A New and Simple Method to Capture Small Arboreal Mammals: The Suspended Pitfall

Abstract

The suspended pitfall demonstrates a new and simple mechanism to capture small arboreal and scansorial mammals. It is an arboreal version of the pitfalls traditionally used to capture terrestrial amphibians and reptiles. Buckets with bait inside are raised by a rope until they reach a tree branch at the desired height. Tests were performed in the Atlantic Forest at three different sites at the mouth of Doce River in Linhares, southeastern Brazil. In one of them suspended pitfalls were set up in the understory of a shaded cacao plantation (cabruca agroforest) in the branches of cacao trees between 2 and 3 m in height, and in the other they were placed in a native forest between 5 to 15 m in height. At the third site, suspended pitfalls were tested together with the other live traps used hitherto in the understory of other cabruca agroforest. The marsupials Didelphis aurita, Caluromys philander, Marmosa (Micoureus) paraguayana, Gracilinanus microtarsus, Marmosa murina and the rodent Rhipidomys mastacalis were captured by suspended pitfall. This live trap was capable of catching all sizes of small arboreal mammals, including juvenile individuals. This method proved to be functional for the capture of some small arboreal mammals and may be a complementary alternative for sampling in high forest strata.

Dimensões Ecológicas, Geológicas e Humanas em Estudos de Longa-Duração no Parque Nacional da Restinga de Jurubatiba, Rio de Janeiro.

“…O PNRJ compartilha também com outras unidades de conservação de regiões serranas, como o Parque Nacional da Serra dos Órgãos, a Reserva Florestal de Morro Grande e a Estação Ecológica de Bananal, o fato de ter sido alvo de estudos de longa duração, o que provavelmente contribuiu para o elevado número de espécies registradas. Os hábitos locomotores e alimentares variados dos pequenos mamíferos demandam a combinação de múltiplas técnicas de captura e registro para gerar estimativas mais acuradas da riqueza local, e esse uso combinado de métodos tem sido frequentemente recomendado em trabalhos recentes na Mata Atlântica , Bovendorp et al 2017b, José et al 2019, Palmeirim et al 2019). Contudo, a elevada riqueza de espécies registrada no PNRJ sugere que a duração dos inventários também é um fator-chave nas estimativas de riqueza, não somente devido ao maior esforço acumulado em estudos de longa duração, mas especialmente devido à possibilidade de detectar espécies em baixas densidades e com flutuações populacionais imprevisíveis, como possivelmente é o caso de Marmosops incanus e Cryptonanus agricolai no PNRJ.…”

Mammal diversity among vertical strata and the evaluation of a survey technique in a central Amazonian forest

“…The line transect technique (hereafter LnTT) is broadly used to survey midsize to large-bodied mammals, especially those ISSN On-Line: 1807-0205 ISSN Printed: 0031-1049 ISNI: 0000-0004-0384-1825 with terrestrial and diurnal behaviors (Munari et al, 2011;Peres & Cunha, 2011;Pontes, 2004). The live-trapping technique (LvTT), which includes Sherman, Tomahawk, and pitfall traps, is especially used for nonvolant small mammals (< 1 kg) (Ardente et al, 2017;Malcolm, 1991), which can be located in the canopy stratum (José et al, 2019). Finally, the camera-trapping technique (CTT) is one of the newest to be implemented to mammal surveys, and its use has drastically increased in recent years (Burton et al, 2015;Wearn & Glover-Kapfer, 2017).…”