2024-03-29T10:40:31Zhttps://research-repository.st-andrews.ac.uk/oai/requestoai:research-repository.st-andrews.ac.uk:10023/6872019-07-01T10:15:58Zcom_10023_181com_10023_39col_10023_183
The frontal system of the Antarctic Circumpolar Current : marine mammals as ocean explorers
Boehme, Lars
Fedak, Mike
Oceanography
Elephant seal
Marine mammal
Climate change
Antarctica
Antarctic Circumpolar Current
Drake Passage
South Georgia
In this thesis, I describe large-scale and small-scale features of the Antarctic Circumpolar Current (ACC) by merging conductivity-temperature-depth (CTD) data
obtained by novel animal-borne sensors with data obtained by more conventional
means. Twenty-one CTD-Satellite Relay Data Loggers (CTD-SRDLs) were attached
to Southern elephant seals (Mirounga leonina) on South Georgia in 2004 and 2005.
This was part of a larger international study (Southern Elephant Seals as Oceanographic Samplers; SEaOS), in which I played a major role in developing the oceanographic approach used to integrate physical data from a range of sources, and the means to link biological findings to oceanographic parameters.
The development of animal-borne oceanographic sensors and their potential place within an ocean observing system is reviewed initially. Then, I describe the Series 9000 CTD-SRDL in detail, discussing its performance in the lab and during two field experiences with Southern elephant seals and Weddell seals (Leptonychotes weddellii ).
Following this, a detailed study of the ACC frontal system in the South Atlantic is
presented that uses merged Argo float data and CTD-SRDL data. The structure of
the frontal field revealed by this unique dataset is examined, and unprecedented insight into its variability is obtained. Amongst the important findings is that, contrary to most climate models, our in situ data suggest a northward shift of the ACC east of 40W in 2004 and 2005 compared to previous work. Next, two CTD-SRDL sections
are presented to identify the locations of the ACC fronts across Drake Passage,
and an empirical relationship between upper ocean temperature and baroclinic mass
transport is used to determine the transport through Drake Passage at the times of
the sections. This technique is a powerful complement to more conventional means
of data collection in this region, especially given the ability of the seals to conduct "sections" at times when ship-based fieldwork is logistically most challenging, i.e. in the winter time.
The CTD-SRDLs do not only record hydrographic data, but simultaneously record
seal movements and diving behavior. This enables insight to be obtained on the behavioral and physiological responses of Southern elephant seals to spatial environmental variability throughout their circumpolar range. The resulting energetic consequences of these variations could help explain recently observed spatially varying population trends. With a stable population at South Georgia and declining populations at
Kerguelen and Macquarie Island. This study also highlights the benefits to the sensorcarrying animals themselves by showing the usefulness of this approach in examining
the sensitivity of top predators to global and regional-scale climate variability. More
importantly, I conclude that, by implementing animal-borne sensors into ocean observing strategies, we not only gain information about global ocean circulation and enhance our understanding of climate and the corresponding heat and salt transports,
but at the same time we increase our knowledge about ocean’s top predators, their
life history and their sensitivity to climate change.
2009-05-14
2009-05-14
2008-11-27
Thesis
http://hdl.handle.net/10023/687
en
http://creativecommons.org/licenses/by/3.0/
Creative Commons Attribution 3.0 Unported
192
University of St Andrews
The University of St Andrews
Sea Mammal Research Unit
oai:research-repository.st-andrews.ac.uk:10023/178602021-03-16T11:09:05Zcom_10023_181com_10023_39col_10023_183
Communication accommodation theory : a dolphin perspective
Jones, Brittany
Janik, Vincent
Marine Alliance for Science and Technology for Scotland (MASTS)
Scottish Funding Council
Tursiops
Acoustics
Communication accommodation theory
Vocalizations
Bottlenose dolphins
Marine mammal
Convergence
Accommodation
Audience
Signature whistle
Vocal exchange
Playbacks
For humans, there is a well-established theory, which explains much of the variation in human verbal dyadic speech behavior, the “communication accommodation theory (CAT)”. In its most basic form, CAT predicts that as two conversation partners become more similar in their speech patterns, the more likely they are to perceive the interaction, and/or the other person favorably. In this exploration of CAT in a non-human mammal, I look for the cornerstones of the theory in bottlenose dolphin communication. Dolphins depend largely on acoustic communication to maintain ever-changing social interactions in a marine environment. Dolphins have individually specific signature whistles that allow them to broadcast their identity, and also are able to encode additional information across those whistle emissions. They often use these whistles in antiphonal exchanges with other dolphins. In Chapter 2, I show that dolphins use signature whistles more often when conspecifics are present, suggesting a socially mediated system for signature whistle use. I find that male allies do not converge their signature whistles from pre-alliance to alliance formation, as previously suggested, nor over the course of alliance (Chapter 3). I do find that allies have more similar signature whistles to their male partner than to non-allies and in Chapter 4, find that male allies subtly accommodate during antiphonal signature whistle exchanges. During experimental playbacks of manipulated whistles to a bottlenose dolphin, I recorded subtle parameter accommodation in the frequency pitch shifts from one unit of a signature whistle playback to the next, suggesting that even when there is no difference in reinforcement, dolphins have the propensity for accommodation during signature whistle interactions. This thesis presents the first suggestion that the CAT may be a good model for the study for animal communication systems moving forward.
2019-06-10
2019-06-10
2019-06-26
Thesis
http://hdl.handle.net/10023/17860
https://doi.org/10.17630/10023-17860
en
2024-05-30
Thesis restricted in accordance with University regulations. Print and electronic copy restricted until 30th May 2024
xii, 208 p.
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/179772021-03-19T12:05:21Zcom_10023_45com_10023_17com_10023_181com_10023_39com_10023_792col_10023_47col_10023_183col_10023_793
Not just fat : investigating novel physiological state biomarkers in cetacean blubber
Kershaw, Joanna
Hall, Ailsa J.
Miller, Patrick
Despite its importance as a predictor of fitness, no consensus has been reached about how to
assess the nutritive body condition of free-ranging cetaceans. Standard indices of condition
used in terrestrial ecology were assessed in cetaceans using data and samples from stranded
animals. The most appropriate morphometric indices were identified as mass/length2 and
girth/length (where mass data were unavailable). Blubber thickness, and blubber lipid content
were poor indicators of condition. Variation in lipid content suggested that there may be tradeoffs
occurring between different blubber functions involved in energy storage, controlling
buoyancy, and preserving thermoregulatory properties in species with different life-history
strategies.
Novel blubber biomarkers of physiological state were investigated as objective and widely
applicable tools for estimating body condition. Blubber cortisol concentrations were negatively
correlated with morphometric indices of condition in stranded animals from two cetacean
families. Blubber cortisol concentrations were thus identified as a candidate biomarker. When
applied to a 13-year dataset of biopsy samples from female humpback whales (Megaptera
novaeangliae), cortisol concentrations showed significant inter-annual variation.
Concentrations were weakly correlated with annual pregnancy rates. High individual
variability in blubber cortisol concentrations was likely a result of the multi-functional nature
of cortisol. Cortisol concentrations thus probably provide a ‘snap shot’ of the metabolic state
of the tissue when sampled.
A proteomic approach was developed to extract and identify proteins in blubber. A range of
proteins involved in numerous metabolic processes and pathways were identified. These
proteins likely capture the range of physiological processes experienced by individuals at the
time of sampling. This new proteomic approach will help to assign novel functions to marine
mammal blubber in keeping with current understanding of the multi-functional role of adipose
tissue as an endocrine organ in mammals. It will also allow the future development of protein
biomarkers of health and physiological state.
2019-06-26
2019-06-26
2019-06-26
Thesis
http://hdl.handle.net/10023/17977
https://doi.org/10.17630/10023-17977
en
200 p.
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/68022019-07-01T10:17:53Zcom_10023_45com_10023_17com_10023_181com_10023_39com_10023_792col_10023_47col_10023_183col_10023_793
Abundance and distribution of delphinids in the Red Sea (Egypt)
Costa, Marina
Heinrich, Sonja
Hammond, Philip S.
Distance sampling
Red Sea
Habitat modelling
Mark recapture
Dolphins
Knowledge about cetaceans in the Red Sea is limited with only a handful of sporadic or
spatially-limited studies carried out to date. Funded by the Italian Cooperation through
a Debt-for-Nature Swap programme and carried out in collaboration with the Egyptian
NGO HEPCA, this thesis presents the results from the first ever systematic vessel-based
surveys conducted in the southern Egyptian Red Sea from 2010 to 2013 using linetransect
methodology. The main aims of the thesis were (a) to estimate cetacean
abundance, (b) to determine distribution patterns and habitat use of the cetacean
species, (c) to investigate movement patterns for species for which individual
recognition techniques were suitable and (d) to identify areas of conservation concern
for cetaceans with a particular focus on existing protected areas. Eight species were
identified, of which five were commonly encountered (Stenella longirostris, S.
attenuata, Tursiops truncatus, T. aduncus, and Grampus griseus) and three were rare
(Pseudorca crassidens, Sousa plumbea, Balaenoptera edeni). Estimates of abundance
using design-based line transect sampling techniques were obtained for five species: S.
attenuata 10,268 (CV=0.26); S. longirostris 6,961 (CV=0.26); T. aduncus 659 (CV=0.69);
T. truncatus 509 (CV=0.33), and G. griseus 367 (CV=0.37). Habitat modelling revealed
that the two Stenella species were widely distributed across the study area. In
contrast, T. truncatus was concentrated in waters around Ras Banas peninsula (in
particular Satayah offshore reef), and T. aduncus was mainly found along the coast
with possibly separate sub-populations in the northern and southern study area. G.
griseus was only encountered in the southern part. The information provided in this
study will allow the development of a conservation strategy for the protected areas
and will serve as baseline information to carry out future survey work in the Red Sea.
2015-06-11
2015-06-11
2015-06-24
Thesis
http://hdl.handle.net/10023/6802
en
http://creativecommons.org/licenses/by-nc-nd/4.0/
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
294
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/10022019-12-09T14:30:14Zcom_10023_45com_10023_17com_10023_181com_10023_39col_10023_47col_10023_183
Genetic characterisation and social structure of the East Scotland population of bottlenose dolphins (Tursiops truncatus)
Islas, Valentina
Janik, Vincent
Graves, Jeff
Consejo Nacional de Ciencia y Tecnología (CONACyT) (Mexico)
MarBEF
Royal Society (Great Britain)
Population structure
Bottlenose dolphins
Male alliances
Association patterns
The Eastern Scottish population of bottlenose dolphins (Tursiops truncatus) is
the northernmost population of this species. The resident core of this
population consists of 120 to 150 different individuals. This small size and its
geographical isolation from other populations raises questions about its
viability and whether the population has behavioural patterns that differ
from those common to other populations of the same species. Microsatellite
genetic diversity was low and mitochondrial DNA genetic diversity values
were lowest in East Scotland compared to other populations worldwide and
to neighbouring populations around UK waters. It has been well
documented, from four different field sites worldwide, that male bottlenose
dolphins form alliances with preferred male associates. These alliances can
last for several years and the males involved show association coefficients similar to those of mothers and calves (0.8-1.0). These alliances
appear to be of great importance in obtaining matings for the males. In the
Eastern Scottish population males do not form alliances. No evidence of
strong associations between individuals of either sex was found and there
was no correlation between association and relatedness patterns. I suggest
that the isolation and small size of the population together with reduced
genetic diversity affects the pressure of kin selection for altruistic behaviours.
There is no gain in competing or associating with close relatives for access to
mates and it might be more important to avoid inbreeding by dispersing.
Although evidence of gene flow between East Scotland and its neighbouring
populations was not confirmed with Bayesian clustering analysis, a small set
of individuals from Wales were found to be closely related to individuals
from the East Coast of Scotland. In general the dynamics found in UK water
populations resemble those of the Western North Atlantic with sympatric
populations of coastal as well as pelagic individuals.
2010-09-20
2010-09-20
2010-06-23
Thesis
http://hdl.handle.net/10023/1002
en
viii, 154 p.
University of St Andrews
The University of St Andrews
Sea Mammal Research Unit, School of Biology
oai:research-repository.st-andrews.ac.uk:10023/3262019-07-01T10:16:22Zcom_10023_181com_10023_39col_10023_183
Investigating monitoring options for harbour seals in Special Areas of Conservation in Scotland
Cunningham, Louise
Boyd, Ian
Duck, Callan
Scottish Natural Heritage (SNH)
Habitats Directive
Managing a wild population effectively requires knowledge of the abundance and behaviour of the species. Harbour seals (Phoca vitulina) are usually counted when they come ashore at haul-out sites, and so it is important to understand how the number of seals counted at this time relates to total population size. Satellite telemetry studies confirmed that harbour seals on the west coast of Scotland showed a degree of site fidelity and coastal foraging. Most trips taken by tagged animals involved travelling only 10-30 km from haul-outs and lasted less than a day (mean 21.07 hours, SE = 0.54), although some seals travelled over 100 km. Eighteen percent of the time these tagged seals spent hauled out was in the Special Area of Conservation where they were caught.
Individual seals can be recognised from their unique pelage patterns using computer-assisted photo-identification. Capture histories for adult harbour seals at a site in north-west Scotland indicated that the number of seals using the study area between April and October was 3.4 times higher than the number counted during an aerial survey made during the August moult. In the UK, aerial surveys of harbour seals are usually conducted during the first three weeks of August, when seals are moulting. These counts have a coefficient of variation of around 15%. Land-based counts made at study sites on the north-west coast of Scotland indicated that the number of seals hauled out was most consistent during the moult, but highest counts were from the pupping period. Analysis of moult counts indicated that starting surveys one week earlier (on 7th August) and surveying 1½ hours earlier in the tidal cycle would reduce the count variation. There was spatial, seasonal, diurnal and sex-related variation in the proportion of time harbour seals hauled out. Thus the relationship between counts and total population size is likely to vary spatially and temporally. This variation should be included in the estimates of the CV of correction factors.
A 5% annual change in harbour seal population size was predicted to take around 14 years to detect based on annual surveys and a CV = 0.15. This detection period increases when monitoring methods with lower precision are used, or surveys are made less frequently. Trends in seal abundance at pairs of haul-out sites were not synchronous and so it is unlikely that counts from small land-based protected areas, such as Special Areas of Conservation, can be used to monitor overall population status.
2007-05-05
2007-05-05
2007-06-22
Thesis
http://hdl.handle.net/10023/326
en
http://creativecommons.org/licenses/by-nc-nd/3.0/
Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported
244
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/263972022-11-16T03:03:58Zcom_10023_45com_10023_17com_10023_181com_10023_39col_10023_47col_10023_183
Behavioural responses by seals to offshore energy activities
Whyte, Katherine Fae
Hastie, Gordon Drummond
Russell, Deborah Jill Fraser
Thomas, Len
Sparling, Carol E.
Great Britain. Department for Business, Energy & Industrial Strategy. Offshore Energy Strategic Environmental Assessment (SEA)
University of St Andrews. School of Biology
Renewable energy
Movement ecology
Pinnipeds
Biologging
Behaviour
Disturbance
Behavioural response
To effectively manage interactions between industrial activities and wildlife populations in increasingly urbanised environments, it is essential to understand how animals may be affected by different anthropogenic activities. In this thesis, I used biologging devices to investigate the potential effects of sound disturbance on seals. By simulation study, I evaluated the use of statistical tools (Mahalanobis distance) to detect unusual instances of movement and dive behaviour in seal biologging data. The results of these simulations were used to produce recommendations for future studies aiming to detect behavioural changes in animal movement data. Building on the findings of this work, I examined the movement and dive behaviour of 24 harbour seals (Phoca vitulina) during pile driving construction at an offshore wind farm in the UK. Using GPS location data collected on animal-borne tags, I identified statistically unusual horizontal movement events during pile driving, typically consisting of increases in speed, the cessation of horizontal movement, or the sudden initiation of travel. Using dive data from animal-borne tags, I identified statistically unusual groups of dives, and also characterised the effect of pile driving activity on behaviour-switching between different dive types (by hidden Markov models). Seals were found to switch dive behaviours more often during pile driving (compared to baseline periods), and the identified unusual dives were typically shorter and shallower, with longer post-dive surface intervals. For both horizontal and diving responses, dose-response curves were produced to estimate the relationship between the received sound level of pile driving and the probability of a behavioural change. By examining behaviour at the individual-level, improved insights of at-sea seal behaviour during disturbance events were gained. The results of this thesis also inform future offshore activities, enabling the renewable energy industry to develop in a timely and environmentally-responsible manner.
2022-11-15
2022-11-15
2022-06-15
Thesis
http://hdl.handle.net/10023/26397
https://doi.org/10.17630/sta/222
BEIS OESEA-16-74
en
http://hdl.handle.net/10023/21156
Whyte , K F , Russell , D JF , Sparling , C E , Binnerts , B & Hastie , G D 2020 , ' Estimating the effects of pile driving sounds on seals : pitfalls and possibilities ' , Journal of the Acoustical Society of America , vol. 147 , no. 6 , pp. 3948-3958 . https://doi.org/10.1121/10.0001408 [http://hdl.handle.net/10023/21156]
http://creativecommons.org/licenses/by-nc-nd/4.0/
2025-04-18
Thesis restricted in accordance with University regulations. Restricted until 18th April 2025
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
x, 267, 40 p.
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/191112021-03-23T17:20:08Zcom_10023_181com_10023_39col_10023_183
Energetics of moulting in phocid seals
Paterson, William David
Thompson, David
Marine Alliance for Science and Technology for Scotland (MASTS)
University of St Andrews
Scottish Natural Heritage (SNH)
Scotland. Marine Scotland
Institut polaire français Paul-Emile Victor
Terres australes et antarctiques françaises
Carnegie Trust for the Universities of Scotland
The moult in phocid seals is a distinct period when behavioural and physiological
changes occur. During this key stage in the annual life cycle animals elevate skin
temperature to facilitate proliferation of hair follicle cells as they shed and renew their
entire pelage. Due to the physiological constraints of raising skin temperature while in
the water animals must haul out on land with increasing duration as the moult proceeds.
The overall aim of this thesis was to provide insight into the physiology of moulting in
phocid seals and to determine the physiological consequences associated with changes
in haulout behaviour caused by anthropogenic disturbance. In harbour seals, metabolic
rate was higher during the moult compared to when the moult had finished, particularly
during the first 40 minutes after hauling out. Subcutaneous temperature increased at a
faster rate and reached a higher asymptote when seals were moulting. High skin
temperatures were also recorded in moulting southern elephant seals resulting in
increased heat flux to the surrounding environment. Heat loss values equated to animals
having a metabolic rate of up to 2.3 x Kleiber. Disturbance trials of harbour seals showed
that individuals were highly site faithful to haulout locations despite repeated
disturbance. The impact of disturbance is therefore not to cause animals to transition to
another site but to increase the frequency with which animals enter the water and the
duration of time spent at sea. Similar levels of disturbance may have thermoregulatory
consequences when seals are in a moulting state. These results demonstrate physiological changes during the moult that incur an increased metabolic demand.
Anthropogenic disturbance that causes seals to enter the water at a higher frequency
than normal when moulting may incur a cumulative energetic cost. Mitigation to protect
seals at haulout sites during the moult are supported by these findings.
2019-12-10
2019-12-10
2019-06-26
Thesis
http://hdl.handle.net/10023/19111
https://doi.org/10.17630/10023-19111
en
2021-06-06
Thesis restricted in accordance with University regulations. Print and electronic copy restricted until 6th June 2021
xviii, 279 p.
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/141892019-03-29T10:34:23Zcom_10023_45com_10023_17com_10023_181com_10023_39col_10023_47col_10023_183
Abundance estimate, survival and site fidelity patterns of Blainville’s (Mesoplodon densirostris) and Cuvier’s (Ziphius cavirostris) beaked whales off El Hierro (Canary Islands)
Reyes Suárez, Crístel
Aguilar de Soto, Natacha
Hammond, Philip S.
Beaked whales
Cuvier's beaked whale
Blainville's beaked whales
Abundance estimate
Survival
Site fidelity
Canary Islands
Photo-ID
Northeast Atlantic
Mark-recapture methods
Island-associated populations
Beaked whales (Fam. Ziphiidae) comprise 22 different species, however due to their cryptic behaviour, information on these species is very limited. Beaked whales appear to be highly sensitive to anthropogenic noise, which can lead to mass strandings. The scarcity of knowledge about the abundance and population dynamics of most beaked whale species impedes the correct assessment of the effects that these impacts have on their populations. Coastal, year round populations of Blainville’s and Cuvier’s beaked whales were found in El Hierro (Canary Islands) in 2003. Long-term photo-ID studies have been conducted since then using a combination of land and at sea observations. Here I present the first results relating to site fidelity, abundance estimates and apparent survival for Blainville’s and Cuvier’s beaked whales in the Northeast Atlantic. The number of identifiable adults, i.e. animals with regular to very good photos and recognizable marks in the same area of the body, comprises 69 Blainville´s and 66 Cuvier´s beaked whales. Individuals that were captured in only one year are considered transients (T) while animals seen in multiple years are defined here as recaptured (R). Analysis of site fidelity patterns showed that 35% and 53% of the marked population on Blainville’s and Cuvier’s, respectively, were recaptured and form island-associated populations with a pattern of residence in the area. In Blainville’s, females spend longer periods in coastal waters than males and indeterminate whales (subadults or adult females never observed with calves). Males visit the area during shorter periods and there is an apparent hierarchy in individual male use of the area. Indeterminate individuals seem to emigrate after a 3 year period. These data coincide with results from Bahamas in showing a higher number of females than males with high site philopatry, and less philopatry in subadults. It has been proposed that these observations in Bahamas could be explained by males fighting for access to the female resident population for polygynous mating, and some subadults leaving the area. In Cuvier’s beaked whales, there is no apparent sexual segregation in the use of the area albeit a low number of calves challenge a robust identification of adult females. More data are needed to define social structure of the Cuvier’s beaked whale population.
Mark-recapture methods were used to calculate abundance estimate and apparent survival in both species. Data was restricted to six years (2010 to 2015) in order to apply open and also closed population models that could account for heterogeneity in the data. Results of closed model estimates (Chapman analysis of two periods pooling data biannually: 2010-2013 and 2012-2015) are robust and provide best estimates corrected by the proportion of marked individuals of 33 (95% CI: 24-46) island associated Blainville´s beaked whales for both periods, and 53 (95% CI: 38-71, for 2010-2013) and 39 (95% CI: 34-44 for 2012-2015) island associated Cuvier´s beaked whales. POPAN open model analyses of the full period provides best estimates of total abundances of 103 (95% CI: 85-125) and 87 (95% CI: 73-103) for Blainville´s and Cuvier´s beaked whales, respectively.
2018-06-18
2018-06-18
2018-06-27
Thesis
http://hdl.handle.net/10023/14189
en
http://creativecommons.org/licenses/by-nc-nd/4.0/
Attribution-NonCommercial-NoDerivatives 4.0 International
xi, 89 p.
University of St Andrews
The University of St Andrews
Natural Environment Research Council (Great Britain). Sea Mammal Research Unit
oai:research-repository.st-andrews.ac.uk:10023/4322019-04-01T11:11:36Zcom_10023_181com_10023_39col_10023_183
Assessing grey seal (Halichoerus grypus) diet in western Scotland
Harris, R.N.
Hammond, Philip S.
Scottish Natural Heritage (SNH)
Scottish Executive Environment and Rural Affairs Department (SEERAD)
Grey seal diet was last comprehensively studied in western Scotland in 1985. Since then, the grey seal population has increased by approximately 30% and relative abundance of fish stocks in the area has changed markedly. The aim of this study was to provide a current assessment of diet to inform policy issues related to the impact of the still increasing grey seal population on commercial fish populations. During 2002, nine sampling trips totalling 56 days were completed around western Scotland, resulting in the collection of 1,589 grey seal scats. Forty-nine prey species were recorded in these samples revealing that grey seals on the west coast of Scotland remain highly catholic in their diet. Seasonal and regional variation in diet composition was assessed and the annual consumption of commercial fish species estimated. Proportions, by weight, of prey species indicated that gadoids were the main prey. Sandeels were also an important component of the diet. Comparisons between 1985 and 2002 revealed many similarities in diet composition but declines in the importance of sandeels, ling and megrim were balanced by increases in haddock, lemon sole, pelagic species and several benthic species. Changes in the size of fish stocks partially explain some of these changes. One exception is cod, which, despite very low abundance in 2002, formed a significant part of grey seal diet in western Scotland. Results from this study highlight the need for better methods for assessing absolute stock abundances for ‘critical’ fish species west of Scotland. Reducing the uncertainty over estimates of grey seal population size would also improve consumption estimates. The results from this study will be important to conservation and fisheries managers in Scotland.
2008-03-04
2008-03-04
2007-11-30
Thesis
http://hdl.handle.net/10023/432
en
100
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/48782019-07-01T10:08:28Zcom_10023_45com_10023_17com_10023_181com_10023_39col_10023_47col_10023_183
Population dynamics and distribution of northern Norwegian killer whales in relation to wintering herring
Kuningas, Sanna
Hammond, Philip S.
Holst, Jens Christian
Killer whale
Herring
Population dynamics
Norway
The northern Norwegian killer whale (Orcinus orca) is an important predator but little is known about its population dynamics, particular in response to changes in its main prey, the highly dynamic Norwegian spring spawning (NSS) herring (Clupea harengus). The main aims of this thesis were to estimate killer whale population parameters, to explore the future viability of the population, and to explore the response of this predator to changes in distribution and abundance of its main prey over the last 25 years. Population size was estimated as ~ 700 individuals, taking heterogeneity of capture probabilities into account and correcting for unmarked animals. Apparent survival rates of 0.974 (SE = 0.006) for adult males and 0.984 (SE = 0.006) for adult females were estimated accounting for temporary emigration, transience and trap-dependency. Temporary emigration was greater for males than females. Calving intervals ranged from 3 to 14 years (mean = 5.06); equivalent to 0.197 calves per mature female per year. Future viability of the killer whale population was evaluated under various plausible scenarios. The baseline scenario using the best available information predicted a viable population and indicated that the population may be increasing size. Analysis of data on naval sonar activity, killer whale sightings and herring abundance showed that naval sonar activity appeared to have a negative effect on killer whale presence during a period of low prey availability. A time lag of four years was found between the first sign of NSS herring changing its distribution and reduced killer whale presence inside the fjord system. Analysis of energy budgets showed that killer whales spent more time travelling/foraging in 2005/06 than the 1990s. The fjord system was inferred to be a preferred habitat for killer whales when there was a higher density of NSS herring in this area compared to offshore area.
2014-06-13
2014-06-13
2014-06-25
Thesis
http://hdl.handle.net/10023/4878
en
http://creativecommons.org/licenses/by-nc-nd/4.0/
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
xi, 248 p.
University of St Andrews
The University of St Andrews
Sea Mammal Research Unit
oai:research-repository.st-andrews.ac.uk:10023/44842019-07-01T10:15:19Zcom_10023_45com_10023_17com_10023_181com_10023_39com_10023_792col_10023_47col_10023_183col_10023_793
The effects of physical, biological and anthropogenic noise on the occurrence of dolphins in the Pacific region of the Panama Canal
Campbell Castillo, Inez
Hammond, Philip S.
SENACYT/IFARHU
Rufford Foundation
University of St Andrews. Scottish Oceans Institute
Dolphins
Background noise
Soniferous fish
Dolphin whistles
Anthropogenic noise
Fish chorus
Panama Canal
Temporal models
Spatial models
Occurrence
The main aim of this thesis was to investigate the occurrence of dolphins in Pacific waters adjacent to the Panama Canal in the context of biological, temporal and spatial factors. Acoustic data were collected at 101 sites at a range of distances and depths from the shipping region. Data were collected between March 2010 and April 2011 in a diurnal cycle over a total of 114 recording days. Received sound levels were split into 1/3 Octave bandwidths to study variation in sound pressure levels and then converted to spectrum density levels to show the sound components of the background noise in this region. Generalised Linear Models were used to relate dolphin whistle detections to temporal, spatial, environmental and acoustic variables.
The major sources of background noise were biological noise from soniferous fish and snapping shrimp and anthropogenic noise from vessels characterised by mid to high frequencies produced by artisanal fishing boats. There was monthly and diurnal variation with some locations characterised by loud sounds in the mid to high frequencies at night.
Whistle characteristics analysis revealed that the frequencies and range of the whistles were different to those previously reported under similar conditions. Whistles varied diurnally and in the presence of fish chorus and fishing boats. The study highlights a strong correlation between fish choruses and whistle detection.
Temporal and spatial models showed that whistle detections varied monthly and in relation to fish noise and small vessel engine noise. Dolphins were distributed throughout most of the study area; however, whistle detections varied with distance from the coast.
The results provide new knowledge about background noise composition in this region and provide the first information on the ecology of dolphin whistles in relation to this background noise, especially to fish chorus.
2014-02-28
2014-02-28
2014-06
Thesis
http://hdl.handle.net/10023/4484
en
http://creativecommons.org/licenses/by-nc-nd/4.0/
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
276
University of St Andrews
The University of St Andrews
Sea Mammal Research Unit
oai:research-repository.st-andrews.ac.uk:10023/41092019-03-29T10:37:07Zcom_10023_45com_10023_17com_10023_181com_10023_39col_10023_47col_10023_183
The seasonal movements and dynamics of migrating humpback whales off the east coast of Africa
Banks, Aaron M.
Hammond, Philip S.
Cockcroft, Vic
Findlay, Ken P.
Graves, Jeff
Humpback whale
Megaptera novaeangliae
Population dynamics
Africa
Migration
Photo identification
Genetics
Abundance
Southern right whale
Eubalaena australis
Habitat use
Skin lesions
Data collected during boat-based and aerial surveys were used to describe population structure, movements, temporal patterns of migration and skin condition of humpback whales in breeding sub-stock C1-S off southern Africa. Results confirmed that the migration route along the south coast of South Africa is linked to the winter ground off Mozambique. A lack of exchange between breeding sub-stocks C1-N and C1-S was found, suggesting that these are independent of each other. Molecular analysis revealed unexpected levels of population structure between the migration route and the winter ground of C1-S, as well as the possibility that this migration route is also utilised by some individuals from breeding sub-stock C3. A skin condition of unknown aetiology that primarily affects humpback whale mother-calf pairs was identified. The first assessment of its prevalence and severity was made, providing a baseline for future monitoring. Humpback whale abundance in an inshore region of Bazaruto Archipelago, Mozambique was estimated and attempts were also made to use the limited information off Plettenberg Bay/Knysna, South Africa. In addition to improving our understanding of humpback whales from Breeding Stock C, knowledge about another baleen whale species utilising the southwest Indian Ocean was extended. The first evidence of southern right whale presence off the coast of Mozambique since the cessation of whaling was documented. It remains unknown whether this is a remnant sub-stock or the recovering South African sub-stock reoccupying its historical range.
2013-10-22
2013-10-22
2013-11-29
Thesis
http://hdl.handle.net/10023/4109
en
228
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/155602019-09-27T08:55:36Zcom_10023_181com_10023_39col_10023_183
Counting the cost of tagging : quanitifying and reducing the behavioural and energetic impacts of tags in a large marine vertebrate
McKnight, Joseph Christopher
Thompson, David
Russell, Deborah Jill Fraser
NERC Sea Mammal Research Unit (SMRU)
Despite the invaluable contribution of animal-borne sensors to research, an underlying issue with their use is the potential to impact the behaviour and energetics of instrumented animals, which could have consequences for both animal welfare and data validity. Here I show that the presence of a SMRU GPS/GSM phone tag affects the behaviour and energetics of harbour seals (Phoca vitulina) and grey seals (halichoerus grypus). To reduce the impacts of tagging a computational fluid dynamic (CFD) modelling exercise was undertaken to quantify and describe the additional drag from a phone tag, which informed the redesign of a ‘new’ low drag phone tag. Central to the CFD modelling exercise was a biological relevant and spatially accurate geometry of a swimming harp seal (Pagophilus groenlandicus) generated by a three dimensional (3D) photogrammetrical methodology, developed and calibrated on sea carcasses. CFD modelling predicted additional drag from a phone tag on a 100kg harp seal was 16%. Tag redesign generated a more streamlined tag that reduced tag induced drag by 46%. Comparing the behaviour and energetics of juvenile grey seals carrying the ‘new’ or existing phone tag showed that despite significant reductions in drag resulting from redesign, there was limited amelioration of behavioural impacts and no reduction in the impact on energetics. To better understand the energetics of diving seals, a novel animal-borne sensor was developed. The sensor (PortaSeal) used non-invasive near-infrared spectroscopy ot measure the haemodynamics and oxygenation in the brain and blubber of juvenile harbour seals. Data from the PortaSeal provided numerous insights into the haemodynamic basis of oxygen management of phocid seals.
2018-07-19
2018-07-19
2018
Thesis
http://hdl.handle.net/10023/15560
en
2022-04-18
Thesis restricted in accordance with University regulations. Print copy restricted until 18th April 2020. Electronic copy restricted until 18th April 2022
xi, 168 p.
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/3272019-11-05T12:45:16Zcom_10023_45com_10023_17com_10023_181com_10023_39col_10023_47col_10023_183
Modelling space-use and habitat preference from wildlife telemetry data
Aarts, Geert
Matthiopoulos, Jason
Defence Science and Technology Laboratory (Great Britain)
Natural Environment Research Council (NERC)
ARGOS
Spatial autocorrelation
Serial correlation
Wildlife conservation
Generalized additive models
Generalized linear models
Mixed-effects models
Multi-colinearity
Spatial models
Resource selection
Satellite telemetry
Grey seal (Halichoerus grypus)
Northern gannet (Morus Bassanus)
Management and conservation of populations of animals requires information on where they are, why they are there, and where else they
could be. These objectives are typically approached by collecting data on the
animals’ use of space, relating these to prevailing environmental conditions
and employing these relations to predict usage at other geographical regions.
Technical advances in wildlife telemetry have accomplished manifold
increases in the amount and quality of available data, creating the need for a
statistical framework that can use them to make population-level inferences
for habitat preference and space-use. This has been slow-in-coming because
wildlife telemetry data are, by definition, spatio-temporally autocorrelated,
unbalanced, presence-only observations of behaviorally complex animals,
responding to a multitude of cross-correlated environmental variables.
I review the evolution of techniques for the analysis of space-use and
habitat preference, from simple hypothesis tests to modern modeling
techniques and outline the essential features of a framework that emerges
naturally from these foundations. Within this framework, I discuss eight
challenges, inherent in the spatial analysis of telemetry data and, for each, I
propose solutions that can work in tandem. Specifically, I propose a logistic,
mixed-effects approach that uses generalized additive transformations of the
environmental covariates and is fitted to a response data-set comprising the
telemetry and simulated observations, under a case-control design.
I apply this framework to non-trivial case-studies using data from
satellite-tagged grey seals (Halichoerus grypus) foraging off the east and
west coast of Scotland, and northern gannets (Morus Bassanus) from Bass
Rock. I find that sea bottom depth and sediment type explain little of the
variation in gannet usage, but grey seals from different regions strongly
prefer coarse sediment types, the ideal burrowing habitat of sandeels, their
preferred prey. The results also suggest that prey aggregation within the
water column might be as important as horizontal heterogeneity. More
importantly, I conclude that, despite the complex behavior of the study
species, flexible empirical models can capture the environmental
relationships that shape population distributions.
2007-05-07
2007-05-07
2007-06-20
Thesis
http://hdl.handle.net/10023/327
en
http://creativecommons.org/licenses/by-nc-nd/3.0/
Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported
197 p.
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/208232020-10-27T03:03:39Zcom_10023_181com_10023_39col_10023_183
Causes of individual variation in fasting fuel allocation and consequences for diving behaviour in grey seal pups (Halichoerus grypus)
Bennett, Kimberley A.
Fedak, Mike
Grey seal pups are weaned abruptly after a short, intensive nursing period, during
which
they lay down fat and protein. Fat stores are crucial for insulation when they
first go to sea and protein is essential for muscle and oxygen store development. Both
components also provide them with energy to sustain them during an extended
postweaning fast and their first days and weeks at sea until they can forage
effectively. There is thus a trade off between the requirements for fat and protein in
metabolism and for other functions. It is crucial for the survival of grey seal pups that
they begin to feed before these reserves become critically depleted. The ability to do
so
depends on the size of their fat and protein stores at weaning, energy partitioning
during the postweaning fast and the development of adequate diving and foraging
capabilities. The management of fat and protein stores through energy partitioning
and
appropriate timing of departure are key to survival but the mechanism by which
this management is achieved is unknown.
To
investigate the mechanism that controls energy partitioning and timing of
departure from the colony, changes in body mass and composition and levels of
hormones that are involved in energy balance in other mammals were measured
during the postweaning fast of wild grey seal pups. The impact of initial energy
reserves and hormone levels on
energy use and departure was investigated directly, by
manipulation of energy reserves and hormone levels, using supplementary feeding
and hormone treatment. This is the first time such intervention studies have been
performed in wild fasting pups. The impact of the stress of repeated handling on
hormone levels and energy utilisation was also examined. The movement patterns and
development of maximum diving capabilities of pups after departure were
investigated using satellite telemetry.
Leptin was present in grey seal serum but could not be measured accurately using two
currently available immunoassays. Prolactin was not detected in postweaned pup
serum and was eliminated as a
potential candidate for control of fuel use and timing
of
departure from the colony. Cortisol and thyroid hormones (TH) were measured in
serum but Cortisol could not be measured in grey seal saliva.
Cortisol and TH are
potentially involved in energy expenditure and fuel partitioning
during fasting. Cortisol and total thyroxine levels decreased from weaning to midway through the fast. Both hormones increased in response to both natural and artificially
induced
changes in fuel availability. Dexamethasone, a potent Cortisol analogue,
caused a short-term increase in mass
loss, and induced reversible and short-lived
changes in Cortisol levels and immune function, but its impact on energy partitioning
was unclear. The effects of the
drug were not mediated through TH. There were no
changes in TH or Cortisol consistently associated with the timing of departure and
dexamethasone did not induce
departure. Neither hormone therefore seemed likely to
be involved
directly in the cue to leave the breeding colony. Handling regime did not
impact significantly on Cortisol secretion, TH levels or long-term fuel use in grey seal
pups.
Fatter animals, or those provided with additional food, relied more heavily on
fat to meet
energetic requirements than leaner pups. There was no difference in
energy partitioning between the sexes. Grey seal pups had a greater tolerance to
protein depletion than terrestrial mammals but may have reached critical protein
levels soon after
departure from the colony. They were therefore under considerable
pressure to begin to feed very soon after they have gone to sea, despite their extensive
fat reserves.
Pups showed marked inter-individual differences in movement patterns, which
were
very different from those of adults. Initially they undertook coastal movement,
but showed wide
dispersal from the colony within their first few months at sea. They
began to exhibit adult-like repeated trips from known haul-outs to discrete offshore
areas 4-5 months after
departure. They were able to reach almost all areas and depths
available in the North Sea, but were constrained in their ability to remain submerged,
in terms of dive duration, post-dive surface interval and percentage of time spent
diving over extended periods, compared with adults. Their maximum ability to remain
submerged when they first went to sea was related to the duration of the postweaning
fast and thus the
degree of development on land. In contrast, maximum diving
capabilities achieved during the first three months at sea did not vary substantially
between animals and increased with time since
departure, and were thus likely to be a
product of diving-induced development of oxygen stores and cardiovascular control.
Overall, larger body size and longer fast duration conferred increased diving
capabilities, which may present one mechanism for increased survivorship in bigger
animals.
2020-10-26
2020-10-26
2005-06-24
Thesis
http://hdl.handle.net/10023/20823
en
xvii, 394 p.
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/238352021-08-25T11:30:31Zcom_10023_45com_10023_17com_10023_181com_10023_39col_10023_47col_10023_183
Fantastic feasts and where to find them : using biologging to investigate foraging behaviour of marine megafauna across a range of spatiotemporal scales
Vance, Heather Margaret
Johnson, Mark
Hooker, Sascha
University of St Andrews. School of Biology
Germany. Bundesamt für Naturschutz (BfN)
Megafauna
Optimal foraging theory
Biologging
Predator-prey interactions
Prey capture
Spatial scales of foraging
Understanding the strategies animals use to locate, select, and capture prey can guide more robust conservation efforts. In marine megafauna, foraging is often inferred from infrequent surface positions using biotelemetry tags. In this thesis I argue that finer-scale measurements of predator movements, prey availability and behaviour are critical to understanding foraging decisions. To explore this I used multi-sensor, high-resolution biologging tags on three megafauna species and compared optimal foraging predictions to actual behaviour over a hierarchy of spatiotemporal scales. At the landscape scale, I studied a central-place forager, the harbour seal, which accesses distant and nearshore prey although the relative importance of these resources is poorly understood. I found that prey encounter rates were similar for the two resources but while prey were distributed extensively offshore, inshore foraging was concentrated in just a few discrete patches. I suggest that the trade-off between accessibility and conspecific competition may influence site selection. At the patch scale, I studied a bulk-filter feeder, whale sharks, which are presumed to be highly-selective to offset the energetic cost of this strategy. Using novel sonar tags to record fine-scale behaviour and prey densities, I found that sharks did not selectively harvest rare dense patches. Instead, a less-selective strategy with continual-patch assessment may be advantageous when prey density is highly heterogenous. At the scale of prey captures, I studied the sensory and locomotor responses of an echolocating predator to evasive prey. Results revealed rapid responses to prey movements which scale with the acceleration of prey, enabling this energetically constrained mammal to reliably capture high-energy prey. Within each study, detailed biologging measurements were critical to understanding factors influencing foraging choices and capabilities. Such data help define the plasticity with which predators can respond to changing prey distribution, density, and performance, and provide critical insights to focus effective conservation actions.
2021-08-25
2021-08-25
2021-12-01
Thesis
http://hdl.handle.net/10023/23835
https://doi.org/10.17630/sta/125
Cluster 7, Z1.2-53302/2010/14
FKZ 3515822000
en
http://creativecommons.org/licenses/by-nc-nd/4.0/
2024-07-06
Thesis restricted in accordance with University regulations. Print and electronic copy restricted until 6th July 2024
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
[13], 208 p.
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/8952019-04-01T11:11:36Zcom_10023_181com_10023_39col_10023_183
On the dynamics and selective transport of fatty acids and organochlorines in lactating grey seals (Halichoerus grypus)
Arriola Ortiz, Aline
Pomeroy, Paddy
Organochlorines
Fatty acids
Grey seals
Mobilization
Transfer
Regional differences
This thesis examines fatty acid (FA) and polychlorinated biphenyl (PCB)
dynamics in a marine top predator, the grey seal (Halichoerus grypus,) and their
transfer during lactation from mother to offspring. It examines regional and annual
variations in FA composition and PCB loads, and also how the physical and chemical
characteristics of these molecules (e.g. their polarity and size) can affect the rates of
accumulation, mobilization and transfer of specific FAs or PCBs. Two UK grey seal
colonies (North Rona (NR) and Isle of May (IOM) were studied during three
consecutive years (1996-1998 and 2004-2006). Lactating grey seals and their pups
were repeatedly captured during the lactation period and sampled for blubber, serum
and milk and analysed for FAs and PCBs.
Overall, the two colonies were clearly distinguished from each other,
suggesting that the main prey species had different FA composition, and possibly
that the seals from these colonies had different diets . These differences are probably
a direct consequence of differences in prey community structure in the two regions
where seals from these two colonies are thought to feed. Within each colony, annual
differences could be detected between some years but not between others. During
1996-98, IOM seals showed a clear change in their FA profiles while NR seals did
not. In contrast, during 2004-2006 NR seals showed a clear change while IOM seals
did not. The changes observed in IOM during 1996-1998 are consistent with the
large-scale regime shift that occurred in the North Sea during the 1990‟s.
The relative proportions of each FA that were mobilized from blubber and
transferred to the milk during lactation were very similar between colonies, and
could be explained to a large degree by their physico-chemical properties. For a given
carbon chain length the mobilization increased with increasing number of double
bonds; and for a given number of double bonds the mobilization decrease with
increasing carbon chain length. However, the mobilization also appeared to be
influenced by the specific nutritional requirements of the growing pups. For instance,
FAs that are considered essential for pup development or efficient energy storage
(e.g. saturated FAs) were more highly mobilised than expected. This selectivity was
also reflected in the FA composition of the different body compartments (maternal blubber and milk, pup blubber) that persisted throughout lactation. These changes
were also similar between the colonies.
Colonies could also be clearly distinguished by their blubber PCB profiles. IOM
seals had higher total concentrations on average than NR seals (1327.9 vs. 680.2
ng/g lipid in 2005 and 1199.7 vs. 819.0 ng/g lipid in 2006). IOM seals also had
higher total amounts in both years (79.2 vs. 38.0 mg in 2005 and 61.7 vs. 53.4 mg in
2006). One of the main differences between colonies was that females from IOM had
higher concentrations of highly chlorinated congeners than NR seals.PCB
concentrations in blubber increased towards the end of lactation. Serum and milk
PCB concentrations also increased rapidly, especially for the highly chlorinated
congeners. These results were consistent with other studies showing the increase in
concentrations as a result of lipid loss. Serum concentrations stayed constant during
the first part of lactation and increased at late lactation. This was also observed in
milk PCB concentrations. The changes in the PCB profiles in the three body
compartments were very similar between colonies. However IOM seals always had
higher total concentrations of PCBs in all of the body compartments. The
concentrations of individual congeners relative to PCB-153 showed that blubber
contained higher proportions of the highly chlorinated PCBs relative to other tissues.
There were no clear changes in these proportions in blubber during lactation, but the
relative proportions of highly chlorinated PCB In serum and milk increased
throughout lactation while the less chlorinated PCBs stayed constant. The highly
chlorinated PCBs were found in lower concentration in the milk compared to the less
chlorinated compounds suggesting a selective release from blubber to blood and a
selective transfer of PCBs to the milk.
2010-06-03
2010-06-03
2010
Thesis
http://hdl.handle.net/10023/895
en
vii, 242
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/41532019-03-29T10:41:12Zcom_10023_45com_10023_17com_10023_181com_10023_39com_10023_792col_10023_47col_10023_183col_10023_793
Ecology of the Guiana dolphin (Sotalia guianensis) in the Southern area of the Gulf of Morrosquillo, Colombia : implications for conservation
Dussán-Duque, Beatriz Salomé
Hammond, Philip S.
Wells, Randall
Sotalia guianensis
Vulnerable
Habitat modelling
Abundance
Survival rate
Site fidelity
Cooperative feeding
Conservation
Sotalia guianensis is listed as “Data Deficient” by the IUCN and as “Vulnerable” in Colombia. This study aimed to advance understanding of the ecology of this species and its habitats, and to provide information to conservation management in the southern Gulf of Morrosquillo, Colombia. Systematic boat-based surveys were conducted during 395 days in 2002-2006 and 2009-2010, following established routes. Total survey effort was 15,199 km in an area covering ~ 310km². Fine scale habitat use and behavioural modelling, photo-identification and mark-recapture techniques were used to analyze the ecological patterns for this species. The most recent abundance estimate of dolphins using the study area during dry and rainy seasons, varied from 225 (CV = 0.34; 95% CI: 118-426) to 232 (CV = 0.32; 95% CI: 127-246). Annual survival rate is estimated at 0.948 (95% CI = 0.876-0.980). Overall density was 0.74/km². Dolphins were present year-round in the whole study area. Results indicate that they do not use the study area uniformly and that the use of particular zones is related to eco-geographic variables. Dolphins showed a preference for waters greater than 3m in depth with a slightly increased preference for waters about 5m and 15-25m deep. The average group size was nine individuals. Some individuals show long-term high site fidelity to some zones within the study site boundaries. Even though the site fidelity to feeding areas varied individually, all the individuals focused primarily on one specific area. Foraging was among one of the most predominant behaviours observed. The individual movements show that some dolphins use both bay and gulf waters. Dolphins show a range of surface cooperative foraging and feeding strategies. These cooperative behaviours were influenced by zone, group size and prey type. Based on these results an area of special management for the species will be created in Colombia.
2013-11-04
2013-11-04
2013-11-29
Thesis
http://hdl.handle.net/10023/4153
en
xi, 229
University of St Andrews
The University of St Andrews
Sea Mammal Research Unit, University of St Andrews and Sarasota Dolphin Research Program, Mote Marine Laboratory, USA
oai:research-repository.st-andrews.ac.uk:10023/34632019-07-01T10:12:25Zcom_10023_45com_10023_17com_10023_165com_10023_39com_10023_181com_10023_792col_10023_47col_10023_167col_10023_183col_10023_793
Estimating whale abundance using sparse hydrophone arrays
Harris, Danielle Veronica
Thomas, Len
Harwood, John
UK Defence Science and Technology Laboratory
Abundance estimation
Passive acoustic monitoring
Cetaceans
Passive acoustic monitoring has been used to investigate many aspects of marine mammal ecology, although methods to estimate absolute abundance and density using acoustic data have only been developed in recent years. The instrument configuration in an acoustic survey determines which abundance estimation methods can be used. Sparsely distributed arrays of instruments are useful because wide geographic areas can be covered. However, instrument spacing in sparse arrays is such that the same vocalisation will not be detected on multiple instruments, excluding the use of some abundance estimation methods. The aim of this thesis was to explore cetacean abundance and density estimation using novel sparse array datasets, applying existing methods where possible, or developing new approaches.
The wealth of data collected by sparse arrays was demonstrated by analysing a 10-year dataset collected by the U.S. Navy’s Sound Surveillance System in the north-east Atlantic. Spatial and temporal patterns of blue (Balaenoptera musculus) and fin whale (Balaenoptera physalus) vocal activity were investigated using generalised additive models.
Distance sampling-based methods were applied to fin whale calls recorded by an array of Ocean Bottom Seismometers in the north-east Atlantic. Estimated call density was 993 calls/1000 km².hr⁻¹ (CV: 0.39). Animal density could not be estimated because the call rate was unknown. Further development of the call localisation method is required so the current density estimate may be biased. Furthermore, analysing a single day of data resulted in a high variance estimate.
Finally, a new simulation-based method developed to estimate density from single hydrophones was applied to blue whale calls recorded in the northern Indian Ocean. Estimated call density was 3 calls/1000 km².hr⁻¹ (CV: 0.17). Again, density of whales could not be estimated as the vocalisation rate was unknown. Lack of biological knowledge poses the greatest limitation to abundance and density estimation using acoustic data.
2013-04-03
2013-04-03
2012-06-20
Thesis
http://hdl.handle.net/10023/3463
en
http://creativecommons.org/licenses/by-nc-nd/3.0/
2017-09-20
Thesis restricted in accordance with University regulations. Print and electronic copy restricted until 20th September 2017, pending formal approval
Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported
iv, 331
University of St Andrews
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/284292023-09-21T10:43:26Zcom_10023_45com_10023_17com_10023_181com_10023_39com_10023_792col_10023_47col_10023_183col_10023_793
Sounds beneath the surface : a multiple-approach study of bottlenose dolphin acoustic communication
Casoli, Marco
Tyack, Peter Lloyd
Johnson, Mark
Jensen, Frants
University of St Andrews. School of Biology
Scottish Universities Life Sciences Alliance (SULSA)
Strategic Environmental Research and Development Program (SERDP)
Dolphin Quest
Animal behaviour
Acoustic communication
Bottlenose dolphin
Signature whistles
Signature whistle copies
Biologging
Playback experiment
DTAG
Signal grading
Contact call
Addressing signaling function
Bottlenose dolphins (Tursiops truncatus) live in complex individualized societies that combine stable social units with fluid groups, and they largely rely on sound to interact with one another. This thesis applies a suite of approaches to study their acoustic communication. I studied the wild population of Sarasota, which offers long-term behavioural data and opportunities to deploy sound-and-movement recording tags. Bottlenose dolphins display a wide call repertoire, including graded sounds challenging to classify. I use dolphin social interactions to present a novel tag-based approach for studying communicative roles of call parameters changes. Applying continuously-sampled parameters, this approach examines how individuals change movements as a function of signal features. I focus then on signature whistles, sounds encoding identity information that in Sarasota are documented for most individuals. Signature whistles function as individually-distinctive contact calls, for instance between closely-bonded animals during separation, but their function between groups is poorly documented. Analysing Dtag data from instances of group encounters, I show that dolphins did not regularly produce signature whistles upon detecting another group, nor systematically before joining; instead, signatures appeared to be used strategically depending on the encountered individuals. Dolphins sometimes imitate the signature whistle of others, which is thought to function for addressing known individuals. Performing first-ever playbacks of natural signature whistle copies, I show that free-ranging subjects turned more frequently towards the playback upon hearing copies of their signature vs signature whistles of others, supporting the addressing function of copies. Signature whistle copies are often produced right after the subject’s signature, in so-called vocal matching interactions. Using playbacks with temporarily-captured subjects, I test whether signature whistle matching, or vocal matching per se, has an addressing signalling role. Subjects turned more times and produced their signature more frequently in response to signature whistle matching vs matching of other calls, supporting the former hypothesis.
2023-09-20
2023-09-20
2023-11-28
Thesis
http://hdl.handle.net/10023/28429
https://doi.org/10.17630/sta/615
RC-20-1097 (SERDP)
en
https://figshare.com/s/18cdc2832f5aaad73964
https://doi.org/10.6084/m9.figshare.14040218.v3
https://doi.org/10.6084/m9.figshare.14130338
https://doi.org/10.1007/s00265-022-03154-0
Marco Casoli - Jan2023 - PhD thesis - datasets
Casoli, M., University of St Andrews, Figshare, 2023. https://figshare.com/s/18cdc2832f5aaad73964
Manuscript "Parameterizing animal sounds and motion with animal-attached tags to study acoustic communication" - dataset of first case study
Casoli, M. (Contributor), Johnson, M. (Contributor), McHugh, K. (Contributor), Wells, R. (Contributor) & Tyack, P. L. (Contributor), Figshare, 1 Jan 2022. DOI: https://doi.org/10.6084/m9.figshare.14040218.v3
Manuscript "Parameterizing animal sounds and motion with animal-attached tags to study acoustic communication" - dataset of second case study
Casoli, M. (Creator), Johnson, M. (Creator), McHugh, K. (Creator), Wells, R. (Creator) & Tyack, P. L. (Creator), Figshare, 2022. DOI: https://doi.org/10.6084/m9.figshare.14130338
Casoli, M., Johnson, M., McHugh, K. A., Wells, R. S., & Tyack, P. L. (2022). Parameterizing animal sounds and motion with animal-attached tags to study acoustic communication. Behavioral Ecology and Sociobiology, 76(4), [59]. https://doi.org/10.1007/s00265-022-03154-0
http://creativecommons.org/licenses/by-nd/4.0/
2028-09-07
Thesis restricted in accordance with University regulations. Restricted until 7th September 2028
Creative Commons Attribution-NoDerivatives 4.0 International
202
The University of St Andrews
oai:research-repository.st-andrews.ac.uk:10023/156452023-03-20T13:35:47Zcom_10023_45com_10023_17com_10023_181com_10023_39col_10023_47col_10023_183
Getting below the surface : density estimation methods for deep diving animals using slow autonomous underwater vehicles
Gkikopoulou, Kalliopi Charitomeni
Tyack, Peter Lloyd
Smout, Sophie Caroline
Johnson, Mark
Gillesie, Douglas
Natural Environment Research Council (NERC)
Office of Naval Research (ONR)
Underwater gliders can provide an alternative cost-effective platform for passive acoustic monitoring surveys, compared to boat surveys, for abundance estimation and to collect high resolution environmental data for habitat studies. Gliders are usually equipped with one acoustic sensor, which limits the methods available for abundance estimation from acoustic data. Estimation of parameters used in distance sampling methodology, such as the detection function and cue rates, must be estimated separately from the glider deployment. A methodology for deriving the acoustic detection function of vocal animals is demonstrated in chapter 2 with a combined biologging and passive acoustic experiment. The methodology consists of distance estimation of the clicks produced by the tagged animal and detected at acoustic receivers placed at different depths, using surface bounce detections to estimate range. In addition, different detection algorithms were tested for the detectability of Blainville’s beaked whales. Detectability was found to vary with depth for Blainville’s beaked whales in the area of El Hierro (Canary Islands). The depth dependent detectability for this species was tested further in chapter 3 with a wider dataset from two different geographic populations of Blainville’s beaked whales, those of El Hierro and the Bahamas. Differences in detectability were found using depth and animal movement data as recorded on the DTAG in a simulated network of receivers placed at different depths. In addition, sequences of clicks, called click scans, were tested as an additional “cue” for cue counting methodology. The high directionality of beaked whale regular clicks leads to reduced detection ranges for receivers close to the surface or for receivers placed much deeper than the foraging depths of the wales and this reduction translates into varying lengths and numbers of detected click clusters as a function of distance and receiver depth. Chapter 4 presents a method for estimating density of animals from underwater gliders and tests the method in a simulated glider survey using different distribution and density scenarios using clicks and click scans as cue for density estimation.
2018-07-23
2018-07-23
2018
Thesis
http://hdl.handle.net/10023/15645
https://doi.org/10.17630/10023-15645
en
188 p.
University of St Andrews
The University of St Andrews