Post-copulatory sexual
selection in the houbara bustard
A three year PhD position is available to work on a collaborative
project dealing with the post-copulatory sexual selection in the houbara
bustard.
In most animal
species, females mate with multiple males giving rise to the potential for
sperm competition and cryptic female choice. These post-copulatory components
of sexual selection add to those acting on males to attract mates
(pre-copulatory sexual selection).
Although the study of
post-copulatory sexual selection has flourished in the last decade, there are
very few biological systems that are amenable to the experimental study of
sperm competition and cryptic choice.
Houbara bustards are
endangered bird species living in North Africa (Chlamydotis undulata), Middle East and Central Asia (Chlamydotis macqueeni). In order to
restore and reinforce natural populations of houbara in Middle East, the
National Avian Research Center (NARC) has promoted a captive breeding program
in Abu Dhabi (EAU) under the leadership of the International Fund for Houbara
Conservation. This breeding program is based on the collection of sperm which
is subsequently used to artificially inseminate females under standardized
conditions (Saint Jalme et al. 1994). This allows investigating several aspects
related to sperm competition and cryptic choice, in a species where both pre-
and post-copulatory sexual selection is supposed to be a strong selective
force. Indeed, males harbor extravagant sexual displays (Chargé et al. 2010,
2011; Preston et al. 2011) and females have been shown to mate with multiple
males in the wild, where the proportion of clutches sired by multiple fathers
is fairly high (60%) (Lesobre et al. 2010).
In the first stage of
the PhD thesis, we expect to better characterize sperm traits that determine
the likelihood to successfully fertilize eggs. Then, experimental work could be
conducted to explore the following questions:
1) Is there a trade-off between pre-
and post-copulatory components of sexual selection?
2) Is fertilization success mostly
driven by sperm competition or cryptic choice?
3) Is there a scope for sexual conflict
in this system?
In addition to their
fundamental interest, the obtained results could also be valuable with respect
to the genetic management of the captive breeding. On one hand, inseminating
with a mix of semen could facilitate insemination procedure by reducing the time
spent to select precise pedigree and by optimizing semen utilization (mixture
of small ejaculates that are usually discarded could be easily used). On the
other hand, sperm competition might result in severely biased paternity with a
potential for strong involuntary selection acting on breeding males.
This is a
collaborative project involving the NARC (Yves Hingrat, Loic Lesobre, Tony
Chalah) where all the experimental work will be carried out and where the
successful applicant will spend most of the time, the French CNRS in Dijon
(Gabriele Sorci) and the Museum of Natural History in Paris (Michel Saint
Jalme).
Interested applicants
should send a CV and the name of three references to Gabriele Sorci (gabriele.sorci@u-bourgogne.fr) and Michel Saint Jalme (mstjalme@mnhn.fr).
Salary: 1,250 euros per
month. Accommodation and food is provided by the NARC with no fees for the
student.
Selected articles published by the group related to the project
Chargé R. et al. 2011. Immune-Mediated
Change in the Expression of a Sexual Trait Predicts Offspring Survival in the
Wild. PLoS ONE 6: e25305.
Preston B. et al. 2011. Sexually
extravagant males age more rapidly. Ecology Letters 14: 1017-1024.
Chargé et al. 2010. Male health status,
signalled by courtship display, reveals ejaculate quality and hatching success
in a lekking species. Journal of Animal Ecology 79: 843-850.
Lesobre L. et al. 2010. Conservation
genetics of Houbara Bustard (Chlamydotis undulata undulata): population
structure and its implications for the reinforcement of wild populations.
Conservation Genetics 11: 1489-1497.
Lesobre L. et al. 2010. Absence of male
reproductive skew, along with high frequency of polyandry and conspecific brood
parasitism in the lekking Houbara bustard Chlamydotis undulata undulata.
Journal of Avian Biology 41: 117-127.
Saint Jalme M. et al. 1994. Artificial insemination in Houbara bustard
(Chlamydotis undulata): influence of the number of spermatozoa and insemination
frequency on fertility and ability to hatch. Journal of Reproduction and
Fertility 100: 93-103.