Male European starlings do not use egg spots as a cue to adjust investment in nestlings

Publication Type:Journal Article
Year of Publication:2013
Authors:M. A. W. Hornsby, Fairn, E. R., Barber, C. A.
Journal:The Wilson Journal of Ornithology

The effects of post-laying egg spottiness on nestling condition and parental provisioning were investigated in a nest box-breeding population of European Starlings (Sturnus vulgaris). Our objectives were to ascertain whether egg spottiness was associated with the nest ectoparasite Carnus hemapterus, and to examine potential relationships between egg spottiness, presence of C. hemapterus, nestling condition, and parental provisioning effort in European Starlings. Spotted-egg clutches were present over all 3 years in our population, but the spots did not reflect C. hemapterus abundance. Nestlings from spotted-egg clutches did not have more C. hemapterus than those from unspotted-egg clutches. However, nestlings from spotted clutches were in better condition than those from unspotted clutches. Nestling condition was not associated with C. hemapterus abundance. Adult male and female provisioning rates to the offspring did not differ between spotted and unspotted clutches. Similarly, the proportion of provisioning visits by males did not differ significantly between spotted and unspotted clutches, indicating that parents in our population of European Starlings do not use egg spots as a cue to altering their provisioning effort. Further research is required to fully understand the cause and consequences of egg spots in European Starlings.

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Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith