Influence of long-term climatic changes on breeding of the Chilean flamingo in Mar Chiquita, Córdoba, Argentina

Abstract

We report a comparative analysis of the environmental conditions prevailing at each successful breeding event of the Chilean flamingo (Phoenicoptarus chilensis) during the 1969–2010 period in Mar Chiquita, a large salt lake near Córdoba, Argentina. Breeding was monitored annually by air. The following parameters were measured: rainfall, water level water salinity, availability of shoreline and offshore (islands) mudflats, presence of brine shrimp (Artemia franciscana), and presence of the Argentine silverside fish (Odonthotestes bonariensis). During the study period, Mar Chiquita underwent great variations in level, reaching the highest level in its geological history. Salinity ranged from 274 down to 22 g l−1. Artemia was present during the high-salinity periods and was absent when salinity dropped below 55 g l−1, and the lake was invaded by the silverside. Flamingos bred irregularly during both high- and low-salinity periods (11 successful attempts in 42 years). Comparison of breeding and non-breeding years showed that the only environmental factor always associated with breeding events was availability of mudflats, mostly bordering islands. Water level increases over 0.90 m during the breeding season may flood the nesting areas and affect breeding success. Rapid decreases in lake level may also affect breeding by favoring predation or via nutrient availability. Other factors (water level, water salinity, local rainfall, and presence of Artemia and silverside) were within similar ranges in breeding and non-breeding years. Our surveys provided indirect evidence suggesting that food availability may influence flamingo breeding in Mar Chiquita. Management implications of our study include: (a) habitat suitability analysis of wetlands like Mar Chiquita should consider that availability of offshore mudflats free of vertebrate predators is an essential requirement for flamingo conservation and (b) drastic and rapid increases or decreases in water level due to human control of river inflows may affect chances of successful flamingo breeding and therefore should be evaluated carefully.