During 1994, participants in the Beach Patrol Scheme patrolled 3253 km of the New Zealand coastline. 5477 dead seabirds of 55 species, plus 121 individuals of 25 non-seabird species were found. Unusual finds were the first New Zealand record of a Newell’s shearwater (Puffinus newelli), one soft-plumaged petrel (Pterodroma mollis) and one eastern little tern (Sterna albifrons sinensis). Large numbers of Kerguelen petrels (Lugensa brevirostris), flesh-footed shearwaters (Puffinus carneipes) and Buller’s mollymawks (Diomedea bulleri) were beach-cast in 1994. Fisheries-related mortality was identified for some seabirds found on beach patrols.
The saddleback (Philesturnus carunculatus) is now confined to New Zealand offshore islands free of the introduced carnivorous mammals, i.e. rats, feral cats and mustelids, which are assumed to have exterminated the species on the mainland during the last century. The North Island saddleback (Philesturnus carunculatus rufusater) coexists with the Polynesian rat (Rattus exulans) while the South Island saddleback (P c. carunculatus) thrives only on rat-free islands. An experimental transfer to Kapiti Island, where Norway (R. norvegicus) and Polynesian rats occur, provided an opportunity to test the hypothesis that North Island saddlebacks could coexist with both rat species. I compared the survival of saddlebacks on Kapiti Island with that on Cuvier and Little Barrier Islands where the only rodent is R. exulans. On Kapiti Island, saddlebacks suffered high mortality, and despite high productivity, there was insufficient recruitment of young to balance losses of adults. Significantly more nests sited less than one metre above the ground were preyed on by rats on Kapiti Island than on Cuvier and Little Barrier Islands. Saddlebacks on Kapiti Island which roosted in high or secure cavities survived longer than those birds which roosted in low or vulnerable places. These observations are consistent with the ground-foraging and predatory behaviour of R. norvegicus. On Kapiti Island, 21 rat-killed birds were found at nests and roosts, whereas no rat-killed birds were found at nests and roosts on Cuvier and Little Barrier Islands, although the contents of some nests were preyed on by R. exulans. On Kapiti Island, R. norvegicus faeces were found with the remains of several dead birds, providing direct evidence that this rat was the predator. The poor survival and recruitment of saddlebacks on Kapiti Island, coupled with observations of rat-killed birds and plundered nests near the ground, suggest that saddlebacks are unable to coexist with both rat species, and that R. norvegicus is probably an important predator. The cavity nesting and roosting habits of the saddleback make this species especially vulnerable to mammalian predators.
In October-November 1992 the island of Mangaia, Cook Islands, was surveyed for tanga’eo (Halcyon tuta ruficollaris). The tanga’eo was found to be primarily a forest bird, preferring continuous forest canopy. Its abundance was influenced by forest type, extent, and degree of habitat modification. A number of potential threats to the survival of tanga’eo were identified including habitat loss and disturbance by common mynas (Acridotheres tristis). A brief survey of rodents was carried out. Although the tanga’eo population was estimated to have been between 250 and 450 birds, low numbers of birds in apparently suitable forest in the southwest of Mangaia indicate that further research is needed to determine population trends and conservation requirements.
Pipit (Anthus novaeseelandiae) numbers on nine count routes in the Wellington region ranged from 0.16 to 6.22 per km on average. Estimated densities in regions with some favourable habitat varied between 1.0 and 2.5 per square kilometre. Highest numbers were in the hills south and west of Karori, and on the southern and western beaches between Owhiro Bay and Titahi Bay. Densities were lower over the rest of the region due to intensive farming, unfavourable plant succession pathways to bush, and urban development.
On Ewing Island, Auckland Islands, during the austral summer of 1991-92, Auckland Island teal Anas aucklandica aucklandica were dispersed principally as pairs occupying and vigorously defending small all-purpose territories. Most territories were around the margins of the island, either within a narrow fringe of grassland, or at the very edge of Olearia lyallii forest with access to boulder beaches or low wave platforms. Few territorial pairs lived entirely within the forest. A small number of juveniles and unpaired adults assembled as a flock at one protected coastal location where food was super-abundant, but other unpaired birds appeared to live furtively around the margins of occupied territories. Some non-territorial pairs persistently tried to occupy sections of shoreline in the face of defence by territorial pairs. Only territorial pairs were observed breeding. Females sited their nests on the ground well hidden from view above and laid eggs each of which weighed, on average, 14.8% of body mass. Mean clutch size in 45 nests was 3.4 eggs and hatching success of 86 eggs was 93%. Ducklings were first seen on 11 December and most broods had been reduced to a singleton within eight days of hatching. The probability of a duckling surviving from hatching to 30 days was 0.272. The estimated mean size of extant broods at fledging was 1.6. By estimation, only 14% of ducklings may survive to fledging, and up to two-thirds of all breeding pairs may fail to raise any young. Re-laying by unsuccessful pairs may extend the breeding season into April. Males contributed fully to care of the brood but were not always seen in close attendance. By comparison with other related Australasian teals, Auckland Island teal have a more terrestrial lifestyle and show more enduring territoriality.
Foraging flights of three female Auckland Island wandering albatross (Diomedea exulans gibsoni) were tracked from Adam Island in the Aucklands group by satellite radio telemetry. Two of the birds were incubating eggs, while the third was in the early stages of chick raising. All three birds made long flights of 11-13 days and 1000-1500 km into the Tasman Sea. The chick-rearing female also made shorter flights of less than 4 days and 900 km. The distances covered were similar to those recorded for other wandering albatross subspecies, but foraging strategies differed. Auckland Island birds initially flew fairly directly and at high speed, then seemed to slow down and change direction more frequently for a few days, before flying directly back to the Auckland Islands. Two explanations are suggested: birds may have been “commuting” to favoured foraging areas, or were blown by the winds. Speeds reached during the “commuting” phase were similar to those recorded for D. e. chionoptera, but were slower at other times. The Tasman Sea between latitudes 45°S and 40°S is an important foraging area for some female wandering albatross breeding on Adam Island.
Five surveys for the North Island kokako were carried out in the Hunua Range, Auckland between October 1992 and March 1994. Twenty six-28 kokako were recorded, including 3 possibly 4 pairs. Results suggest that there has been a decline in kokako numbers since the previous survey in 1986-1988. All kokako were recorded in tawa-podocarp forest. The birds ranged in altitude between 320 m and 640 m. Birds were distributed in the following catchments: Mangatangi (13 birds), Mangatawhiri (12 birds), Orere (2 birds), Tapapakanga (1 bird). Nearly all records (65%) were of birds heard rather than seen. Two pairs were seen.