Magpie interactions with other birds in New Zealand: results from a literature review and public surveySubmitted by osnz-admin on Tue, 03/15/2011 - 22:46
|Title||Magpie interactions with other birds in New Zealand: results from a literature review and public survey|
|Publication Type||Journal Article|
|Year of Publication||2005|
|Authors||Morgan, D, Waas, JR, Innes, J|
|Type of Article||paper|
|Keywords||Artamidae, Austalian magpie, Gymnorhina tibicen, interspecific aggression, interspecific competition|
Accounts of magpie Gymnorhina tibicen attacks on birds in New Zealand were collated from literature and a survey of the public, and then summarised to identify the frequency and characteristics of reported attacks on different species. Magpies were reported attacking 45 bird species. Species commonly found in rural habitats (e.g., harrier hawk Circus approximans, blackbird Turdus merula) where magpies are abundant were attacked most; however, a directly proportional relationship between species abundance in rural habitats and reported attack frequency did not occur. Species consuming similar foods to magpie tended to be attacked more often, probably because these foods are more abundant in rural areas. Attacks on smaller birds (e.g., grey warbler Gerygone igata) regularly (66%) resulted in death, but deaths declined as victim weight increased. Non-contact attacks were most common for the largest species (e.g., kereru Hemiphaga novaeseelandiae). Non-contact and non-lethal contact attacks occurred throughout the year while attacks resulting in death occurred mainly during the magpie's breeding season (July to November). This study indicates that magpies can attack a wide range of species but fails to determine why (no one explanation satisfies all cases). Limitations of the dataset and future research to control these are discussed.