Out of the dark : diurnal activity in the bat Hipposideros ruber on São Tomé island (West Africa)

Russo, D; Maglio, G; Rainho, A; Meyer, Christoph FJ; Palmeirim, JM

Abstract

Geographical areas historically characterized by a lower risk of diurnal avian predation should in theory
allow bats to be active in daytime too, especially to forage. Oceanic islands are ideal for studying temporal
niche shifts in bats since they often feature depauperate avian assemblages with fewer birds of prey. We
report on the second case of diurnal activity known for an insular insectivorous bat, Hipposideros ruber
on the island of São Tomé (Gulf of Guinea). We present observations of daylight flights made at several
sites on the island in six months (from July to November and in January). We also carried out daytime
(09h00–16h00) emergence counts at three roosts. In this time interval, bats were continuously active,
although activity rates changed: bats tended to return to roosts in early afternoon and, at two sites, to
decrease emergence rate under intense light probably to reduce the risk of hyperthermia. At one roost,
we observed that heavy rain caused abrupt daytime returns of large numbers of bats. In daytime bats
did forage and kept echolocating. Social interactions (chases) were also frequently observed. In daytime
adult males were significantly more frequent than females, while the opposite was noticed at night, an
intersexual segregation possibly leading to temporal niche partitioning.

Citation

Russo, D., Maglio, G., Rainho, A., Meyer, C. F., & Palmeirim, J. (2011). Out of the dark : diurnal activity in the bat Hipposideros ruber on São Tomé island (West Africa). Mammalian Biology, 76(6), 701-708. https://doi.org/10.1016/j.mambio.2010.11.007

• Journal Article Type: Article
• Acceptance Date: Nov 17, 2010
• Publication Date: Nov 1, 2011
• Deposit Date: Jan 25, 2016
• Journal: Mammalian Biology - Zeitschrift für Säugetierkunde
• Print ISSN: 1616-5047
• Publisher: Elsevier
• Volume: 76
• Issue: 6
• Pages: 701-708
• DOI: https://doi.org/10.1016/j.mambio.2010.11.007
• Publisher URL: http://dx.doi.org/10.1016/j.mambio.2010.11.007
• Additional Information: Funders : FCT