Climate variability and trends in the reproductive habitat of the critically endangered hooded grebe

LANCELOTTI, JULIO L.; PESSACG, NATALIA L.; ROESLER, IGNACIO C.; PASCUAL, MIGUEL A.

AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS

JOHN WILEY & SONS LTD

Año: 2020 vol. 30 p. 554 - 564

1052-7613

1. The population of the critically endangered hooded grebe (Podiceps gallardoi) hasdecreased drastically during recent decades. The effects of climate change ontheir reproductive area (Southern Patagonia) have been proposed as one of thepotential causes of their critical situation. However, there is much uncertaintyabout climate variability and climate trends at local scales in Patagonia, and theireffects on the hooded grebe habitat.2. Variability and trends in temperature, precipitation, and wind from 1960 to 2016in one of the most important reproductive areas of hooded grebe ? the LakeStrobel plateau ? were analysed. A Landsat satellite image series (1973?2016)was used to evaluate changes in lake area in the region.3. Generalized linear models were used to analyse the relationship between the variationin lake area and climatic variables, including the Antarctic Oscillation Mode(AAO) index, which is the most important year to year pattern in climate variabilityat high latitudes of the Southern Hemisphere.4. High inter-annual variability and increasing coefficients of variation in precipitationand wind were found, as well as a significant positive trend in temperature.Total lake area, as well as the area specifically used by hooded grebe to reproduce,decreased significantly over time, with high inter-annual variability. Variationin lake area was significantly correlated with variation in precipitation, andwith the AAO index.5. The loss of reproductive habitat may force the hooded grebe to use sub-optimal environments, such as lakes with lower food supply, lower macrophyte cover, and less protection from wind ? a potential major handicap for this declining species.6. Information on lake variation in response to climatic variability could be used toguide hooded grebe conservation strategies, directing more resources and specialefforts to those reproductive lakes that are more resilient to the effects of climatefluctuations.