TY - JOUR
T1 - Parental correlates of offspring sex ratio in Eurasian Oystercatchers
AU - Heg, D.
AU - Dingemanse, N.J.
AU - Lessells, C.M.
AU - Mateman, A.C.
N1 - Reporting year: 2000
Metis note: 2720; CTE; PVD ; AnE; file:///L:/Endnotedatabases/NIOOPUB/pdfs/Pdfs2000/Heg_ea_2720.pdf
PY - 2000
Y1 - 2000
N2 - We investigated hatchling and fledgling sex ratios in Eurasian Oystercatchers (Haematopus ostralegus) using random amplified polymorphic DNA markers. The overall hatchling (53% males, n = 374 hatchlings from 177 broods) and fledgling (49% males, n = 51) sex ratio did not differ significantly from unity. Hatchling and fledgling sex ratios were not correlated with laying date, clutch size, brood size, egg-laying sequence, territory quality male age, or male breeding experience, but hatchling sex ratio was positively correlated with age and breeding experience of females (0.05 <P <0.075, n = 71). Older females produced more sons irrespective of the position of the offspring in the egg-laying sequence. Fledging mass was not correlated with female age, so the Trivers and Willard (1973) hypothesis is unlikely to explain our results. Sons dispersed less than daughters, so the local resource competition hypothesis of Clark (1978) might apply. The adaptive significance of a male-biased sex ratio in clutches produced by older females is speculative because the costs and benefits of dispersing versus philopatric offspring to parents and offspring are largely unknown. [KEYWORDS: Local resource competition; haematopus-ostralegus; monogamous oystercatcher; reproductive success; territory quality; paternal age; birds; selection; population; helpers]
AB - We investigated hatchling and fledgling sex ratios in Eurasian Oystercatchers (Haematopus ostralegus) using random amplified polymorphic DNA markers. The overall hatchling (53% males, n = 374 hatchlings from 177 broods) and fledgling (49% males, n = 51) sex ratio did not differ significantly from unity. Hatchling and fledgling sex ratios were not correlated with laying date, clutch size, brood size, egg-laying sequence, territory quality male age, or male breeding experience, but hatchling sex ratio was positively correlated with age and breeding experience of females (0.05 <P <0.075, n = 71). Older females produced more sons irrespective of the position of the offspring in the egg-laying sequence. Fledging mass was not correlated with female age, so the Trivers and Willard (1973) hypothesis is unlikely to explain our results. Sons dispersed less than daughters, so the local resource competition hypothesis of Clark (1978) might apply. The adaptive significance of a male-biased sex ratio in clutches produced by older females is speculative because the costs and benefits of dispersing versus philopatric offspring to parents and offspring are largely unknown. [KEYWORDS: Local resource competition; haematopus-ostralegus; monogamous oystercatcher; reproductive success; territory quality; paternal age; birds; selection; population; helpers]
U2 - 10.1642/0004-8038(2000)117[0980:PCOOSR]2.0.CO;2
DO - 10.1642/0004-8038(2000)117[0980:PCOOSR]2.0.CO;2
M3 - Article
SN - 0004-8038
VL - 117
SP - 980
EP - 986
JO - The Auk
JF - The Auk
IS - 4
ER -