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Licensed Unlicensed Requires Authentication Published by De Gruyter February 27, 2023

Every flight is a surprise: first records of the southern maned three-toed sloth (Bradypus crinitus: Bradypodidae) through drones

  • Paloma Marques Santos ORCID logo EMAIL logo , Mariane da Cruz Kaizer ORCID logo , Danielle Oliveira Moreira ORCID logo , Fabiano Rodrigues de Melo ORCID logo and Sérgio Lucena Mendes ORCID logo
From the journal Mammalia


Drones (unmanned aerial vehicles, UAVs), are an advanced technology that allows the collection of large amounts of data in a short amount of time, including the detection of cryptic and arboreal animals. Here, we report the first records of the southern maned sloth Bradypus crinitus obtained with thermal cameras from a drone. As far as we know, this is the first time a sloth has been observed by a drone. We recorded four individuals of B. crinitus in the Brazilian Atlantic Forest, plus first records of Procyon cancrivorus, which were all resting in the forest canopy. The individuals’ thermal responses demonstrate that the use of drones for research on these species may be a viable option to study still unexplored aspects of their ecology or conservation.

Corresponding author: Paloma Marques Santos, Instituto Nacional da Mata Atlântica (INMA), Av. José Ruschi, 4, CEP: 29.650-000, Centro, Santa Teresa, Espírito Santo, Brasil; and Instituto de Pesquisa e Conservação de Tamanduás no Brasil, R. Acanã, 11, CEP: 45655-718, Nossa Senhora do Carmo, Ilhéus, Bahia, Brasil, E-mail:

Award Identifier / Grant number: 300845/2022-7

Award Identifier / Grant number: 300893/2022-1

Award Identifier / Grant number: 318063/2021-2


The authors thank the Augusto Ruschi Biological Reserve and all ICMBio team for the logistical support.

  1. Author contributions: PMS, MCK, DOM, FRM, and SLM conducted the fieldwork and conceptualized the study; PMS led the writing; all authors edited and approved the manuscript.

  2. Research funding: This study was supported by the Programa de Capacitação Institucional from Instituto Nacional da Mata Atlântica (PCI/INMA), which also provided fellowships via CNPq to PMS (300893/2022-1), MCK (318063/2021-2), and DOM (300845/2022-7).

  3. Research ethics: All the procedures were in accordance with the national laws. The drone is registered at the National Aviation Agency (ANAC), through the Unmanned Aircraft System (SISANT), and for each flight we ask for authorization by SARPAS. There is also a mandatory insurance against third parties, called Reta.

  4. Conflict of interest statement: The authors declare that they have no conflicts of interest regarding this article.


Agostini, I., Pizzio, E., Varela, D., Iezzi, M.E., Cruz, P., Paviolo, A., and Di Betti, M. (2022). Camera trapping arboreal mammals in Argentina’s Atlantic forest. Mammalia 86: 551–561, in Google Scholar

Anderson, K. and Gaston, K.J. (2013). Lightweight unmanned aerial vehicles will revolutionize spatial ecology. Front. Ecol. Environ. 11: 138–146, in Google Scholar

Berger-Tal, O. and Lahoz-Monfort, J.J. (2018). Conservation technology: the next generation. Conserv. Lett. 11: 1–15.10.1111/conl.12458Search in Google Scholar

Burke, C., Rashman, M., Wich, S., Symons, A., Theron, C., and Longmore, S. (2019). Optimizing observing strategies for monitoring animals using drone-mounted thermal infrared cameras. Int. J. Rem. Sens. 40: 439–467, in Google Scholar

Chiarello, A.G. (1998a). Activity budgets and ranging patterns of the Atlantic forest maned sloth Bradypus torquatus (Xenarthra: Bradypodidae). J. Zool. 246: 1–10, in Google Scholar

Chiarello, A.G. (1998b). Diet of the atlantic forest maned sloth Bradypus torquatus (Xenarthra: Bradypodidae). J. Zool. 246: 11–19, in Google Scholar

Corcoran, E., Denman, S., and Hamilton, G. (2021). Evaluating new technology for biodiversity monitoring: are drone surveys biased? Ecol. Evol. 11: 6649–6656, in Google Scholar PubMed PubMed Central

Getzin, S., Wiegand, K., and Schöning, I. (2012). Assessing biodiversity in forests using very high-resolution images and unmanned aerial vehicles. Methods Ecol. Evol. 3: 397–404, in Google Scholar

Giné, G.A.F., Cassano, C.R., Almeida, S.S., and Faria, D. (2015). Activity budget, pattern and rhythm of maned sloths (Bradypus torquatus): responses to variations in ambient temperature. Mamm. Biol. 80: 459–467, in Google Scholar

IUCN (2020). IUCN red list: 2017-2020 report.Search in Google Scholar

Kaizer, M.C., Alvim, T.H.G., Novaes, C.L., Mcdevitt, A.D., and Young, R.J. (2022). Snapshot of the Atlantic Forest canopy: surveying arboreal mammals in a biodiversity hotspot. Oryx 56: 825–836, in Google Scholar

Kays, R., Sheppard, J., Mclean, K., Welch, C., Paunescu, C., Wang, V., Kravit, G., and Crofoot, M. (2019). Hot monkey, cold reality: surveying rainforest canopy mammals using drone-mounted thermal infrared sensors. Int. J. Rem. Sens. 40: 407–419, in Google Scholar

Koh, L.P. and Wich, S.A. (2012). Dawn of drone ecology: low-cost autonomous aerial vehicles for conservation. Trop. Conserv. Sci. 5: 121–132, in Google Scholar

Lara-Ruiz, P. and Chiarello, A.G. (2005). Life-history traits and sexual dimorphism of the Atlantic forest maned sloth Bradypus torquatus (Xenarthra: Bradypodidae). J. Zool. 267: 63–73, in Google Scholar

Marvin, D.C., Koh, L.P., Lynam, A.J., Wich, S., Davies, A.B., Krishnamurthy, R., Stokes, E., Starkey, R., and Asner, G.P. (2016). Integrating technologies for scalable ecology and conservation. Glob. Ecol. Conserv. 7: 262–275, in Google Scholar

Melo, F.R. (2021). Drones for conservation: new techniques to monitor muriquis. Oryx 55: 171, in Google Scholar

Miranda, F.R., Garbino, G.S.T, Machado, F.A., Perini, F.A., Santos, F.R., and Casali, D.M. (2022). Taxonomic revision of maned sloths, subgenus Bradypus (Scaeopus), Pilosa, Bradypodidae, with revalidation of Bradypus crinitus Gray, 1850, (R. Moratelli, ed.). J. Mammal. 104: 1–18, in Google Scholar

Moreira, D.O., Leite, G.R., Siqueira, M.F., Coutinho, B.R., Zanon, M.S., and Mendes, S.L. (2014). The distributional ecology of the maned sloth: environmental influences on its distribution and gaps in knowledge. PLoS One 9: e110929, in Google Scholar PubMed PubMed Central

Pimm, S.L., Alibhai, S., Bergl, R., Dehgan, A., Giri, C., Jewell, Z., Joppa, L., Kays, R., and Loarie, S. (2015). Emerging technologies to conserve biodiversity. Trends Ecol. Evol. 30: 685–696, in Google Scholar PubMed

Reis, N.R., Peracchi, A.L., Pedro, W.A., Lima, I.P. (2006). Mamíferos do Brasil. 1st ed. Londrina: Universidade Estadual de Londrina.Search in Google Scholar

Santos, P.M., Chiarello, A.G., Ribeiro, M.C., Ribeiro, J.W., and Paglia, A.P. (2016). Local and landscape influences on the habitat occupancy of the endangered Maned Sloth Bradypus torquatus within fragmented landscapes. Mamm. Biol. - Zeitschrift für Säugetierkd 81: 447–454, in Google Scholar

Santos, P.M., Bailey, L.L., Ribeiro, M.C., Chiarello, A.G., and Paglia, A.P. (2019). Living on the edge: forest cover threshold effect on endangered maned sloth occurrence in Atlantic Forest. Biol. Conserv. 240: 108264, in Google Scholar

Santos, P.M., Maria, K., Micchi, P., Ferraz, D.B., Ribeiro, M.C., Niebuhr, B.B., Vancine, M.H., Chiarello, A.G., and Paglia, A.P. (2022). Natural forest regeneration on anthropized landscapes could overcome climate change effects on the endangered maned sloth (Bradypus torquatus, Illiger 1811). J. Mammal. 103: 1383–1396, in Google Scholar

Scarton, F. and Valle, R.G. (2020). Could we assess the hatching success of Pied Avocets (Recurvirostra avosetta Linnaeus, 1758) by drone monitoring? A pilot study. Lav. - Soc. Veneziana di Sci. Nat. 45: 139–142.Search in Google Scholar

Snaddon, J., Petrokofsky, G., Jepson, P., and Willis, K.J. (2013). Biodiversity technologies: tools as change agents. Biol. Lett. 9: 20121029, in Google Scholar PubMed PubMed Central

Spaan, D., Burke, C., McAree, O., Aureli, F., Rangel-Rivera, C.E., Hutschenreiter, A., Longmore, S.N., McWhirter, P.R., and Wich, S.A. (2019). Thermal infrared imaging from drones offers a major advance for spider monkey surveys. Drones 3: 1–19, in Google Scholar

Watts, A.C., Ambrosia, V.G., and Hinkley, E.A. (2012). Unmanned aircraft systems in remote sensing and scientific research: Classification and considerations of use. Rem. Sens. 4: 1671–1692, in Google Scholar

Wich, S., Dellatore, D., Houghton, M., Ardi, R., and Koh, L.P. (2016). A preliminary assessment of using conservation drones for sumatran orang-utan (Pongo abelii) distribution and density. J. Unmanned Veh. Syst. 4: 45–52, in Google Scholar

Supplementary Material

This article contains supplementary material (

Received: 2022-11-02
Accepted: 2023-02-14
Published Online: 2023-02-27
Published in Print: 2023-05-25

© 2023 Walter de Gruyter GmbH, Berlin/Boston

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