Fish feed on faeces and vomits of New Zealand fur seals: marine mammals bring nutrients from open to inshore waters

Marine mammals are significant tourist attractions around New Zealand, however, the impact of eco-tourism on these species is poorly documented. Effective management to mitigate any negative effects requires an understanding of target species? reactions to tourist activities. We have studied the effects of tourist activities on New Zealand fur seals (Arctocephalus forsteri) using a novel combination of observations and controlled approaches. Three study areas were selected reflecting a range of visitor density, type of tourism, and the anticipated sensitivity of fur seals to disturbance. Behaviour was observed using instantaneous scan sampling and attributes of tourist approaches were tested experimentally by controlled approaches. Approaches were made on land, by kayak, and motorboat. Fur seal responses and the distance at which the seal responded were recorded. Our results indicate that A. forsteri behaviour was being modified by tourist activities. Habituation was occurring at study areas with high levels of tourist activity. Approachers following current minimum approach distances still caused some animals to modify their behaviour and new minimum approach distances are recommended based on controlled approaches to seals at all study areas. Our work demonstrated that controlled approaches can be a useful tool to develop effective management guidelines to lessen impacts from eco-tourism activities.

Download Full-text

An assessment of thermal-image acquisition with an unmanned aerial vehicle (UAV) for direct counts of coastal marine mammals ashore

Journal of Unmanned Vehicle Systems ◽

10.1139/juvs-2016-0029 ◽

2018 ◽

Vol 6 (2) ◽

pp. 100-108 ◽

Cited By ~ 5

Author(s):

Oliver Jordan Gooday ◽

Nicholas Key ◽

Sharyn Goldstien ◽

Peyman Zawar-Reza

Keyword(s):

New Zealand ◽

Thermal Imaging ◽

Marine Mammals ◽

Forest Canopy ◽

Infrared Camera ◽

Canopy Cover ◽

Future Research ◽

Infrared Thermal Imaging ◽

Coastal Marine ◽

Fur Seals

We investigated the efficacy of infrared thermal imaging devices for detecting coastal marine mammals in forested coastal environments. Our objective was to determine whether pinnipeds could be detected through the forest canopy using thermal imagery. We used a UAV-mounted and a ground-mounted infrared camera to survey New Zealand fur seals (Arctocephalus forsteri) located in Ohau Stream and Point Kean coastal shrub forest on the east coast of New Zealand. These methods were compared to paired photographs and walk-through counts. Ground-mounted thermal images detected more seals than paired photographs during the cooler times of the day (morning and evening). In contrast, aerial thermal videos were successful in detecting fur seals in open areas, but were less successful in areas of high canopy cover (>80%). We discuss the advantages and limitations of thermal imaging for population sampling and provide some recommendations for future research.

Download Full-text

First Complete Wing of a Stem Group Sphenisciform from the Paleocene of New Zealand Sheds Light on the Evolution of the Penguin Flipper

Diversity ◽

10.3390/d12020046 ◽

2020 ◽

Vol 12 (2) ◽

pp. 46 ◽

Cited By ~ 1

Author(s):

Gerald Mayr ◽

Vanesa L. De Pietri ◽

Leigh Love ◽

Al A. Mannering ◽

Joseph J. Bevitt ◽

...

Keyword(s):

New Zealand ◽

Marine Mammals ◽

Early Stage ◽

Foraging Strategies ◽

Cold Climates ◽

Functional Categories ◽

Stem Group ◽

Partial Skeleton

We describe a partial skeleton of a stem group penguin from the Waipara Greensand in New Zealand, which is tentatively assigned to Muriwaimanu tuatahi. The fossil includes the first complete wing of a Paleocene penguin and informs on previously unknown features of the mandible and tibiotarsus of small-sized Sphenisciformes from the Waipara Greensand. The wing is distinguished by important features from that of all geologically younger Sphenisciformes and documents an early stage in the evolution of wing-propelled diving in penguins. In particular, the wing of the new fossil exhibits a well-developed alular phalanx and the distal phalanges are not flattened. Because the wing phalanges resemble those of volant birds, we consider it likely that the wing feathers remained differentiated into functional categories and were not short and scale-like as they are in extant penguins. Even though the flippers of geologically younger penguins may favor survival in extremely cold climates, they are likely to have been shaped by hydrodynamic demands. Possible selective drivers include a diminished importance of the hindlimbs in subaquatic propulsion, new foraging strategies (the caudal end of the mandible of the new fossil distinctly differs from that of extant penguins), or increased predation by marine mammals.

Download Full-text

Records of vagrant fur seals (family Otariidae) in South Australia

Australian Mammalogy ◽

10.1071/am13038 ◽

2014 ◽

Vol 36 (2) ◽

pp. 154 ◽

Cited By ~ 4

Author(s):

Peter D. Shaughnessy ◽

Catherine M. Kemper ◽

David Stemmer ◽

Jane McKenzie

Keyword(s):

New Zealand ◽

South Australia ◽

The South ◽

South Indian Ocean ◽

Fur Seals ◽

South Indian ◽

Fur Seal ◽

New Zealand Fur Seal ◽

The Antarctic ◽

Subantarctic Fur Seals

Two fur seal species breed on the southern coast of Australia: the Australian fur seal (Arctocephalus pusillus doriferus) and the New Zealand fur seal (A. forsteri). Two other species are vagrants: the subantarctic fur seal (A. tropicalis) and the Antarctic fur seal (A. gazella). We document records of vagrant fur seals in South Australia from 1982 to 2012 based primarily on records from the South Australian Museum. There were 86 subantarctic fur seals: 49 specimens and 37 sightings. Most (77%) were recorded from July to October and 83% of all records were juveniles. All but two specimens were collected between July and November. Sightings were prevalent during the same period, but there were also nine sightings during summer (December–February), several of healthy-looking adults. Notable concentrations were near Victor Harbor, on Kangaroo Island and Eyre Peninsula. Likely sources of subantarctic fur seals seen in South Australia are Macquarie and Amsterdam Islands in the South Indian Ocean, ~2700 km south-east and 5200 km west of SA, respectively. There were two sightings of Antarctic fur seals, both of adults, on Kangaroo Island at New Zealand fur seal breeding colonies. Records of this species for continental Australia and nearby islands are infrequent.

Download Full-text

Handbook of Marine Mammals. Volume 1: The Walrus, Sea Lions, Fur Seals and Sea Otter. Sam H. Ridgway , Richard J. HarrisonHandbook of Marine Mammals. Volume 2: Seals. Sam H. Ridgway , Richard J. Harrison

The Quarterly Review of Biology ◽

10.1086/412998 ◽

1982 ◽

Vol 57 (4) ◽

pp. 480-481

Author(s):

Bernd Würsig

Keyword(s):

Marine Mammals ◽

Sea Otter ◽

Sea Lions ◽

Fur Seals

Download Full-text

Blunt trauma observed in a common dolphin delphinus sp. Likely caused by a vessel collision in the Hauraki Gulf, New Zealand.

Pacific Conservation Biology ◽

10.1071/pc130019 ◽

2013 ◽

Vol 19 (1) ◽

pp. 19 ◽

Cited By ~ 13

Author(s):

E Martinez ◽

K A Stockin

Keyword(s):

Spinal Cord ◽

New Zealand ◽

Public Education ◽

Marine Mammals ◽

Vertebral Column ◽

Common Dolphin ◽

Post Mortem ◽

Immature Male ◽

Blunt Force Trauma ◽

The Impact

While coastal cetaceans can become habituated to watercraft, that may not prevent their injury or mortality as a consequence of vessel strike. Here we report a case of a likely collision between a Common Dolphin Delphinus sp. and a recreational vessel in the Hauraki Gulf, New Zealand. Injuries sustained by the immature male dolphin were fatal. Recovery and subsequent post-mortem of the carcass revealed a transection of the spinal cord, with the vertebral column sustaining fractures between L17 and Cd7 and between Cd3 and Cd8 of the neural and transverse processes, respectively. Cd4 likely received the brunt of the impact given the vertebral body and epiphyses were also fractured. Paralysis of the lower truck and associated extensive internal injuries resulted in a live stranding and subsequent mortality. Injuries sustained were consistent of those of blunt force trauma, a consequence of an impact caused by a collision with a small watercraft, most likely a jet-ski. This incident reinforces the need for continued public education concerning safe water practices around marine mammals, which are protected under the New Zealand Marine Mammals Protection Act 1978 and Marine Mammals Protection Regulations 1992.

Download Full-text

Faecal testosterone concentrations and the acoustic behaviour of two captive male Australian fur seals

Australian Mammalogy ◽

10.1071/am09009 ◽

2009 ◽

Vol 31 (2) ◽

pp. 117 ◽

Cited By ~ 5

Author(s):

Joy S. Tripovich ◽

Tracey L. Rogers ◽

Geoff Dutton

Keyword(s):

High Frequency ◽

Seasonal Changes ◽

Marine Mammals ◽

Breeding Period ◽

Testosterone Concentration ◽

Acoustic Behaviour ◽

Future Studies ◽

Preliminary Information ◽

Fur Seals ◽

Hormonal Fluctuations

Seasonal changes in reproductive and acoustic behaviour are potentially affected by hormonal fluctuations; however, as it is difficult to routinely sample marine mammals, these associations are mostly inferred. Australian fur seals are vocal marine mammals that have a highly synchronous breeding season. The present study collected information on the testosterone concentration in faeces, vocalisations and behaviour of two captive male Australian fur seals to determine whether there are any associations between these variables. Positive associations were evident between the non-interactive agonistic behaviours (Head sway, Lay down and Head up) and an increase in calling rate of the bark calls in males. Barks were highest during August through to October, corresponding to the breeding period, while faecal testosterone levels peaked in September, coinciding with the high frequency in the calling rates of barks. Guttural threat calls were rarely heard throughout the year, but peaked in August. This call was not frequently heard but was associated with specific behaviours that were produced during more intense fighting interactions. This study presents preliminary information on the vocalisations, behaviour and hormone profiles for two captive Australian fur seals. Future studies with increased sample sizes from both wild and captive animals would clarify the intricate association between these factors.

Download Full-text

Seasonal dive behaviour of lactating New Zealand fur seals (Arctocephalus forsteri)

Canadian Journal of Zoology ◽

10.1139/z97-187 ◽

1998 ◽

Vol 76 (2) ◽

pp. 350-360 ◽

Cited By ~ 14

Author(s):

R H Mattlin ◽

N J Gales ◽

D P Costa

Keyword(s):

New Zealand ◽

Dive Depth ◽

Dive Duration ◽

Early Summer ◽

Late Winter ◽

Individual Values ◽

Dive Behaviour ◽

Fur Seals ◽

Fur Seal ◽

Bay Islands

The dive behaviour of 18 female New Zealand fur seals (Arctocephalus forsteri) from Taumaka, Open Bay Islands, New Zealand (43°52'S, 168°53'E), was recorded during early (summer; December-February), mid (autumn; March-May), and late (winter; June-August) lactation. Mean dive depth, dive duration, and bottom time for dives >=6 m in depth increased from summer through winter. Variation in individual seal dive behaviour within a season accounted for approximately 11, 9, and 11% of the observed difference between seasons in dive depth, dive duration, and bottom time, respectively. Seasonal dive data (mean ± 1 SD) were as follows: summer: dive depth 30 ± 37 m, dive duration 1.4 ± 1.1 min, and bottom time 0.5 ± 0.6 min; autumn: dive depth 54 ± 47 m, dive duration 2.4 ± 1.3 min, and bottom time 1.0 ± 0.8 min; winter: dive depth 74 ± 64 m, dive duration 2.9 ± 1.5 min, and bottom time 1.2 ± 1.1 min. Maximum recorded dive depth was 274 m for a 5.67-min dive in autumn. Maximum duration was 11.17 min for a dive to 237+ m in winter. New Zealand fur seals are the deepest diving fur seal species reported thus far. The estimated theoretical aerobic dive limit was exceeded on 18.4% of dives (range of individual values 0.2-57.8%). Females (n = 12) were ashore about 1.8 days at a time during February through November, and this increased to about 4.3 days during December and January. Average time spent away from the rookery ranged from 3 to 15 days.

Download Full-text