Home sweet home? Adjustments in the ecology, behaviour and vocalisations of Amazonian squirrel monkeys inhabiting an Atlantic forest fragment

Abstract

Inadvertent or intentional introductions of species in non-native habitats are forcing them to adapt quickly, resulting in evolutionarily significant changes in their ecology and social organisation. Understanding how these species are adapting in non-native areas will elucidate evolutionary aspects of migration and adaptation skills of exotic species in general. Thus, we investigated how Amazonian squirrel monkeys (Saimiri sciureus) have adjusted their behavioural ecology and call propagation in an Atlantic forest fragment in north-eastern Brazil. Behavioural ecology data were obtained via instantaneous scan and ad libitum sampling methods. Call propagation data were obtained through playback experiments conducted in the Atlantic and Amazon forests. Atlantic forest squirrel monkey diet was found to be composed, primarily, of fruits considered “exotic” to the region. There was no variation between dry and wet months in food-resource exploitation except for flowers. Squirrel monkeys spent most of their time engaged in locomotion and foraging activities and had a preference for the Atlantic forest mid-strata. Nevertheless, resting, locomotion and social activities were most frequently demonstrated in the dry months, whereas foraging behaviours were mostly performed in the wet months. We found no variation between dry and wet months in the vertical use of the stratum, daily path length or home range size. The propagation of squirrel monkey isolation calls was more efficient in the Amazon compared with the Atlantic forest, with call acoustic parameters degrading faster in the Atlantic forest. Our results indicate that exotic squirrel monkeys have adjusted their activity pattern and diet in the Atlantic forest, resulting in behavioural variations consistent with the existing resources. Vocalisations, however, despite not being fully adapted for propagation in the Atlantic forest, do not appear to interfere in the occupation success of the species in the Atlantic forest.

key words:

• exotic species
• adaptation
• activity pattern
• behavioural flexibility
• use of space
• playback experiment

ACKNOWLEDGEMENTS

We greatly appreciate the welcome and support from Sra Valdete and her family during the fieldwork period in the Atlantic forest. We also thank the Comando Militar do Nordeste, 10 Brigada de Infantaria Motorizada and Ricardo Brennand Institute for permission to access the Atlantic forest fragment. We thank volunteer students Aline Silva, Isabel Guedes, Guilherme Varela, Willyams Martins and Julianne Silva, and 14 soldiers for their help during the fieldwork. We are thankful to Dr Paulo Carvalho, Dr Carla Castro, Dr Luciano Naka and Dr Adrian Barnett for valuable discussions over the course of the study. We also thank Professor Wilson Spironello, Professor Renato Cintra and MSc Matheus Castro for logistical support during fieldwork in the Amazon. We are also thankful to Rebecca Umeed for manuscript grammar revision.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

ETHICAL STANDARDS

The study was non-invasive and complies with Brazilian Law (SISBIO licence number: 50,956-1).

AUTHOR CONTRIBUTIONS

A.C. Campêlo, J.P. Souza-Alves and B. Bezerra conceptualised the study. A.C. Campêlo collected the data. I.M. Silva de Lima, L.R. Bezerra Oliveira-Silva and A.C. Lima Arajúo worked in the field assisting A.C. Campêlo. All the authors contributed to writing and revising the article. All the authors approved the final version of the manuscript.

SUPPLEMENTAL DATA

Supplementary data for this article can be accesed at https://doi.org/10.1080/03949370.2018.1522517

Additional information

Funding

A.C. Campêlo was funded by a CNPq grant (Conselho Nacional de Desenvolvimento Científico e Tecnológico/CNPq; grant number: 132854/2016-3) and Programa de Pós-Graduação em Biologia Animal. J.P. Souza-Alves was funded by a PNPD/CAPES grant (Coordination for the Improvement of Higher Education Personnel, grant number: #527091) and FACEPE (Fundação de Amparo a Ciência e Tecnologia do Estado de Pernambuco, grant number: BCT-0025-2.05/17). I.M. Silva Lima was supported by a PIBIC/UFPE/CNPq scientific initiation grant (Grant number: 17027382PO). The study was supported by FACEPE grants (Grant numbers: APQ-1534-2.04/10; APQ-0143-2.04/14) and a CNPq Universal grant (Grant number: Universal 445071/2014-1) to B. Bezerra.