Autonomous
Recording
Units
(ARU)
are
a
passive
acoustic
monitoring
technology
that
useful
for
detecting
the
presence
and
distribution
of
cryptic
nocturnal
animals
in
challenging,
remote
environments
as
they
can
be
deployed
extended
periods
time.
However,
ARUs
vary
their
detection
ability,
thus
making
it
critical
to
evaluate
them
real
world
environments.
In
American
Samoa,
three
Procellariiform
seabird
species
nest
on
island
Ta‘ū
difficult
access
summit
scrub
habitat,
which
we
have
little
knowledge
about
presence.
Given
lack
these
species,
coupled
with
need
test
different
ARUs,
our
goal
was
investigate
differences
probability
Song
Meter
sensors
(Song
SM2
SM4)
under
habitat
environmental
conditions
Detection
ranges
calls
varied
from
<10
m
high
wind
conditions,
up
90
low
conditions.
Under
ideal
range
40
100
SM4
70
sensors.
Knowing
capabilities
will
allow
better
design
sensor
spacing,
combination
recording
situ
weather
data
calculations
detectable
areas
facilitation
determining
animal
densities.
Global Ecology and Conservation,
Год журнала:
2022,
Номер
35, С. e02058 - e02058
Опубликована: Фев. 15, 2022
Populations
of
bears
in
Asia
are
vulnerable
to
extinction
and
effective
monitoring
is
critical
measure
direct
conservation
efforts.
Population
abundance
(local
density)
or
growth
(λ)
the
most
sensitive
metrics
change.
We
discuss
value
implementing
spatially
explicit
capture-recapture
(SCR),
current
gold
standard
for
density
estimation,
open
population
SCR
(OPSCR)
monitor
changes
over
time.
provide
guidance
designing
studies
estimates
with
sufficient
power
detect
changes.
Because
wide
availability
camera
traps
interest
their
use,
we
consider
six
estimation
methods
extensions
developed
use
traps,
specific
consideration
assumptions
applications
Asian
bears.
conducted
a
analysis
calculate
precision
needed
populations
reference
IUCN
Red
List
criteria.
performed
systematic
review
empirical
trap
considered
sample
sizes,
effort,
model
required
achieve
adequate
monitoring.
found
OPSCR,
reliant
on
"marked"
individuals,
currently
only
enough
reliably
even
moderate
major
(20–80%)
declines.
Camera
unmarked
individuals
rarely
achieved
large
declines
(80–90%),
although
some
exceptions
(e.g.,
situations
densities,
number
sampling
sites,
inclusion
ancillary
local
telemetry
data.
describe
additional
options
including
line
transects,
observations,
age-specific
survival
reproductive
rates,
hybrid/integrated
methodologies
that
may
have
potential
work
bear
populations.
conclude
possible
but
will
require
collaboration
among
researchers
broad
spatial
extents
extensive
financial
investment
overcome
biological
logistical
constraints.
strongly
encourage
practitioners
study
design
effort
meet
objectives
by
conducting
simulations,
analyses,
assumption
checks
prior
efforts,
reporting
standardized
dispersion
measures
such
as
coefficients
variation
allow
assessment
precision.
Our
relevant
other
low-density
wide-ranging
species.
In
October
2020,
a
new
population
of
invasive
brown
treesnakes
(
Boiga
irregularis
)
was
discovered
on
the
33-ha
Cocos
Island,
2.5
km
off
south
coast
Guam.
Island
is
unique
conservation
resource,
providing
refuge
for
many
lizards
and
birds,
including
endangered
species,
which
were
extirpated
from
mainland
Guam
by
predators
treesnakes.
We
sought
to
evaluate
usefulness
toxic
baiting
with
acetaminophen-treated
carrion
baits
cage
trapping,
common
tools
control
Guam,
as
potential
eradication
Island.
evaluated
multiple
bait
types
presentations:
ground,
suspended
in
canopy
emulating
aerial
applications
four
plastic-tube
station
configurations
intended
exclude
non-target
species.
monitored
all
time-lapse
cameras.
Despite
improved
exclusion
non-targets
design,
most
quickly
removed
particularly
coconut
crabs
Birgus
latro
Mariana
monitors
Varanus
tsukamotoi
).
Monitoring
1,250
available
2,427
nights
resulted
no
observations
taking
any
bait.
Subsequently,
we
tested
two
trap
commonly
used
compared
trapping
success
live
versus
dead
mouse
lures.
10,553
using
lures,
only
captured
one
treesnake,
lure.
These
rates
are
so
low
be
ineffectual
practical
purposes.
Concurrent
visual
searching
hand
capture
during
initial
rapid
response
efforts
demonstrates
that
these
not
result
snake
density.
make
case
our
assumption
ineffectiveness
due
context
extremely
high
abundance
preferred
prey,
primarily
large
geckos
birds.
Our
results
have
profound
ramifications,
because
future
island
invasions
likely
occur
within
similarly
prey-rich
environments
where
methods
might
ineffective.
Remote Sensing in Ecology and Conservation,
Год журнала:
2022,
Номер
9(1), С. 152 - 164
Опубликована: Авг. 26, 2022
Abstract
A
suite
of
recently
developed
statistical
methods
to
estimate
the
abundance
and
density
unmarked
animals
from
camera
traps
require
accurate
estimates
area
sampled
by
each
camera.
Although
viewshed
is
fundamental
achieving
estimates,
there
are
no
established
guidelines
for
collecting
this
information
in
field.
Furthermore,
while
complexities
detection
process
motion
sensor
photography
generally
acknowledged,
viewable
(the
common
factor
between
time
lapse
photography)
on
its
own
has
been
underemphasized.
We
establish
a
set
terminology
identify
component
parts
area,
contrast
photographic
capture
measurements
photography,
review
estimating
use
case
study
demonstrate
importance
estimates.
Time
combined
with
allow
researchers
assume
that
probability
equals
1.
Motion
requires
measuring
distances
animal
fitting
distance
sampling
curve
account
<1.
Global Ecology and Conservation,
Год журнала:
2022,
Номер
38, С. e02268 - e02268
Опубликована: Авг. 18, 2022
Population
monitoring
is
critical
to
wildlife
conservation,
but
density
estimation
difficult
for
wide-ranging,
unmarked
species
inhabiting
remote
habitats.
Furthermore,
recent
investigations
into
with
camera
trap
data
has
revealed
models
be
potentially
unreliable,
prompting
cautious
application
and
continued
model
development.
Two
related
approaches
increasing
appeal
include
spatial
count
(SC),
which
infer
latent
identities
from
the
pattern
of
detections,
partial
identity
(SPIM),
additionally
leverage
covariates
(e.g.,
sex,
antler
point
count,
presence
GPS/radio
collar).
To
assess
performance
models,
we
applied
SC
SPIM
threatened
boreal
caribou
in
Canada,
are
declining
have
few
rigorous
estimates
across
their
broad
distribution
inform
conservation
efforts.
In
particular,
focused
on
two
spatially
proximate
ranges
northern
Alberta,
Canada
that
differ
estimated
demographic
trends,
disturbance
histories,
abundances
predators
apparent
competitors.
Estimates
varied
over
a
4
year
period
(2016
–
2019),
were
higher
region
more
stable
reported
growth
rates
less
anthropogenic
(mode
estimates:
155
225/1000
km2
vs.
19
96/1000
km2).
However,
differed
by
modeling
approach
had
low
variable
precision,
hindering
inferences
about
population
status
trajectories.
Simulations
suggest
may
been
biased
precise.
likely
underestimated
mistaking
detections
neighboring
individuals
as
recaptures
single
individual,
although
also
overestimated
inflating
assignment
probabilities
non-existent
individuals.
Findings
highlight
need
explore
how
grouping
dynamics
non-independent
movement
violate
assumptions
reduce
ability
distinguish
We
advocate
investigation
accuracy
approaches,
ecological
sampling
conditions
appropriate
different
coordination
efforts
analyses
improve
inferences.
Over
the
last
century,
large
carnivore
populations
in
Europe
were
severely
depleted.
By
1950s,
only
five
of
Eurasian
lynx
(Lynx
lynx)
persisted
isolated
ranges,
including
L.
l.
carpathicus
subspecies
within
Carpathian
Mountains.
Although
this
population
today
is
an
important
source
genetic
diversity
for
reintroduction
and
recolonisation,
little
research
has
focused
on
its
occurrence
activity
Polish
Carpathians.
The
main
objective
study
was
to
evaluate
dynamic
structure
across
space
time.
We
conducted
a
continuous
5-year
(2015-2019)
using
camera
traps
how
detections
varied
(1)
years
between
four
seasons,
(2)
diel
periods
(3)
their
social
status.
recorded
2261
20
trap
locations,
with
89%
records
one
solitary
individual
per
detection
10%
females
cubs,
remaining
1%
adult
pairs.
While
solitaries
detected
all
families
utilised
9
locations.
Based
generalised
linear
model,
increased
during
breeding
period
from
January
till
March.
Additionally,
number
decreased
at
night
compared
daylight
(p<0.001)
twilight
(p<0.001).
Families
individuals
season
more
active
day.
Our
results
indicate
that
promote
conservation
area,
wildlife
managers
may
consider
maintaining
areas
limited
human
disturbance,
especially
season.
Wildlife Society Bulletin,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 6, 2025
Abstract
Increasing
the
quantity
and
quality
of
mark‐reencounter
data
can
be
important
when
individual
identification
are
needed
to
address
research
or
management
questions.
Physical
recapture
methods
tend
labor‐intensive
therefore
expensive,
while
remote
detection
not
easily
applied
all
taxa
proprietary
thus
difficult
customize.
However,
partnerships
between
wildlife
scientists
engineers
have
potential
provide
innovative
solutions
that
improve
collection
reducing
costs.
We
describe
a
collaborative
effort
on
an
invasive
reptile,
brown
treesnake
(
Boiga
irregularis
).
In
laboratory
trials
conducted
Guåhan
(CHamoru;
Guam
in
English)
2021,
we
assessed
feasibility
detecting
snakes
fitted
with
passive
integrated
transponder
(PIT)
tags
using
customized
PIT‐tag
readers
(RePTaR)
paired
baited
snake
traps.
evaluated
differences
scanning
success
as
function
traits,
location
PIT
within
snakes,
distance
tag
from
reader.
successfully
scanned
individuals,
average
529
times
but
ranging
3
6,436
times,
during
12‐hour
designed
customizable
RePTaR
unit.
Snake
characteristics
marking
explained
little
variability
success,
reader
best‐supported
covariate.
By
building
cross‐disciplinary
partnerships,
develop
technological
additional
tools
which
challenges
management.
Remote Sensing in Ecology and Conservation,
Год журнала:
2023,
Номер
10(2), С. 141 - 155
Опубликована: Июль 24, 2023
Abstract
Over
the
past
few
decades,
use
of
camera‐traps
has
revolutionized
our
ability
to
monitor
populations
wild
terrestrial
mammals.
While
methods
estimate
abundance
from
individually‐identifiable
animals
are
well‐established,
they
mostly
restricted
species
with
clear
natural
markings
or
else
necessitate
invasive
and
often
costly
animal
tagging
campaigns.
Estimating
density
unmarked
remains
challenging.
Several
models
recently
developed
deal
this
issue
promising,
but
not
widely
used
by
field
ecologists.
Here,
we
a
framework
for
applying
Space‐To‐Event
(STE)
model—originally
designed
be
time‐lapse
images—on
motion‐triggered
camera‐trap
data.
Our
approach
involves
performing
bootstrap
resampling
on
photographic
dataset
generate
multiple
datasets
that
then
as
input
STE
model.
We
tested
29
datasets,
including
17
ungulate
eight
sites,
in
six
different
countries
various
ecosystems.
Then,
conducted
regression
analysis
evaluate
how
variations
ecological
sampling
conditions
across
studies
affected
bias
precision
estimates.
study
shows
information
activity
effective
detection
distances
animals,
model
can
analyze
motion‐trigger
provide
population
estimates
similar
those
other
methods.
found
measuring
camera
viewshed
was
critical
prevent
major
negative
biases
Moreover,
using
1‐s
window
important
avoid
positive
results
violating
instantaneous‐sampling
assumption.
increased
greater
effort
higher
populations.
Based
these
results,
highlight
several
issues
have
applied
original
timelapse‐based
addresses.
caution
model,
whether
timelapse
relies
strict
assumptions.
Any
violations
assumptions,
such
non‐instantaneous
application
angle
distance
provided
manufacturer,
cause
directions
may
difficult
differentiate.
Ecological Applications,
Год журнала:
2022,
Номер
32(5)
Опубликована: Апрель 5, 2022
Abstract
Applications
of
genetic‐based
estimates
population
size
are
expanding,
especially
for
species
which
traditional
demographic
estimation
methods
intractable
due
to
the
rarity
adult
encounters.
Estimates
breeding
(
N
S
)
particularly
amenable
approaches
as
parameter
can
be
estimated
using
pedigrees
reconstructed
from
genetic
data
gathered
discrete
juvenile
cohorts,
therefore
eliminating
need
sample
adults
in
population.
However,
a
critical
evaluation
how
genotyping
and
sampling
effort
influence
bias
pedigree
reconstruction,
these
biases
subsequently
,
is
needed
evaluate
efficacy
approach
under
range
scenarios.
We
simulated
model
system
understand
interactive
effects
on
error
program
COLONY
.
then
evaluated
errors
reconstruction
influenced
precision
three
different
rarefaction
estimators.
Results
indicated
that
minimal
when
adequate
available,
such
sizes
large
and/or
individuals
genotyped
at
many
informative
loci.
even
cases
limited,
results
simulation
analysis
magnitude
sources
still
estimating
applied
federally
endangered
Atlantic
sturgeon
Acipenser
oxyrinchus
Delaware
River,
USA.
Our
likely
orders
lower
compared
with
historic
sizes,
considerable
advancement
our
understanding
status
River.
analyses
broadly
applicable
design
interpretation
studies
seeking
estimate
help
guide
conservation
decisions
ecological
uncertainty
high.
The
utility
expected
grow
rapid
advances
technologies
increase
popularity
monitoring
estimation.
PeerJ,
Год журнала:
2022,
Номер
10, С. e13510 - e13510
Опубликована: Май 27, 2022
The
use
of
camera
traps
(CTs)
has
become
an
increasingly
popular
method
studying
wildlife,
as
CTs
are
able
to
detect
rare,
nocturnal,
and
elusive
species
in
remote
difficult-to-access
areas.
It
thus
makes
them
suited
estimate
animal
density
abundance,
identify
activity
patterns
new
behaviours
animals.
However,
animals
can
react
when
they
see
the
this
lead
bias
population
estimates.
While
may
provide
many
advantages,
improved
understanding
their
impacts
on
individual’s
behaviour
is
necessary
avoid
erroneous
Yet,
impact
detected
individuals,
such
human
odour
near
device
environment,
or
infrared
illumination,
received
relatively
little
attention.
To
date,
there
no
clear
procedure
remove
potential
bias.
Here,
we
trap
distance
sampling
(CTDS)
(1)
quantify
resulting
from
different
responses
determining
(2)
test
if
olfactory,
visual
auditory
signals
have
influence
animals’
reaction
CTs.
Between
March
2019
2020,
deployed
at
267
locations
distributed
systematically
over
entire
Taï
National
Park.
We
obtained
58,947
videos
which
analysed
four
medium-
to-large-bodied
(Maxwell’s
duiker
(
Philantomba
maxwellii
),
Jentink’s
Cephalophus
jentinki
pygmy
hippopotamus
Choeropsis
liberiensis
)
Western
chimpanzee
Pan
troglodytes
verus
))
displaying
towards
then
established
species-specific
ethograms
describing
behavioural
Using
these
responses,
observed
that
Maxwell’s
reacted
weakly
(about
0.11%
data),
contrary
duiker,
with
high
frequencies,
representing
32.82%,
52.96%
16.14%
data,
respectively.
Not
taking
into
account
artificial
doubling
tripling
populations’
sizes.
All
more
close
distances.
Besides,
significantly
night
than
during
day.
Finally,
for
olfactory
signals,
probability
first
days
after
installation
was
weak
but
concerned
18%
video
captures
chimpanzees
decreasing
time,
remained
(65%
70%
respectively).
Careful
consideration
should
be
given
animal’s
response
analysis
field,
by
reducing
human’s
around
installation.