DOI: 10.5061/dryad.wwpzgmsj8
title: Weather fluctuations are linked to nesting success and renesting decisions in saffron finches

description: 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.
description: <strong>This dataset has three comma-separated
 spreadsheets:</strong> Broods data: one brood per
 row. Includes spatiotemporal and nest content information.<br>
 Marques-Santos_et_al_broods_SIFL_dryad.csv Eggs data:
 one egg per row. Includes egg mass, spatiotemporal information, brood, and
 female identification.<br>
 Marques-Santos_et_al_eggs_SIFL_dryad.csv Nestlings
 data: one nestling per row. Includes nestling mass, spatiotemporal
 information, brood, and female identification.<br>
 Marques-Santos_et_al_nestlings_SIFL_dryad.csv
 <strong>Data description:</strong>
 Season<br> 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<br> Location identity. Either of the two locations
 5km apart. Female<br> 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<br> Technically
 defined plumage colour as ‘Dull’ or ‘Yellow’, following Marques-Santos et al. 2018 Onset of breeding<br> On which day relative to the spring equinox each female laid her first egg of the season. Laying date<br> On which day relative to the spring equinox the first egg of the clutch was laid. Incubation date<br> On which day relative to the spring equinox the clutch was completed. Hatching date<br> 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<br> Conservative and evidence-based last known date (relative to the spring equinox) that the researcher observed the nest with eggs or nestlings. Clutch size<br> The total number of eggs laid during the focal breeding attempt. Only includes completed clutches. Incubation period<br> The period between the incubation date and hatching date. Number hatched<br> The number of eggs that hatched. Hatched<br> Whether the clutch has hatched at least one egg; 0 = no eggs hatched. Nest attempt<br> A sequential number within each season that indicates each nest of a female that had at least an egg or nestling. Nest success<br> Either if the nest attempt fledged at least one young. 0 = no young fledged. Number of fledglings<br> The number of fledglings produced during the focal breeding attempt. Renested<br> Whether the female made a following attempt in the same season. 0 = no following attempts. Nest id<br> Brood identity. The brood-specific unique identifier associated with each nest attempt. Egg mass<br> Egg mass (g) of fresh eggs. Nestling mass<br> Nestling mass (g) at age 8 days (hatching date = age 0 days) NA<br> Missing values (applicable to multiple variables listed above).