Self-assessment strategy during contest decisions between male Great Himalayan leaf-nosed bats

The potential function of forehead gland secretions in conflict resolution of the male Great Himalayan leaf-nosed bats

“…Similar results have been obtained in male Seba's short-tailed fruit bats Carollia perspicillata (Fernandez et al, 2014), Asian particolored bats Vespertilio sinensis (Zhao et al, 2018), and Indian False Vampire bats Megaderma lyra (Bastian & Schmidt, 2008). Hipposideros armiger use agonistic displays to defend their roosting territory, accompanied by vocal signals (Sun et al, 2019). Given these previous results, it is interesting that the presence or absence of vocal signals had no effect on contest duration or on the rate of agonistic displays.…”

“…The Great Himalayan leaf-nosed bat (Hipposideros armiger) is a highly gregarious species that usually roosts in caves, sharing day and night roosts among hundreds of individuals (Cheng & Lee, 2004). Our previous studies found that adult males in daily roosts usually maintain a minimum distance of 10-15 cm between individuals and defend their roosting territory using conspicuous agonistic displays such as broadband calls, wing flapping, boxing and wrestling (Sun et al, 2019). Our unpublished observations suggest that protrusion if the facial gland may also have a similar function (CM, pers.…”

“…We removed the hair around the forehead gland before the trial to clearly detect the presence of a protrusion of the forehead gland and to avoid recapturing the tested bats. To exclude the effect of body size on the contest duration, intensity and outcome, we staged dyadic agonistic interactions between the paired males matched in body mass (0.9 < the ratio of body mass between males < 1.1; Sun et al, 2019) and in forearm length (the difference between males in forearm length /male-average length < 2% ± 1.2%; Green & Patek, 2015). We carried out trials where individuals either both were capable of gland protrusion, or neither was capable of gland protrusion, or one could and one could not protrude the gland.…”

“…We used QvodPlayer (Version 5.0.80,Shenzhen Qvod Technology Co.,Ltd.,Guangdong,China) to analyze video recordings from 60 dyadic agonistic interactions and to describe agonistic behavior. To compare the differences in contest duration and intensity among 3 trial conditions, we analyzed contest duration, proportion of physical fight, proportion of nonphysical fight, frequency of aggressive displays and proportion of aggressive displays (for description of contest duration and behavioral parameters see Table 4; Clement et al, 2006;Sun et al, 2019). Table 4.…”

Individuality and function of chemical signals during conflict resolution of a mammal

“…H. armiger is a nocturnal and highly gregarious species that usually roosts in caves, sharing day and night roosts among hundreds of individuals 22 . Our previous studies 23 showed that adult males defend their private roosting territory using conspicuous agonistic displays (Table S1, online only; description of behavioral terms follows Clement et al 24 . and Fernandez et al 25 …”