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

GOROSITO IL; BUSCH M; MARZIALI BERMÚDEZ M; BENÍTEZ AM

Mammal Research

Springer

Año: 2021 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, potentiallyaffecting 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 thelive-trapping detectability of two hantavirus-host rodent species inhabiting Pampean agroecosystems in the Northern areaof Buenos Aires province: Akodon azarae and Oligoryzomys flavescens. We carried out a field experiment on an abandonedrailway embankment during winter 2016. The experiment consisted of two capture-mark-and-recapture samplings of rodentswith 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 (withoutfood addition), likely due to a lower foraging activity. On the other hand, O. flavescens increased its detectability in spiteof 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 forcapture-mark-and-recapture studies. Our findings highlight the importance of evaluating detectability as a dynamic feature,especially under variable environmental conditions.