1 |
Patterns of seasonal occurrence of sympatric killer whale lineages in waters off Southern Vancouver Island and Washington state, as determined by passive acoustic monitoringRiera, Amalis 10 August 2012 (has links)
Killer whales inhabiting coastal waters of the northeastern Pacific are listed under the Canadian Species at Risk Act, which requires the identification of critical habitats for the recovery of their populations. Little is known about their distribution during the winter and what areas are important for their survival during these months. Passive acoustic monitoring is a valuable complementary method to traditional visual and photographic surveys although it has seldom been used to study killer whales and there are limitations in practice. There is a need to develop tools and protocols to maximize the efficiency of such studies. In this thesis, long-term acoustic data collected with autonomous recorders were analyzed 1) to assess the performance of two types of analysis (Manual and Long Term Spectral Averages) for detecting and identifying killer whale calls and to compare the effects of using two different duty cycles (1/3 and 2/3); and 2) to investigate the seasonal occurrence of different killer whale populations at two sites off the west coasts of Vancouver Island and Washington: Swiftsure Bank and Cape Elizabeth. Both the use of Long Term Spectral Averages and a lower duty cycle resulted in a decrease in call detection and resolution of call identification, leading to underestimations of the amount of time the whales spent at the site. A compromise between a lower resolution data processing method and a higher duty cycle (and vice-versa) is therefore suggested for future passive acoustic monitoring studies of killer whales. Killer whale calls were detected on 186 days at Swiftsure Bank and on 39 days at Cape Elizabeth. The seasonal occurrence of killer whales at Swiftsure Bank highlights its importance as a killer whale hotspot, with year-round presence of Southern Residents and British Columbia Transients, Northern Residents in spring and fall, and California Transients on rare occasions. These results support the expansion of Southern Resident’s critical habitat to include Swiftsure Bank. Temporal habitat partitioning between Resident populations was observed at Cape Elizabeth, with Southern Residents detected from January through June and Northern Residents from July to September. These results show that Northern Residents use the southern parts of their range more frequently than previously thought. Both Transient populations were frequently detected throughout the year, suggesting habitat overlapping. / Graduate
|
2 |
Species diversity, habitat utilization and blood parasites of amphibians in and around Ndumo Game Reserve / Edward Charles NetherlandsNetherlands, Edward Charles January 2014 (has links)
Ndumo
Game
Reserve
is
the
only
officially
protected
area
within
the
Phongolo
Floodplain;
an
area
in
the
northern
parts
of
KwaZulu-‐Natal
known
to
boast
a
rich
diversity
of
amphibians,
thus
becoming
one
of
the
focal
areas
for
this
study.
The
study’s
aim
was
to
monitor
and
record
amphibian
diversity,
as
well
as
associated
blood
parasite
biodiversity.
For
the
purpose
of
monitoring,
a
number
of
active
and
passive
techniques
were
employed.
Habitat
preferences
for
the
expected
species
were
divided
into
five
types,
namely
endorheic,
lacustrine,
palustrine,
riverine
and
terrestrial.
Endorheic
habitats
were
found
to
harbour
the
highest
diversity
(70%)
of
frog
species.
A
permanent
song
meter
was
used
to
passively
record
calling
activity
of
frog
species
associated
with
endorheic
systems.
This
call
data
indicated
peak
breeding
season,
preferred
calling
times
and
intensities
of
the
different
species.
Historical
records
from
the
same
area
were
used
as
a
basis
to
which
this
study’s
data
were
compared.
In
the
case
of
the
polychromatic
Argus
Reed
Frog
Hyperolius
argus
Peters,
1854,
questions
were
raised
concerning
the
major
colour
changes
during
development
of
the
apparent
sub-‐adult
to
adult
life
stages,
an
observation
which
was
has
caused
some
confusion
as
to
whether
these
forms
represented
a
single
species
or
multiple
cryptic
species.
These
issues
were
clarified
using
techniques
such
as
DNA
extraction
and
polymerase
chain
reaction
(PCR).
Furthermore,
a
blood
parasite
survey
was
conducted.
Thin
blood
smears
for
morphometrics
and
whole
blood
for
molecular
work,
were
collected
from
29
species
and
436
individual
frogs.
For
the
majority
of
the
recorded
parasites,
techniques
such
as
light
microscopy
were
utilized
for
the
morphological
description
and
classification
of
these
parasites.
Among
the
recorded
frog
blood
parasites
observed,
20%
of
the
frog
specimens
were
infected
with
at
least
one
blood
parasite
group.
Hepatozoon
and
Trypanosoma
species
accounted
for
most
of
the
infections;
the
former
demonstrated
significant
differences
in
intensity
of
infection
across
species,
families
and
habitat
types
(P
=
0.028;
P
=
0.006;
P
=
0.007
respectively).
Methods,
such
as
transmission
electron
microscopy,
examining
the
ultrastructure,
as
well
as
parasite
DNA
extraction
and
18S
rDNA
gene
sequences
for
the
molecular
and
phylogenetic
characterization,
were
reserved
for
Hepatozoon
species
infecting
common
toad
species
(Amietophrynus).
Parasite
stages
observed
were
measured
and
compared
to
each
other,
as
well
as
to
other
described
African
bufonid
haemogregarines.
Resulting
sequences
were
compared
with
each
other
and
to
comparative
haemogregarine
sequences
selected
from
GenBank.
In
the
current
study
a
number
of
important
aspects
with
regards
to
monitoring
and
assessment
of
amphibians
in
their
natural
environment
were
explored,
including
looking
at
and
determining
diversity
and
prevalence
of
blood
parasites.
Furthermore,
important
data
on
gaining
a
better
understanding
of
amphibians
and
their
behavioural
activities
were
also
gathered,
which
should
be
able
to
assist
in
conservation
actions
to
effectively
protect
South
African
anurans
and
their
required
habitat
types. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015
|
3 |
Species diversity, habitat utilization and blood parasites of amphibians in and around Ndumo Game Reserve / Edward Charles NetherlandsNetherlands, Edward Charles January 2014 (has links)
Ndumo
Game
Reserve
is
the
only
officially
protected
area
within
the
Phongolo
Floodplain;
an
area
in
the
northern
parts
of
KwaZulu-‐Natal
known
to
boast
a
rich
diversity
of
amphibians,
thus
becoming
one
of
the
focal
areas
for
this
study.
The
study’s
aim
was
to
monitor
and
record
amphibian
diversity,
as
well
as
associated
blood
parasite
biodiversity.
For
the
purpose
of
monitoring,
a
number
of
active
and
passive
techniques
were
employed.
Habitat
preferences
for
the
expected
species
were
divided
into
five
types,
namely
endorheic,
lacustrine,
palustrine,
riverine
and
terrestrial.
Endorheic
habitats
were
found
to
harbour
the
highest
diversity
(70%)
of
frog
species.
A
permanent
song
meter
was
used
to
passively
record
calling
activity
of
frog
species
associated
with
endorheic
systems.
This
call
data
indicated
peak
breeding
season,
preferred
calling
times
and
intensities
of
the
different
species.
Historical
records
from
the
same
area
were
used
as
a
basis
to
which
this
study’s
data
were
compared.
In
the
case
of
the
polychromatic
Argus
Reed
Frog
Hyperolius
argus
Peters,
1854,
questions
were
raised
concerning
the
major
colour
changes
during
development
of
the
apparent
sub-‐adult
to
adult
life
stages,
an
observation
which
was
has
caused
some
confusion
as
to
whether
these
forms
represented
a
single
species
or
multiple
cryptic
species.
These
issues
were
clarified
using
techniques
such
as
DNA
extraction
and
polymerase
chain
reaction
(PCR).
Furthermore,
a
blood
parasite
survey
was
conducted.
Thin
blood
smears
for
morphometrics
and
whole
blood
for
molecular
work,
were
collected
from
29
species
and
436
individual
frogs.
For
the
majority
of
the
recorded
parasites,
techniques
such
as
light
microscopy
were
utilized
for
the
morphological
description
and
classification
of
these
parasites.
Among
the
recorded
frog
blood
parasites
observed,
20%
of
the
frog
specimens
were
infected
with
at
least
one
blood
parasite
group.
Hepatozoon
and
Trypanosoma
species
accounted
for
most
of
the
infections;
the
former
demonstrated
significant
differences
in
intensity
of
infection
across
species,
families
and
habitat
types
(P
=
0.028;
P
=
0.006;
P
=
0.007
respectively).
Methods,
such
as
transmission
electron
microscopy,
examining
the
ultrastructure,
as
well
as
parasite
DNA
extraction
and
18S
rDNA
gene
sequences
for
the
molecular
and
phylogenetic
characterization,
were
reserved
for
Hepatozoon
species
infecting
common
toad
species
(Amietophrynus).
Parasite
stages
observed
were
measured
and
compared
to
each
other,
as
well
as
to
other
described
African
bufonid
haemogregarines.
Resulting
sequences
were
compared
with
each
other
and
to
comparative
haemogregarine
sequences
selected
from
GenBank.
In
the
current
study
a
number
of
important
aspects
with
regards
to
monitoring
and
assessment
of
amphibians
in
their
natural
environment
were
explored,
including
looking
at
and
determining
diversity
and
prevalence
of
blood
parasites.
Furthermore,
important
data
on
gaining
a
better
understanding
of
amphibians
and
their
behavioural
activities
were
also
gathered,
which
should
be
able
to
assist
in
conservation
actions
to
effectively
protect
South
African
anurans
and
their
required
habitat
types. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015
|
4 |
Monitoring Marine Mammals in Onslow Bay, North Carolina, Using Passive AcousticsHodge, Lynne Elizabeth Williams January 2011 (has links)
<p>Passive acoustic monitoring is being used more frequently to examine the occurrence, distribution, and habitat use of cetaceans. Long-term recordings from passive acoustic recorders allow the examination of diel, seasonal, and inter-annual variation in the occurrence of vocalizing marine mammals. With the increased use of passive acoustics as a tool for studying marine mammals, the ability to classify calls to the species level is becoming more important. While studies have found distinctive vocalizations in some cetacean species, further work is required in order to differentiate the vocalizations of delphinid species. I sought to classify odontocete vocalizations to species and to describe temporal variation and depth-related differences in the occurrence of cetacean vocal events detected in archival passive acoustic recordings in Onslow Bay, North Carolina. To determine if odontocete species in offshore waters of North Carolina could be distinguished by their whistles and clicks, I used a towed hydrophone array to make acoustic recordings of species encountered during concurrent visual and acoustic surveys between 2007 and 2010. I recorded whistles from four species (Atlantic spotted dolphins, bottlenose dolphins, rough-toothed dolphins, and short-finned pilot whales) and clicks from five species (Risso's dolphins in addition to the four species listed above). After running a classification and regression tree (CART) analysis on 22 measured variables from the contours of four species' whistles, I generated an optimal classification tree that had a correct classification rate of 74.2%. My results indicate that species-specificity exists in the four species' whistles. My examination of the spectral structure of clicks showed that only Risso's dolphins produced clicks with distinctive spectral banding patterns, although I found that other click parameters, particularly peak and center frequency, might be useful in differentiating the other species. I then used the distinctive banding pattern that I observed in Risso's dolphin clicks to identify this species in recordings made by archival passive acoustic recorders that were deployed at various times and locations between 2007 and 2010. I used these recordings to determine how vocal events varied temporally and spatially in Onslow Bay. My analysis of vocal events observed in these recordings showed that Risso's dolphins, sperm whales, and other delphinids are present in Onslow Bay throughout the year; Kogia spp. occur sporadically; and fin and minke whales produce calls that can be detected only between late fall and early spring. I also detected low-frequency downsweeps and two types of low-frequency pulse trains produced by unknown species. After looking at the occurrence of fin whale 20-Hz pulses in relation to downsweeps, I suggest that the downsweeps are produced by sei whales due to the lack of overlap in occurrence. When I looked for diel patterns in the odontocete vocal events, I found a nocturnal increase in the occurrence of clicks from Risso's dolphins and sperm whales, but no diel variation in Kogia clicks. I also found that unidentified delphinids showed either an increase in click events at dawn or at night, depending on the time of year and recording location. Finally, my analysis of acoustic data from five recorders deployed in three different depth ranges revealed that there was greater unidentified delphinid and sperm whale vocal activity on recorders located in deep waters, suggesting a greater diversity and density of animals in deeper waters of Onslow Bay. Together, the results of my dissertation demonstrate the value of passive acoustic monitoring in understanding the distribution and temporal trends in cetacean occurrence, and highlight the importance of classifying sounds to the species level in order to better understand the temporal and spatial patterns found.</p> / Dissertation
|
5 |
Assessing use of passive acoustic detection to document behavior of two sympatric pomacentrid speciesPilzer, Sarah Jean 12 March 2016 (has links)
Videotape and audio recordings of a patch reef in Ant Atoll, Pohnpei, Micronesia were analyzed for the presence of bioacoustic activity produced by species of the teleost family Pomacentridae. The acoustic parameters of fish calls were measured and then identified as belonging to either Amphiprion melanopus or Stegastes nigricans. Visual and statistical methods of analysis were combined to compare the calls of the two species and to test for measurable differences in the acoustic parameters of their calls. Soundscape data showed similar patterns to previously observed tropical reef environments. Fish produced single or multi-pulsed calls in the frequency range of 0-1000 Hz that were often accompanied by observable behaviors such as a chases and displays of dominance. Results indicated that the species on this atoll produce similar calls that cannot be distinguished using acoustic data alone. Visual confirmation was necessary for definitive identification of sound producers and in many cases was not possible beyond the family level. Implications for passive acoustic monitoring are that acoustic data collection alone may be able to capture fish abundance but may not be sufficient to fully capture species richness in regions where populations of closely related fish have similar signals.
|
6 |
Underwater vocal repertoire and their function in three ice-breeding seals in the Arctic / 北極圏に生息する氷上繁殖型アザラシ3種の水中音声レパートリーとその機能Mizuguchi, Daisuke 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19547号 / 理博第4207号 / 新制||理||1603(附属図書館) / 32583 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 幸島 司郎, 教授 伊谷 原一, 教授 村山 美穂 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
|
7 |
Analysis of Lepilemur edwardsi Seasonal Acoustic ActivityHenry, Samantha 01 January 2023 (has links) (PDF)
Passive acoustic monitoring (PAM) has historically been used as a noninvasive technique to study biodiversity, activity patterns, distribution, and species dispersal. The use of acoustic data has expanded in ecological research; however, studies focusing on primates are underrepresented, especially for nocturnal species. This study seeks to increase the understanding of acoustic activity in the nocturnal Milne-Edwards' sportive lemur (Lepilemur edwardsi). This species is endangered and endemic to the lowland dry forests in northwest Madagascar. Specifically, this study aims to describe the daily and annual acoustic activity patterns of the L. edwardsi. The PAM survey was conducted using AudioMoth recorders in the Mariarano Forest at 20 sites, with a recording being taken one minute every hour for a year. L. edwardsi presence and absence data were obtained from the recordings by using semi-automated analysis tools from ARBIMON (Rainforest Connection®). The results show that the parametric coefficients, Month and Hour, have an effect on the vocal activity of L. edwardsi with the various locations of the sites being taken into account. The probability of recording a L. edwardsi presence increases as the year progresses. Conversely, the probability of a L. edwardsi presence being recorded increases as the night progresses until midnight and decreases until the early morning hours. These results suggest that acoustic communication is important in L. edwardsi offspring rearing and parental investment. In addition, this study demonstrates the great potential of PAM in monitoring endangered and elusive species.
|
8 |
Quantitative analysis of coral reef soundscapes using five different acoustic indicesZhu, Linzhi 30 September 2022 (has links)
Soundscape ecology is a rising field in recent years as the effects of anthropogenic sound pollution are widely discussed. Nowadays, scientists are trying to find the best way to describe environmental health using quantitative acoustic measurements. In search of the best acoustic index/indices that can be used for real-time and long-term underwater acoustic monitoring, we tested five different acoustic indices for their effectiveness and suitability for distinguishing and differentiating various types of sounds. One dataset with anthropogenic noises (boat, ship, and diver noises), natural ambient sounds (wind, water turbulence, and reef background noises), and biotic sounds (damselfish Dascyllus reticulatus and snapping shrimps sounds) was analyzed using Raven Pro and R. Our results suggest that acoustic richness (AR) and acoustic complex index (ACI) are capable of separating sound types with the consistency of subjective impression. We also find a strong positive linear correlation between sound exposure level (SEL) and average power spectral density (PSD). The AR exhibits a polynomial relationship with the increase of SEL. Acoustic entropy (H) does not have a significant difference between the three types of sounds. These results agree with the previous studies that AR can be used for differentiating random noises and pure tones, and ACI is capable of quantifying sound complexity. / 2024-09-30T00:00:00Z
|
9 |
A Passive Acoustic and Experimental Study of Juvenile Blue Catfish, Ictalurus furcatus, Sound Production and Agnostic Behavior in the Tidal Freshwater James RiverMorgan, Laura 05 May 2014 (has links)
Blue catfish, Ictalurus furcatus, are an invasive species in the James River, VA. They produce stridulation sounds and passive acoustic monitoring may prove useful in locating and monitoring their populations. Little is known about their behavior, therefore my goal was to examine agonistic behavior and the use of sound in defending a territory. This thesis consists of two manuscripts: 1) A passive acoustic study of the tidal freshwater James River, 2) An experimental study of agonistic behavior in juvenile Blue catfish, Ictalurus furcatus. The first study showed that three sounds (click, run croak) occurred more often in warmer months than cooler months. The second study showed that Blue catfish utilized a variety of agonistic behaviors in territory defense, with residency status and size having an effect on the type and number of displays used. Stridulation sounds were not present in territorial contests although Blue catfish produce stridulatory pulses when held.
|
10 |
Determining temporal recording schemes for underwater acoustic monitoring studiesLindseth, Adelaide Virginia 21 February 2019 (has links)
Soundscape Ecology, the physical combination of sounds at a particular time and place, is a rapidly growing field. As acoustic technology advances, several possible future uses of passive acoustic monitoring (PAM), such as biodiversity counts and monitoring of habitat health, are being explored. This thesis is divided into two chapters; each is a stand-alone paper. The first chapter provides a review of soundscape ecology, ambient sound, current recording methods and data analysis used in PAM studies, and identifies several major future recommendations for the field. One of these recommendations is to standardize recording methods and indices used during analysis in long-term studies. The second chapter analyzes a 55-minute continuous recording on a coral reef in Tunicate Cove, Belize in 1996 by Professor P. Lobel. This recording was then subsampled with several intermittent recording schedules to explore the amount of acoustic information lost as periods of active and inactive recording vary. The continuous recording consisted of a high frequency band (3-4 kHz), which may correspond to abiotic sounds, and a low frequency band (0.1-0.5 kHz), which generally corresponds to biotic sounds. Two recording schedules, 30 seconds every 4 minutes and 2 minutes every 10 minutes, were significantly correlated with the continuous recording. The statistical significance of the other five recording schedules varied among the three parameters tested in this study (average power (dB), average entropy, and aggregate entropy).
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