https://hdl.handle.net/10182/35 2018-01-25T15:18:13Z https://hdl.handle.net/10182/8796 Colony dynamics and social attraction in black-fronted terns, Chlidonias albostriatus Hamblin, Courtney Black-fronted terns (Chlidonias albostriatus) are one of six endemic bird species that rely on New Zealand’s braided river ecosystems for breeding. Black-fronted terns have a small, declining population and are classified as globally endangered, primarily due to predation. Unlike many other endangered species in New Zealand, black-fronted terns cannot be translocated to offshore, predator-free islands as braided river habitat exists only on the mainland. Currently, predator control, at varying scales, and habitat enhancement are the primary management strategies for black-fronted terns, neither of which have proven more than locally effective at reversing current population declines. Effective black-fronted tern management is challenging, not only due to the dynamic and unpredictable nature of the braided river environment, but also the behaviour of the terns themselves. Black-fronted terns frequently change their breeding colony locations both within and between years. The current research aimed to investigate black-fronted tern colony dynamics, and determine the viability of social attractants as a tool for black-fronted tern conservation. The location and size of black-fronted tern breeding colonies have been recorded from braided river bird surveys conducted over 13 years (2004-2015). Black-fronted terns are believed to have low site-fidelity due to the instability of their breeding habitat, small colony sizes and exposure to high predation rates. Two out of nine rivers analysed had colony distributions significantly different to random, a further two rivers had significant clustering of colony locations. Although the clustering was only significant in two rivers, the trend of clustering was consistent across all rivers analysed. There was no overall trend between colony size and the proximity of colonies in the previous or following seasons. Overall, these results support our a priori hypothesis of low site-fidelity in black-fronted terns, although, consistent clustering and spatial distribution trends suggest that they may exhibit greater fidelity to sites which remain suitable. Social attractants, decoys and audio playback, were deployed at ten sites within nine Canterbury braided rivers in the 2016 breeding season. We found that the terns interacted significantly (P < 0.001) more with the social attractants compared to the control plots (social attractants absent). Differences in tern interactions observed could not be explained by the differences in habitat between the experimental plots. Nearest tern breeding was recorded for eight of the ten sites, with five of these nesting records occurring within 300 m of the experimental plots. These results suggest that social attraction has the potential for use in black-fronted tern conservation. However, further research is required to determine the most attractive social attractant set up and whether the attractants can influence tern breeding colony locations. Camera traps were also trialled, recording tern behaviour at the experimental plots. At this stage, camera traps are not recommended as a replacement for human observation. 2017-07-01T00:00:00Z https://hdl.handle.net/10182/8791 Mohoua ochrocephala abundance in the Catlins following aerial 1080 control Katzenberger, J. K.; Ross, James G. Pest control using aerially-distributed 1080 bait could threaten non-target native bird species either by primary or secondary poisoning. To understand the impact of aerial 1080 control on the abundance of mohua (Mohoua ochrocephala), a vulnerable endemic forest bird, we analysed bird counts from the Catlins State Forest Park recorded over the period 1998-2002. Statistical modelling showed that mohua occupancy varied during the study and actually increased after 1080 control in 1999, but not significantly so. Concurrently with high predator numbers in the area during a beech (Nothofagus spp.) mast event, mohua abundance significantly declined in 2001 but then recovered in 2002. In conclusion, this study shows no negative effect for the nationally vulnerable mohua following a single aerial 1080 possum (Trichosurus vulpecula) control operation. In fact, with improvements in the experimental design and survey effort this study suggests future work could show positive effects of aerial possum control on populations, based on the increase in mohua occupancy observed directly after 1080 application. 2017-01-01T00:00:00Z https://hdl.handle.net/10182/8569 A comparison of horizontal versus vertical camera placement to detect feral cats and mustelids Nichols, M.; Glen, A. S.; Garvey, P.; Ross, James G. © New Zealand Ecological Society. Invasive predators are a threat to biodiversity in New Zealand. However, they are often difficult to monitor because of the animals’ cryptic, mobile behaviour and low densities. Camera traps are increasingly being used to monitor wildlife, but until recently have been used mainly for large species. We aimed to determine the optimal camera alignment (horizontal or vertical) for detecting feral cats (Felis catus) and mustelids (Mustela furo, M. erminea and M. nivalis). We deployed 20 pairs of cameras, each pair with one horizontal and one vertical camera. We compared the number of photos of target species, non-target species, and false triggers (i.e. camera triggered with no animal present) between camera orientations. Horizontally oriented cameras captured approximately 1.5 times as many images of the target species compared with vertically oriented cameras, and also detected more non-target animals. Orientation did not have a significant effect on the number of false triggers. 2017-01-01T00:00:00Z https://hdl.handle.net/10182/8555 Susceptibility of four grapevine rootstocks to Cylindrocladiella parva Brown, Dalin S.; Jaspers, Marlene V.; Ridgway, Hayley J.; Barclay, Candice J.; Jones, Elizabeth E. The susceptibility of four common grapevine rootstocks (101-14, Schwarzmann, 5C and Riparia Gloire) to Cylindrocladiella parva (black foot disease) infection was assessed in a pot experiment. The roots of 4-month-old callused rooted cuttings were wounded in situ and inoculated with 50 ml C. parva conidial suspension (106/ml) or sterile water (controls). After 6 months of growth, shoot dry weight was significantly higher for control plants (24.2 g) than for those inoculated with C. parva (16.5 g), but did not differ between rootstock varieties. Root dry weight was not significantly affected by C. parva inoculation, but root dry weight of 101-14 was significantly higher than other rootstocks. Incidence and severity of trunk infection were significantly affected by rootstock variety, being lowest in rootstock 101-14 plants than other rootstocks. None of the rootstocks tested was resistant to this pathogen. 2013-01-01T00:00:00Z