Alternative reproductive strategies in the ruff, Philomachuspugnax: a mixed ESS? FREDRIK WIDEMO Section of Animal Ecology, Department of Zoology, Uppsala University and Department of Zoology, Norwegian University of Science and Technology, Trondheim.
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Alternative reproductive strategies in the ruff, Philomachuspugnax: a mixed ESS?FREDRIK WIDEMOSection of Animal Ecology, Department of Zoology, Uppsala Universityand Department of Zoology, Norwegian University of Science and Technology, Trondheim
Widemo, Fredrik. (1998). Alternative reproductive strategies in the ruff, Philomachus pugnax: a mixed ESS?. Animal Behaviour, 56(2), 329-336. doi: 10.1006/anbe.1998.0792. Summary by Jordan Gash, Daniel Vakili, and Matthew Yamamoto
The ruff is a lekking wader which breeds throughout
From PCAS Feathers e-newsletter, July 2008
“In classical leks, individuals gather within sight of each other to court and compete. Physical contest in these situations is frequent, and plays a major role in the mating rituals of certain shorebird and gamebird species”.(Wikipedia)
Adapted From Libb Thims
-Resident - Alpha male within a lek circle, the one who attracts the females
-Marginal - Independent, seeks to be
Alpha male, a threat to the Resident.
-Gains access to Resident’s lek by
submitting to him:
aka. letting the Resident peck his
head.(termed “coupling”). This further
attracts females to that Resident’s lek
-Gets the females that the Resident doesn’t
Is this a mixed ESS?
- An evolutionarily stable strategy cannot be replaced by an alternate strategy easily, and should be consistent over time.- Observe a population of ruffs during the breeding seasons of 1990–1997- Analyze reproductive success >between the Resident and Satellite strategies>between coupled and non-coupled Residents- Relationship and interaction of the two
Some major results-Females were found inside the territories of coupled Residents much more often than expected by chance-The presence of females increased Resident-Satellite couplings, and absense of females resulted in decreased coupling.-More pecking at the Satellite attracted more females
between number of
females in a lek
and number of satellites
Adapted from Fredrik Widemo
-Residents copulate more when coupled with Satellites-Satellites copulate almost exclusively when coupled with a resident.-From 1990 to 1996, Percent of copulations performed by Residents (~83-91%) and Satellites(~8-13) remained stable, evidence of the stability of both reproductive strategies.
Adapted from Fredrik Widemo
-Questions of equal fitness between residents and satellites
- Is it a ritualized fight? Coalition? Agreed hierarchy?
- Are the satellites just attracted to Residents the same way females
-The Satellite strategy
may represent a
strategy, for both
Adapted from Spark Notes, types of natural selection
The presence of females increased Resident-Satellite couplings, and absense of females resulted in decreased coupling
More Pecking at the Satellite by the Resident attracted more females
Females have a strong impact on the coupling of Residents and Satellites such that the presence of females brings about quicker, longer lasting, and higher retention rates of couplings.
1. It is still unclear for the exact reasoning of Satellites and Females to visit a Resident’s Lek.
2. The evolutionary benefits of having multiple reproductive strategies among male ruffs is still unclear.
3. Couldn’t calculate overall male lek attendance for Satellites and marginals.Critical Review