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 |
Developing methods to use static acoustic click detectors for long term monitoring of coastal delphinids along the Cape south coast, South AfricaBetts, Monica Elizabeth January 2016 (has links)
This thesis investigated the use of a static acoustic data logger known as a Cetacean and Porpoise Detection (C-POD) device for monitoring two species of dolphins that occur in Mossel Bay, South Africa: the Indo-Pacific bottlenose dolphin, Tursiops aduncus, and the Indian Ocean humpback dolphin, Sousa plumbea. These two species have a near shore distribution which brings them into frequent contact with human activities such as boating, fishing, desalination plants and the onshore component of gas extraction facilities which can potentially affect their behaviour and populations dynamics. Although both species are relatively well studied within South Africa in terms of biology and abundance, this has been limited to the KwaZulu-Natal coast and Algoa Bay with little information available for areas west of Algoa Bay, and almost no information available locally on their acoustic behaviour.
This study aimed to: 1) calculate the detection range and effective detection radius (EDR) of C-PODs for T. aduncus and S. plumbea taking into account environmental and group parameters that may affect these and 2) distinguish T. aduncus from S. plumbea based on temporal variation in specific echolocation click parameters. Field work took place in Mossel Bay from a land-based platform during the period May 2013 to August 2014. A surveyor‟s theodolite was used to collect positional data on dolphins and behavioural information was collected through visual observations. A C-POD was deployed near the land based site and serviced and downloaded on a monthly basis for the same survey period. Visual detections were matched to acoustic detections (echolocation clicks) made within a 60 sec and 30 sec time window. Data were analysed using the software programme R. General Estimating Equations (GEE) were used to 1) model the detection probability and EDR of a C-POD for both species during both time windows; 2) model differences between the two species for seven click parameters produced by the C-POD. The impact of background noise on C-POD detections was also assessed.
As cetaceans are not the only form of sound in a marine environment distinguishing dolphin clicks from all other noise sources can be a challenge. Sources of background noise include clicking shrimp, movement of sediment, boat traffic and chorusing by reef fish and crustaceans during reproductive or territorial displays and storms which can either mask the clicks produced by dolphins or fill up the memory card. Data collected from two different deployment locations at different depths were subsequently compared after significant
ix
interference from other noise source was detected at the first deployment location. Mean number of detected dolphin clicks after filtering increased from 6463.33 to 97820 clicks per deployment and mean number of minutes in which detections were recorded increased from 0.23 min to 2.79 min per deployment.
Average detection probability for bottlenose dolphins was 0.357 (95% CI: 0.352 - 0.363) for the 60 sec window and 0.257 (95% CI: 0.253 - 0.262) for the 30 second window. For humpback dolphins the average detection probability was 0.084 (95% CI: 0.082 - 0.087) for the 60 sec window, and 0.043 (95% CI: 0.042 - 0.044) for the 30 sec window. EDR for bottlenose dolphins was 1161.38 mm (95% CI: 1150.14m – 1172.62 m) for the 60 sec window and 1035.761 m (95% CI: 1024.89 m – 1046. 64 m) for the 30 sec window. EDR for humpback dolphins was 765.25m (95% CI: 755.64 m – 774.85 m) for the 60 sec window and 751.00 m (95% CI: 741. 40 m – 760. 60 m) for the 30 sec window. Detection probability and EDR were higher for bottlenose dolphins than humpback dolphins over both time windows. For both species, during both windows, detection probability was significantly influenced by group size (p < 0.05). Four out of the seven parameters produced by the C-POD yielded significant pairwise differences (p < 0.05) between the species. Average inter-click interval was the only co-variable that was significant in the GEE model. The average ICI for bottlenose dolphins was 55.91 ms (95% CI: 51.23 – 60.60) whilst the average ICI for humpback dolphins was longer at 119.76 ms (95% CI: 119.76 – 174.00). The interaction between average ICI and modal frequency was also significant (p < 0.05) indicating that a combination of co-variables might be required in order to differentiate between the two species. Despite the small sample size and the challenges associated with acoustic studies in a noisy marine environment this study provided valuable information regarding the use of static acoustic data loggers such as C-POD in South Africa. As newer versions of C-POD are frequently introduced many of the challenges encountered in this study will be minimized. / Dissertation (MSc)--University of Pretoria, 2016. / Zoology and Entomology / Unrestricted
|
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 |
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
|
5 |
Correlates and temporal variation in call phenology of eastern Ontario frogsKLAUS, SAMANTHA P 14 November 2012 (has links)
Climate change has been predicted to have long-term consequences for North American ecosystems. Amphibians in particular are considered indicators of ecosystem health because of their sensitivity to environmental change – due in part to their semi-permeable skin and aquatic developmental requirements. Amphibians have been experiencing population declines on a global scale, suggested in part to be due to changes in reproductive behaviour and timing. My thesis examines the abiotic correlates of timing of calling in southeastern Ontario anurans, as well as the extent to which the timing of calling events vary within and among species. I focused on eight species of frogs using both a 40-year historical dataset and a 5-year field-collected dataset of environmental variation and anuran activity. From analysis of the historical dataset, Lithobates pipiens was the only species out of eight to emerge significantly earlier, by an estimated 22 days over four decades. Both L. pipiens and Anaraxyus americanus have advanced initiation of calling over a four-decade span significantly earlier by an estimated 37.2 and 19.2 days, respectively, correlating with significant regional increases in spring air temperatures (2.8°C over four decades). Global frog declines or range shifts relate ultimately to changes in reproductive behaviour and timing mediated by shifting climate. From my analysis of the field-collected dataset, I concluded that species varied in the environmental predictors that best predicted this variation may be a consequence of varying reproductive strategies between early spring “explosive” breeders versus late prolonged breeders. There was also significant among-location variation in calling activity for four prolonged breeding species, which may be an effect of significant microclimatic variation between locations surveyed. My study suggests that local temperature increases have affected the timing of emergence and the onset of calling activity in some frogs and that microclimatic differences among breeding habitats may be influencing the timing of breeding in some prolonged breeding species. My research aids future conservation and management strategies for North America’s dwindling amphibian populations by quantifying how abiotic factors influence breeding behaviour on both a fine and extended temporal scale as well as by developing and testing standardized methods for long-term species monitoring. / Thesis (Master, Biology) -- Queen's University, 2012-11-12 23:05:34.12
|
6 |
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
|
7 |
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.
|
8 |
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
|
9 |
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.
|
10 |
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
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