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Leopard seal (Hydrurga leptonyx) moult affects the application of glued tags used to monitor activity. Considering the possible effects of climate change on leopard seal activity and climate on pinniped moult, we assessed aspects of leopard seal moult in a warm region (New Zealand) of their range for the first time. Moult pelage colours resembled those found in their primary range and indicated a progressive degeneration akin to that of the pre-moult of other pinnipeds. Unexpectedly, pelage loss commonly resulted in black areas, that may be skin or short dark post-moult pelage. The reverse pattern of moult, reported for the first time in this species, was more prevalent than the standard pattern. In the reverse pattern, black areas commonly progressed from the neck down the spine. Pre-moult was uncommon, but active moult occurred year-round. Year-round moulting may have implications for glued tagging in climatically similar regions of their range. [ABSTRACT FROM AUTHOR]

In contrast to previous reports that leopard seals (Hydrurga leptonyx) are rare vagrants to New Zealand, we show that this species is a regular member of the marine fauna of this region. We present a first analysis from the New Zealand Leopard Seal Database – an extensive collation of 2,711 records of leopard seals within New Zealand between 1200 and 2018. Of these records, 51.2% (n = 1,408) were photographic. Leopard seal sightings have increased over time and been reported in all seasons and regions of New Zealand. Sightings are predominantly of adult individuals of good or excellent body condition, which differs to previous hypotheses suggesting that leopard seals visiting New Zealand shores are primarily juvenile animals in poor health condition. A total of 176 unique individuals have been identified in the New Zealand Leopard Seal Catalogue between 2014 and 2018 and preliminary results indicate that numbers per annum have continued to increase over time. Three leopard seal births and a number of juvenile animals (34% of the NZ records) have been documented. Considering the information presented here and the current definitions in the New Zealand Threat Classification System, the threat status of leopard seals within New Zealand waters should be reclassified from Vagrant to Resident. [ABSTRACT FROM AUTHOR]

On a global scale, false killer whales ( Pseudorca crassidens) remain one of the lesser-known delphinids. The occurrence, site fidelity, association patterns, and presence/absence of foraging in waters off northeastern New Zealand are examined from records collected between 1995 and 2012. The species was rarely encountered; however, of the 61 distinctive, photo-identified individuals, 88.5% were resighted, with resightings up to 7 yr after initial identification, and movements as far as 650 km documented. Group sizes ranged from 20 to ca. 150. Results indicate that all individuals are linked in a single social network. Most observations were recorded in shallow (<100 m) nearshore waters. Occurrence in these continental shelf waters is likely seasonal, coinciding with the shoreward flooding of a warm current. During 91.5% of encounters, close interspecific associations with common bottlenose dolphins ( Tursiops truncatus) were observed. Photo-identification reveals repeat inter- and intraspecific associations among individuals with 34.2% of common bottlenose dolphins resighted together with false killer whales over 1,832 d. While foraging was observed during 39.5% of mixed-species encounters, results suggest that social and antipredatory factors may also play a role in the formation of these mixed-species groups. [ABSTRACT FROM AUTHOR]

Forty-nine species of cetaceans have been recorded in the literature with cookie cutter shark (Isistius sp.) bites. The first record of a cookie cutter shark bite mark on orca (Orcinus orca) was from New Zealand waters in 1955. We present 37 unpublished records of cookie cutter shark bite marks on orca in tropical to cold waters; a further six published records were collated, and additionally 35 individuals with bite marks were noted in photo-identification catalogues. A total of 120 individuals and 198 bite marks were recorded, with the northernmost at 70° 44′ N and the southernmost at 77° 14′ S. We provide the first healing rate of a cookie cutter shark bite mark on an orca in New Zealand waters, with a maximum of 150 d between open wound and healed scar. Longevity of scars is considered, with one particular bite mark still visible as a dark grey oval/elliptic mark 1,158 d post photographing the open wound. Open cookie cutter shark bite marks were not observed on orca photographed in Antarctic waters, despite the majority of bite marks being recorded on Antarctic orca. This suggests a high level of movement outside the Antarctic cold water regions as the known distribution of cookie cutter sharks is in warm temperate to tropical waters. Supporting evidence for these movements is given by records of Antarctic orca in New Zealand waters with open cookie cutter shark bite marks. [ABSTRACT FROM AUTHOR]

The article presents a study about events involving attacks by Antarctic peninsula killer whales on preys, including five seals and a penguin, that were hauled out on ice floes. The total size of the ice floes in these events were estimated by comparing them to the average size of the seal. The study also determined the sex and age class of the individual killer whales based on their relative size. The attack on a penguin using wave-washing method by a single juvenile killer whale is also discussed.