Predation is the primary source of mortality of dabbling duck nests, so a key aspect of parental investment is defending the nest from predators. The hen's presence on the nest is widely considered to be a good measure of nest defense; an incubating female camouflages the nest and may physically deter nest predators. Parental-investment theory suggests that investment should increase with the reproductive benefits expected from the current clutch of eggs. We used nest-temperature loggers to study how the rhythms of waterfowl incubation changed after the nest was partially destroyed by a predator. Contrary to the expected-benefits hypothesis, we found that hens significantly increased their investment after partial clutch loss: they took fewer recesses from incubation per day and extended their incubation by more than 200 min after a partial depredation. We suggest that when predators pose little risk to the incubating adult, those hens unable or unwilling to abandon a nest after partial clutch loss will increase parental investment to obtain at least some reproductive benefits.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 115 • No. 2