Southern Giant Petrels get counted on Argentinia’s Isla Observatorio

 
Southern Giant Petrel and chick on a South Atlantic island; artwork by Leigh Wolfaardt

 Ulises Balza (Laboratorio de Ecología y Conservación de Vida Silvestre, Ushuaia, Argentina) and colleagues have published in the journal Polar Biology on censuses of breeding seabirds, including Southern Giant Petrels Macronectes giganteus, on Isla Observatorio in the Isla de los Estados (Staten Island) group: 387 pairs were counted in 2016.

The paper’s abstract follows:

“Continental islands are often sites of low diversity and endemism, as well as important areas for the protection of bird populations, especially seabirds. On Isla Observatorio and the Año Nuevo Islands, in the Southwestern Atlantic, the latest assessment of avifauna dates from more than 20 years ago. In this study, we use a combination of methods to update the status of the main seabird colonies and the most abundant avian terrestrial predator at Observatorio and Goffré Islands during the breeding season. In only 4.5 km², the islands would harbour ~ 90,000 breeding seabirds. Seabird colonies occupied different areas of the islands and varied in their population status, with Imperial Shags (Leucocarbo atriceps) showing an increase and a decrease according to the last surveys. Magellanic Penguin (Spheniscus magellanicus) population estimations also suggest a decrease but the last survey was based on total, and not on occupied nest sites. We recorded and assessed one new breeding species: The globally near-threatened Striated Caracara (Phalcoboenus australis), which has an important breeding population of around 15 territorial pairs at Observatorio Island. These islands appear to be an important regional bird site and future studies would determine their trends and threats, especially those related with invasive species.”

With thanks to Ulises Balza and Maro Favero.

Reference

Balza, U., Liljesthröm, M., Pimper, L., Franco-Navarro, I., Cañas-Barrovecchio, S., Zunino, F., Domato, I., Acardi, S., Iturraspe, R., Cano, J. & Raya-Rey, A. 2022.  Status of breeding birds at Observatorio and Goffré Islands, Argentina.  Polar Biology 45: 667-673.

John Cooper, ACAP Information Officer, 13 April 2022