck was observed in the population at NRZ, where the ratio of Ne to abundance (N) was greater than 1. Clustering analysis also showed that one subdivision of the KKOZ population shared allelic variability with the NRZ population. This suggests that genetic drift, with a possible recent and mixed origin, occurred in the initial NRZ population, indicating historical transfer between captivities. These captive stork populations require improved genetic variability and a greater population size, which could be achieved by choosing low-related individuals for future transfers to increase the adaptive potential of reintroduced populations. Forward-in-time simulations such as those described herein constitute the first step in establishing an appropriate source population using a scientifically managed perspective for an in situ and ex situ conservation program in Thailand.
Captive breeding programs for endangered species can increase population numbers for eventual reintroduction to the wild. Captive populations are typically small and isolated, which results in inbreeding and reduction of genetic variability, and may lead to an increased risk of extinction. The Omkoi Wildlife Breeding Center maintains the only Thai captive Chinese goral (Naemorhedus griseus) population, and has plans to reintroduce individuals into natural isolated populations. Genetic variability was assessed within the captive population using microsatellite data. Although no bottleneck was observed, genetic variability was low (allelic richness = 7.091 ± 0.756, H e = 0.455 ± 0.219; H e < H o) and 11 microsatellite loci were informative that likely reflect inbreeding. Estimates of small effective population size and limited numbers of founders, combined with wild-born individuals within subpopulations, tend to cause reduction of genetic variability over time in captive programs. This leads to low reproductive fitness and limited ability to adapt to environmental change, thereby increasing the risk of extinction. Management of captive populations as evolutionarily significant units with diverse genetic backgrounds offers an effective strategy for population recovery. Relocation of individuals among subpopulations, or introduction of newly captured wild individuals into the captive program will help to ensure the future security of Chinese goral. Implications for future conservation actions for the species are discussed herein.
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