Tore Slagsvold's Article Featured in Animal Behaviour
Karen Wiebe and Tore Slagvold's article explores paternal feeding decisions in three species of cavity nesting birds
Great tit brood with a gaping chick. Notice the bright colour of the flanges of the bill that may help parents locate the chick when providing food in a dark cavity.
Photo: Kari Wigdahl Kleiven.
This month's edition of the journal Animal Behaviour has highlighted as being of special importance a research article by the Karen Wiebe of the University of Saskatechewan and CEES' Tore Slagsvold. The executive editors of the journal selected their new article to be a Featured Article in the journal's 'In Focus' section.
Karen and Tore studied northern flickers in British Columbia and pied flycatchers and great tits at Tore's long running field site in Akershus, just outside of Oslo. All three species nest in small, dark cavities of trees, which raised the question for Wiebe and Slagsvold as to what cues parents use to determine whom to feed in the nest. They tested the importance of nestling size and the brightness of the flange (the yellowish mouth edge around the gape on young birds) in determining which chick the parents fed the most. By equalizing the number of small and large nestlings in each cavity and painting the flanges black for either all the large or small nestlings in each of the nests, Wiebe and Slagsvold were able to separate out the relative importance of size and colourfulness in parental provisioning of food.
They found that both size and colour were important, but that parents preferred to feed larger chicks whether they had bright or dark flanges. Furthermore, they calculated the weight advantage the chicks with darkened flanges would require to be frequently as the control nestmates.
Stay tuned for more from Tore Slagsvold, as he has another article that will be featured as an 'In Focus' article in the February 2013 edition of Animal Behaviour.