Parental overproduction allows siblicidal bird to adjust brood size to climate-driven prey variation

Parental overproduction is hypothesized to hedge against uncertainty over food availability and stochastic death of offspring and to improve brood fitness. Understanding the evolution of overproduction requires quantifying its benefits to parents across a wide range of ecological conditions, which has rarely been done. Using a multiple hypotheses approach and 30 years of data, we evaluated the benefits of overproduction in the Blue-footed booby, a seabird that lays up to three eggs asynchronously, resulting in an aggressive brood hierarchy that facilitates the death of last-hatched chicks under low food abundance. Results support the resource-tracking hypothesis, as low prey abundance (estimated from sea surface temperature and chlorophyll-a concentration) led to rapid brood reduction. The insurance hypothesis was supported in broods of three, where last-hatched chicks’ survival increased after a sibling’s death. Conversely, in broods of two, results suggested that parents abandoned las..., Every year, from 1989 to 2019, all nests in our study areas (2.6 ha) were monitored over the breeding season from February through July. During nest inspections, every 3-6 days, breeders were identified and sexed based on vocal dimorphism (females grunt, males whistle), and chicks were marked with colored plastic bands after hatching, then measured (ulna length, mm), weighed and fitted with numbered steel bands at 70 days, when they fledged. , , # Parental overproduction allows siblicidal bird to adjust brood size to climate-driven prey variation

Climatic and biological data used in the article.

## Description of the data and file structure

The data is a zip file containing two Excel files

File list:

* DATA.xlsx
* ReadME_DATA.xlsx

## File descriptions

The DATA.xlsx file contains all the data utilized in the article. It comprises 16 sheets, each containing a distinct set of data utilized for the analyses. Correspondingly, the ReadME_DATA.xlsx file mirrors this structure, also consisting of 16 sheets. Each sheet in the ReadME_DATA.xlsx file offers a description of the columns' meanings within the associated dataset, along with a brief explanation of the data provided in that particular dataset.

\"NA\" stands for non-available values when climatic and oceanic data were missing, or biological data could not be registered.