Heat‑related massive chick mortality in an Imperial Cormorant Leucocarbo atriceps colony from Patagonia, Argentina

• Autores: Quintana, Flavio; Uhart, Marcela M.; Gallo, Luciana; Mattera, María Belén; Rimondi, Agustina; Gómez‑Laich, Agustina
• Año de publicación: 2022
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Polar Biology 45 (2) : 275-284 (Febrero 2022)
• Materia: Climate Change; Thermoregulation; Mortality; Cormorants; Cambio Climático; Termorregulación; Mortalidad; Argentina; Cormorán; Heat Wave; Ola de Calor; Leucocarbo atriceps; Región Patagónica
• Institución: Instituto Nacional de Tecnología Agropecuaria

Climate change has exacerbated the frequency and severity of heat waves, which on occasion lead to mass mortalities. Here, we report a massive mortality event in Imperial Cormorant Leucocarbo atriceps chicks that took place during December 2016 at Punta León, one of the two largest colonies (> 6000 pairs) and the northernmost colony for the species in coastal Patagonia, Argentina. During a 2-day period, we estimate that approximately 86.5% of the chicks died. Our results suggest that the mortality event was heat-related, as consequence of an intense heat wave during the brooding period. During two consecutive days, chicks between 12 and 19 days old were exposed to air temperatures above the historical mean of maxima for a total of 25 h. On one of these days, the air temperature reached a maximum of 38.1 °C with records above 35 °C sustained during four consecutive hours. Chicks were found dead throughout the colony, mostly in the nests with no evidence of external injuries other than occasional scavenging by seagulls. Acute mortality from disease was ruled out based on clinical presentation and negative results for avian influenza virus, saxitoxins, and domoic acid (two common marine toxins). Our work underscores the importance of long-term studies in understanding heat associated breeding failure of one of the largest Imperial Cormorant colonies along its breeding range in coastal Patagonia.
Instituto de Virología
Fil: Quintana, Flavio. Consejo Nacional de Investigaciones Científcas y Técnicas. Instituto de Biología de Organismos Marinos; Argentina
Fil: Uhart, Marcela M. University of California Davis. School of Veterinary Medicine. One Health Institute; Estados Unidos
Fil: Gallo, Luciana. Consejo Nacional de Investigaciones Científcas y Técnicas. Instituto de Biología de Organismos Marinos; Argentina
Fil: Mattera, María Belén. Instituto Nacional de Investigación y Desarrollo Pesquero; Argentina
Fil: Rimondi, Agustina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; Argentina
Fil: Gómez‑Laich, Agustina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución. Departamento de Ecología, Genética y Evolución; Argentina