Long‐term decline in abundance of male sperm whales visiting Kaikōura, New Zealand

2021 ◽  
Author(s):  
Tamlyn R. Somerford ◽  
Stephen M. Dawson ◽  
Elisabeth Slooten ◽  
Marta Guerra ◽  
Simon J. Childerhouse ◽  
...  
Keyword(s):  
PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244204
Author(s):  
Hayao Kobayashi ◽  
Hal Whitehead ◽  
Masao Amano

Little is known about the social structure of male sperm whales (Physeter macrocephalus) after they leave their natal units. While previous studies found no evidence for preferred associations among males, the observation of mass-strandings consisting exclusively of males, suggest that they have strong social bonds. To investigate the social associations among male sperm whales, we used half weight index of association, permutation tests and standardized lagged association rate models on a large photo-identification database collected between 2006 and 2017 in Nemuro Strait, Japan. Our results suggest that while male sperm whales are not as social as females, they do form long term associations, have preferred companionship, and forage in social proximity to each other. The best-fitting model to the standardized lagged association rate showed that associations among males last for at least 2.7 years and as most males leave the area after 2 years, associations may last for longer. Twenty dyads were observed associating over more than 2 years, for a maximum 5 years. One dyad was observed associating on 19 different days and clustered on 7 different days. Male associations may function to enhance foraging or to fend off predators. Such relationships seem to be adapted to a pelagic habitat with uncertain resource availability and predation pressure.


2002 ◽  
Vol 80 (7) ◽  
pp. 1189-1196 ◽  
Author(s):  
Erland Lettevall ◽  
Christoph Richter ◽  
Nathalie Jaquet ◽  
Elizabeth Slooten ◽  
Steve Dawson ◽  
...  

Sperm whales (Physeter macrocephalus) are sexually dimorphic in several respects, including size, latitudinal distribution, and social structure. Females are known to have complex social structures, including long-term bonds, but the social structures of sexually mature or maturing males have received much less attention. Using data from aggregations of males off Norway, Nova Scotia, New Zealand, and the Galápagos Islands, we examined aggregation size, residence times within aggregations, clustering at the surface, and long-term bonds. Results were generally consistent among study areas. The aggregations found in each area contained around 10–30 males at any time, and were usually a few tens of kilometres across. Mean residence times within aggregations ranged from a few days to a few weeks. Close clustering at the surface was rare, but present at each site. There was no evidence for preferred companionship between individuals at any temporal scale in any of the study areas. The rarity of clustering and the apparent lack of long-term relationships amongst male sperm whales contrast strongly with results of studies on females, suggesting that both close spatial proximity at the surface and permanent bonds between individuals may be a consequence of the need for care of the young.


2006 ◽  
Vol 22 (1) ◽  
pp. 46-63 ◽  
Author(s):  
Christoph Richter ◽  
Steve Dawson ◽  
Elisabeth Slooten

2000 ◽  
Vol 78 (3) ◽  
pp. 407-419 ◽  
Author(s):  
Nathalie Jaquet ◽  
Stephen Dawson ◽  
Elisabeth Slooten

Male sperm whales (Physeter macrocephalus) were the preferred target of the whaling industry between 1950 and 1985, but despite hundreds of thousands of kills, very little is known about their ecology. To partially redress this, we present data on residency, seasonal distribution, and diving behaviour of individually identified sperm whales off Kaikoura, South Island, New Zealand, gathered during 15 field seasons over 8 years. One hundred and thirty-six sperm whales were identified within the study area. A lack of statistically significant differences in the abundance of sperm whales between summer and winter, and among the 15 seasons of fieldwork, suggests an adequate food supply year-round. Significant differences in distribution between summer and winter suggest that off Kaikoura, male sperm whales may change their diet in response to fluctuations in prey biomass. Diving behaviour was also significantly different between summer and winter: sperm whales dived for longer, stayed longer at the surface, and travelled farther between consecutive fluke-ups in summer than in winter. Unlike female sperm whales, males at Kaikoura spent little time at the surface; they spent about 83% of their total time under water. This paper represent the most extensive non-invasive study of male sperm whales and provides new insights into their ecology.


1996 ◽  
Vol 12 (3) ◽  
pp. 447-451 ◽  
Author(s):  
S. J. Childerhouse ◽  
S. M. Dawson ◽  
E. Slooten
Keyword(s):  

2017 ◽  
Vol 70 ◽  
pp. 160-164 ◽  
Author(s):  
G.W. Bourdôt ◽  
S. Jackman ◽  
D.J. Saville

Flupropanate (sodium 2,2,3,3 tetrafluoropropanate), a slow-acting lipid bio- synthesis-inhibiting herbicide, was recently registered in New Zealand as Taskforce (745 g/L flupropanate as the sodium salt) for the selective and long-term control of Nassella trichotoma (nassella tussock) in pastures. In five dose-response experiments in permanent hill pastures in Canterbury, conducted between 2012 and 2016, we measured the efficacy of the herbicide against established plants of N. trichotoma and its residual activity against recruiting seedlings. Mortality, as an average across the five sites, was 93% 1.5 years after applying 1.49 kg flupropanate/ha (the label-recommended rate), and 100% at 2.98 kg/ha. This indicates that an application rate higher than the label rate will be necessary for complete control of a N. trichotoma infestation. The presence of 1,000 and 6,250 visible seedlings of N. trichotoma/ha in the autumn 3.2 and 2.1 years after applying 1.49 kg flupropanate/ha (at a Greta Valley and Scargill site respectively) indicates that the herbicide’s soil residues had decayed within 12 months to a concentration lower than necessary to kill the germinating seedlings of N. trichotoma.


2020 ◽  
Author(s):  
Hiran Thabrew ◽  
Karolina Stasiak ◽  
Harshali Kumar ◽  
Tarique Naseem ◽  
Christopher Frampton ◽  
...  

BACKGROUND Approximately 10% to 12% of New Zealand children and young people have long-term physical conditions (also known as chronic illnesses) and are more likely to develop psychological problems, particularly anxiety and depression. Delayed treatment leads to worse physical and mental healthcare, school absence, and poorer long-term outcomes. Recently, electronic health (eHealth) interventions, especially those based on the principles of Cognitive Behavior Therapy (CBT), have been shown to be as good as face-to-face therapy. Biofeedback techniques have also been shown to enhance relaxation during the treatment of anxiety. However, these modalities have rarely been combined. Young people with long-term physical conditions have expressed a preference for well-designed and technologically-based support to deal with psychological issues, especially anxiety. OBJECTIVE This study aimed to co-design and evaluate the (i) acceptability and (ii) usability of a CBT and biofeedback-based, 5-module eHealth game called ‘Starship Rescue’ and (iii) to provide preliminary evidence regarding its effectiveness in addressing anxiety and quality of life in young people with long-term physical conditions. METHODS Starship Rescue was co-designed with children and young people from a tertiary hospital in Auckland, New Zealand. Following this, 24 young people aged 10 to 17 years were enrolled in an open trial, during which they were asked to use the game for an 8-week period. Acceptability of the game to all participants was assessed using a brief, open-ended questionnaire, and more detailed feedback was obtained from a subset of 10 participants via semi-structured interviews. Usability was evaluated via the System Usability Scale (SUS) and device-recorded frequency and duration of access on completion of the game. Anxiety levels were measured prior to commencement, on completion of the game, and 3 months later using the Generalized Anxiety Disorder 7-item scale (GAD-7) and Spence Child Anxiety Scales (SCAS), and at the start of each module and at the end of the game using an embedded Likert/visual analog scale. Quality of life was measured prior to commencement and on completion of the game using the Pediatric Quality of Life Scale (PEDS-QL). RESULTS Users gave Starship Rescue an overall rating of 5.9 out of 10 (range 3-10 and a mean score of 71 out of 100 (SD 11.7; min 47.5; max 90) on the System Usability Scale (SUS). The mean time period for use of the game was just over 11-weeks (78.8 days, 13.5 hours, 40 minutes). Significant reductions in anxiety were noted between the start and end of the game on the GAD-7 (-4.6 (p=0.000)), SCAS (-9.6 (p=0.005)), and the Likert/visual analogue scales (-2.4 (p=0.001)). Quality of life also improved on the PedsQL scale (+4.3 (p=0.042)). All changes were sustained at 3-month follow-up. CONCLUSIONS This study provides preliminary evidence for Starship Rescue being an acceptable, usable and effective eHealth intervention for addressing anxiety in young people with long-term physical conditions. Further evaluation is planned via a more formal randomized controlled trial. CLINICALTRIAL Australian New Zealand Clinical Trials Network Registry (ANZCTR): ACTRN12616001253493p;https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=371443 (Archived by WebCite at http://www.webcitation.org/6sYB716lf)


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 758
Author(s):  
Fiona Esam ◽  
Rachel Forrest ◽  
Natalie Waran

The influence of the COVID-19 pandemic on human-pet interactions within New Zealand, particularly during lockdown, was investigated via two national surveys. In Survey 1, pet owners (n = 686) responded during the final week of the five-week Alert Level 4 lockdown (highest level of restrictions—April 2020), and survey 2 involved 498 respondents during July 2020 whilst at Alert Level 1 (lowest level of restrictions). During the lockdown, 54.7% of owners felt that their pets’ wellbeing was better than usual, while only 7.4% felt that it was worse. Most respondents (84.0%) could list at least one benefit of lockdown for their pets, and they noted pets were engaged with more play (61.7%) and exercise (49.7%) than pre-lockdown. Many respondents (40.3%) expressed that they were concerned about their pet’s wellbeing after lockdown, with pets missing company/attention and separation anxiety being major themes. In Survey 2, 27.9% of respondents reported that they continued to engage in increased rates of play with their pets after lockdown, however, the higher levels of pet exercise were not maintained. Just over one-third (35.9%) of owners took steps to prepare their pets to transition out of lockdown. The results indicate that pets may have enjoyed improved welfare during lockdown due to the possibility of increased human-pet interaction. The steps taken by owners to prepare animals for a return to normal life may enhance pet wellbeing long-term if maintained.


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