CBB Seminar: Toward a better understanding of direct and indirect interactions between invasive predators and terrestrial native bird species on islands: Improvement of the trophic ecology toolbox. ” Event as iCalendar


21 February 2013

18 - 18pm

Venue: University of Auckland Tamaki Campus Blg 733 Rm 321

Host: Centre for Biodiversity and Biosecurity

Diane Zarzoso-Lacoste

Mediterranean Institute of Biodiversity and of continental and marine Ecology (IMBE)

When studying the effects of introduced predators on island birds, the unequivocal detection and identification of preyed bird species is essential to precisely evaluate predator impact, especially when focusing on rare and endangered species. This would help to design appropriate conservation strategies. Because the morphological identification of prey remains is often challenging, we developed a DNA-based method to accurately detect and identify prey DNA in predator diet samples. These two methods were combined to study the direct (predation) and indirect (competition) trophic relationships between a critically endangered bird (Todiramphus gambieri) and three invasive predators (Felis silvestris catus, Rattus rattus and Rattus exulans) on a Pacific island (Niau, French Polynesia). The molecular method provided significantly greater bird detection and identification results than the morphological method. Although no kingfisher predation was detected, our results highlighted a possible trophic competition between kingfishers and the two rat species, especially upon large terrestrial arthropods and lizards.