Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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    Larger foraging area means greater fisheries interaction risk for juvenile yellow-eyed penguins in their sub-Antarctic range
    (Springer-Verlag GmbH, 2025-12-01) Muller CG; Chilvers BL; French RK; Battley PF
    Seabird foraging success is crucial for individual survival and therefore also for recruitment, breeding success, and population stability. However, there is limited information on the movements of juvenile seabirds, including penguins. This study investigates the foraging range of juvenile yellow-eyed penguins from Enderby Island, in the sub-Antarctic Auckland Islands, and their overlap with protected areas where commercial fishing is prohibited. Two juvenile penguins were tracked using GPS-Argos tags, and their movements were compared to those of breeding adults. Juveniles travelled up to 275.2 km from the colony, significantly farther than the maximum 46.7 km for breeding adults. Juveniles also used a much larger foraging area of 18,027 km2, compared to 738 km2 for adults. Only 7% of juvenile foraging occurred within the protected area, highlighting their potential vulnerability to commercial fishing activities. Juveniles had a 17% overlap with commercial fishing areas, compared to 4% for adults. The extensive foraging range and low overlap with protected areas suggest that juveniles are at higher risk of encountering threats, which may contribute to higher mortality rates. These findings underscore the need for conservation efforts to investigate and address threats in the broader foraging areas used by juveniles. Future research should track additional juvenile penguins and study prey availability to support effective conservation strategies for this endangered species.
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    The Validity and Reliability of a Global Navigation Satellite System in Canoe Slalom
    (MDPI (Basel, Switzerland), 2022-01-21) Macdermid PW; Coppelmans A; Cochrane D; Keogh J
    This study investigates the usefulness of a 10 Hz GPS device for tracking scalar performance in canoe slalom through assessing the validity of automated-informed-aerial video tracking (30 fps and 10 fps) and GPS capability in relation to a known track. Additionally, a real-world (canoe-slalom). A comparison between manual-aerial video tracking (10 fps) and the 10 Hz GPS was performed. All three methods of tracking used during the dry-land test (30 fps or 10 fps video and GPS) reported significantly lower distances (−3.2, −5.1 and −8.5%, p < 0.0001) but were deemed useful based on sample rate and body positioning difference. Intra-method reliability was good (CV = 2.5−2.6%) but requires visual inspection for dataset errors. Informed-colour filtered automated tracking on-water was not possible, but manual tracking provided fewer dataset errors than dry-land automated tracking. GPS significantly (p < 0.0001) under reports distance travelled at key moments during real-world slalom with a bias ± SD of 2.26 ± 2.07 m compared to 10 fps manual-aerial video tracking. The aerial video combined with manual tracking proved most suitable for tracking canoe slalom athlete trajectory in a real-world setting but needs to be automated into an application-based package to make it useable for coaches. GPS, as presented, provides insight but does not accurately quantify movements critical in determining the performance of canoe slalom.