ORCID Profile
0000-0002-4384-978X
Current Organisation
The University of Auckland
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Publisher: Wiley
Date: 23-01-2023
Abstract: The global pet trade provides a pathway for introduced species to invade new environments. Most studies use trade data as an indirect proxy for propagule pressure exerted by the pet trade. Instead, we quantify the reported rate of loss of captive birds, assess factors that might influence this rate, simulate the survival and retrieval of birds and the overall cumulative propagule pressure exerted by pet birds on the environment. We used online listings of lost birds to estimate the propagule pressure that the pet trade exerts on the establishment of introduced bird species in Aotearoa–New Zealand. Listings from two popular websites were monitored daily for over 3.5 years, and information was recorded on the frequency, location, species composition and characteristics of the loss events. We investigated a range of factors that may influence the rate of loss events, such as season and human population size. We also developed a simulation approach to investigate the cumulative propagule pressure in Auckland, New Zealand's largest city. A total of 1205 birds and at least 33 species were reported lost nationwide during our monitoring period, 92% of which were parrots. We found that the reported loss rate was higher in areas of higher human population size and median income, and lower in the winter months. Simulation results predict that in any given month in Auckland there is an average of at least 491 escaped birds, including 136 potential breeding pairs, and for seven species the chance that at least one locality has a male/female pair at large exceeds 80%. Synthesis and applications . Online listings of lost pets provide an excellent source of data from which to identify species with high propagule pressure in specific localities. We identified escaped parrot species as a high‐risk invasion pathway, as they contribute to a high and consistent propagule pressure. A preventative approach, by banning the sale of these species, is the most appropriate pest management strategy for reducing the probability of establishment and potential impact.
Publisher: Wiley
Date: 10-2013
DOI: 10.1890/12-1657.1
Abstract: Superpopulation capture-recapture models are useful for estimating the abundance of long-lived, migratory species because they are able to account for the fluid nature of annual residency at migratory destinations. Here we extend the superpopulation POPAN model to explicitly account for heterogeneity in capture probability linked to reproductive cycles (POPAN-tau). This extension has potential application to a range of species that have temporally variable life stages (e.g., non-annual breeders such as albatrosses and baleen whales) and results in a significant reduction in bias over the standard POPAN model. We demonstrate the utility of this model in simultaneously estimating abundance and annual population growth rate (lamda) in the New Zealand (NZ) southern right whale (Eubalaena australis) from 1995 to 2009. DNA profiles were constructed for the in idual identification of more than 700 whales, s led during two sets of winter expeditions in 1995-1998 and 2006-2009. Due to differences in recapture rates between sexes, only sex-specific models were considered. The POPAN-tau models, which explicitly account for a decrease in capture probability in non-calving years, fit the female data set significantly better than do standard superpopulation models (deltaAIC > 25). The best POPAN-tau model (AIC) gave a super-population estimate of 1162 females for 1995-2009 (95% CL 921, 1467) and an estimated annual increase of 5% (95% CL--2%, 13%). The best model (AIC) gave a superpopulation estimate of 1007 males (95% CL 794, 1276) and an estimated annual increase of 7% (95% CL 5%, 9%) for 1995-2009. Combined, the total superpopulation estimate for 1995-2009 was 2169 whales (95% CL 1836, 2563). Simulations suggest that failure to account for the effect of reproductive status on the capture probability would result in a substantial positive bias (+19%) in female abundance estimates.
Publisher: Wiley
Date: 29-08-2013
DOI: 10.1111/MEC.12453
Abstract: Determining the origin of in iduals caught during a control/eradication programme enables conservation managers to assess the reinvasion rates of their target species and evaluate the level of success of their control methods. We examine how genetic techniques can focus management by distinguishing between hypotheses of 'reinvasion' and 'survivor', and defining kin groups for invasive stoats (Mustela erminea) on Secretary Island, New Zealand. 205 stoats caught on the island were genotyped at 16 microsatellite loci, along with 40 stoats from the opposing mainland coast, and the age and sex were determined for each in idual. Using these data, we compare and combine a variety of genetic techniques including genetic clustering, population assignment and kinship-based techniques to assess the origin of each stoat. The population history and in idual movement could be described in fine detail, with results indicating that both in-situ survival and breeding, and reinvasion are occurring. Immigration to the island was found to be generally low, apart from in 1 year where around 8 stoats emigrated from the mainland. This increased immigration was probably linked to a stoat population spike on the mainland in that year, caused by a masting event of southern beech forest (Nothofagus sp.) and the subsequent rodent irruption. Our study provides an ex le of some of the ways genetic analyses can feed directly into informing management practices for invasive species.
Publisher: Inter-Research Science Center
Date: 09-2015
DOI: 10.3354/ESR00686
Start Date: 2024
End Date: 2027
Funder: Marsden Fund
View Funded ActivityStart Date: 2021
End Date: 2024
Funder: Marsden Fund
View Funded Activity