PARENT SESSION
Poster Session 39: Late Breaking and Newsworthy Posters
Friday, August 12, 8:30 AM - 10:30 AM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Winter movement patterns of European Starlings, with particular attention to consequences for seed dispersal in fleshy-fruited invasive plants.

LaFleur, Nancy ^*,1, Rubega, Margaret¹, ¹ University of Connecticut, Storrs

ABSTRACT- Fleshy-fruited plants, particularly those with seeds dispersed by birds, are an important component of the invasive flora of the northeastern United States; however, the contributions of avian seed dispersers to the spread of such plants is not well understood. Several factors determine how effective birds are in distributing plant seeds across the landscape, including the amount of time seeds are retained in the digestive system, the distance a bird moves during this time, and the fidelity of a bird to a particular home range. By combining passage rate data from captive birds with information on movement collected from free-living radio-tagged birds, we investigated the ability of European Starlings (Sturnus vulgaris) to move the seeds of three invasive plants: autumn olive (Elaeagnus umbellata), multiflora rose (Rosa multiflora) and Asiatic bittersweet (Celastrus orbiculatus). Of 43 birds radio-tagged in the fall and winter of 2003-2004 and 2004-2005, two had tags that were lost, and six moved out of tracking range. Of the remaining 35 starlings, 43% were never located away from the site where they were tagged, while 14% were never relocated at the site where they were tagged. The remaining 43% were relocated at the site where they were tagged as well as other locations. Preliminary analysis of our first year's tracking data shows that starlings ranged over an area of 30.76 ± 75.30 ha in a 2 hour tracking period. We also found that starlings moved, on average, 393.62 ± 85.39 meters from the point they were first located in 30 minutes, the time by which most multiflora rose and autumn olive seeds are voided, and 515.81 ± 108.95 meters in 40 minutes, the time by which most bittersweet seeds are voided. Our results suggest that the seed dispersal services starlings provide contribute to the range expansion of the invasive plants whose seeds they ingest.

Key words: invasives, Sturnus vulgaris, avian seed dispersal