Habitat use, bed‐site selection and mortality rate in neonate fallow deerDama dama

Abstract

An understanding of mortality patterns, and especially the variation in juvenile mortality, is an important component in vertebrate population dynamics. Our study investigates, for the first time, neonate mortality and two levels of spatial behaviour, in a free‐ranging fallow deerDama damapopulation in southwestern Sweden. In the summers of 2008 and 2009, 36 fawns were marked with radio‐collars. Neonate mortality calculated by the Kaplan‐Meier method was 23.6%. Mortality caused by predation was low, since only one of eight non‐surviving fawns died from predation, probably by red foxVulpes vulpes. The spatial behaviour of the neonates was examined by habitat selection at home‐range level, which in fact is a selection made by the mother, and at bed‐site level within that habitat. Compositional analysis revealed a significant preference for arable land, pasture and coniferous forest between 5‐15 m high, compared to young forest. Selected bed sites showed significantly lower visibility and higher amount of canopy cover than random sites. Surprisingly, we did not find any relationship between canopy cover and visibility in selected bed sites while it showed a significant and negative relationship at random bed sites. We interpret this finding as while high canopy cover and low visibility covary at the habitat level, fawns seem to select these two bed‐site variables independently, perhaps for thermoregulatory reasons. Since there are few predators in our study area and predation pressure is low, this behaviour is not connected to actual survival rates in this area, but would rather be in support of the hypothesis of ‘pleiotropy’ as thermoregulatory reasons for bed‐site selection in neonate fawns might be the most important contemporary selection force in the absence of large predators.