Red Phalarope Phalaropus fulicarius and Red-necked Phalarope Phalaropus lobatus behavioural response to Arctic Tern Sterna paradisaea colonial alarms

• Main Authors: Peter Søgaard Jørgensen, Mikkel Willemoes Kristensen, Carsten Egevang
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; Greenland; Arctic tern; Phalaropus fulicarius; Phalaropus lobatus; Red Phalarope; Red-necked Phalarope; Sterna paradisaea
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.607.2828; http://www.dof.dk/sider/images/stories/doft/dokumenter/2007_3_73-78_red_phalarope.pdf

Abstract The breeding association between Arctic Terns and Red and Red-necked Phalaropes has been men-tioned several times in the ornithological literature, though mostly anecdotally. The present study, conducted at the Kitsissunnguit archipelago in western Greenland, investigates phalarope behavioural response to Arctic Tern colonial alarms, specifically the relationship between type and duration of tern alarms and phalarope response type. The majority of tern alarms elicited a visible response from the phalaropes. No difference in phalarope response type was detected between true alarms (tern responses to the presence of gulls, falcons or humans) and dreads (false alarms). Tern alarms to which the phalaropes reacted were of longer duration than alarms that caused no change in phalarope behaviour, whereas no relationship was found between tern alarm duration and phalarope response type (passive vs active). In conclusion, phalaropes respond strongly to tern alarms, but do not differentiate between predator-related alarms and dreads. These findings support the view that phalaropes, where possible, take advantage from Arctic Tern colonies, and that this relationship – fulfilling the criteria of both the information parasitism and the defence parasitism hypotheses – explains the high densities of phalaropes at Kitsissunguit.