Evaluating the efficiency of different sampling techniques to survey non-flying small mammals in the Amazon

Abstract

AbstractSmall non-flying mammals represent 44% of Brazilian mammal species and have a wide range of habits and life-history strategies. This wide diversity requires different sampling methods in survey studies. We compared the efficiency of pitfall and live-traps in different vertical positions in relation to the alpha and beta diversity of small mammals in three forest fragments with different levels of conservation and in a continuous area in the southwestern Amazon, Acre state. Captures were carried out using a combination of pitfall traps and live-traps on the ground, understorey, and canopy. Taxonomic identification was performed by morphological and molecular analyses. Alpha diversity was evaluated using Hill numbers (q = 0 and q = 1). The turnover between different types of traps and different vertical strata (beta diversity) was analysed using permutation analysis of variance. Species richness between areas ranged from 6 to 21. The highest species richness was observed in ground traps, and the lowest species richness was observed in the canopy. Live-traps on the ground recorded a greater diversity in two areas. Pitfall traps recorded the greatest number of unique species in three areas. The different types of traps and the different vertical positions acted in a complementary way in the small mammal samplings. The turnover in relation to trap type and stratum indicated the formation of two significantly different groups: ground traps and aboveground traps. However, the use of canopy traps did not contribute significantly to an increase in the estimated species richness and diversity in three of the four localities.