An alternative method for calf density and recruitment estimation using pregnancy on wild guanacos (Lama guanicoe)

MAROZZI ANTONELA; PANEBIANCO ANTONELLA; GOMEZ, F.M.; SCHROEDER, N. M.; GREGORIO PABLO; MORENO PABLO; OVEJERO AGUILAR RAMIRO; PEÑA FIAMA; LEGGIERI LEONARDO RAMÓN; CARMANCHAHI PABLO

Congreso; 2020 Society for Mathematical Biology; 2020

Society for Mathematical Biology

Per capita recruitment is a parameter that determines most of the variation in population growth rate in wild temperate ungulates and it is generally estimated by young:female ratio. It has beenproposed that this approach should be improved since only count data is used in most cases and the probability of observing calves at heel declines with the age of the calf because it is more independent of the mother. In this study, we propose an alternative method to estimate calf density (ACD) using pregnancy rate obtained from hormonal fecal metabolites and total density estimates. Then we useACD to calculate recruitment by young:female ratio and compare the results with recruitment estimates using traditional count data (TCD). To set the parameters of ACD we used information of apartially-migratory guanaco (Lama guanicoe) population of La Payunia Provincial Reserve (Mendoza-Argentina).