Raising frogs and advancing science

With over 40% of species at risk of extinction, amphibians are among the most imperiled groups on Earth. The biodiversity hotspot of Madagascar is not immune from this problem with nearly 47% of its endemic frog species at risk.

In 2010, Association Mitsinjo began working with IUCN and the government to develop an amphibian breeding facility. PhD Candidate Devin Edmonds has been working with the facility and their conservation programs. In addition to establishing captive assurance populations, this facility has provided important information on frog reproductive biology. The facility has successfully reared and released captive bred endangered Golden Mantella frogs into created habitat.

A paper, published today, reported on 1,272 captive breeding events from 11 additional frog species, including phenology, clutch sizes, oviposition, and larval development time. This information is often hard to obtain in the field, and these observations were the first described for many of these species.

Most of the species bred seasonally, but one, Mantella betsileanus, bred throughout the year and made up 86% of egg masses. Most species did not require environmental stimuli, aligning their behaviors with natural seasons, however Heterixalus betsileo only bred when placed in a modified rain chamber.

Researchers also learned that Gephyromantis mitsinjo lays eggs on land where tadpoles develop terrestrially within jelly, a behavior previously theorized but never observed.

The findings can help inform other captive breeding programs and increase success of conservation efforts for other imperiled species.

Read the complete paper in Zoobiology: Rakotoarisoa, Justin Claude, Andolalao RakotoarisonSolonirina RasoanantenainaEric RobsomanitrandrasanaSamina Sidonie Sam EdmondsJeanne SoamiarimampiononaEdupsie TsimialomananaSebastian WolfDevin Edmonds. 2024. Captive breeding reveals insights into the ecology and reproductive biology of 11 little-known Malagasy frog species. Zoobiology: https://doi.org/10.1002/zoo.21876

 

New paper on endangered Harlequin Mantella populations

Mantella cowani frog
photo by Devin Edmonds

The Harlequin Mantella is one of Madagascar’s most threatened frog species, known from 13 localities. The small, strikingly-colored frog that inhabits mountainous streams has been impacted by habitat degradation and illegal collection for the pet trade.

As part of a species conservation plan, PhD Candidate Devin Edmonds and his colleagues surveyed 11 of those sites and detected the frog at eight sites. The species is believed extirpated from the other three sites. Knowledge from local community members revealed two previously unknown locations, highlighting the importance of collaboration and engagement with the community.

Based on repeated surveys of three of the sites between 2015 and 2023, these small frogs can live 9 or more years in the wild as adults encountered in 2015 were still alive in 2023.

Despite finding two new sites, the populations are small and the frog is still imperiled. Conservation recommendations include upgrading the species to Critically Endangered. Continued monitoring of populations and habitats, and protection from poaching are necessary to conserve the species.

Read the paper published today in PeerJLife https://peerj.com/articles/17947

Edmonds, D., R.R. Andriantsimanarilafy, A. Crottini, M.J. Dreslik, J. Newton-Youens, A. Ramahefason, C. J. Randrianantoandro, and F. Andreone. 2024. Small population size and possible extirpation of the threatened Malagasy poison frog Mantella cowanii. PeerJ, DOI 10.7717/peerj.17947

 

New paper on Baron’s mantella frog, co-authored by Devin Edmonds

frog on moss
Mantella baroni photo by Devin Edmonds

INHS PaCE Lab PhD candidate Devin Edmonds co-authored a recent paper on habitat features of Baron’s Mantella Frog. Tantely Rasoarimanana (Université d’Antananarivo) and Olivier Marquis (Paris Zoo) led the collaboration with the NGO Man and the Environment. The study aimed to identify what microhabitat features explain the presence of Baron’s mantella frog (Mantella baroni) and also estimate their population sizes in Vohimana Reserve, eastern Madagascar. We found that leaf litter depth and the number of small trees in a quadrat were important habitat features; deeper leaf litter and fewer small trees explained if M. baroni was present.

Saving the Harlequin Mantella

Mantella cowani frog

PACE Lab graduate student Devin Edmonds has been working to save one of the most threatened amphibian species in Madagascar. Listen to an interview he did with Amphibiacast about Mantella frogs, his time working in Madagascar, and his graduate research to conserve the Harlequin Mantella. A new conservation action plan will be released in the coming months.

Listen to the episode

Learn more about Devin’s research