Few studies have investigated the impacts of established invasive birds on the native threatened avifauna. However, measuring the levels of mortality in native birds from exotic birds can help with management decisions on whether or not such introduced species need to be controlled. The black robin Petroica traversi is an endangered bird endemic to the Chatham Islands of New Zealand. Black robins build cup-like nests either within tree cavities ('cavity' nests) or in the sub-canopy vegetation ('open' nests). Nest predation, most likely by the invasive European starling Sturnus vulgaris, was the largest cause of nest failure in the main population of the black robin on Rangatira Island. Nest predation rate over five breeding seasons was 20.6% in comparison with 7.74% of nests failing because of severe weather events (the second largest cause for nest failure). Cavity nests experienced a significantly higher rate of predation (36.33%) than open nests (10.82%). The greater frequency of open nests (63.5% out of 244 nests monitored) may be a result of higher selection pressure by starlings on cavity nests. Nest height also influenced predation, with predation risk increasing from 4.88% for nests below 1 m to 31.89% for nests above 3 m. Overall, predation on black robin nests decreased chick production in the population by 15.6% annually. For a population of only 220-240 birds, this loss may be limiting continued population growth and we recommend that efforts be made to reduce predation through either the culling of starlings or the installation of nest boxes at the low heights avoided by starlings. bs_bs_banner Animal Conservation. Print ISSN 1367-9430 Starling predation and endangered black robins M. Massaro, M. Stanbury and J. V. Briskie

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Delta traps containing 6-pentyl-2H-pyran-2-one in a polyethylene bag at 2 m above the ground is the recommended method for monitoring NZFT, significantly improving the sensitivity, accuracy and labour input compared with prior methods. Long-term monitoring of NZFT could lead to more accurate economic damage thresholds and timing for when to apply insecticides. © 2014 Society of Chemical Industry.

Although it is well known that birds can assess predation risk through visual and auditory cues, there has been little research into whether similar processes occur with olfactory cues. We examined the role of odor cues in assessing nest predation risk in four species of passerine birds in New Zealand. We compared the ability of two introduced European species (common starling Sturnus vulgaris and song thrush Turdus philomelos) and two native New Zealand species (rifleman Acanthisitta chloris and South Island robin Petroica australis) to respond to the scent of rat urine placed in the nest. Rats are an introduced predator in New Zealand and we expected the native birds, which did not co-evolve with any mammalian predators, to lack behavioral adaptations to the scent of rats at their nest. As expected, both riflemen and robins failed to show any change in their behavior at their nest when rat urine was present compared to a control period in which no scent was present. However, a similar lack of response was observed in the introduced song thrush; only the common starling changed its behavior in the presence of the rat urine. Starlings with rat urine at the nest box were more likely to hesitate before entering and they also approached the nest, but refused to enter more often in the presence of rat scent. Both responses suggest they detected the presence of a predator and changed their behavior to minimize risk to themselves. Although based on a small number of species, our results suggest that responses to predator scent may be less common in New Zealand species, and may be a factor contributing to the vulnerability of native birds to introduced mammalian predators [Current Zoology 61 (1): [34][35][36][37][38][39][40][41] 2015].

This project investigated how kairomone lures, camera traps, and counting software could together contribute to pest management. Images of cumulative daily catch of New Zealand Flower Thrips (NZFT) attracted to a ripe peach lactone (6-pentyl-2H-pyran-2-one; 6-PAP) were automatically loaded to the internet and compared with scanned bases checked weekly using in-house software and manual counting. Camera traps were able to provide thrips counts equivalent to delta traps, but daily and remotely. An 11-fold greater NZFT count occurred within 24 h in passive traps after polyethylene sachets loaded with 250 mg of 6-PAP were placed in trees. Intensive trapping, by placing 1, 2, 4, and 8 traps per tree (500 mg/trap), resulted in a maximum 32-fold increase in thrips per tree. While 6-PAP has proved to be a useful tool for monitoring NZFT numbers, our results suggest that it is not likely to be suitable for mass trapping. Future research should investigate NZFT behavior to better understand population movement on an area-wide basis. Camera traps can be a valuable tool for recording insect flight activity remotely, but the number of traps required for statistically reliable estimates may be prohibitive.