How science helps the conservation of sloths in Ecuador

We follow the post-release monitoring of Bravo, a male two-toed sloth that arrived in March 2021 at Guayaquil´s Mansión Mascota veterinary clinic.

Guest blog post by Ricardo Villalba-Briones

Choloepus hoffmanni capitalis is a poorly known subspecies of two-toed sloth that inhabits coastal southern Colombia and Ecuador(Hayssen 2011). In Ecuador, according to local reports from rehabilitation centers and events recorded by the press, this species is apparently not widely trafficked for pet trade, but it is known to be illegally hunted and consumed, the impact of which is difficult to trace and evaluate. Nevertheless, the conservation status of the two-toed sloths C.h. capitalis Ecuadorian coast keeps leaning towards more threatened categorizations, and nowadays is established as vulnerable (Tirira, 2021).

The sloths Bravo and Linda during rehabilitation.

Its habitat is a hotspot for conservation in all its extent, as it is threatened. In addition, due to multiple origins of impact, it has been recorded as the second most abundant mammal (from the list of animals subjected to wildlife traffic and bushmeat consumption according to Environment Ministry reports) received in the busy rehabilitation center of Guayaquil, Ecuador (Villalba-Briones et al., 2021).

Xenarthrans have been relatively poorly studied, specially sloths (Superina and Loughry 2015), and due to the species’ inconspicuous strategy, it is also difficult to detect and perform population evaluations (Martínez et al. 2020). Taking in account the slow reproduction rate of Choloepus gen., having one offspring every 3 years (Hayssen 2011), it is critical to consider the importance of reintroductions (Paterson et al. 2021, Villalba-Briones et al. 2022), but, to all effects, nothing can substitute the implementation of efficient regulation to cease hunting and bushmeat consumption.

Choloepus hoffmanni. Photo by briangratwicke under a CC BY 4.0 license

In-situ studies, understanding its ecology, behavior, abundance etc., could provide the necessary tools to estimate its populations, and evaluate its conservation status. Alternatively, non-invasive opportunistic studies in ex-situ programs during rehabilitation procedures could provide improvements in the aspects as diets and health, increasing the survival rate and fitness to release of rehabilitated sloths.

I strongly consider it important that this species is duly studied, in order to appreciate it and support its conservation. In our work, “Release and follow-up of a rehabilitated two-toed sloth (Choloepus hoffmanni) in a tropical dry forest in Ecuador”, published in the journal Neotropical Biology and Conservation, we follow the post-release monitoring of Bravo, a male two-toed sloth that arrived in March 2021 at Guayaquil´s Mansión Mascota veterinary clinic.

We suggest considering follow-up activities to check the animals’ safety during their adaptation to the natural environment. We also propose the inclusion of a follow-up term to redeem the post-release supportive monitoring, develop its scope, and to rely on the presence and readiness of the caregivers or researchers to help the animal during the first weeks after release.

In order to track Bravo after his release, a handmade biodegradable backpack with Bluetooth signal transmission capacity was fitted to his body. The lightweight Tile Bluetooth device did not pose any harm to the sloth, and after some heavy rains cardboard-made attachment just disintegrated, releasing the device.

In our work, the presence in the area of a territorial carnivore individual led to the end of the follow-up activity. Consequently, in the case of probable undesired situations, we propose the use of devices to track the animals and monitor their presence daily. Alternatively, accounting for the relationship between movement patterns of the individual and detection probability, we propose 7 pm as the best time for observations of this mainly nocturnal species.

Due to the difficulty monitoring nocturnal animals, economic constraints in conservation, accessibility, and safety of the animals, biodegradable Bluetooth-based backpacks are recommended to ease the location of the animal and support its survival in the wild. The range of detectability of the device used indicates its suitability for tracking low-mobility animals.

Map showing the movements and tree use of the rehabilitated two-toed sloth (Choloepus hoffmanni) in a dry tropical forest in the coastal region of Ecuador.

This first record of the follow-up of a rehabilitated Choloepushoffmanni and the detectability analysis offer valuable information for the future release and follow-up of individuals belonging to the genus Choloepus, and sloths in general.

The knowledge about released animals’ survival could help in clearing rehabilitation uncertainties, and, always, can give the animals the second chance they deserve.  Monitoring animal survival after release is essential for recording whether the rehabilitation process has been accomplished, but it is rarely done in practice, given the amount of funds required. It can, however, be substantially cheaper and affordable if the right techniques are used. These activities are more feasible when strategic planning and support exist.

Nowadays, the scarcity of funds to fulfill the needs of conservation projects on sloths (Superina and Loughry 2015, Choperena-Palencia and Mancera-Rodríguez 2018) seems to be an important obstacle. However, with a sensitized population, management effort, and support, it could be possible to understand and preserve the Choloepus hoffmanni capitalis.

References:

Choperena-Palencia MC, Mancera-Rodríguez NJ (2018) EVALUACIÓN DE PROCESOS DE SEGUIMIENTO Y MONITOREO POST-LIBERACIÓN DE FAUNA SILVESTRE REHABILITADA EN COLOMBIA. Luna Azul: 181–209. https://doi.org/10.17151/luaz.2018.46.11

Hayssen V (2011) Choloepus hoffmanni (Pilosa: Megalonychidae). Mammalian Species 43: 37–55. https://doi.org/10.1644/873.1

Martínez M, Velásquez A, Pacheco-Amador S, Cabrera N, Acosta I, Tursios-Casco M (2020) El perezoso de dos dedos (Choloepus hoffmanni) en Honduras: distribución, historia natural y conservación. Notas sobre Mamíferos Sudamericanos 01: 001–009. https://doi.org/10.31687/saremNMS.20.0.25

Paterson JE, Carstairs S, Davy CM (2021) Population-level effects of wildlife rehabilitation and release vary with life-history strategy. Journal for Nature Conservation 61: 125983. https://doi.org/10.1016/j.jnc.2021.125983

Superina M, Loughry WJ (2015) Why do Xenarthrans matter?: Table 1. Journal of Mammalogy 96: 617–621. https://doi.org/10.1093/jmammal/gyv099

Villalba-Briones R, Molineros E, Monros, J. S. (2021). Estudio retrospectivo de rescates y retenciones de especies de fauna silvestre sujetas a tráfico de fauna en guayaquil, Ecuador. Comité científico.

Villalba-Briones R, Jiménez ER, Monros JS (2022) Release and follow-up of a rehabilitated two-toed sloth (Choloepus hoffmanni) in a tropical dry forest in Ecuador. Neotropical Biology and Conservation 17(4): 253-267. https://doi.org/10.3897/neotropical.17.e91332

Tirira, D. G. (ed.). 2021. Lista Roja de los mamíferos del Ecuador, en: Libro Rojo de los mamíferos del Ecuador (3a edición). Asociación Ecuatoriana de Mastozoología, Fundación Mamíferos y Conservación, Pontificia Universidad Católica del Ecuador y Ministerio del Ambiente, Agua y Transición Ecológica del Ecuador. Publicación Especial sobre los mamíferos del Ecuador 13, Quito.

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