scholarly journals Microhabitat preference of the critically endangered golden mantella frog in Madagascar

2019 ◽  
pp. 207-213
Author(s):  
Wayne Edwards

The golden mantella (Mantella aurantiaca) is a critically endangered (CR) frog, endemic to the eastern rainforestsof Madagascar. Although the species is very popular in the pet trade and widely bred in captivity, its specific habitat requirements in the wild are poorly understood. Ten forested sites in the Moramanga district of Madagascar were surveyed for microhabitat and environmental variables, and the presence or absence of golden mantellas in quadrats positioned along transects in the vicinity of breeding sites. Mixed models were used to determine which variables best explained microhabitat use by golden mantellas. Sites where golden mantellas were found tended to have surface temperatures of 20-23 ˚C, UVI units at about 2.9, about 30 % canopy cover, and around 30 % herbaceous cover. Within sites, golden mantellas preferred microhabitats that had 70 % leaf litter coverage and relatively low numbers of tree roots. This information can be used to improve the identification and management of habitats in the wild, as well as to refine captive husbandry needs.

2021 ◽  
Vol 2 ◽  
Author(s):  
Graham P. Dixon-MacCallum ◽  
Johnathan L. Rich ◽  
Natasha Lloyd ◽  
Daniel T. Blumstein ◽  
Axel Moehrenschlager

Conservation translocations, which involve the intentional movement and release of organisms for conservation benefit, are increasingly required to recover species of conservation concern. In order to maximize post-release survival, and to accomplish conservation translocation objectives, animals must exhibit behaviors that facilitate survival in the wild. The Vancouver Island marmot (Marmota vancouverensis) is a critically endangered endemic in Canada which has been captive-bred for 24 years for reintroductions and reinforcements that have increased the wild population from ~30 to more than 200 individuals. Despite this success many marmots are killed by predators after release and predation represents a major hurdle to full marmot recovery. To better understand if captive-bred marmots are prepared for the novel environment into which they will be released, and to determine whether such suitability changes over time, we presented taxidermy mounts of mammalian predators and non-predators to marmots that were wild-caught, and captive born for between one and five generations. We also examined mortality of offspring from marmots we tested that had been released to the wild. A minimum of 43% of offspring were killed by predators in the wild over 17 years, most by cougars. Marmots in captivity generally responded to taxidermy mounts by decreasing foraging and increasing vigilance, and overall responded more strongly to predators than non-predators, especially wolves. However, marmots in captivity for more than two generations lacked discrimination between cougars, non-predators, and controls, suggesting a rapid loss of predator recognition. This study was only possible because predator-recognition trials were initiated early in the conservation translocation program, and could then be repeated after a number of generations. The finding that changes occurred relatively rapidly (within five generations during which changes in genetic diversity were negligible) suggests that behavioral suitability may deteriorate more rapidly than genetics would suggest. Strategies addressing potential behavior loss should be considered, including sourcing additional wild individuals or pre-release training of captive-born individuals. Subsequently, post-release survival should be monitored to determine the efficacy of behavior-optimization strategies.


2020 ◽  
Vol 14 (2) ◽  

The Philippine or Palawan Forest Turtle Siebenrockiella leytensis is the only endemic turtle known to occur in the Philippines. It was assessed as Critically Endangered in 2000 and has been considered as one of the world’s top 25 most endangered turtles since 2003. The species is accorded protection nationally by the Wildlife Protection and Conservation Act of 2001 and its international commercial trade is regulated by the Convention on International Trade in Endangered Species (CITES). However, the publication of its rediscovery in 2004 triggered unrelenting poaching and trafficking for the pet trade nationally and internationally. With the aim of quantifying the extent of poaching and to provide insight on the trade dynamics, we analyzed seizure records from 2004–2018 and conducted physical and online market surveys in 2017–2018. Twenty-three (23) seizure incidents involving 4,723 Philippine Forest Turtles were recorded in the last 15 years. Based on an online survey, we estimated that an additional 1,200 Philippine Forest Turtles were smuggled and illegally sold in China in 2015. The majority of the 74 live individuals exported legally from the Philippines were likely sourced illegally from the wild and declared fraudulently as captive bred by exporters to obtain CITES permits. While habitat loss or degradation is a major threat, the illegal pet trade remains the most important factor threatening the survival of the Philippine Forest Turtles in the wild.


Oryx ◽  
2015 ◽  
Vol 50 (2) ◽  
pp. 355-359 ◽  
Author(s):  
Rasmus Gren Havmøller ◽  
Junaidi Payne ◽  
Widodo Ramono ◽  
Susie Ellis ◽  
K. Yoganand ◽  
...  

AbstractThe Critically Endangered Sumatran rhinoceros Dicerorhinus sumatrensis formerly ranged across South-east Asia. Hunting and habitat loss have made it one of the rarest large mammals and the species faces extinction despite decades of conservation efforts. The number of individuals remaining is unknown as a consequence of inadequate methods and lack of funds for the intensive field work required to estimate the population size of this rare and solitary species. However, all information indicates that numbers are low and declining. A few individuals persist in Borneo, and three tiny populations remain on the Indonesian island of Sumatra and show evidence of breeding. Rhino Protection Units are deployed at all known breeding sites but poaching and a presumed low breeding rate remain major threats. Protected areas have been created for the rhinoceros and other in situ conservation efforts have increased but the species has continued to go locally extinct across its range. Conventional captive breeding has also proven difficult; from a total of 45 Sumatran rhinoceros taken from the wild since 1984 there were no captive births until 2001. Since then only two pairs have been actively bred in captivity, resulting in four births, three by the same pair at the Cincinnati Zoo and one at the Sumatran Rhino Sanctuary in Sumatra, with the sex ratio skewed towards males. To avoid extinction it will be necessary to implement intensive management zones, manage the metapopulation as a single unit, and develop advanced reproductive techniques as a matter of urgency. Intensive census efforts are ongoing in Bukit Barisan Selatan but elsewhere similar efforts remain at the planning stage.


2021 ◽  
Author(s):  
J-M Ballouard ◽  
X Bonnet ◽  
J Jourdan ◽  
A Martinez-Silvestre ◽  
S Gagno ◽  
...  

AbstractTwo types of pathogens cause highly contagious upper respiratory tract diseases (URTD) in Chelonians: testudinid herpesviruses (TeHV) and a mycoplasma (Mycoplasma agassizii). In captivity, these infections are frequent and can provoke outbreaks. Pet trade generates international flow of tortoises, often without sanitary checking; individuals intentionally or accidentally released in the wild may spread pathogens. A better understanding of the transmission of infectious agents from captivity to wild tortoises is needed. Many exotic individuals have been introduced in populations of the endangered western Hermann’s tortoise (Testudo hermanni hermanni), notably spur-thighed tortoises (Testudo graeca). We assessed the presence of TeHV and mycoplasma in native western Hermann’s tortoises and in potential pet vectors in south-eastern France. Using a large sample (N=572 tortoises), this study revealed the worrying presence of herpesvirus in 7 free-ranging individuals (3 sub-populations). Additionally, Mycoplasma agassizii was detected in 15 of the 18 populations sampled with a frequency ranging from 2.5 to 25%. Exotic spur-thighed tortoises showed high frequency of Mycoplasma infection in captivity (18%) and in individuals (50%) found in native Hermann’s tortoise sub-populations, suggesting that this species could be a significant vector. The paucity of information of TeHV on European tortoise’ URTD in natural settings, especially in combination with mycoplasma, prompts for further studies. Indeed, sick tortoises remain concealed and may not be easily detected in the field. Our results indicate that both the prevalence and health impact of URTD are high should be scrutinized in the field.


2021 ◽  
pp. 24-27
Author(s):  
Jay Redbond

The Nguru spiny pygmy chameleon (Rhampholeon acuminatus) is endemic to the Nguru mountains in Tanzania. It is assessed as Critically Endangered and is collected from the wild for the pet trade. An ex-situ population of this species was recently established at The Wild Planet Trust, Paignton Zoo, in the hope of learning more about the husbandry and biology of this species. We report on the captive husbandry of adults and the successful breeding, hatching and rearing of juveniles. Females carried four eggs but laid them in pairs. When eggs were incubated at 19.2-22.8 °C, hatchlings emerged roughly 180 days after laying. The hatchlings had a total length of about 30 mm and weighed 0.2-0.3 g. To our knowledge, this is the first published account of captive breeding for this species. The husbandry methods described could be used to establish populations of this and other Rhampholeon species in captivity, which in turn would reduce the demand for wild caught (Rhampholeon), as well as inform future conservation breeding programmes for this species.


2021 ◽  
Vol 168 (5) ◽  
Author(s):  
Ramón Bonfil ◽  
Paola Palacios-Barreto ◽  
Oscar Uriel Mendoza Vargas ◽  
Melina Ricaño-Soriano ◽  
Píndaro Díaz-Jaimes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marina B. Blanco ◽  
Lydia K. Greene ◽  
Robert Schopler ◽  
Cathy V. Williams ◽  
Danielle Lynch ◽  
...  

AbstractIn nature, photoperiod signals environmental seasonality and is a strong selective “zeitgeber” that synchronizes biological rhythms. For animals facing seasonal environmental challenges and energetic bottlenecks, daily torpor and hibernation are two metabolic strategies that can save energy. In the wild, the dwarf lemurs of Madagascar are obligate hibernators, hibernating between 3 and 7 months a year. In captivity, however, dwarf lemurs generally express torpor for periods far shorter than the hibernation season in Madagascar. We investigated whether fat-tailed dwarf lemurs (Cheirogaleus medius) housed at the Duke Lemur Center (DLC) could hibernate, by subjecting 8 individuals to husbandry conditions more in accord with those in Madagascar, including alternating photoperiods, low ambient temperatures, and food restriction. All dwarf lemurs displayed daily and multiday torpor bouts, including bouts lasting ~ 11 days. Ambient temperature was the greatest predictor of torpor bout duration, and food ingestion and night length also played a role. Unlike their wild counterparts, who rarely leave their hibernacula and do not feed during hibernation, DLC dwarf lemurs sporadically moved and ate. While demonstrating that captive dwarf lemurs are physiologically capable of hibernation, we argue that facilitating their hibernation serves both husbandry and research goals: first, it enables lemurs to express the biphasic phenotypes (fattening and fat depletion) that are characteristic of their wild conspecifics; second, by “renaturalizing” dwarf lemurs in captivity, they will emerge a better model for understanding both metabolic extremes in primates generally and metabolic disorders in humans specifically.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Swetlana G. Meshcheryagina ◽  
Alexey Opaev

Abstract Background In the last decade, enigmatic male-like cuckoo calls have been reported several times in East Asia. These calls exhibited a combination of vocal traits of both Oriental Cuckoo (Cuculus optatus) and Common Cuckoo (Cuculus canorus) advertising calls, and some authors therefore suggested that the enigmatic calls were produced by either Common × Oriental Cuckoo male hybrids or Common Cuckoo males having a gene mutation. However, the exact identity of calling birds are still unknown. Methods We recorded previously unknown male-like calls from three captive Oriental Cuckoo females, and compared these calls with enigmatic vocalizations recorded in the wild as well as with advertising vocalizations of Common and Oriental Cuckoo males. To achieve this, we measured calls automatically. Besides, we video-recorded captive female emitting male-like calls, and compared these recordings with the YouTube recordings of calling males of both Common and Oriental Cuckoos to get insight into the mechanism of call production. Results The analysis showed that female male-like calls recorded in captivity were similar to enigmatic calls recorded in the wild. Therefore, Oriental Cuckoo females might produce the latter calls. Two features of these female calls appeared to be unusual among birds. First, females produced male-like calls at the time of spring and autumn migratory activity and on migration in the wild. Because of this, functional significance of this call remained puzzling. Secondly, the male-like female call unexpectedly combined features of both closed-mouth (closed beak and simultaneous inflation of the ‘throat sac’) and open-mouth (prominent harmonic spectrum and the maximum neck extension observed at the beginning of a sound) vocal behaviors. Conclusions The Cuculus vocalizations outside the reproductive season remain poorly understood. Here, we found for the first time that Oriental Cuckoo females can produce male-like calls in that time. Because of its rarity, this call might be an atavism. Indeed, female male-like vocalizations are still known in non-parasitic tropical and apparently more basal cuckoos only. Therefore, our findings may shed light on the evolution of vocal communication in avian brood parasites.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Surya Prasad Sharma ◽  
Mirza Ghazanfarullah Ghazi ◽  
Suyash Katdare ◽  
Niladri Dasgupta ◽  
Samrat Mondol ◽  
...  

AbstractThe gharial (Gavialis gangeticus) is a critically endangered crocodylian, endemic to the Indian subcontinent. The species has experienced severe population decline during the twentieth century owing to habitat loss, poaching, and mortalities in passive fishing. Its extant populations have largely recovered through translocation programmes initiated in 1975. Understanding the genetic status of these populations is crucial for evaluating the effectiveness of the ongoing conservation efforts. This study assessed the genetic diversity, population structure, and evidence of genetic bottlenecks of the two managed populations inhabiting the Chambal and Girwa Rivers, which hold nearly 80% of the global gharial populations. We used seven polymorphic nuclear microsatellite loci and a 520 bp partial fragment of the mitochondrial control region (CR). The overall mean allelic richness (Ar) was 2.80 ± 0.40, and the observed (Ho) and expected (He) heterozygosities were 0.40 ± 0.05 and 0.39 ± 0.05, respectively. We observed low levels of genetic differentiation between populations (FST = 0.039, P < 0.05; G’ST = 0.058, P < 0.05 Jost’s D = 0.016, P < 0.05). The bottleneck analysis using the M ratio (Chambal = 0.31 ± 0.06; Girwa = 0.41 ± 0.12) suggested the presence of a genetic bottleneck in both populations. The mitochondrial CR also showed a low level of variation, with two haplotypes observed in the Girwa population. This study highlights the low level of genetic diversity in the two largest managed gharial populations in the wild. Hence, it is recommended to assess the genetic status of extant wild and captive gharial populations for planning future translocation programmes to ensure long-term survival in the wild.


Sign in / Sign up

Export Citation Format

Share Document