Satellite tracking, with the CLS:Argos system, has provided enormous benefits to wildlife studies, especially for oceanic bird species. The system provides 2 locations, (1 from each side of the satellite orbit), but they are irregular over time and of variable accuracy. Procedures are described here to identify outlier locations and retain the maximum number of valid observations from DIAG files, thus producing a more homogeneous data set from which to map distributions, track movements, and investigate behaviour, while determining the rate and direction of travel.
Bird observations made during visits to Motuhoropapa Island between Nov 2004 and Sep 2006 have been compiled and compared to a bird list published in 1985. Variable oystercatcher (Haematopus unicolor) and paradise shelduck (Tadorna variegata) were recorded on the island for the 1st time, and tui (Prosthemadera novaeseelandiae) and morepork (Ninox novaeseelandiae) were recorded breeding. The island has now been free of introduced rats since 2002; the implications of the absence of rodents for birds on the island are discussed.
Roost sites in Whangarei Harbour and Ruakaka Estuary were used regularly by 12 wader species and 6 other species were present occasionally between 1974 and 2000. Counts at 7 roost sites in Nov, Jun/Jul, and Mar showed that 4 species, eastern bar-tailed godwit (Limosa lapponica), lesser knot (Calidris canutus), pied stilt (Himantopus leucocephalus), and South Island pied oystercatcher (Himantopus ostralegus finschi) contributed 70–99% (median 94%) of the waders. Most of the common waders used several roosts at each tide, but numbers and species richness of resident and vagrant species were greatest along the southern margin of the harbour. Changes in roost structure and proximity to feeding areas, and differences in migration patterns affected counts at individual roosts and the overall totals of wading birds counted in the harbour and its environs.
New Zealand average atmospheric temperatures showed little increase from the 1850s onwards for almost 100 years, but increased rapidly after c. 1940. The increase in temperatures was accompanied, at least in parts of New Zealand, by an increase in precipitation,. We investigated the relationship between the arrival years (1st breeding) of the bird species that self-introduced to New Zealand during the 20th century and the period of turpentine increase. Because these birds come from Australia the warming might be a prerequisite to colonize New Zealand. When considering the 1st breeding years as events in a univariate point process the process is non-stationary and the rate function has its estimated maximum in 1953. This estimate may indicate that the sequence of invasions of New Zealand by additional bird species could be a response to climate changes although the coincidence is on its own not sufficient to prove that climate changes have affected the self-introduction of birds from Australia into New Zealand. Alternative and additional explanations are discussed.
The CLS:Argos location and data collection system is used widely by researchers tracking the movements of animals. The accuracy of the Argos location classes is undefined for most Argos locations for studies involving tracking animals. Published empirical data on the accuracy of animal-mounted transmitters are limited to stationary units. The accuracy of the positions is defined by Argos, except for location classes (LC) = 0, A, B, and Z. The distinction between ‘accuracy’ and ‘precision’ is discussed using field measurements from 24,466 Argos records collected throughout the world, but mostly in the Southern Hemisphere, between 1992 and 2001. Factors affecting the defined ‘accuracy’ and ‘precision’ are identified from this analysis. Neither the transmitter’s age, nor its attachment to a bird degraded its performance. However, the performance of transmitters in terms of the locations they provided was affected when the objects they were attached to moved rapidly, and, with 1 platform transmitter terminal (PTT), by altering of the proportion of location classes within the experiment, but not the ‘precision’ of the classes (LC = 3, 2, 1, and A). The ‘precision’ (rounded, measured as 1 SD of the mean of the distance of the location from the actual position occupied by the transmitter, for ”Location Classes” 3, 2, and 1 was <2.5 km; that for LC = A, 15 km; LC = 0, 25 km, and for LC =B, 56 (latitude) and 94 km (longitude). The ‘accuracy’ (mean distance between the Argos location and the actual position of the transmitter, was 0.1-5.0 km for LC = 3 to B, which covers almost all the locations used by animal telemetry studies. The variation in ‘accuracy’ was, therefore, negligible compared to the variation in ‘precision’.
Males that defend territories with song benefit from sharing song types with their neighbours. Repertoire size, repertoire overlap between neighbouring birds, and song type delivery strategy were described for the South Island saddleback (Philesturnus carunculatus carunculatus). The song elements of 27 male South Island saddlebacks in the Ulva Island population near Stewart Island was categorised into one of 33 discrete phrase types; 10 common and 23 rare types. No stereotyped song types were found in the population. All syllables had harmonics and were simple in structure, consisting of a maximum of 2 or 3 elements. Male South Island saddlebacks had small to moderate phrase type repertoires and exhibited relatively high degrees of phrase type sharing with neighbours, which was even more prevalent when phrase cores and introductory syllables were analysed separately. Birds used a mixed-mode singing strategy, but also repeated partial and full phrases in song bouts. Compared to song studies of its North Island counterpart, the South Island saddleback had a larger phrase repertoire size, but phrase type sharing between neighbours seems to be important in both subspecies.
Roost sites in Whangarei Harbour and Ruakaka Estuary were used regularly by 12 wader species and 6 other species were present occasionally between 1974 and 2000. Counts at 7 roost sites in Nov, Jun/Jul, and Mar showed that 4 species, eastern bar-tailed godwit (Limosa lapponica), lesser knot (Calidris canutus), pied stilt (Himantopus leucocephalus), and South Island pied oystercatcher (Haematopus ostralegus finschi) contributed 70-99% (median 94%) of the waders. Most of the common waders used several roosts at each tide, but numbers and species richness of resident and vagrant species were greatest along the southern margin of the harbour. Changes in roost structure and proximity to feeding areas, and differences in migration patterns affected counts at individual roosts and the overall totals of wading birds counted in the harbour and its environs.
We investigated whether the abundance of the South Island robin (Petroica australis australis) could be explained by the abundance, species richness, diversity, or evenness of leaf-litter invertebrates. We recorded robin abundance indices and collected leaf-litter invertebrates in 3 forest types: mature Douglas fir (Pseudotsuga menziesii); mature Monterey pine (Pinus radiata); and old growth kanuka-manuka (Kunzea ericoides – Leptospermum scoparium). Robins were attracted to stations using 5-min playbacks of robin full song in each forest type. Invertebrates were extracted from leaf-litter samples using ‘Tullgren-type’ heat extraction funnels. There was no significant difference between the numbers of robins detected in the Douglas fir (1.14 5 min count-1), or kanuka-manuka forest (0.86 5 min count-1), and no robins were detected in the Monterey pine forest. Kanuka-manuka forest had the greatest biomass and species richness of leaf-litter invertebrates, but the lowest evenness. We believe that the abundance of the South Island robin can not be sufficiently explained by the density or directly of leaf-litter invertebrates.
Collections of bird specimens assembled by T.F. Cheeseman’s family in the late 1800s and early 1900s, are well-documented as to collecting localities and dates of collection. They provide a record of bird-life in the Auckland, New Zealand, region at that time. An inventory of the Auckland specimens is given, as well as information on 2 of Cheeseman’s siblings: William Joseph Cheeseman, who collected (i.e. shot) birds; and Emma Cheeseman, who prepared study skins. Of greatest interest among the bird specimens are species no longer present at the localities near Auckland city at which they were collected, including brown kiwis (Apteryx mantelli) at Waitakere (1881), brown teal (Anas chlorotis) at Ellerslie (1878) and Remuera (1880, 1886), fairy terns (Sterna nereis) at Orakei (1878), kokako (Callaeas wilsoni) at Titirangi (1878), and fernbirds (Bowdleria punctata) (1878) and pipits (Anthus novaeseelandiae) (1887) at Remuera. It would be very unusual to see black-fronted terns (Sterna albostriata) at the Manukau Harbour (recorded in 1879), and black stilts (Himantopus novaezelandiae) at Mangere (recorded in 1879) today.