Female effect on antlers of pampas deer (Ozotoceros bezoarticus)

Abstract

Size and bone mineralization of deer antlers are related to testosterone concentrations, and antler cast is observed after withdrawal of testosterone concentration. Our objectives were to determine if (i) contact with hinds stimulates antler development and increases hard antler period length in pampas deer ( Ozotoceros bezoarticus (L., 1758)) and (ii) antlers from males that were or were not in contact with hinds differ in colour. While 5 males were in breeding paddocks consisting of 1 adult stag and 5–10 hinds, the other 6 males were allocated as a single-male group. We collected, weighed, and measured the volume, circumferences, and lengths of antlers, and determined their colour. First antler cast tended to be later in males in contact with females than those in the single-male group. Antler mass and volume were greater in antlers from males in contact with females. Circumference at the base of first and second tines was also greater in antlers collected from males in contact with females. Surfaces of antlers from these males were darker than those of antlers from males that remained isolated from females in all points. Hind contact stimulated male pampas deer, increasing antler mass, size, and darkness, as well as possibly hard antler period length.

Ontogenetic and static scaling of antler mass in White-tailed Deer (Odocoileus virginianus)

“…Scaling relationships between body size and antler size have usually been estimated among species (Gould 1974; Clutton-Brock et al 1980; Plard et al 2011; Lemaître et al 2014; Tidière et al 2017, 2020). The fewer number of studies that have estimated antler scaling relationships within a cervid species have either estimated an ontogenetic scaling relationship or static scaling relationships, but few have estimated both (Stewart et al 2000; Ungerfeld et al 2011; Melnycky et al 2013; Jones et al 2018; Tidière et al 2020). Our estimates of static scaling relationships between body mass and antler mass reflected the findings from the ontogenetic scaling relationship.…”

“…Scaling relationships are often estimated to summarize relationships between body mass and sexually selected traits such as antler size (Gould 1974; Clutton-Brock et al 1980; Ditchkoff et al 2001; Plard et al 2011; Lemaître et al 2014; Tidière et al 2017, 2020). There are numerous studies estimating interspecific body–antler size scaling relationships, but fewer intraspecific studies (Stewart et al 2000; Ungerfeld et al 2011; Melnycky et al 2013; Jones et al 2018). Intraspecific studies are needed to examine how a trait develops with body mass from young to old age regarding factors that might constrain growth and antler size (Pélabon et al 2013; Jones et al 2018).…”

“…Growth rate might vary if antler growth is constrained by mineral limitations in skeletal bone or juvenile growth is reduced because of dietary nutritional deficits (Stewart et al 2000; Lemaître et al 2014; Tidière et al 2017; Jones et al 2018). Static scaling relationships estimate scaling relationships across individuals at discrete ages or age classes (Huxley 1931; Ungerfeld et al 2008, 2011; Plard et al 2011; Melnycky et al 2013; Lemaître et al 2014). Static scaling relationships are useful to determine whether the scalar (slope) changes with age, and whether factors consistently influence scaling coefficients across different ages.…”

Phenology of Antler Casting and Occurance of Late-Breeding in Nebraska White-Tailed Deer

“…Antler cycle is closely related to androgen concentrations (Bubenik 1990b) and several studies on cervids have observed that artificially elevated testosterone delays normal antler casting (Lincoln et al 1972, Semepere andBoissin 1982). Late antler casting is not uncommon amongst individuals in good condition within cervid populations, for example male pampas deer (Ozotoceros bezoarticus) in the presence of females cast their antlers later compared to male-only groups (Ungerfeld et al 2009) which indicates increased testosterone levels. Female white-tailed deer that remain in estrus or come into estrus late may cause extended periods of elevated testosterone levels in males and result in late antler casting which may explain the late-breeding male retaining antlers until at least 14 April 2019 and the antlered male documented on 15 April 2020 represent additional observations of late antler casting for this region.…”