Interactions among invasive bird species have received relatively little attention despite the potential important consequences for community dynamics and invasion spread. Where species occupy similar environments the outcome may be particularly unpredictable. In this study we examined the foraging behaviours of 2 sympatric invasive birds in Mo’orea, the common myna (Acridotheres tristis) and the red-vented bulbul (Pycnonotus cafer), to determine if they exhibit behavioural or habitat partitioning. We investigated the ratio of foraging to vigilance behaviour of both species at novel food stations, as well as the effects of foraging group size and species composition on their behaviour. While the myna and bulbul exhibit similar behaviour, sites where they occur were partitioned within habitats. Novel food stations however, encouraged foraging at the cost of vigilance behaviours. Behaviours were not influenced by conspecific group size, and intraspecific interactions were more frequent, and of a greater intensity than interspecific interactions. These results suggest that the 2 species minimise competitive interactions by occupying different sites within the same habitat, and prioritise food acquisition in a new environment. Sympatric introduced species may avoid competitive exclusion if habitat usage limits the frequency of interactions.
Information was collected on the calling and display behaviour of 3 peacocks in the absence of peahens at Mansion House Historic Reserve, Kawau Island. The peacocks used an exploded lek display structure from late August to late December. Peacocks predominantly used the eow and occasionally the ka notes during tail displays but were silent during many displays. The overall composition of call notes given during the breeding period differed from than those used in a large dense peafowl breeding population in Japan.
This paper reports recent at-sea sightings of the little-known Heinroth’s shearwater (Puffinus heinrothi) within the Solomon Islands. Feeding habits are described and compared to those of black noddy (Anous minutus). Observations suggest that Heinroth’s shearwater occurs in dark, intermediate and pale forms, and may be better considered as a polymorphic species.
In New Zealand, translocation of native species is increasingly being proposed and carried out by community groups as well as the Department of Conservation (DOC). Usually a formal translocation proposal needs to be prepared and approved. Trends in the number and type of proposals approved during 2002-2010 are discussed. Over 300 translocation proposals were approved in this period. Many proposals consisted of more than one transfer. In 2002, proposals from community groups and joint proposals with DOC made up 16% of the approved proposals. In 2005 this had increased to 58%, but it dropped down to 38% in 2007 and in 2010 it had again increased to 71%. Proposals to move birds made up the largest proportion of applications (74%), followed by reptiles (15%), plants (6%) and invertebrates (5%). Kiwi (Apteryx spp.), robin (Petroica spp.), North Island kokako (Callaeas wilsoni) and seabird species (including Procellariformes, Spheniscidae and Laridae) were the most commonly translocated species. In response to the increased number of applications from community groups to carry out translocations, DOC has revised and improved the process for carrying out native species translocation projects.
We present the first detailed data on the Great Barrier Island (GBI) sub-population of the northern New Zealand dotterel (NNZD; Charadrius obscurus aquilonius). The breeding season population has averaged 48 birds (range: 41– 64) since 2000. At Awana on GBI, productivity has averaged >1.0 fledged chick per pair-year. The apparent survivorship of adult birds was less than that in the North Auckland sub-population. After breeding, most GBI birds congregated at Whangapoua Estuary/Okiwi Spit in the north of the island, making this a site of international importance under the Ramsar Convention (1971). The post-breeding population of c.56 birds (range: 41 – 77) was augmented by local juveniles and input from elsewhere. Banding returns provided evidence of movement between GBI and the adjacent mainland sub-population on the Coromandel Peninsula. There was no evidence that fewer predatory mammal species on GBI benefits the species at present. Conservation emphasis should focus on controlling mammalian predators and managing human impacts at breeding sites, especially early in the breeding season.
Pipit (Anthus novaeseelandiae) numbers and distribution were assessed at 7 sites near Whangarei, Northland. Foot surveys located significantly more pipits than car surveys at my study site on Ormiston Road. Car-based surveys identified Ormiston Road as a pipit site 88% of the time in summer, and other subsequent car surveys recorded pipits at rates of 0.06 – 0.07 birds/km on Whangarei roads. Calling and breeding behaviours commenced in August but no fledged young were seen before January. Monitored pairs fledged between 0 and 1 young per pair between 1999-00 and 2002-03. Pipits were generally recorded during the breeding season at densities of less than 1.6 birds/km, but up to 16.7 birds/km post breeding.
Reliable techniques need to be developed for monitoring the distribution and abundance of the endangered Australasian bittern (matuku, Botaurus poiciloptilus). We trialed 2 complementary methods for estimating the number of booming Australasian bitterns: acoustic triangulation from fixed listening stations, and using kayaks to quietly approach booming birds. Trials were conducted over 2 booming seasons (2011 and 2012) at Hatuma Lake, Hawkes Bay. The 2 methods gave similar estimates of the number of bitterns using Hatuma Lake (2011: 8-9 bitterns by triangulation and 9-10 bitterns by close approaches; 2012: 8-9 bitterns using triangulation and 7-8 bitterns by close approaches). We recommend using close approaches because there appeared to be less count-error or a combination of the 2 methods to estimate numbers of Australasian bitterns on small wetlands (
The Chatham Islands tui (Prosthemadera novaeseelandiae chathamensis) is a large forest honeyeater with a threat ranking of nationally endangered. It is restricted to a single population commuting between Pitt and South East Islands, with an estimated global population of 260 adults. We carried out a translocation of 54 juvenile tui from South East Island (42 females, 12 males) to the Awatotara Valley, Chatham Island in March 2009 (14 birds) and February 2010 (40 birds). Tui were held captive in an aviary for 2-8 days on the source island, and 3-6 days at the release site. Tui lost weight in captivity prior to transfer, but birds held for longer periods recouped more weight than those held briefly. Post-release survival was high; all birds from the 2009 cohort survived their first winter to breed at the release site. Survival of the 2010 cohort was less (54%), but this may have been due to our reduced ability to detect birds following wider dispersal. This translocation was part of a community project and has seen unprecedented support from the Chatham Island community and is a major step forward in the development of community driven conservation in the Chatham Islands.
Home range size and overlap in adult (> 4.5 years) and subadult (