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Weather fluctuations are linked to nesting success and renesting decisions in saffron finches


Marques-Santos, Fernando; Wischhoff, Uschi; Rodrigues, Marcos (2021), Weather fluctuations are linked to nesting success and renesting decisions in saffron finches, Dryad, Dataset,


Life‐histories of neotropical birds seem to vary beyond what is expected according to patterns from northern temperate regions. This variation is well exemplified by saffron finches Sicalis flaveola in subtropical Brazil. They breed for five months on a climate that is relatively warm and rainy throughout the year. Females may attempt from one nest with two eggs up to three nests with five eggs per season. Previous work showed that age and individual quality were insufficient to explain variation in their breeding traits. Thus, other factors may still influence reproductive traits of investment and productivity in females. We asked 1) whether breeding traits of individual females were related to temperature and rain from previous weeks, and 2) whether fluctuations in weather during nest phases influenced egg and nestling survival. We monitored 237 nests of 70 marked females for four years. We found that the odds of a female starting a subsequent nest increased when temperatures on the preceding 15–6 weeks were low. Nest success decreased alongside the temperatures before laying dates. The odds of eggs surviving until hatching increased when weather was cold and rainy during incubation. There was no correlation between past weather and laying dates, clutch sizes, egg or nestling masses, incubation periods or number of fledglings per nest. The adverse effects of warmer temperatures and the survival benefit of increased rainfall are surprising and contrary to other birds' patterns. The mechanisms that link weather to renesting probability and nest success in saffron finches are still unknown, and we give some suggestions about their nature. We advocate that further studies with this widespread species might provide further insights into the variability of life‐histories in the region.

Usage Notes

This dataset has three comma-separated spreadsheets:

Broods data: one brood per row. Includes spatiotemporal and nest content information.

Eggs data: one egg per row. Includes egg mass, spatiotemporal information, brood, and female identification.

Nestlings data: one nestling per row. Includes nestling mass, spatiotemporal information, brood, and female identification.

Data description:

Season identity. In which season the clutch was laid. Includes the end of a year and the beginning of the next because the spring starts in September in the southern hemisphere.

Location identity. Either of the two locations 5km apart.

Female bird identity. Individual-specific unique code identifier. ‘SA’: unringed females. Several codes start with ‘-’, thus some adjustment is necessary if using Microsoft Excel.

Plumage colour
Technically defined plumage colour as ‘Dull’ or ‘Yellow’, following Marques-Santos et al. 2018

Onset of breeding
On which day relative to the spring equinox each female laid her first egg of the season.

Laying date
On which day relative to the spring equinox the first egg of the clutch was laid.

Incubation date
On which day relative to the spring equinox the clutch was completed.

Hatching date
On which day relative to the spring equinox that eggs hatched. Defined a posteriori as the day when at least 50% of surviving nestlings hatched (i.e., excluding eggs that never hatched).

Nest last active date
Conservative and evidence-based last known date (relative to the spring equinox) that the researcher observed the nest with eggs or nestlings.

Clutch size
The total number of eggs laid during the focal breeding attempt. Only includes completed clutches.

Incubation period
The period between the incubation date and hatching date.

Number hatched
The number of eggs that hatched.

Whether the clutch has hatched at least one egg; 0 = no eggs hatched.

Nest attempt
A sequential number within each season that indicates each nest of a female that had at least an egg or nestling.

Nest success
Either if the nest attempt fledged at least one young. 0 = no young fledged.

Number of fledglings
The number of fledglings produced during the focal breeding attempt.

Whether the female made a following attempt in the same season. 0 = no following attempts.

Nest id
Brood identity. The brood-specific unique identifier associated with each nest attempt.

Egg mass
Egg mass (g) of fresh eggs.

Nestling mass
Nestling mass (g) at age 8 days (hatching date = age 0 days)

Missing values (applicable to multiple variables listed above).


Deutscher Akademischer Austauschdienst, Award: 91679451

Deutscher Akademischer Austauschdienst, Award: 91505977

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Award: number not available

Conselho Nacional de Desenvolvimento Científico e Tecnológico, Award: 141265/2016­7

Conselho Nacional de Desenvolvimento Científico e Tecnológico, Award: 141272/2016-3