Position in the laying order has sex-specific consequences for reproductive success in adult black-headed gulls

Mothers who produce multiple offspring within one reproductive attempt often allocate resources differentially; some maternally-derived substances are preferentially allocated to last-produced offspring and others to first-produced offspring. The combined effect of these different allocation regimes on the overall fitness of offspring produced early or late in the sequence is not well understood, partly because production order is often coupled with birth order, making it difficult to separate effects of pre-natal maternal allocation from those of post-natal social environments. In addition, very little is known about the influence of laying order on fitness in later-life. In this study, we used a semi-natural captive colony of black-headed gulls to test whether an offspring’s position in the laying order affected its early life survival and later life reproductive success, independent of its hatching order. Later-laid eggs were less likely to hatch, but among those that did, survival t..., Data were collected from a captive population of wild-type black-headed gulls between 2012 and 2021. Each year, breeding attempts in the colony were monitored to collect data on egg laying order, hatching success, survival of offspring, and among adults, various reproductive parameters such as breeding status and nesting success. Data pertaining to each individual were collated in excel., Microsoft excel, R., # Title of Dataset: Position in the laying order has sex-specific consequences for reproductive success in adult black-headed gulls

Dataset contains 3 excel files:

1. Early survival

BreedPair: unique identifier for breeding pair
ID: unique identifier for individual egg
Year: calendar year of laying
EggLumped: order in the laying sequence of the individual egg. Factor with 4 levels (A-CD)
Hatched: binary coding for whether the egg hatched (1) or not (0)
Survived: binary coding for whether the nestling inside the egg survived (1) or not (0) to independence at one year old
IncludeSurvivalAnalysis: binary coding for whether this egg was included (1) or not (0) in the analysis of survival to 1 year (see article for description of inclusion criteria).
2. Breeding position

Colour rings: unique identifying code for individual
Sex: molecular sex binary (0 = female, 1 = male)
BirthYear: calendar year of hatching
NatalNest: unique identifier for br...