Inter-male aggression in relation to female availability and residence status in corn mice Calomys musculinus

Abstract

We conducted an experimental study to test the hypothesis that, at low female availability, males show intrasexual aggressive behaviour and home range owners are more aggressive than home range intruders. Using field dyadic arena test, we carried out 35 male-male trials in four 0.25 ha enclosures, two male-biased (experimental enclosures) and two unbiased (control enclosures). Dyadic encounters were conducted between unrelated and sexually mature males of similar weight and age which established home ranges in the same enclosure at the same trapping session. Each inter-male encounter was performed in the home range of one of the opponents between the home range owner and a home range intruder. When sex ratios were male-biased, intermale amicable behaviour was absent and we found significant rates of inter-male aggressiveness, being home range owners much more aggressive than intruders. In the unbiased enclosures, inter-male encounters resulted mainly in noninteractive or amicable interactions. We found that inter-male aggression varied in relation to female availability being more evident in home range owners.

Multiple paternity in a wild population of the corn mouse: its potential adaptive significance for females

“…Sommaro et al (2010b) found that C. musculinus females maintain their territories regardless of population density values and that at high population density they limit the size of the breeding population by constraining other females from settling. On the other hand, the upper limit in the number of C. musculinus breeding males is reached through induced territoriality derived from intrasexual social restrictions (Sommaro et al 2010b;Steinmann and Priotto 2011). Thus, C. musculinus spacing behavior would explain the similarity between multiple paternity rates at low and high population density found in this study.…”

“…Before this study, C. musculinus promiscuity was assumed through behavioral characteristics of males and females in relation to space use, territoriality, mating, nesting, offspring guarding, and mate discrimination (Cutrera et al 1988;Yunes et al 1991;Laconi and Castro-Vázquez 1998;Laconi et al 2000;Steinmann et al 2009;Sommaro et al 2010b;Coda et al 2011;Steinmann and Priotto 2011). In the absence of paternal information, relatedness coefficients and paternity patterns among pups sharing a mother were inferred based on their genotypes.…”

“…In corn mice, Calomys musculinus (Cricetidae, Sigmodontinae), a promiscuous mating system has been proposed, based until now on behavioral studies (Laconi et al 2000;Steinmann et al 2006aSteinmann et al , 2006bSteinmann et al , 2009Sommaro et al 2010aSommaro et al , 2010bCoda et al 2011;Steinmann and Priotto 2011). During the breeding period, C. musculinus males have large home ranges that overlap with several females and males, while females keep smaller home ranges crossed by both transient and resident males but never by breeding females (Steinmann et al 2005(Steinmann et al , 2006aSteinmann 2006).…”

Female Intrasexual Territoriality and its Potential Adaptive Significance: The Pampean Grassland Mouse as an Ecological Model Species

“…; Steinmann et al. ; Steinmann & Priotto ). In polygynous species, male aggressiveness leads to an increase in reproductive success by defending territories containing breeding females (Clutton‐Brock ; Shuster & Wade ; Waterman ); meanwhile, female territorial behaviour has been proposed as a strategy for defence of food resources (Hrdy ; Ims ; Ostfeld ; Tamarin et al.…”

Space Use and Social Mating System of the Hantavirus Host, Oligoryzomys longicaudatus

“…A greater degree of imbalance in the OSR leads to a greater expected variance in reproductive success among members of the limited sex, affecting directly the degree of polygyny (Trivers 1972;Clutton-Brock and Parker 1992;Mitani et al 1996;Aloise King 2013). Many studies at the population level have revealed the impact of population density and OSR on spacing and mating behaviours of vole and mice (Ochiai and Susaki 2002;Steinmann et al 2006a, b;Stradiotto et al 2009;Sommaro et al 2010;Steinmann and Priotto 2011;Bonatto et al 2015;A ´vila et al 2016). For example, in some promiscuous and polygynous vole species, male home range size and overlap degree are negatively correlated with population density (Ostfeld et al 1985;Ostfeld 1986;Nelson 1995a, b;Bond and Wolff 1999;Moorhouse and Macdonald 2008;A ´vila et al 2016) and receptive female availability (Steinmann et al 2006a;Steinmann and Priotto 2011), while females maintain the size and exclusivity of its home ranges regardless of population density (Saitoh 1981;Ostfeld 1985;Erlinge et al 1990;Sommaro et al 2010;A ´vila et al 2016).…”