From Vagrant to Resident: occurrence, residency and births of leopard seals (<i>Hydrurga leptonyx</i>) in New Zealand waters

Hupman, Krista; Visser, Ingrid N.; Fyfe, Jim; Cawthorn, M. W.; Forbes, Giverny; Grabham, Alexander A.; Bout, Rick; Mathias, Brittany; Benninghaus, Ella; Matucci, Kimberly; Cooper, Tracy E.; Fletcher, London; Godoy, Daniel A.

doi:10.1080/00288330.2019.1619598

Cited by 18 publications

(22 citation statements)

References 33 publications

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“…In NZ, year-round air and sea temperatures are distinctly higher, resulting in a complete lack of sea ice, yet 15.8% (n = 3) of the total birth records we collated occurred within this region. Whilst we were not able to locate any records of pups in NZ, Hupman et al (2020) reported that 34% of leopard seal sightings within that region were of juveniles. If those juveniles were travelling from the Antarctic to NZ, one might expect them to arrive in NZ with compromised body condition, as is evidenced in juveniles documented in another northerly region, Australia (Rounsevell and Pemberton 1994).…”

Section: Occurrence By Regionmentioning

confidence: 79%

“…The NZ leopard seal birth records reported herein are an illustration of how such research can be applied to management and conservation initiatives. For example, local birth records supported the recent reclassification of leopard seals in NZ from 'Vagrant' to a 'Resident' species under the New Zealand Threat Classification System (Baker et al 2019;Hupman et al 2020). Such observations emphasise how the systematic collection of leopard seal sighting records in NZ should be continued and expanded upon to include more active monitoring of reproductive biology.…”

Section: Importance Of Further Researchmentioning

confidence: 95%

“…If those juveniles were travelling from the Antarctic to NZ, one might expect them to arrive in NZ with compromised body condition, as is evidenced in juveniles documented in another northerly region, Australia (Rounsevell and Pemberton 1994). However, in contrast, the majority of juvenile leopard seals sighted in NZ waters have been reported as being in good or excellent body condition (Hupman et al 2020). This may suggest that more leopard seal births are occurring on the mainland, offshore islands or the sub-Antarctic Islands of NZ, than has been documented.…”

Section: Occurrence By Regionmentioning

confidence: 99%

“…Generally, these extralimital occasional records involve juvenile animals, which appear to be the most mobile (Rounsevell and Pemberton 1994;Rogers et al 2005). Conversely, leopard seals have been recorded in New Zealand (hereafter NZ) waters since the twelfth century (Smith 1985) and the species has been documented yearround and includes immature and mature individuals of both sexes, in all regions (Hupman et al 2020).…”

Section: Introductionmentioning

confidence: 99%

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A review of leopard seal (Hydrurga leptonyx) births and pups using a standardised age-class classification system

Linde

Visser

Bout³

et al. 2022

Polar Biol

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Despite the ecological importance of leopard seals (Hydrurga leptonyx) as apex marine predators, little is known about their reproductive biology. To address this paucity, we reviewed leopard seal birth and pup records and applied a standardised age-class classification system to differentiate between births/newborns (offspring ≤ 14 days old) and pups (> 14 days but < 6 months old). We compiled 19 birth/newborn and 141 pup records and examined their occurrence by month, region, substrate, birth-specific attributes (i.e. birth observations, fresh umbilicus or placental), standard length, weight, presence of mother, presence of lanugo, sex, status (e.g. born alive) and fate. These records indicate that leopard seal births occur between September and December, with peak records from September to November, whilst pup records peaked between August and December. The regions with the most birth/newborn records were the sub-Antarctic Islands (31.6%) and Chile (31.6%), followed by Antarctica (15.8%), New Zealand (15.8%) and the Falkland Islands (5.3%). Pups were recorded predominantly in the sub-Antarctic Islands (54.6%), followed by the Antarctic (42.6%), Chile (2.1%) and Australia (0.7%). Whilst leopard seal birth records were predominantly on ice, they were also found on terra firma. The northernmost published leopard seal birth records occurred in New Zealand whilst the northernmost published leopard seal pup records occurred in Australia. This study contradicts the long-standing hypothesis that leopard seals only give birth on Antarctic pack ice, and instead, here we indicate that 84.2% and 57.4% of collated leopard seal birth and pup records, respectively, occur outside of Antarctica. Our records illustrate the importance of northern regions as part of the leopard seal’s range. We emphasise the need to conduct research focused on the reproductive biology of this keystone species throughout its range and that future management of leopard seal populations should also consider their northern range.

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Section: Occurrence By Regionmentioning

confidence: 79%

Section: Importance Of Further Researchmentioning

confidence: 95%

Section: Occurrence By Regionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A review of leopard seal (Hydrurga leptonyx) births and pups using a standardised age-class classification system

Linde

Visser

Bout³

et al. 2022

Polar Biol

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“…Finally, the contributions to marine mammal research from stakeholders such as whale and dolphin watching companies, citizen scientists, Iwi (Māori tribes), NGO's, other operators on the water, as well as the public, is vital. Those contributions have immense value in platforms-of-opportunity research (Hupman et al, 2015), in targeted research (this chapter) and in long-term monitoring of individual animals and populations (e.g., Berghan & Visser, 2001;Hupman et al, 2019). As such, we strongly encourage contributors to take high-resolution (e.g., RAW files) images which improve the chances of matching individuals (Urian et al, 2014;.…”

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confidence: 99%

ARGENTINEAN ORCA (ORCINUS ORCA) AS AN UMBRELLA SPECIES: CONSERVATION & MANAGEMENT BENEFITS

Copello¹,

Bellazzi²,

Cazenave³

et al. 2021

Contributions to the Global Management and Conservation of Marine Mammals

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O conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons Atribuição-Não-Comercial NãoDerivativos 4.0 Internacional (CC BY-NC-ND 4.0). Direitos para esta edição cedidos à Editora Artemis pelos autores. Permitido o download da obra e o compartilhamento, desde que sejam atribuídos créditos aos autores, e sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais.A responsabilidade pelo conteúdo dos artigos e seus dados, em sua forma, correção e confiabilidade é exclusiva dos autores. A Editora Artemis, em seu compromisso de manter e aperfeiçoar a qualidade e confiabilidade dos trabalhos que publica, conduz a avaliação cega pelos pares de todos manuscritos publicados, com base em critérios de neutralidade e imparcialidade acadêmica.

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Evaluating the performance of semiautomated photographic identification programs for leopard seals

Grabham,

van der Linde,

Nelson

2024

Wildlife Society Bulletin

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The photographic identification (photo‐ID) of individual animals can be time‐consuming and erroneous. Recent efforts to collect photographs of leopard seals (Hydrurga leptonyx) from across their range have necessitated the technological streamlining of photo‐ID. We constructed a dataset containing 595 photographs of the head and body of individuals recorded in New Zealand between 2008 and 2022 to test the performance of semiautomated 3 photo‐ID programs: HotSpotter, Interactive Individual Identification System's Pattern+ (I3S), and Wild‐ID. We classified attributes of photographs (e.g., quality) and individuals (i.e., pelage patterns) to assess their effect on performance. We compared performance using Top20 and Top1 Accuracy, defined as the proportion of test photographs where the highest ranked correct identity was in the top 20 and top 1, respectively, matched reference photographs. HotSpotter outperformed I3S and Wild‐ID in both Top20 and Top1 Accuracy of most assessed attributes. Maximizing HotSpotter's performance may be achieved through several methods, including increasing the number and variety of photographs of individuals in the dataset. HotSpotter will likely perform better with photographs without obstructions (e.g., debris from beaches), such as on the pack ice of their primary Antarctic range. We highlight the viability of HotSpotter in assisting the photo‐ID of leopard seals, and more broadly, other species with similar markings.

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From Vagrant to Resident: occurrence, residency and births of leopard seals (Hydrurga leptonyx) in New Zealand waters

Cited by 18 publications

References 33 publications

A review of leopard seal (Hydrurga leptonyx) births and pups using a standardised age-class classification system

A review of leopard seal (Hydrurga leptonyx) births and pups using a standardised age-class classification system

ARGENTINEAN ORCA (ORCINUS ORCA) AS AN UMBRELLA SPECIES: CONSERVATION & MANAGEMENT BENEFITS

Evaluating the performance of semiautomated photographic identification programs for leopard seals

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