Short-term extra food supply effects on detectability of two rodent species in Pampean agroecosystems, Argentina

GOROSITO, IRENE LAURA; BERMÚDEZ, MARIANO MARZIALI; BENÍTEZ, AILÉN MARINA; BUSCH, MARIA

Mammal Research

SPRINGER NATURE

Año: 2022 vol. 67 p. 61 - 72

2199-2401

Greater availability of food in the environment can lead to a reduction of rodents? home range and foraging time, potentially affecting their detectability in live-trapping studies. Hence, a good understanding of the effect of food availability on species? detectability is necessary for reliable ecological studies. In this work, we evaluate the effects of food availability on the live-trapping detectability of two hantavirus-host rodent species inhabiting Pampean agroecosystems in the Northern area of Buenos Aires province: Akodon azarae and Oligoryzomys flavescens. We carried out a field experiment on an abandoned railway embankment during winter 2016. The experiment consisted of two capture-mark-and-recapture samplings of rodents with the addition of food supply between sampling periods. Using a relatively simple modeling approach, we found that A. azarae?s detectability decreased after food supply, in contrast with the increment observed during previous winters (without food addition), likely due to a lower foraging activity. On the other hand, O. flavescens increased its detectability in spite of the similar conditions and temporal closeness between samplings, which might indicate some interaction between species. In addition, we observed a trap-phobic memory effect in O. flavescens, which could have important implications for capture-mark-and-recapture studies. Our findings highlight the importance of evaluating detectability as a dynamic feature, especially under variable environmental conditions.