10.5061/DRYAD.8TR8B48
Adalsteinsson, Solny A.
University of Delaware
Washington University in St. Louis
Buler, Jeffrey J.
University of Delaware
Bowman, Jacob L.
University of Delaware
D'Amico, Vincent
US Forest Service
Ladin, Zachary S.
University of Delaware
Shriver, W. Gregory
University of Delaware
Data from: Post‐independence mortality of juveniles is driven by
anthropogenic hazards for two passerines in an urban landscape
Dryad
dataset
2018
post-fledging
anthropogenic mortality
Dumetella carolinensis
Hylocichla mustelina
2018-07-13T14:11:30Z
2018-07-13T14:11:30Z
en
https://doi.org/10.1111/jav.01555
234718 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Urban environments impose novel selection pressures with varying impacts
across species and life history stages. The post‐fledging stage for
migratory passerines, defined as the period of time from when hatch‐year
birds fledge until their first migration, is a poorly understood component
of annual productivity that potentially limits population growth. We
studied two migratory passerines with positive and negative population
responses to urbanization, respectively: Gray Catbird (Dumetella
carolinensis) and Wood Thrush (Hylocichla mustelina). Our goals were to
estimate post‐fledging survival rates for urban bird populations and
determine which features of the urban landscape impact mortality risk
during the post‐fledging stage. From 2012–2014, we tracked 127 fledglings
(60 Gray Catbirds and 67 Wood Thrushes). Over 55 days after fledging,
cumulative survival of Gray Catbirds (0.32 [95% CI: 0.22–0.47]) was
approximately half that of Wood Thrushes (0.63 [95% CI: 0.52–0.75]). Thus,
survival rates during the post‐fledging stage, taken in isolation, do not
explain differential trajectories of Gray Catbird and Wood Thrush
populations in urban environments. Most mortality (86%) for both species
was due to predation. However, after reaching independence from parental
care, 6 birds (9.4% of mortalities) died of anthropogenic causes (e.g.
building, car strikes). Crossing roads significantly increased mortality
risk, but increasing daily movement distance decreased mortality risk. Our
results raise the question of whether anthropogenic sources of mortality
are compensatory or additive to natural mortality; we emphasize the need
to monitor fledgling survival beyond the parental‐dependence stage in
order to fully understand the impacts of anthropogenic hazards on juvenile
birds.
Fledgling survival dataThis file contains survival and daily tracking data
for each of the 127 individual fledglings in the study. On separate tabs
are time-independent (e.g., nest distance to edge) and time-dependent
(e.g., step length) metrics. See metadata tab for descriptions of each
data field.survival data and movement metrics.xlsx
Delaware
Maryland
Pennsylvania