DOI: 10.5061/dryad.x69p8czh0
title: Dynamic sensitivity to resource availability influences population responses to mismatches in a shorebird

description: Climate change has caused shifts in seasonally recurring biological events
 leading to the temporal decoupling of consumer-resource pairs – i.e.,
 phenological mismatching. Although mismatches often affect individual
 fitness, they do not invariably scale up to affect populations, making it
 difficult to assess the risk they pose. Individual variation may
 contribute to this inconsistency, with changes in resource availability
 and consumer needs leading mismatches to have different outcomes over
 time. Nevertheless, most models estimate a consumer’s match from a single
 timepoint, potentially obscuring when mismatches matter to populations. We
 analyzed how the effects of mismatches varied over time by studying
 precocial Hudsonian godwit (Limosa haemastica) chicks and their
 invertebrate prey from 2009 to 2019. We developed individual and
 population level models to determine how age-specific variation affect the
 relationship between godwits and resource availability. We found that
 periods with abundant resources led to higher growth and survival of
 godwit chicks, but also that chick survival was increasingly related to
 the availability of larger prey as chicks aged. At the population level,
 estimates of mismatches using age-structured consumer demand explained
 more variation in annual godwit fledging rates than more commonly used
 alternatives. Our study suggests that modeling the effects of mismatches
 as the disrupted interaction between dynamic consumer needs and resource
 availability clarifies when mismatches matter to both individuals and
 populations.
description: During 2009 – 2011, 2014 – 2016, and 2019, we monitored godwit
 chicks in two plots – North (550 Ha) and South (120 Ha) – near Beluga
 River, Alaska (61.21°N, 151.03°W). We followed radioed chicks until
 fledge, resighting every 2-3 days and capturing each week to measure mass
 through time. In all years (shortened seasons of 2012 and 2017), we
 collected invertebrates each day along two, 100-m transects of five traps
 within godwit breeding habitat according to the Arctic Shorebird
 Demographics Network Breeding Camp Protocol, Version 5. We recorded
 identified all adult invertebrates to taxonomic order, but excluded
 Collembola from analyses (see text for details). We measured body lengths
 in mm and converted these to order-specific dry-mass using published
 equations. We estimated three metrics from invertebrate sampling data:
 resource peak, resource abundnance, and median resource quality. Resource
 peak was where the first derivative of a quadratic curve fit to
 invertebrate biomass abundnance was 0 (absolute maximum of the curve),
 resource abundance was the total biomass per day, averaged between the two
 transects, and resource quality was the per capita median body mass of
 sampled invertebrates. Using these two datasets -
 invertebrates and chick mass, we performed analyses to determine the
 factors driving chick growth, chick survival, and the trends through time
 of invertebrate metrics.
description: This dataset accompanies open-source code at the authors GitHub
 page
 (https://github.com/luke-wilde/DynSens2ResAvail_ECY21-0841.R1).