DOI: 10.5061/dryad.stqjq2c7c
title: Patterns in avian reproduction in the Prudhoe Bay Oilfield, Alaska, 2003–2019

description: The Arctic Coastal Plain is one of the most important avian breeding
 grounds in the world; however, many species are in decline.
 Arctic-breeding birds contend with short breeding seasons, harsh climatic
 conditions, and now, rapidly changing, variable, and unpredictable
 environmental conditions caused by climate change. Additionally, those
 breeding in industrial areas may be impacted by human activities. It is
 difficult to separate the impacts of industrial development and climate
 change, however, long-term datasets can help show patterns over time. We
 evaluated factors influencing reproductive parameters of breeding birds at
 Prudhoe Bay, Alaska, 2003–2019, by monitoring 1265 shorebird nests, 378
 passerine nests, and 231 waterfowl nests. We found that nest survival
 decreased significantly nearer high-use infrastructure for all guilds.
 Temporally, passerine nest survival declined across the 17 years of the
 study, while there was no significant evidence of change in their nest
 density. Shorebird nest survival did not vary significantly across years,
 nor did nest density. Waterfowl nest density increased over the course of
 the study, but we could not estimate nest survival in all years. Egg
 predator populations varied across time; numbers of gulls and ravens
 increased in the oilfields from 2003–2019, while Arctic fox decreased, and
 jaeger numbers did not vary significantly. Long-term datasets are rare in
 the Arctic, but they are crucial for understanding impacts to breeding
 birds from both climate change and increasing anthropogenic activities. We
 show that nest survival was lower for birds nesting closer to high-use
 infrastructure in Arctic Alaska, which was not detected in earlier,
 shorter-term studies. Additionally, we show that Lapland longspur nest
 survival decreased across time, which is concerning considering the
 continent-wide declines in many passerine species. The urgency to
 understand these relationships cannot be expressed strongly enough, given
 change is continuing to happen and the potential impacts are large.
description: We used generalized linear models and a logit link (Program MARK)
 to evaluate daily nest survival. We examined a hierarchical model set.
 Models of daily nest survival varied by year, guild (shorebird, waterfowl
 or passerine), habitat (wetland, moist, upland), initiation date, and
 incubation strategy (biparental or uniparental, shorebirds only), distance
 to infrastructure, area of infrastructure within a 2 km radius of the
 nest, and distance to the nearest road. We ran all main effects models,
 then combined ‘strong’ effects additively and multiplicably. We included
 one post-hoc model to further evaluate the relationship between spring
 conditions and incubation strategy where we held passerines and waterfowl
 constant but allowed shorebird daily survival rate to vary by individual
 year and incubation strategy (DSR<sub>year*strategy</sub>). We
 compared models using AIC<em><sub>c</sub></em>
 (Akaike’s Information Criterion corrected for small sample sizes), in
 which we considered the model with lowest
 AIC<em><sub>c</sub></em> value to be the
 best-fitting and models with a
 ΔAIC<em><sub>c</sub></em> &lt; 2 that did not
 add to model complexity to be plausible (Arnold 2010, Burnham and Anderson
 2002). We calculated estimates of nest density (i.e.,
 the cumulative number of nests found throughout the study plots divided by
 the total area of the plots (km<sup>2</sup>)) by year, guild,
 and incubation strategy (shorebirds only).
description: Program Mark