Behaviour of bats during a lunar eclipse

Usman, Khalid; Habersetzer, Jörg; Subbaraj, R.; Gopalkrishnaswamy, G.; Paramanandam, K.

doi:10.1007/bf00302522

Cited by 27 publications

(11 citation statements)

References 7 publications

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“…Usman et al . () (see also Singaravelan & Marimuthu, ) observed a marked increase in activity during a lunar eclipse in India (Fig. ), despite a drop in insect activity during the eclipse.…”

Section: Predator Avoidance In An Ecological Contextmentioning

confidence: 64%

Do predators influence the behaviour of bats?

2013

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Many aspects of animal behaviour are affected by real-time changes in the risk of predation. This conclusion holds for virtually all taxa and ecological systems studied, but does it hold for bats? Bats are poorly represented in the literature on anti-predator behaviour, which may reflect a lack of nocturnal predators specialized on bats. If bats actually experience a world with minimal anti-predator concerns, then they will provide a unique contrast within the realm of vertebrate ecology. Alternatively, such predator-driven behaviour in bats may not yet be fully understood, given the difficulties in working with these highly mobile and nocturnal animals. We provide a wide-ranging exploration of these issues in bat behaviour. We first cover the basic predator-prey information available on bats, both on potential predators and the ways in which bats might perceive predators and respond to attacks. We then cover work relevant to key aspects of bat behaviour, such as choice of daytime roosts, the nature of sleep and torpor, evening roost departures, moonlight avoidance, landscape-related movement patterns, and habitat selection. Overall, the evidence in favour of a strong influence of predators on bat behaviour is equivocal, with the picture clouded by contradictory results and a lack of information on potential predators and the perception of risk by bats. It seems clear that day-active bats run a considerable risk of being killed by diurnal raptors, which are able to capture bats with relative ease. Thus, bats taking advantage of a pulse of insects just prior to sunset are likely taking risks to gain much-needed energy. Further, the choice of daytime roosts by bats is probably strongly influenced by roost safety. Few studies, however, have directly addressed either of these topics. As a group, insectivorous temperate-zone bats show no clear tendency to avoid apparently risky situations, such as activity on moonlit nights. However, some observations are consistent with the idea that predation risk affects choice of movement paths and feeding areas by temperate-zone bats, as well as the timing of roost departures. The behaviour of tropical bats, on the other hand, seems more generally influenced by predators; this is especially true for tropical nectarivores and frugivores, but also for insectivorous bats. Presumably there are more serious predators on bats in the tropics (e.g. specialized raptors or carnivorous bats), but the identity of these predators is unclear. More information is needed to assess fully the influence of predators on bat behaviour. There is much need for work on the ways in which bats perceive predators via auditory, visual, and olfactory cues, and whether bats have some knowledge of the risks posed by different predators. Also needed is information on how predators attack bats and how bats react to attacking predators. Difficult to obtain, but of critical value, will be information on the nature of the predation risk experienced by bats while away from roosts and during the full darkness of night.

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Section: Predator Avoidance In An Ecological Contextmentioning

confidence: 64%

Do predators influence the behaviour of bats?

2013

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“…To the best of our knowledge clear cases of lunar phobia in bats are restricted to tropical frugivores and sanguivores (e.g. Turner, 1975;Morrison, 1978;Usman et al, 1980;Fleming, 1988). It is known that owls, including tawny owls Strix aluco, which are common at our study site (B. Lind pers.…”

Section: Discussionmentioning

confidence: 99%

“…In contrast, in the tropics, the short-tailed fruit bat Carollia perspicillata, which has been studied intensively, reduces foraging activity considerably during bright moonlight, more so in the dry season than in the wet season (Fleming, 1988). Such`lunar phobia' is apparently widespread in tropical frugivorous bats (Morrison, 1978;Usman et al, 1980) and has also been observed in vampire bats Desmodus rotundus (Turner, 1975). Frugivores and sanguivores are perhaps most at risk when they approach their food sources.…”

Section: Introductionmentioning

confidence: 96%

No lunar phobia in swarming insectivorous bats (family Vespertilionidae)

2002

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The purpose of this study was to evaluate the impact of moonlight on the swarming activity of bats at an abandoned mine in southern Sweden. The mine serves as a hibernaculum for six species of insectivorous bats. Swarming activity at one of the mine entrances was measured on 12 nights between 1 August and 8 September 2000, by electronically counting the number of bats passing through an opening (about 30640 cm) leading to a mine tunnel. The number of bat passes outside the mine was also counted, using a bat detector. Most bats were males, as con®rmed by mist-netting outside the mine. Low frequency vocalizations, indicating territorial interactions, were heard frequently. The number of bats entering the mine was closely correlated with the number of bats¯ying outside, and neither was affected by moonlight. We conclude that the insectivorous bats at high latitudes may not have been exposed to signi®cant nocturnal predator pressure, leading to the evolution of lunar phobia, as have many tropical bats.

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“…It has been reported that foraging activity in some bat species completely stops on moonlit nights (Fenton et al, 1977;Usman et al, 1980); but in some cases moonlight does not suppress activity (Reith, 1982), has a positive effect (Erickson and West, 2002) or even no effect (Negraeff and Brigham, 1995). Negative effects are explained by a switch from open to more shaded areas to avoid predation or to feed on lunophobic insects (Fenton et al, 1977;Usman et al, 1980). Ponds at La Michilía are open spaces with little or no shaded area.…”

Section: Relationship With Environmental Variablesmentioning

confidence: 97%