Climatic variation affects seasonal survival of an alpine bird species
Wildlife Biology,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 23, 2025
Mountains
are
particularly
exposed
to
climate
change,
and
empirical
studies
have
shown
that
montane
bird
species
highly
sensitive
the
ongoing
changes.
Modelling
mortality
risks
under
climatic
variation
will
give
insight
into
species‐specific
sensitivity.
Willow
ptarmigan
Lagopus
l.
lagopus
is
a
common
resident
in
many
northern
alpine
ecosystems,
with
an
important
role
predator–prey
dynamics.
moult
white
feathers
during
autumn,
which
provides
camouflage
winter
snow.
With
shorter
periods
of
snow
cover,
phenological
mismatch
between
cover
moulting
time
may
affect
risk.
Simultaneously,
risk
through
limiting
access
nutrient‐rich
food
increasing
risk‐taking.
Detailed
relationships
require
high‐resolution
data
uncover.
We
collected
from
willow
(n
=
272)
equipped
VHF
transmitters
over
seven
years
central
Norway.
Field
collection
was
performed
on
monthly
basis,
except
darkest
period
winter.
Using
Cox
proportional
hazards
models,
we
estimated
whether
related
spring
autumn
seasons.
found
earlier
arrival
led
increased
for
yearlings,
but
not
adults,
following
spring.
Further,
lower
when
there
less
In
differed
only
sexes.
our
study
survival
affected
by
variation,
where
magnitude
effects
population
dynamics
depend
age
distribution
population.
hypothesise
competing
connected
versus
risk‐taking
limited
resources,
different
importance
conditions.
Language: Английский
Atypical winter coat coloration of snowshoe hares near the southern extent of their range
Ecosphere,
Journal Year:
2025,
Volume and Issue:
16(3)
Published: March 1, 2025
Abstract
Many
species
have
a
variety
of
adaptations
to
winter
weather,
but
these
could
become
maladaptive
if
snowfall
and
temperatures
are
more
variable.
Snowshoe
hares
(
Lepus
americanus
)
molt
from
brown
summer
coat
white
coat,
reductions
in
snow
cover
result
phenotypic
mismatch,
which
turn
reduce
survival.
Hare
populations
near
the
southern
extent
their
range
might
be
especially
sensitive
mismatch
because
variable
variation
coloration
allow
for
persist
inconsistent
conditions.
Using
capture
data
n
=
59
individual
hares)
spanning
8
years,
we
document
prevalence
three
atypical
color
phenotypes
(brown
bodies,
brown‐ringed
eyes,
ears)
snowshoe
hare
population
Pennsylvania.
The
majority
our
study
(84.7%)
exhibited
at
least
one
phenotypes,
with
high
probability
having
eyes
or
ears,
four
remaining
during
winter.
presence
non‐white
beneficial
this
winters
mild
low
cover.
If
genetic
basis,
there
may
evolutionary
potential
range,
even
face
changing
winters.
Language: Английский
Spring fever: collared lemmings warm up above the snow despite predation risk
Frontiers in Ecology and Evolution,
Journal Year:
2025,
Volume and Issue:
13
Published: April 3, 2025
Small
mammals
inhabiting
cold
climates
face
high
heat
losses
and
thus,
energy
demands
for
body
temperature
regulation.
However,
behavioral
adaptations,
such
as
seeking
refuge
from
extreme
in
the
subnivean
space,
can
reduce
energetic
cost
of
thermoregulation.
Using
automated
cameras,
we
monitored
collared
lemmings
(
Dicrostonyx
groenlandicus
)
at
northern
limit
their
range,
they
surfaced
snow
burrows
spring,
to
assess
effect
weather
variables
on
occurrence
this
behavior.
We
hypothesized
that
thermoregulation
when
come
surface
spring.
As
expected,
frequency
activity
increased
with
air
temperature,
but
decreased
cloud
cover
wind
speed.
In
addition,
operative
was
higher
above
than
below,
while
profiles
showed
absence
liquid
water
snowpack.
These
findings
support
lemming
spring
is
a
strategy.
observations
several
predators
study
area,
combined
vigilance
behavior
observed
surface,
stress
risks
associated
exposure
snow.
therefore
suggest
may
trade-off
between
predation
risk.
Given
data
winter
ecology
are
scarce,
also
exploited
gather
valuable
knowledge
molting
phenology
reproduction.
Overall,
our
results
provide
insight
into
complex
other
needs
small
climates,
highlight
some
potential
implications
arctic
ecosystem
dynamics
based
predator-prey
interactions.
Language: Английский
A Picky Predator and Its Prey: How Snow Conditions and Ptarmigan Abundance Impact Gyrfalcon Feeding Behaviour and Breeding Success
Ecology and Evolution,
Journal Year:
2025,
Volume and Issue:
15(4)
Published: April 1, 2025
ABSTRACT
Species
interactions
can
be
altered
by
climate
change
but
also
mediate
its
effects.
The
gyrfalcon
(
Falco
rusticolus
)
and
the
ptarmigan
Lagopus
spp.)
form
a
predator–prey
couple
that
reflects
dynamics
of
boreal,
tundra,
alpine
ecosystems.
To
determine
how
may
impact
food
web,
we
investigated
abundance
local
weather
diet
feeding
behaviour,
nest
occupancy,
reproductive
success.
Using
wildlife
cameras,
monitored
nests
throughout
nestling
period
to
collect
data
on
behaviour.
We
quantified
gyrfalcon's
functional
response
describing
kill
rates
relate
density.
Additionally,
numerical
demographic
aggregative
success
respectively,
were
related
density,
using
from
large‐scale
monitoring
projects.
Ptarmigan
dominant
prey
species,
representing
98%
diet.
proportion
in
breeding
increased
springs
with
more
snow,
decreased
snow
during
period.
Gyrfalcon
was
positively
occupancy
rate
not
These
results
indicate
effect
is
straightforward,
investigating
(a)biotic
factors
both
predator
relevant
predicting
will
respond
change.
Following
current
predictions,
spring
occur
earlier,
which
food‐web
structure
through
availability
diversity
other
species.
This
requires
adaptations
gyrfalcons
predators.
emphasise
predators
species
accurately
evaluated
multi‐species
level
rather
than
individually.
Language: Английский