Remote Sensing in Ecology and Conservation,
Journal Year:
2019,
Volume and Issue:
6(3), P. 301 - 315
Published: April 29, 2019
Abstract
Distance
sampling
is
widely
used
to
estimate
animal
population
densities
by
accounting
for
imperfect
detection
of
individuals
with
increasing
distance
from
an
observer.
assumes
that
distances
are
measured
without
error;
however,
it
often
applied
human
estimated
distances,
which
known
be
inconsistent,
inaccurate,
and
biased.
We
present
objective
technique
estimating
vocalizing
relies
on
the
relative
sound
level
(
RSL
)
vocalization
extracted
autonomous
recording
unit
ARU
recordings
show
error
less
than
a
literature
case
study.
predicted
can
obtained
manual
measurement
in
viewing
software,
or
automatically
automated
signal
recognition
software.
built
calibration
datasets
Ovenbirds
Seiurus
aurocapilla
Common
Nighthawks
Chordeiles
minor
recorded
at
regression
those
predict
distance.
There
was
no
bias
when
compared
Nighthawk,
minimal
Ovenbird,
all
literature.
then
simulated
point
count
surveys
density
test
whether
prediction
does
not
violate
assumption
error.
difference
estimates
distance,
while
contaminated
were
significantly
lower
found
dataset
approximately
300
vocalizations
suitable
minimize
both
species,
so
conclude
accessible
method
improving
estimation.
provide
general
recommendations
how
collect
application
other
species
areas.
Ecological Informatics,
Journal Year:
2021,
Volume and Issue:
61, P. 101236 - 101236
Published: Jan. 27, 2021
Variation
in
avian
diversity
space
and
time
is
commonly
used
as
a
metric
to
assess
environmental
changes.
Conventionally,
such
data
were
collected
by
expert
observers,
but
passively
acoustic
rapidly
emerging
an
alternative
survey
technique.
However,
efficiently
extracting
accurate
species
richness
from
large
audio
datasets
has
proven
challenging.
Recent
advances
deep
artificial
neural
networks
(DNNs)
have
transformed
the
field
of
machine
learning,
frequently
outperforming
traditional
signal
processing
techniques
domain
event
detection
classification.
We
developed
DNN,
called
BirdNET,
capable
identifying
984
North
American
European
bird
sound.
Our
task-specific
model
architecture
was
derived
family
residual
(ResNets),
consisted
157
layers
with
more
than
27
million
parameters,
trained
using
extensive
pre-processing,
augmentation,
mixup.
tested
against
three
independent
datasets:
(a)
22,960
single-species
recordings;
(b)
286
h
fully
annotated
soundscape
array
autonomous
recording
units
design
analogous
what
researchers
might
use
measure
setting;
(c)
33,670
single
high-quality
omnidirectional
microphone
deployed
near
four
eBird
hotspots
frequented
birders.
found
that
domain-specific
augmentation
key
build
models
are
robust
high
ambient
noise
levels
can
cope
overlapping
vocalizations.
Task-specific
designs
training
regimes
for
recognition
perform
on-par
very
complex
architectures
other
domains
(e.g.,
object
images).
also
temporal
resolution
input
spectrograms
(short
FFT
window
length)
improves
classification
performance
sounds.
In
summary,
BirdNET
achieved
mean
average
precision
0.791
recordings,
F0.5
score
0.414
soundscapes,
correlation
0.251
hotspot
observation
across
121
4
years
data.
By
enabling
efficient
extraction
vocalizations
many
hundreds
potentially
vast
amounts
data,
similar
tools
potential
add
tremendous
value
existing
future
may
transform
ecology
conservation.
Methods in Ecology and Evolution,
Journal Year:
2018,
Volume and Issue:
10(3), P. 368 - 380
Published: Oct. 10, 2018
Abstract
Assessing
the
presence
and
abundance
of
birds
is
important
for
monitoring
specific
species
as
well
overall
ecosystem
health.
Many
are
most
readily
detected
by
their
sounds,
thus,
passive
acoustic
highly
appropriate.
Yet
often
held
back
practical
limitations
such
need
manual
configuration,
reliance
on
example
sound
libraries,
low
accuracy,
robustness,
limited
ability
to
generalise
novel
conditions.
Here,
we
report
outcomes
from
a
collaborative
data
challenge.
We
present
new
datasets,
summarise
machine
learning
techniques
proposed
challenge
teams,
conduct
detailed
performance
evaluation,
discuss
how
approaches
detection
can
be
integrated
into
remote
projects.
Multiple
methods
were
able
attain
around
88%
area
under
receiver
operating
characteristic
(ROC)
curve
(AUC),
much
higher
than
previous
general‐purpose
methods.
With
modern
learning,
including
deep
bird
achieve
very
high
retrieval
rates
in
data,
with
no
recalibration,
pretraining
detector
target
or
conditions
environment.
Journal of Avian Biology,
Journal Year:
2018,
Volume and Issue:
49(5)
Published: Jan. 10, 2018
Conservationists
are
increasingly
using
autonomous
acoustic
recorders
to
determine
the
presence/absence
and
abundance
of
bird
species.
Unlike
humans,
these
can
be
left
in
field
for
extensive
periods
time
any
habitat.
Although
data
acquisition
is
automated,
manual
processing
recordings
labour
intensive,
tedious,
prone
bias
due
observer
variations.
Hence
automated
birdsong
recognition
an
efficient
alternative.
However,
only
few
ecologists
conservationists
utilise
existing
recognisers
process
unattended
because
software
calibration
exceptionally
high
requires
considerable
knowledge
signal
underlying
systems,
making
tools
less
user‐friendly.
Even
allowing
difficulties,
getting
accurate
results
exceedingly
hard.
In
this
review
we
examine
state‐of‐the‐art,
summarising
discussing
methods
currently
available
each
essential
parts
a
recogniser,
also
software.
The
key
reasons
behind
poor
that
very
noisy,
calls
from
birds
long
way
recorder
faint
or
corrupted,
there
overlapping
many
different
birds.
addition,
large
numbers
species
calling
one
recording,
therefore
method
has
scale
species,
at
least
avoid
misclassifying
another
as
particular
interest.
We
found
areas
importance,
particularly
question
noise
reduction,
amongst
researched.
cases
where
individual
essential,
such
conservation
work,
suggest
specialised
(species‐specific)
passive
monitoring
required.
believe
it
important
comparable
measures,
datasets,
used
enable
compared.
Ecological Applications,
Journal Year:
2019,
Volume and Issue:
29(6)
Published: June 17, 2019
Abstract
Autonomous
sound
recording
techniques
have
gained
considerable
traction
in
the
last
decade,
but
question
remains
whether
they
can
replace
human
observation
surveys
to
sample
sonant
animals.
For
birds
particular,
survey
methods
been
tested
extensively
using
point
counts
and
surveys.
Here,
we
review
latest
evidence
for
this
taxon
within
frame
of
a
systematic
map.
We
compare
sampling
effectiveness
these
two
methods,
output
variables
produce,
their
practicality.
When
assessed
against
standard
counts,
autonomous
proves
be
powerful
tool
that
samples
at
least
as
many
species.
This
technology
monitor
an
exhaustive,
standardized,
verifiable
way.
Moreover,
recorders
give
access
entire
soundscapes
from
which
new
data
types
derived
(vocal
activity,
acoustic
indices).
Variables
such
abundance,
density,
occupancy,
or
species
richness
obtained
yield
sets
are
comparable
compatible
with
counts.
Finally,
allow
investigations
high
temporal
spatial
resolution
coverage,
more
cost
effective
cannot
achieved
by
observations
alone,
even
though
small‐scale
studies
might
when
carried
out
Sound
deployed
places,
scalable
reliable,
making
them
better
choice
bird
increasingly
data‐driven
time.
provide
overview
currently
available
discuss
specifications
guide
future
study
designs.
Biological reviews/Biological reviews of the Cambridge Philosophical Society,
Journal Year:
2022,
Volume and Issue:
97(6), P. 2209 - 2236
Published: Aug. 17, 2022
ABSTRACT
As
biodiversity
decreases
worldwide,
the
development
of
effective
techniques
to
track
changes
in
ecological
communities
becomes
an
urgent
challenge.
Together
with
other
emerging
methods
ecology,
acoustic
indices
are
increasingly
being
used
as
novel
tools
for
rapid
assessment.
These
based
on
mathematical
formulae
that
summarise
features
audio
samples,
aim
extracting
meaningful
information
from
soundscapes.
However,
application
this
automated
method
has
revealed
conflicting
results
across
literature,
conceptual
and
empirical
controversies
regarding
its
primary
assumption:
a
correlation
between
biological
diversity.
After
more
than
decade
research,
we
still
lack
statistically
informed
synthesis
power
elucidates
whether
they
effectively
function
proxies
Here,
reviewed
studies
testing
relationship
diversity
metrics
(species
abundance,
species
richness,
diversity,
abundance
sounds,
sounds)
11
most
commonly
indices.
From
34
studies,
extracted
364
effect
sizes
quantified
magnitude
direct
link
estimates
conducted
meta‐analysis.
Overall,
had
moderate
positive
(
r
=
0.33,
CI
[0.23,
0.43]),
showed
inconsistent
performance,
highly
variable
both
within
among
studies.
Over
time,
have
been
disregarding
validation
those
examining
progressively
reporting
smaller
sizes.
Some
studied
[acoustic
entropy
index
(H),
normalised
difference
soundscape
(NDSI),
complexity
(ACI)]
performed
better
retrieving
information,
sounds
(number
identified
or
unidentified
species)
best
estimated
facet
local
communities.
We
found
no
type
monitored
environment
(terrestrial
versus
aquatic)
procedure
(acoustic
non‐acoustic)
performance
indices,
suggesting
certain
potential
generalise
their
research
contexts.
also
common
statistical
issues
knowledge
gaps
remain
be
addressed
future
such
high
rate
pseudoreplication
multiple
unexplored
combinations
metrics,
taxa,
regions.
Our
findings
confirm
limitations
efficiently
quantify
alpha
highlight
caution
is
necessary
when
using
them
surrogates
especially
if
employed
single
predictors.
Although
these
able
partially
capture
endorsing
some
extent
rationale
behind
promising
bases
developments,
far
biodiversity.
To
guide
efficient
use
review
principal
theoretical
practical
shortcomings,
well
prospects
challenges
Altogether,
provide
first
comprehensive
overview
relation
pave
way
standardised
monitoring.
Ibis,
Journal Year:
2021,
Volume and Issue:
163(3), P. 765 - 783
Published: Feb. 8, 2021
Passive
acoustic
monitoring
is
a
non‐invasive
tool
for
automated
wildlife
monitoring.
This
technique
has
several
advantages
and
addresses
many
of
the
biases
related
to
traditional
field
surveys.
However,
locating
animal
sounds
using
autonomous
recording
units
(ARUs)
can
be
technically
challenging
therefore
ARUs
have
traditionally
been
little
employed
estimate
density.
Nonetheless,
approaches
proposed
in
recent
years
carry
out
acoustic‐based
bird
density
estimations.
We
conducted
literature
review
studies
that
used
estimating
densities
or
abundances
order
describe
applications
improve
future
programmes.
detected
growing
interest
use
last
6
(2014–19),
with
total
31
articles
assessing
topic.
The
most
common
approach
was
relationship
between
number
vocalizations
per
time
abundance
estimated
(61%).
In
26
(79%),
estimates
obtained
by
human
surveyors
agreed
those
ARUs.
Some
proven
able
reduce
surveys,
such
as
considering
imperfect
detection
(spatially
explicit
capture–recapture,
microphone
arrays),
applying
paired
sampling
control
different
radius
humans
ARUs,
including
relative
sound
level
measurements
allow
researchers
distance
recorder.
did
not
include
any
covariates
existing
some
recorder,
which
may
hamper
comparisons
ARU
Future
should
measurement
recorder
obtain
estimations
Finally,
we
provide
guidelines
applicability
infer
population
studies.
Ibis,
Journal Year:
2023,
Volume and Issue:
165(3), P. 1068 - 1075
Published: Feb. 27, 2023
Automated
recognition
software
is
paramount
for
effective
passive
acoustic
monitoring.
BirdNET
a
free
and
recently
developed
bird
sound
recognizer.
I
performed
literature
review
to
evaluate
the
current
applications
performance
of
BirdNET,
which
growing
in
popularity
but
has
been
subject
few
assessments,
provide
recommendations
future
studies
using
BirdNET.
Prior
research
employed
wide
range
purposes
have
linked
detections
ecological
processes
or
real‐world
monitoring
schemes.
Among
evaluated
studies,
average
precision
(%
correctly
identified)
usually
ranged
around
72–85%,
recall
rate
target
species
vocalizations
detected)
33–84%.
Some
did
not
assess
performance,
hampers
interpretation
results
may
poorly
informed
decisions.
Recommendations
on
how
efficiency
are
provided.
The
impact
confidence
score
threshold,
user‐selected
parameter
as
minimum
reported,
output
although
variable
among
consistent.
use
high
thresholds
increases
percentage
classified
lowers
proportion
calls
detected.
selection
an
optimal
depend
priorities
user
goals.
great
tool
automated
it
should
be
used
with
caution
due
inherent
challenges
identification.
continued
refinement
suggests
further
improvements
coming
years.
Journal of Applied Ecology,
Journal Year:
2018,
Volume and Issue:
55(6), P. 2575 - 2586
Published: June 29, 2018
Abstract
Autonomous
sound
recording
is
a
promising
sampling
method
for
birds
and
other
vocalizing
terrestrial
wildlife.
However,
while
there
are
clear
advantages
of
passive
acoustic
monitoring
methods
over
classical
point
counts
conducted
by
humans,
it
has
been
difficult
to
quantitatively
assess
how
they
compare
in
their
performance.
Quantitative
comparisons
species
richness
between
recorders
human
bird
surveys
have
previously
hampered
the
differing
often
unknown
detection
ranges
or
spaces
among
methods.
We
performed
two
meta‐analyses
based
on
28
studies
where
were
paired
with
recordings
at
same
sites.
compared
alpha
gamma
estimated
both
survey
after
equalizing
effective
ranges.
further
assessed
influence
technical
specifications
(microphone
signal‐to‐noise
ratio,
height
number)
performance
unlimited
radius
counts.
show
that
standardizing
ranges,
from
statistically
indistinguishable,
might
be
an
avoidance
effect
Furthermore,
we
microphone
ratio
(a
measure
its
quality),
number
positively
affect
through
increasing
range,
allowing
match
Synthesis
applications
.
demonstrate
when
used
properly,
high‐end
systems
can
sample
wildlife
just
as
well
observers
conducting
Correspondingly,
suggest
first
standard
methodology
autonomous
obtain
results
comparable
enable
practical
sampling.
also
give
recommendations
carrying
out
making
most
recorders.
Biotropica,
Journal Year:
2018,
Volume and Issue:
50(5), P. 713 - 718
Published: July 22, 2018
Abstract
Knowledge
that
can
be
gained
from
acoustic
data
collection
in
tropical
ecosystems
is
low‐hanging
fruit.
There
every
reason
to
record
and
with
day,
there
are
fewer
excuses
not
do
it.
In
recent
years,
the
cost
of
recorders
has
decreased
substantially
(some
purchased
for
under
US
$50,
e.g.,
Hill
et
al
.
2018)
technology
needed
store
analyze
continuously
improving
(e.g.,
Corrada
Bravo
2017,
Xie
2017).
Soundscape
recordings
provide
a
permanent
site
at
given
time
contain
wealth
invaluable
irreplaceable
information.
Although
challenges
remain,
failure
collect
now
would
represent
future
generations
researchers
citizens
benefit
ecological
research.
this
commentary,
we
(1)
argue
need
increase
monitoring
systems;
(2)
describe
types
research
questions
conservation
issues
addressed
passive
(
PAM
)
using
both
short‐
long‐term
terrestrial
freshwater
habitats;
(3)
present
an
initial
plan
establishing
global
repository
recordings.