The complex effect of illumination, temperature, and thermal
acclimation on habitat choice and foraging behavior
of a pit-building wormlion
Jonathan N. Pruitt
Received: 5 April 2017 /Revised: 9 July 2017 /Accepted: 1 August 2017
Springer-Verlag GmbH Germany 2017
Habitat selection has consequences for an animal’s fitness,
especially for sit-and-wait predators with limited mobility,
and which cannot always correct earlier suboptimal choices.
Environmental change may nevertheless lead individuals to
relocate to another site, although such relocations can be en-
ergetically costly or risky. Temperature and illumination are
two important factors that undergo change in seasonal and
daily cycles that may impact habitat quality. Animals must
therefore either acclimate to the new conditions or relocate.
Wormlions are sit-and-wait, trap-building predators whose
success in foraging is highly dependent on their surroundings.
Here, we manipulated temperature (high, low, and moderate)
and let the wormlions choose between lit and shaded
conditions. We found that the typical wormlion preference
for shaded microhabitats decreased with increasing tempera-
ture. We then followed wormlion behavior under a full-
factorial design of two constant illumination conditions
(light vs. shade) and three temperatures. Although both
constant light and high temperature reduced foraging perfor-
mance, expressed in pit construction tendency and pit area,
the two conditions had a non-additive effect. Acclimation to
extreme thermal conditions moderated the negative effects of
such temperatures, expressed in a higher tendency to construct
a pit, and equalized performance across temperatures. Finally,
the high temperature reduced behavioral consistency while
acclimation increased it, suggesting that consistency is im-
paired by unfavorable environmental change. To conclude,
while an environmental change usually affects several envi-
ronmental factors simultaneously, the induced behavioral
change is neither synergic nor additive and can even differ
from the response to each unfavorable environmental factor
Choosing a suitable habitat is essential for survival and
reproduction, especially for sedentary organisms, and requires
the consideration of various environmental conditions.
Acclimating to suboptimal conditions, however, might
conduce to improving performance in a less suitable habitat.
Testing the effect of several environmental conditions on
habitat choice and foraging behavior, before and after
acclimation, has rarely been carried out. Here, we tested the
combined effects of temperature, illumination, and their
interaction, on habitat choice and foraging performance of a
sit-and-wait predator, the wormlion. Wormlions usually
prefer shade, but their preference for light increases with
decreasing temperature. Both temperature and illumination
affect behavior but their joint effect is not additive.
Acclimation, which took place for temperature but not for
illumination, improved certain foraging behaviors. Our
findings highlight the importance of evaluating several envi-
ronmental conditions and behaviors when studying habitat
choice and foraging behavior.
Communicated by J. C. Choe
Electronic supplementary material The online version of this article
(doi:10.1007/s00265-017-2362-9) contains supplementary material,
which is available to authorized users.
* Inon Scharf
School of Zoology, Faculty of Life Sciences, Tel Aviv University,
69978 Tel Aviv, Israel
Department of Ecology, Evolution, and Marine Biology, University
of California, Santa Barbara, California, USA
Behav Ecol Sociobiol (2017) 71:137