DOI: 10.5061/dryad.x69p8czsx
title: Adult survival in a small seabird, Hydrobates leucorhous, covaries with the Atlantic Multidecadal Oscillation over the past six decades

description: Seabirds’ annual survival is influenced by numerous factors, but oceanic
 conditions are among the most significant. Indices used to monitor these
 conditions typically cycle over decades. Using the longest
 capture-mark-recapture (CMR) time-series available for the species
 (1955-2023), we estimated apparent adult survival of Leach’s storm-petrels
 (Hydrobates leucorhous) from Kent Island, New Brunswick. We assessed
 whether survival covaried with large-scale oceanographic indices
 reflecting conditions at various periods in the life cycle. We used
 Cormack-Jolly-Seber CMR models to estimate annual apparent survival rate.
 Mean annual survival was φ = 0.84 ± 0.01 over the 68-year study period,
 and was variable across years (range: 0.62 ± 0.06 to 0.97 ± 0.05) with a
 concentration of high values between 1979-1989. Adult survival rate was
 inversely proportional to the Atlantic Multidecadal Oscillation (AMO)
 index with a small but significant effect (β: -0.70 [-0.92 - -0.47], 13%
 of deviance explained), meaning low survival rates were associated with
 high AMO, indicating positive sea surface temperature anomalies over the
 North Atlantic. Such a relationship could only have been detected with
 extended long-term study since the AMO has a period of 60-80 years.
 Despite the challenges of maintaining long-term studies, they are more
 than ever essential in population ecology.
description: # Adult survival in a small seabird, Hydrobates leucorhous, covaries with
 the Atlantic Multidecadal Oscillation over the past six decades ###
 Survival analysis of Leach’s storm-petrel on Kent Island #### Description
 of the data The data comprises three files. A file
 (LHSP_survival_adults.csv) of the resighting of adult Leach’s storm-petrel
 within 4 different sites (StudyArea) from 1955 to 2023. The columns
 correspond to the adult band number, the study area, and each year from
 1955 to 2023. Years when one adult was sighted are presented as
 "1", otherwise as "NA". A file
 (LHSP_survival_covariates.csv) with the values of several environmental
 covariates over the years of the dataset. Columns are: Year, Atlantic
 Multidecadal Oscillation summer (AMOs), Atlantic Multidecadal Oscillation
 year (AMOy), Annual Global Mean Temparature Anomaly (GMT), North Atlantic
 Oscillation summer (NAOs), North Atlantic Oscillation winter (NAOw), North
 Atlantic Oscillation winter with a one year (NOAw1) and 2 year gap
 (NAOw2), North Atlantic Oscillation year (NAOy), with a 1 year (NAOy1) and
 2 year gap (NAOy2), Southern Oscillation Index winter (SOIw) and Southern
 Oscillation year (SOIy). A script (LHSP_survival_script.txt) run in R
 version 4.2.2 and R Studio 2022.12.0 with the following libraries
 installed: RMark, R2ucare, tidyr, ggplot2, stringr, CMRhelper,
 gridExtra, psych.  The script goes through the process of removing
 transient birds, calculating the goodness of fit and the c.hat. Then the
 script creates several survival and recapture terms and create different
 lists of models, with or without the covariates and extract values of
 interest from the best model, and create figures of the manuscript.