birds

The diets of moa (Aves: Dinornithiformes)

For tens of millions of years the ratite moa (Aves: Dinornithiformes) were the largest herbivores in New Zealand’s terrestrial ecosystems. In occupying this ecological niche for such a long time, moa undoubtedly had a strong influence on the evolution of New Zealand’s flora and played important functional roles within ecosystems. The extinction of moa in the 15th century ce therefore marked a significant event in New Zealand’s biological history, not only in terms of biodiversity loss, but in the loss of an evolutionarily and ecologically distinct order of birds.

Dead birds found after aerial poisoning operations targeting small mammal pests in New Zealand 2003–14

In New Zealand, aerial poisoning with 1080 (sodium fluoroacetate) bait is widely used for control of introduced small mammal pests in remote or forested areas. However this practice is controversial, partly because of perceived risks to native fauna, particularly birds. That perception originally derives from substantial mortality of some native bird species in pre-1980 control operations, which prompted changes in baiting practice to mitigate most of the risk.

Identification of weta foraging on brodifacoum bait and the risk of secondary poisoning for birds on Quail Island, Canterbury, New Zealand

Brodifacoum is a second-generation anticoagulant used for rodent control in New Zealand. Concerns about the poisoning of non-target species have resulted in restrictions being imposed on the mainland. It is, however, still commonly employed on offshore islands. Previous research investigating the poisoning risks of brodifacoum has generally focused on birds eating brodifacoum bait (primary poisoning) or through depredation of live rodents or carrion containing brodifacoum residues (secondary poisoning).

Costs and benefits of aerial 1080 possum control operations using carrot baits to North Island robins (Petroica australis longipes), Pureora Forest Park

Large scale aerial poison operations with 1080-carrot baits are used extensively to control possum (Trichosurus vulpecula) populations in New Zealand forests for ecosystem conservation purposes and to stop the spread of bovine tuberculosis. Although various procedures have been implemented to reduce the incidence of bird kills, dead birds continue to be found after poison operations.

Plant-Species Preferences of Birds in Lowland Rimu (Dacrydium cupressinum) Forest—Implications for Selective-Logging

Plant species preferences of birds were determined by comparing the proportional bird use of plant species during direct observations with the proportions of plant species present on point-height intercepts in lowland rimu (Dacrydium cupressinum) forest in North Okarito, Westland. Plant species and bird use of plant species were divided into 5 m height classes, and rimu trees were divided into four age classes (sapling, pole, mature, and old).

Bird Abundance in Different-Aged Stands of Rimu (Dacrydium cupressinum)—Implications for Coupe-Logging

The abundance of birds in three different-aged stands (young, mature, and old) was examined at North Okarito, a lowland rimu (Dacrydium cupressinum) forest in Westland, using 5-minute counts, transect counts, and mist-netting. Most of New Zealand's common forest bird species were present in the study area, with relatively high numbers of brown creeper (Mohoua novaeseelandiae) and New Zealand robin (Petroica australis), and low numbers of kaka (Nestor meridionalis) and yellow- crowned parakeet (Cyanoramphus auriceps).