Boiten Gust, van Iersel Robin, Pinxten Rianne, Eens Marcel
Behavioural Ecology and Ecophysiology Group, Department of Biology, University of Antwerp, 2610 Antwerp, Belgium.
Research Group Didactica, Antwerp School of Education, University of Antwerp, 2610 Antwerp, Belgium.
Animals (Basel). 2023 Feb 7;13(4):585. doi: 10.3390/ani13040585.
During the breeding season, aggression is expressed to gain access to resources such as territories and mates and protect offspring. Female aggressiveness has received much less attention than male aggressiveness, and few studies have examined female and male aggressiveness towards intruders of both sexes in the same species. We compared female and male aggressiveness towards same- and opposite-sex intruders during the egg-laying period in blue tits () using simulated territorial intrusions. For each sex, we examined the occurrence of different behavioural responses during agonistic encounters, and compared the intensity and individual consistency of intra- and inter-sexual aggression using same- and opposite-sex taxidermy mounts. Our results show that females are the more aggressive sex. Both sexes showed similar behaviours during simulated intrusions, although females were never observed singing and males never entered the nest box. In females, aggression was predominantly independent of the sex of the intruder, while males sang more from a distance during male-male encounters. The relative levels of aggression (pecking and perching on the mounts) during intra- and intersexual conflicts were consistent for females, but not for males. Females might be under stronger selection for aggressive phenotypes due to nest-hole competition and larger reproductive investments.
在繁殖季节，攻击性表现为获取诸如领地和配偶等资源以及保护后代。与雄性攻击性相比，雌性攻击性受到的关注要少得多，而且很少有研究在同一物种中考察雌雄两性对不同性别的入侵者的攻击性。我们利用模拟领地入侵，比较了蓝山雀（）在产卵期对同性和异性入侵者的雌雄攻击性。对于每一种性别，我们研究了在争斗遭遇中不同行为反应的发生情况，并使用同性和异性的标本制作模型比较了同性间和异性间攻击的强度及个体一致性。我们的结果表明，雌性是更具攻击性的性别。在模拟入侵过程中，两性表现出相似的行为，不过从未观察到雌性鸣叫，雄性也从未进入巢箱。在雌性中，攻击性主要与入侵者的性别无关，而在雄性与雄性的遭遇中，雄性会在较远处更多地鸣叫。在同性间和异性间冲突中，雌性攻击的相对水平（啄击和停歇在模型上）是一致的，而雄性则不然。由于巢洞竞争和更大的繁殖投入，雌性可能在攻击性表型上受到更强的选择。
