Daily cycles in body temperature in a songbird change with photoperiod and are weakly circadian

Dawson, Alistair. 2017 Daily cycles in body temperature in a songbird change with photoperiod and are weakly circadian. Journal of Biological Rhythms, 32 (2). 177-183. 10.1177/0748730417691206

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Official URL: http://dx.doi.org/10.1177/0748730417691206

Abstract/Summary

Although it is well known that body temperature (Tb) is higher during the day in diurnal birds than at night, no data are available regarding exactly how Tb varies during a 24-h period, how this differs under different photoperiods, and how it responds to a change in photoperiod. This study used implanted temperature loggers in starlings (Sturnus vulgaris) to address these questions. The duration of elevated Tb was directly related to photoperiod, but the amplitude of the daily cycle was significantly greater under shorter photoperiods. Under all photoperiods, Tb started to increase before dawn and continued to increase after dawn; there was no sudden change associated with dawn. In contrast, Tb decreased immediately and rapidly at dusk (significantly by 15 min). The daily cycle in Tb rapidly adjusted to a change in photoperiod. Following an acute increase in photoperiod, Tb increased immediately at the new earlier dawn but did not decrease until the new later dusk. Following a decrease in photoperiod, Tb did not increase after the time of the missed dawn; it only increased after the new later dawn. It decreased at the new earlier dusk. Following transfer to constant darkness, there was a moderate increase in Tb around the missed dawn, but then Tb gradually decreased before the missed dusk to lower values than during the previous night. The results suggest that the daily cycle in Tb is weakly circadian and may be entrained by dusk rather than dawn.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1177/0748730417691206
UKCEH and CEH Sections/Science Areas:	Watt
ISSN:	0748-7304
Additional Keywords:	body temperature, daily cycle, circadian, bird, starling, melatonin
NORA Subject Terms:	Zoology Biology and Microbiology
Date made live:	26 Apr 2017 09:08 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/516927

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1177/0748730417691206

UKCEH and CEH Sections/Science Areas:

Watt

ISSN:

0748-7304

Additional Keywords:

body temperature, daily cycle, circadian, bird, starling, melatonin

NORA Subject Terms:

Zoology
Biology and Microbiology