caa a22 4500 388096861 CHVBK 20180307125306.0 cr unu---uuuuu 161130e199902 xx s 000 0 eng 10.1079/PNS19990017 doi S0029665199000191 pii (NATIONALLICENCE)cambridge-10.1079/PNS19990017 Preparing for inactivity: How insectivorous bats deposit a fat store for hibernation [Elektronische Daten] During late autumn insectivorous bats must deposit a fat store to cover their energy demands throughout the period of hibernation, yet the density of aerial insects by this time has already declined from its peak in midsummer. Krzanowski (1961) suggested that bats are able to deposit a fat store by manipulating their energy expenditure; specifically by selecting cold roosting locations rather than warm roosts, and depressing their body temperatures during the day roosting period. It was hypothesized that these behavioural changes result in very low daily energy demands, and despite reduced food intake the animals are still able to gain body fat. We made several tests of this hypodiesis. First, we explored the thermo-selection behaviour of long-eared bats (Plecotus auritus) in the summer and in the pre-hibernal period. We found that in summer bats preferred temperatures of about 32-35° (about thermoneutral), but in the pre-hibernal period they preferred much colder temperatures of about 10°. Second, using open-flow respirometry we found that in the cold pre-hibernal bats entered torpor for an average of 14 h each day. Compared with bats held at 30° (that did not go torpid), the bats at 7° expended less energy. The extent of saving was sufficient to positively affect their mass balance, despite the fact that bats at lower temperature also had reduced digestive efficiencies. Our findings support the hypothesis that during the pre-hibernal period insectivorous bats manipulate their mass balance primarily by alterations in their energy expenditure, specifically utilizing energy-sparing mechanisms such as torpor. Copyright © The Nutrition Society 1999 Hibernation nationallicence Thermo-selection nationallicence Torpor nationallicence Energy expenditure nationallicence Insectivorous bats nationallicence Speakman John R. Aberdeen Centre for Energy Regulation and Obesity, Department of Zoology, University of Aberdeen, Aberdeen, AB24 2TZ, UK Rowland Angela Aberdeen Centre for Energy Regulation and Obesity, Department of Zoology, University of Aberdeen, Aberdeen, AB24 2TZ, UK Proceedings of the Nutrition Society Cambridge University Press 58/1(1999-02), 123-131 0029-6651 58:1<123 1999 58 PNS https://doi.org/10.1079/PNS19990017 text/html Onlinezugriff via DOI 1 conference jats NATIONALLICENCE 856 40 https://doi.org/10.1079/PNS19990017 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Speakman John R. Aberdeen Centre for Energy Regulation and Obesity, Department of Zoology, University of Aberdeen, Aberdeen, AB24 2TZ, UK NATIONALLICENCE 700 1- Rowland Angela Aberdeen Centre for Energy Regulation and Obesity, Department of Zoology, University of Aberdeen, Aberdeen, AB24 2TZ, UK NATIONALLICENCE 773 0- Proceedings of the Nutrition Society Cambridge University Press 58/1(1999-02), 123-131 0029-6651 58:1<123 1999 58 PNS CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge