Hatching and brood parasitism associated with climate in Chalk-browed Mockingbird (Mimus saturninus)

MARIA DEL ROSARIO JACOBY; PAOLA SALIO; JUAN CARLOS REBOREDA; VANINA DAFNE FIORINI

Congreso; Animal Behavior Society 2021; 2021

Weather can affect bird populations and their interspecific relations in several ways. The Chalk-browed Mockingbird (Mimus saturninus) is a Neotropical species frequent of the woodlands of Buenos Aires (Argentina) and suffers brood parasitism by Shiny Cowbird (Molothrus bonariensis). We used data from three breeding seasons (2017-18-19) to study how different meteorological variables impact on the hatching probability of mockingbird nests and the probability of brood parasitism. We used maximum temperature (Tmax) and sum (SumPP) and mean of precipitations (XPP) of the egg period. The probability of hatching increased in a 75% with an increment of one degree in Tmax and in a 12% for an increment of one mm in SumPP. Moreover, the probability of parasitism increased 14% when Tmax increased in one degree while intensity of parasitism increased 16% for an increment of one mm in XPP. Our results indicate that weather affects the mockingbird breeding success directly through the hatching probability and indirectly by affecting the brood parasitism. This type of integrated studies helps to better understand the complex relationships between weather and the reproductive success of species.