امروز جمعه , 16 شهریور 1403
شنبه تا پنج شنبه - 9 صبح الی 20 عصر
دانلود مقاله : Dedicated mothers: predation risk and physical burden do not alter thermoregulatory behaviour of pregnant vipers 2013
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دانلود مقاله :
Dedicated mothers: predation risk and physical burden do not alter thermoregulatory behaviour of pregnant vipers 2013
نویسندگان :
Sophie Lorioux , Hélène Lisse , Olivier Lourdais
فرمت:pdf
چکیده :
Escape tactics and optimal refuge use have attracted considerable interest, but the influence of pregnancy
on escape tactics remains understudied. For instance, embryonic sensitivity to environmental
conditions and maternal constraints vary dramatically across pregnancy, and these dynamics should
modulate the costebenefit balance of refuge use. We experimentally studied thermoregulation and
refuge use in pregnant and nonreproductive aspic vipers, Vipera aspis, at different stages of gestation
(first, middle and last third). We determined preferred body temperatures (Tset) in a cost-free environment
to test for fecundity and stage dependencies of maternal Tset. Then, we examined behavioural
responses to repeated simulated predatory attacks. Pregnant females were extremely precise thermoregulators
compared with nonreproductive females, and Tset was independent of litter size or gestation
stage. After simulated attacks, pregnant females limited their time spent in the refuge and thereby their
deviation from Tset. By contrast, nonreproductive females had a greater response to predation exposure
and adjusted their response to risk level. Contrary to our predictions, pregnant females did not vary their
behaviour based on gestation stage, despite increasing physical burden as pregnancy progressed. Overall,
our results illustrate that pregnant females alter their behaviour to benefit their developing embryos
thermally despite risk to themselves (increased exposure). By doing so, however, the female realizes a
benefit by accelerating temperature-sensitive developmental time and thus reducing the duration of
pregnancy and associated physical burden.