Food abundance as an environmental cue for the start of reproduction of Elaenia albiceps

GOROSITO, C.A.; TUERO, D.T.; CUETO, V. R.

Congreso; VII North American Ornithological Conference; 2020

American Ornithological Society

The time of the year whenbirds reproduce has a great impact on their reproductive success. That is, ifthey reproduced when food availability for their nestlings is low, theirsurvival could be reduced. Therefore, birds must synchronize the maturation oftheir gonads with the most favorable environmental conditions for reproduction.Photoperiod length is the main cue that birds use to achieve thissynchronization. However, using other cues, such as food abundance, isnecessary to refine the most suitable moment for reproduction. The aim of thiswork was to study the synchronization between the food used by Elaenia albiceps and its reproduction.The effects of ripe fruit, arthropods and caterpillar abundance on the breedingintensity of this species were evaluated. Caterpillar and ripe fruit abundancesmeasured during the previous 10-day period were the food resources that had thegreatest effects on the number of nests with eggs. These food items couldconstitute important food sources for the preparation of reproduction inadults, providing protein and calcium for egg formation. Ripe fruit abundancein a previous 10-days period also had a great effect on the number of nestswith nestlings. It was observed a synchronization between the moment of maximumabundance of this food resource and the maximum abundance of nests withnestlings. Ripe fruits have a high antioxidant and calcium content, therebythey would be beneficious for nestling growth. Hence, E. albiceps would use ripe fruit abundance as a cue to startreproduction.