Faecal testosterone concentrations and the acoustic behaviour of two captive male Australian fur seals

2009 ◽  
Vol 31 (2) ◽  
pp. 117 ◽  
Author(s):  
Joy S. Tripovich ◽  
Tracey L. Rogers ◽  
Geoff Dutton
Keyword(s):  
High Frequency ◽  
Seasonal Changes ◽  
Marine Mammals ◽  
Breeding Period ◽  
Testosterone Concentration ◽  
Acoustic Behaviour ◽  
Future Studies ◽  
Preliminary Information ◽  
Fur Seals ◽  
Hormonal Fluctuations

Seasonal changes in reproductive and acoustic behaviour are potentially affected by hormonal fluctuations; however, as it is difficult to routinely sample marine mammals, these associations are mostly inferred. Australian fur seals are vocal marine mammals that have a highly synchronous breeding season. The present study collected information on the testosterone concentration in faeces, vocalisations and behaviour of two captive male Australian fur seals to determine whether there are any associations between these variables. Positive associations were evident between the non-interactive agonistic behaviours (Head sway, Lay down and Head up) and an increase in calling rate of the bark calls in males. Barks were highest during August through to October, corresponding to the breeding period, while faecal testosterone levels peaked in September, coinciding with the high frequency in the calling rates of barks. Guttural threat calls were rarely heard throughout the year, but peaked in August. This call was not frequently heard but was associated with specific behaviours that were produced during more intense fighting interactions. This study presents preliminary information on the vocalisations, behaviour and hormone profiles for two captive Australian fur seals. Future studies with increased sample sizes from both wild and captive animals would clarify the intricate association between these factors.

High‐frequency Acoustic Recording Package (HARP) for long‐term monitoring of marine mammals

2006 ◽  
Vol 120 (5) ◽  
pp. 3015-3015
Author(s):  
Sean M. Wiggins ◽  
Chris Garsha ◽  
Greg Campbell ◽  
John A. Hildebrand
Keyword(s):  
High Frequency ◽  
Marine Mammals ◽  
Long Term Monitoring ◽  
Acoustic Recording ◽  
Term Monitoring

Tourist Disturbance On New Zealand Fur Seals (Arctophalus Forsteri)

2002 ◽  
Vol 24 (1) ◽  
pp. 85 ◽  
Author(s):  
LJ Boren ◽  
NJ Gemmell ◽  
KJ Barton
Keyword(s):  
New Zealand ◽  
Marine Mammals ◽  
Effective Management ◽  
Negative Effects ◽  
Management Guidelines ◽  
Tourist Attractions ◽  
Fur Seals ◽  
Fur Seal ◽  
Current Minimum ◽  
The Impact

Marine mammals are significant tourist attractions around New Zealand, however, the impact of eco-tourism on these species is poorly documented. Effective management to mitigate any negative effects requires an understanding of target species? reactions to tourist activities. We have studied the effects of tourist activities on New Zealand fur seals (Arctocephalus forsteri) using a novel combination of observations and controlled approaches. Three study areas were selected reflecting a range of visitor density, type of tourism, and the anticipated sensitivity of fur seals to disturbance. Behaviour was observed using instantaneous scan sampling and attributes of tourist approaches were tested experimentally by controlled approaches. Approaches were made on land, by kayak, and motorboat. Fur seal responses and the distance at which the seal responded were recorded. Our results indicate that A. forsteri behaviour was being modified by tourist activities. Habituation was occurring at study areas with high levels of tourist activity. Approachers following current minimum approach distances still caused some animals to modify their behaviour and new minimum approach distances are recommended based on controlled approaches to seals at all study areas. Our work demonstrated that controlled approaches can be a useful tool to develop effective management guidelines to lessen impacts from eco-tourism activities.

scholarly journals Extreme weather events influence dispersal of naive northern fur seals

2009 ◽  
Vol 5 (2) ◽  
pp. 252-257 ◽  
Author(s):  
Mary-Anne Lea ◽  
Devin Johnson ◽  
Rolf Ream ◽  
Jeremy Sterling ◽  
Sharon Melin ◽  
...  
Keyword(s):  
Bering Sea ◽  
Marine Mammals ◽  
Habitat Choice ◽  
Climatic Conditions ◽  
Extreme Weather Events ◽  
First Year ◽  
Atmospheric Conditions ◽  
Fur Seals ◽  
San Miguel Island ◽  
The Bering Sea

Since 1975, northern fur seal ( Callorhinus ursinus ) numbers at the Pribilof Islands (PI) in the Bering Sea have declined rapidly for unknown reasons. Migratory dispersal and habitat choice may affect first-year survivorship, thereby contributing to this decline. We compared migratory behaviour of 166 naive pups during 2 years from islands with disparate population trends (increasing: Bogoslof and San Miguel Islands; declining: PI), hypothesizing that climatic conditions at weaning may differentially affect dispersal and survival. Atmospheric conditions (Bering Sea) in autumn 2005–2006 were anomalously cold, while 2006–2007 was considerably warmer and less stormy. In 2005, pups departed earlier at all sites, and the majority of PI pups (68–85%) departed within 1 day of Arctic storms and dispersed quickly, travelling southwards through the Aleutian Islands. Tailwinds enabled faster rates of travel than headwinds, a trend not previously shown for marine mammals. Weather effects were less pronounced at Bogoslof Island (approx. 400 km further south), and, at San Miguel Island, (California) departures were more gradual, and only influenced by wind and air pressure in 2005. We suggest that increasingly variable climatic conditions at weaning, particularly timing, frequency and intensity of autumnal storms in the Bering Sea, may alter timing, direction of dispersal and potentially survival of pups.

scholarly journals Restrictive Deterrence in Drug Offenses: A Systematic Review and Meta-Synthesis of Mixed Studies

2021 ◽  
Vol 12 ◽  
Author(s):  
Xin Guan ◽  
T. Wing Lo
Keyword(s):  
Systematic Review ◽  
High Frequency ◽  
Strategy Development ◽  
Facilitative Effect ◽  
Perception Of Risk ◽  
Drug Offenders ◽  
Future Studies ◽  
Drug Offenses ◽  
Restrictive Deterrence

Deterrence by punishment aims to prevent a crime; however, it is not always successful. Restrictive deterrence explains the continuous criminal activities that occur despite deterrence; offenders enact various strategies to avoid detection, which is more typical among drug offenders given that they have a high frequency of offending and exposure to punishment. This systematic review provides an in-depth understanding of restrictive deterrence of drug offenders. Two prominent themes, “restrictive deterrence strategy” and “deterrability and restrictive deterrence,” depict drug offenders' restrictive deterrence and effectively fit within the certainty–severity framework of punishment. Future studies should investigate restrictive deterrence strategies in the after-arrest context, the facilitative effect of perception of risk on strategy development, and facilitators or inhibitors affecting the diffusion of restrictive deterrence strategies.

scholarly journals An assessment of thermal-image acquisition with an unmanned aerial vehicle (UAV) for direct counts of coastal marine mammals ashore

2018 ◽  
Vol 6 (2) ◽  
pp. 100-108 ◽  
Author(s):  
Oliver Jordan Gooday ◽  
Nicholas Key ◽  
Sharyn Goldstien ◽  
Peyman Zawar-Reza
Keyword(s):  
New Zealand ◽  
Thermal Imaging ◽  
Marine Mammals ◽  
Forest Canopy ◽  
Infrared Camera ◽  
Canopy Cover ◽  
Future Research ◽  
Infrared Thermal Imaging ◽  
Coastal Marine ◽  
Fur Seals

We investigated the efficacy of infrared thermal imaging devices for detecting coastal marine mammals in forested coastal environments. Our objective was to determine whether pinnipeds could be detected through the forest canopy using thermal imagery. We used a UAV-mounted and a ground-mounted infrared camera to survey New Zealand fur seals (Arctocephalus forsteri) located in Ohau Stream and Point Kean coastal shrub forest on the east coast of New Zealand. These methods were compared to paired photographs and walk-through counts. Ground-mounted thermal images detected more seals than paired photographs during the cooler times of the day (morning and evening). In contrast, aerial thermal videos were successful in detecting fur seals in open areas, but were less successful in areas of high canopy cover (>80%). We discuss the advantages and limitations of thermal imaging for population sampling and provide some recommendations for future research.

scholarly journals Histochemical localization of enzymes and lipids in the ovary of a vespertilionid bat, Scotophilus heathi, during the reproductive cycle

2005 ◽  
Vol 65 (1) ◽  
pp. 179-186 ◽  
Author(s):  
U. P Singh ◽  
A Krishna ◽  
T. D. Smith ◽  
K. P. Bhatnagar
Keyword(s):  
Enzyme Activity ◽  
Seasonal Changes ◽  
Hydroxysteroid Dehydrogenase ◽  
Interstitial Cells ◽  
The Other ◽  
Breeding Period ◽  
Winter Dormancy ◽  
Total Lipids ◽  
High Incidence ◽  
Reproductive Phases

The present study describes seasonal changes in delta5 3beta hydroxysteroid dehydrogenase (3beta-HSD), glusose-6 phosphates dehydrogenase (G-6-PD), and lipids in the ovary of a vespertilionid bat, Scotophilus heathi. Total lipids and 3beta-HSD activity are restricted to thecal and interstitial cells of the ovary. The total lipids, 3beta-HSD, and G-6-PD significantly increase during recrudescence, and remain high during winter dormancy and breeding as compared to the other reproductive phases. High incidence of lipids and enzyme activity in interstitial cells during the breeding period and at the time of ovulation clearly suggests that these cells are actively involved in steroidogenesis. A decline in enzymes and lipid activity during winter dormancy, which correlates with the declining levels of steroidogenesis, might be the factors responsible for prolonged survival of the Graafian follicle in the ovary of S. heathi.

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