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Tracy E. Cooper

  • Biodiversity Journal, 15 (3): 547-584

    Ingrid N. Visser, Tracy E. Cooper, David Cothran, Gerald McCormack, Heiko Grimm, Pirjo H. Mäkeläinen & Mathieu Cusson
    Images confirm records of Fijian orca (Orcinus orca Linnaeus, 1758), including a group with indistinct saddle patches
    https://doi.org/10.31396/Biodiv.Jour.2024.15.3.547.584

    ABSTRACT
    We collated (n=36) records of orca (Orcinus orca Linnaeus, 1758, also known as the killer whale (Cetacea Delphinidae) in the waters of the Republic of Fiji, South Pacific Ocean. Using standardised criteria, we classified these records into Confirmed, Presumed and Unconfirmed. We then conflated replicated records to create (n=12) unique meta-records between 1994-2024. We confirm, for the first time with photographs/video, the species as present in Fijian waters with evidence (photos/video) for (n=6) records between 2006–2024 which illustrate species-specific characteristics. From within that dataset, we report on a group of five orca which had either extremely faint ‘belt’ shaped saddle patches, or no saddle patches. Based on this pigmentation anomaly we consider that they may be an aberrant group or belong to a previously undescribed tropical ecotype.

  • Biodiversity Journal, 13 (4): 0917-0948

    Krista van der Linde, Ingrid N. Visser, Sarah E. Richard, Tracy E. Cooper, Terry M. Hardie & Rick Bout
    Troubled waters: A case study of cohabitation conflicts for a leopard seal, Hydrurga leptonyx de Blainville, 1820 (Mammalia Phocidae) in northern New Zealand
    https://doi.org/10.31396/Biodiv.Jour.2022.13.4.917.948

    ABSTRACT
    The >9.5-year residency of an adult female leopard seal, Hydrurga leptonyx de Blainville, 1820 (Mammalia Phocidae) in New Zealand (NZ) provided an opportunity to investigate this species in the framework of human-wildlife conflicts and management. We examined >2,000 sighting records and collated observations of this leopard seal. We qualitatively describe conflicts originating from both the humans and leopard seal’s perspectives. Humans created conflicts for the leopard seal by providing misinformation about the species (and therefore negatively influencing public perception), making proposals or threats to disturb/harm, and causing inconvenience, tension, disputes, disturbance and harm to her. Conversely, the leopard seal created conflicts for humans including, causing inconveniences, tension, damage to property and disturbance. Short-term mitigation tools along with longer-term preventive strategies to reduce, mitigate and/or eliminate these conflicts are provided and we recommend that the NZ Government Authorities, who are legally mandated to protect the species, take the lead in implementing these in collaboration with stakeholders. Implementation of these tools and strategies, in a proactive rather than reactive manner, will assist with protection and management of leopard seals in all areas where they cohabitate with humans (both within NZ and internationally).

  • Biodiversity Journal, 13 (3): 0685-0693

    Ingrid N. Visser, Krista van der Linde, Sarah E. Richard, Tracy E. Cooper, Terry M. Hardie & Rick Bout
    Can a leopard seal, Hydrurga leptonyx de Blainville, 1820 (Mammalia Phocidae), change its spots? (Spoiler alert: at least one adult female can)
    https://doi.org/10.31396/Biodiv.Jour.2022.13.3.685.693

    ABSTRACT
    Leopard seals, Hydrurga leptonyx de Blainville, 1820 (Mammalia Phocidae) have variable spots on their pelage, allowing for identification of individuals. We monitored a subset of spots (n=40) on the face and neck of an adult female leopard seal residing in New Zealand. We compared images that were 1,701 days (~4 years and 8 months) apart. The use of scars, acquired from wounds, allowed for cross-matching and confirmation that this was the same individual. We investigated if the spots were more visible when the animal was wet or dry. We found that all 40 spots were visible during this time period and when the animal was both wet and dry. However, they were better defined, and therefore more visible, when the pelage was wet. Additionally, we identified a number of new and emerging spots, none of which masked or obscured the 40 aforementioned spots. These changes illustrate that diligence must be applied when matching individuals over long periods, to ensure that mis-matches and missed matches do not occur. Our findings do not invalidate photo-ID studies for leopard seals, rather they show that this is a robust system of identification, as spots were not lost over time and spot patterns were an effective tool for both individual identification and observing pigmentation change.

  • Biodiversity Journal, 11 (4): 1067-1086

    Ingrid N. Visser, Tracy E. Cooper & Heiko Grimm
    Duration of pseudo-stalked barnacles (Xenobalanus globicipitis) on a New Zealand Pelagic ecotype orca (Orcinus orca), with comments on cookie cutter shark bite marks (Isistius sp.); can they be used as biological tags?
    https://doi.org/10.31396/Biodiv.Jour.2020.11.4.1067.1086

    ABSTRACT
    This is the first published report of a New Zealand Pelagic ecotype orca (Orcinus orca Linnaeus, 1758, killer whale, Mammalia Cetacea) as a host for the pseudo-stalked barnacle (Xenobalanus globicipitis Steenstrup, 1852, Crustacea Coronulidae). The barnacles were documented on an adult female and she hosted >79, >3.5 times higher than any other orca worldwide. They were distributed on her dorsal fin (n=3), pectoral fins (n=>36) and tail flukes (n=>40), with a higher density on her right appendages (n=>48) compared to her left (n=>28). We also document, for the first time, the longevity of X. globicipitis hosted on an orca, with a minimum duration of 36 days. We provide a global overview of the distribution of X. globicipitis on orca, based on historic and recent publications. In previous reviews (spanning 111 years of records) X. globicipitis were documented in ten regions, while we add ten more regions, in just 13 years. This leads us to speculate as to the causes of this rapid increase, which may be linked to observer bias, improved research tools, a change in the distribution of either O. orca or X. globicipitis, with distribution of the latter perhaps influenced by oceanic conditions such as marine heatwaves and acidification triggered by climate change. As such, we discuss if either pseudo-stalked barnacles (or bite marks from cookie cutter sharks, Isistius sp., Chondrichthyes Squaliformes) can be used as biological tags or markers for orca ecotypes. We recommend separate management plans for orca ecotypes.