This study investigates the reproductive and parental roles of polyandrous male pale
chanting-goshawks, Melierax canorus, and speculatively reviews the fitness outcomes of
different skew and relatedness scenarios. The study was conducted over five years in the Little
Karoo, South Africa. Although, polyandrous males participated equally in building nests,
provisioning prey and incubating, in the fertility window the dominant alpha males copulated
31–5 days before the females laid, whereas subordinate beta males only copulated 5–3 days
before laying. If this copulation timing by alpha males was indicative of a high reproductive
skew, alpha males breeding as full sibs could skew paternity in their favour (ratio 68:32) and
produce 0.69 offspring equivalents. Under this scenario, they compensated beta males with
indirect fitness benefits by allowing them to produce 0.54 offspring equivalents, equal to
monogamous males. Alternatively, if beta males controlled reproduction while breeding with
non-relatives under a high skew scenario, they would have to restrain themselves to avoid
eviction and produce 0.28 offspring equivalents to allow the fitness of alpha males at least to
equal that of monogamous males. I suggest that alpha males and their females altered their
reproductive roles to accommodate beta males, thereby increasing their inclusive fitness,
whereas beta males tolerated subordination to acquire reproductive skills that non-breeder
males do not have access to.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:tut/oai:encore.tut.ac.za:d1001001 |
| Date | 01 October 2005 |
| Creators | Malan, G |
| Publisher | African Zoology |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | |
| Rights | African Zoology |
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