Automated body length and body condition measurements of whales from drone videos for rapid assessment of population health
Marine Mammal Science,
Год журнала:
2024,
Номер
40(4)
Опубликована: Май 10, 2024
Abstract
Monitoring
body
length
and
condition
of
individuals
helps
determine
overall
population
health
assess
adaptation
to
environmental
changes.
Aerial
photogrammetry
from
drone‐based
videos
is
a
valuable
method
for
obtaining
measurements
cetaceans.
However,
the
laborious
manual
processing
select
frames
measure
animals
ultimately
delays
assessment
hinders
conservation
actions.
Here,
we
apply
deep
learning
methods
expedite
improve
efficiency
important
morphological
whales.
We
develop
two
user‐friendly
models
automatically
(1)
detect
output
containing
whales
(“DeteX”)
(2)
extract
input
(“XtraX”).
use
gray
compare
versus
automated
(
n
=
86).
Our
results
show
reduced
times
by
one‐ninth,
while
achieving
similar
accuracy
as
(mean
coefficient
variation
<5%).
also
demonstrate
how
these
are
adaptable
other
species
identify
remaining
challenges
help
further
in
future.
Importantly,
tools
greatly
speed
up
key
data
maintaining
accuracy,
which
critical
effectively
monitoring
health.
Язык: Английский
Non-invasive methods characterise the world’s largest tiger shark aggregation in Fuvahmulah, Maldives
Lennart Vossgaetter,
Tim Dudeck,
J. H. Crouch
и другие.
Scientific Reports,
Год журнала:
2024,
Номер
14(1)
Опубликована: Сен. 23, 2024
Abstract
Tiger
sharks
are
apex
predators
with
a
circumglobal
tropical
and
warm-temperate
distribution,
general
lack
of
population
data
for
the
central
Indian
Ocean.
In
Fuvahmulah,
Maldives,
tiger
display
frequent
use
harbour
area,
attracted
by
discarded
fish
waste.
Here,
we
document
structure,
residency,
reproductive
characteristics
world’s
largest
known
shark
aggregation
in
geographically-restricted
area.
Using
non-invasive
methods,
photo
identification
laser
photogrammetry,
identified
239
individual
over
7-year
study
period.
The
was
female-dominated
(84.5%),
both
large
juveniles
adults
present.
Adult
females
were
resighted
entire
period
displaying
strong
inter-
intra-annual
site
fidelity.
Modelled
residency
using
maximum
likelihood
methods
suggests
they
spent
60.7
±
S.E.
7.5
days
larger
size,
shorter
residence
periods
longer
absence
compared
to
juvenile
females.
Prolonged
abdominal
distensions
adult
indicate
likely
stay
near
Fuvahmulah
during
gestation
reproduce
biennially.
seems
provide
suitable
conditions
given
year-round
provision
food
warm
waters,
exhibited
fidelity
temporal
residency.
Our
results
show
indications
thriving
within
confines
protected
waters.
Язык: Английский
Assessing variation in faecal glucocorticoid concentrations in gray whales exposed to anthropogenic stressors
Conservation Physiology,
Год журнала:
2023,
Номер
11(1)
Опубликована: Янв. 1, 2023
Understanding
how
individual
animals
respond
to
stressors
behaviourally
and
physiologically
is
a
critical
step
towards
quantifying
long-term
population
consequences
informing
management
efforts.
Glucocorticoid
(GC)
metabolite
accumulation
in
various
matrices
provides
an
integrated
measure
of
adrenal
activation
baleen
whales
could
thus
be
used
investigate
physiological
changes
following
exposure
stressors.
In
this
study,
we
measured
GC
concentrations
faecal
samples
Pacific
Coast
Feeding
Group
(PCFG)
gray
(Eschrichtius
robustus)
collected
over
seven
consecutive
years
assess
the
association
between
content
metrics
sound
levels
vessel
traffic
at
different
temporal
scales,
while
controlling
for
contextual
variables
such
as
sex,
reproductive
status,
age,
body
condition,
year,
time
year
location.
We
develop
Bayesian
Generalized
Additive
Modelling
approach
that
accommodates
many
complexities
these
data,
including
non-linear
variation
hormone
concentrations,
missing
covariate
values,
repeated
samples,
sampling
variability
some
below
limit
detection.
Estimated
relationships
showed
large
variability,
but
emerging
patterns
indicate
strong
context-dependency
variation,
depending
on
condition
proximity
port.
Our
results
highlight
need
control
baseline
related
context,
which
otherwise
can
obscure
functional
relationship
GCs
stressor
exposure.
Therefore,
extensive
data
collection
determine
sources
well-studied
populations,
PCFG
whales,
shed
light
cetacean
stress
physiology
extend
applicability
less-well-studied
taxa.
analyses
may
offer
greatest
utility
when
employed
part
suite
markers
that,
aggregate,
provide
multivariate
better
estimates
individuals'
health
ultimately
anthropogenic
populations.
Язык: Английский
Skinny dolphins: Can poor body condition explain population decline in Indo-Pacific humpback dolphins (Sousa chinensis)?
The Science of The Total Environment,
Год журнала:
2024,
Номер
917, С. 170401 - 170401
Опубликована: Янв. 26, 2024
Язык: Английский
Closing the air gap: the use of drones for studying wildlife ecophysiology
Biological reviews/Biological reviews of the Cambridge Philosophical Society,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 17, 2025
ABSTRACT
Techniques
for
non‐invasive
sampling
of
ecophysiological
data
in
wild
animals
have
been
developed
response
to
challenges
associated
with
studying
captive
or
using
invasive
methods.
Of
these,
drones,
also
known
as
Unoccupied
Aerial
Vehicles
(UAVs),
and
their
sensors,
emerged
a
promising
tool
the
ecophysiology
toolkit.
In
this
review,
we
synthesise
research
scoping
review
on
use
drones
wildlife
PRISMA‐SCr
checklist
identify
where
efforts
focused
knowledge
gaps
remain.
We
these
results
explore
current
best
practices
provide
recommendations
future
use.
136
studies
published
since
2010,
aided
animal
body
condition
morphometrics,
kinematics
biomechanics,
bioenergetics,
health
(e.g.
microbiomes,
endocrinology,
disease)
both
aquatic
terrestrial
environments.
Focal
taxa
are
biased
towards
marine
mammals,
particularly
cetaceans.
While
conducted
globally,
is
primarily
led
by
institutions
based
North
America,
Oceania,
Europe.
The
obtain
morphometric
through
standard
colour
sensors
single
camera
photogrammetry
predominates.
such
video
tracking
thermal
imaging
allowed
insights
into
other
aspects
ecophysiology,
when
combined
external
techniques
biologgers.
most
used
commercially
available
multirotor
platforms
modification
collect
samples,
integration
techniques,
multidisciplinary
integrate
suite
remote
sensing
methods
more
fully.
outline
how
technological
advances
will
play
key
role
delivery
novel
improved
data.
recommend
that
researchers
prepare
influx
drone‐assisted
advancements
cross‐institutional
collaborations.
describe
diversify
across
species
environments
sources
technologies
comprehensive
results.
Язык: Английский
Variation in faecal testosterone levels in male gray whales on a foraging ground relative to maturity and timing
Conservation Physiology,
Год журнала:
2025,
Номер
13(1)
Опубликована: Янв. 1, 2025
Abstract
Understanding
wildlife
reproductive
seasonality
is
crucial
for
effective
management
and
long-term
monitoring
of
species.
This
study
investigates
the
seasonal
variability
testosterone
in
male
Pacific
Coast
Feeding
Group
(PCFG)
gray
whales,
using
an
eight-year
dataset
(2016–2023)
individual
sightings,
drone-based
photogrammetry
endocrine
analysis
faecal
samples.
We
analyzed
relationship
between
levels
total
body
length
(TL),
condition
(body
area
index,
BAI),
sexual
maturity
day
year
generalized
additive
mixed
models.
Our
findings
reveal
a
significant
increase
mature
males
(MM)
towards
end
foraging
season.
was
not
observed
JM,
highlighting
age-dependent
development
characteristics.
No
found
TL.
Additionally,
BAI
significantly
associated
with
levels.
results
suggest
that
increasing
MM
whales
may
indicate
preparation
mating
before
southbound
migration.
These
provide
valuable
insights
into
biology
PCFG
underscore
importance
non-invasive
sampling
studying
large
whales.
approach
only
provides
further
reproduction
but
also
offers
tools
to
enhance
understanding
baleen
broadly
approaches.
Язык: Английский
A geometric morphometric approach for detecting different reproductive stages of a free-ranging killer whale Orcinus orca population
Scientific Reports,
Год журнала:
2025,
Номер
15(1)
Опубликована: Янв. 25, 2025
The
expansion
of
drone-based
aerial
imagery
has
facilitated
an
increase
in
data
obtained
from
free-ranging
marine
mammal
populations,
particular
cetacean
species.
This
non-invasive
approach
allows
for
body
condition
assessments,
including
nutritional
and
reproductive
health.
Yet,
existing
methods
image
analysis
are
time-consuming
lack
the
granularity
to
determine
early-stage
pregnancies
miscarriage
rates.
In
this
study,
we
leveraged
a
four-year
dataset
paired
with
known
statuses
(i.e.,
non-pregnant,
pregnant,
late-stage
lactating)
killer
whales
(Orcinus
orca)
develop
geometric
morphometric-based
protocol
detecting
status.
We
demonstrate
significant
separation
resulting
shapefiles
related
status
between
all
apart
lactating.
reliably
detects
pregnancy
highlights
morphological
locations
major
shape
changes
during
lactation
period.
illustrate
applicability
our
morphometric
rapid,
robust
determination
work
helps
satisfy
need
universal
tools
non-invasively
gleaning
population
demographic
cetaceans
especially
populations
which
experiencing
prey-related
failures,
understand
rates
trigger
subsequential
conservation
actions.
Язык: Английский
Drones Applied to Cetacean Research: A Case Study of Fin Whales
IntechOpen eBooks,
Год журнала:
2025,
Номер
unknown
Опубликована: Май 21, 2025
The
fin
whale
is
the
only
species
regularly
found
in
Mediterranean
Sea,
with
a
year
around
presence.
However,
aquatic
environment
and
whale’s
diving
behavior
have
posed
challenges
to
studying
this
marine
mammal.
increasing
use
of
drones
cetacean
research
has
significantly
enhanced
our
understanding
species.
Drones
provide
ability
quickly
discreetly
fly
over
whales,
minimizing
disturbance,
while
capturing
high-quality
footage
that
enables
observation
their
characteristic
features
used
for
identification,
as
well
supporting
morphometric
analysis.
Additionally,
can
assist
collecting
blow
samples
guiding
vessels
closer,
more
effective
approaches
conduct
biopsies,
collect
fecal
samples,
or
deploy
tagging
devices.
This
technological
advancement
greatly
contributed
deeper
offering
valuable
insights
into
health
population.
Язык: Английский
Drone-based photogrammetry reveals differences in humpback whale body condition and mass across North Atlantic foraging grounds
Chelsi Napoli,
Nathan Hirtle,
Julia E. F. Stepanuk
и другие.
Frontiers in Marine Science,
Год журнала:
2024,
Номер
11
Опубликована: Июнь 26, 2024
Baleen
whales
are
key
consumers
in
marine
ecosystems
and
can
serve
as
ecosystem
sentinels.
Body
condition,
defined
an
individual’s
energy
stores
relative
to
its
structural
size,
provide
a
useful
proxy
for
health
baleen
whales.
As
capital
breeders,
important
life
history
events
such
seasonal
migrations
reproduction
depend
on
having
sufficient
stores.
Spatiotemporal
variability
of
body
condition
reflect
differences
accumulated
during
the
foraging
season.
Here
we
assess
compare
mass
humpback
(
Megaptera
novaeangliae)
across
four
different
areas
from
West
Indies
distinct
population
segment
Northwest
Atlantic.
Morphometric
measurements
were
obtained
using
unoccupied
aerial
systems
(UAS,
or
drones)
New
York
Bight,
Gulf
Maine,
Iceland,
Greenland.
Uncertainty
morphometric
estimates
was
incorporated
propagated
bootstrapping
approach.
Measurements
used
estimate
volume
calculate
index
(BCI)
each
individual
whale.
Since
is
parameter
understanding
animal
physiology
bioenergetics,
further
compared
whale
size
between
by
converting
tissue
density
tagging
studies.
BCI
showed
significant
with
large
effect
(ANCOVA:
mean
η
2
=
0.168;
all
p<
0.001)
when
incorporating
day
year
covariates.
Humpback
Maine
significantly
higher
than
those
Standardized
Major
Axis
(SMA)
regressions
comparing
log-log
relationships
both
mass,
respectively,
total
length
reinforced
these
results.
elevation
SMAs
other
study
regions
(p<0.001),
implying
that
greater
reserves
given
size.
Estimates
indicate
length,
have
18%
Regional
prey
availability
anthropogenic
threats
could
contribute
observed
patterns
condition.
Our
findings
highlight
importance
regional
environmental
factors
nutritional
Язык: Английский