Lundy sparrow project: part two
Genetic basis of mate choice, immunocompetence and their interaction in the house sparrow.
Our investigation on sexual selection in the house sparrow (Passer domesticus) continued on Lundy Island in the Bristol Channel.
The Lundy house sparrow population was stable between 1990-1996 with 35-45 breeding pairs. However, the population declined dramatically during the winter of 1996-1997 (sparrows were accidentally allowed to have access to poisonous food, which had been used to eradicate rats on the island). In the spring of 2000, 50 birds from the mainland were introduced to the Lundy population (which consisted only of 43 adults). The population has increased gradually to the present.
The project continued to monitor the frequency of extra-pair paternity (EPP) in this population. Before the introduction of mainland birds, the frequency of EPP was close to zero. However, after the introduction, the frequency of EPP reached a level similar to that observed in mainland populations (c. 12 %) and EPP frequencies in 2001 and 2002 were intermediate levels.
This study also clarified what the size of black throat patch (badge) in male sparrows is really signalling. Existing literature agreed that badge size signals dominance and parental care (a male with a larger badge is socially dominant but provide less parental care than one with a smaller badge).
However, some studies provided contradictory evidence regarding the badge size and other correlates (e.g. female preference, reproductive success, survival). For example, in some populations, female prefer males with larger badge size, whereas in other populations the opposite occurs. See our publications below.
Personnel
Shinichi Nakagawa (Postgraduate student, 2003-2006)
Supervisors
Email: t.a.burke@sheffield.ac.uk
Email: b.hatchwell@sheffield.ac.uk
Other personnel involved in the project
Nancy Ockendon (1999-2003, University of Sheffield) - see "Sexual selection in the house sparrow (Passer domesticus)"
Duncan Gillespie (Field assistant and Lab technician, 2003-2005)
This project was supported by The Foundation for Research Science and Technology, New Zealand.
Publications
Nakagawa S & Burke T (2008) The mask of seniority? A neglected age indicator in house sparrows, Passer domesticus .Journal of Avian Biology, 39, 222-225.
Nakagawa S, Lee J, Woodward B, Hatchwell B, Burke T (2008) Differential selection according to the degree of cheating in a status signal. Biology Letters, 4, 667-669.
Nakagawa S, Ockendon N, Gillespie D, Hatchwell BJ, Burke T (2007) Does the badge of status influence parental care and investment in house sparrow? An experimental test. Behavioural Ecology, 18, 831-840.
Nakagawa S, Ockendon N, Gillespie D, Hatchwell BJ, Burke T (2007) Assessing the function of house sparrows´ bib size using a flexible meta-analysis method. Oecologia, 153, 749-760.
Nakagawa S, Gillespie D, Hatchwell BJ, Burke T (2007) Predictable males and unpredictable females: sex difference in repeatability of care in a wild bird population. Journal of Evolutionary Biology, 20, 1674-1681.
Nakagawa S (2006) Genetic basis of mate choice, immunocompetence and their interaction in the house sparrow, Passer domesticus. PhD Thesis, University of Sheffield, UK.