Áreas de alimentación reproductiva de los gaviotines pico amarillo y real en el norte de patagonia, Argentina

GATTO, ALEJANDRO JAVIER; YORIO, PABLO; DOLDÁN, MARÍA DEL SOCORRO; VILLANUEVA GOMILA, LUJAN

Maturín

Congreso; VIII Neotropical Ornithological Congress; 2007

The Neotropical Ornithological Society

Cayenne (Thalasseus sandvicensis eurygnathus) and Royal (Thalasseus maximus)Terns breed sympatrically in Patagonia, Argentina. In this región, very little is known about where tríese species breed and forage and how they forage. Studies are needed to understand their role in coastal ecosystems and develop adequate management strategies. We present Information on the use of foraging áreas by both species at a mixed species colony in the Punta León Protected Área (43° 04´ S, 64° 29´ W), Chubut. Radio-transmitters were deployed on eight nesting adults of each species, which were tracked during twelve days in the late incubation and early chick period. Feeding áreas were identified during 80 foraging trips by rneans of radio-telemetry from the coast, using two fixed tracking each station consistíng of two attached 9-element Yagi antennae. Cayenne and Royal terns foraged often between the colony and 35 km away, mostly in two feeding áreas located both southward and northward from the colony. However, lack of signal reception in some of these trips, indícate that foraging can also take place in waters further away. In general, individual birds were consístent in the use of one particular área. Implications for foraging área partitioning between terns will be discussed.