Tamaño de puesta, sitios de nidificatión y éxito reproductivo del caiquén (Chloephaga picta GMELIN, 1789) en la Reserva de Biosfera Cabo de Hornos, Chile

• Main Authors: Ibarra, J.T., Schüttler, Elke, McGehee, S., Rozzi, R.
• Format: Article in Journal/Newspaper
• Language: Spanish
• Published: Universidad de Magallanes 2010
• Subjects: breeding biology; Chloephaga picta; clutch size; Mayfield; Navarino Island; nesting success; predation; Sub-Antarctic; Antarctic; Cape Horn; Antarc*
• Online Access: https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=10110

Studies on the biology of the Upland Goose (Chloephaga picta) in Chilean Sub-Antarctic ecosystems are scarce and basically constitute anecdotic records of the species. With the aim to broaden this knowledge, we studied its breeding biology in terms of clutch size, nesting sites and breeding success as a function of habitat variables on Navarino Island (54-55ºS), Cape Horn Biosphere Reserve (CHBR), Chile. We monitored 79 nests in coastal habitats during 54 days of breeding activity in the nesting season of 2005/2006 and 59 days in 2006/2007. Clutch size was 6.1 ± 1.2 eggs. Nests were preferably built on coastal sites with low slope (0-10º). The dominantbreeding habitat was shrubland (70.5%) dominated by Chiliotrichum diffussum (30.8%) and Berberis buxifolia (24.4%). Pebbles were the most commonelement on the nesting sites (50.1%). The overhead nest concealment was low (0-25%) in 82.1% of the nests, and lateral coverage was intermediate (25-50%)in 29.5%. 39.7% of the nests were built in habitats with relatively high vegetation cover (>40%). In total, 36.7% of the clutches hatched (successful followingthe traditional method) and 57,0% were predated. Measured habitat variables did not explain success or failure of the nests. The nest survival probability was20,0% (Mayfield method). The two calculated values are lower than those reported in other geese species (>60%) and also than values (61-75%) reported forthis species in Falkland-Malvinas Islands (