Relative to the future success of rare and endangered shorebird species breeding in the Ashley-Rakahuri river, bird numbers in the 2015/16 season generally reflected the improvement of recent years. Wrybill numbers were the second highest (19), after last year’s record of 21. Banded dotterels and pied stilts are also maintaining good numbers, well above the long-term average. Black-billed gull numbers were well down – this being due to the absence of any colonies. Numbers of other species were similar to the long-term average, with the exception of the spur-winged plover, which was the lowest ever recorded.
Breeding success (productivity) is only recorded in detail for the wrybill, black-fronted tern and black-billed gull, and during 2015-16 was poorer than usual. The productivity of the tern and gull was amongst the poorest ever recorded since recent records began in 2004. Wrybill productivity was better than for the gulls and terns, but still below the long term average. The reasons for the poor/reduced productivity of these species is being explored – with loss of bare gravel areas due to weed invasion strongly suspected.
The Group continues to maintain a high profile relative to public awareness and education, assisted by agencies such as DOC and ECan, particularly staff from DOC’s Rangiora Field Base and ECan’s Ashley-Rakahuri Regional Park. During 2015-16, the Group created thirty-four opportunities to improve awareness. Most involved media articles, presentations to schools and local groups, and displays at public events.
A highlight of the past year was the recent publication of a peer-reviewed paper by Eric Spurr and Nick Ledgard in Notornis (June, 2016, Vol 63, Part 2). This reported an upward trend in numbers between 2000 and 2015 for the all the focus species, with statistically significant improvements for wrybill, black-fronted tern, banded dotterel and pied stilt. Numbers of other species, including the black-billed gull, have not changed significantly, in contrast to declining national trends. It is pleasing to note that the authors concluded ‘We suggest that the Rivercare Group’s management actions have contributed to these successes, and support continuation of their actions’.
During all its initial years, the Group relied on outside agencies (eg. Lotteries, WWF) for funds, requiring considerable time and effort in writing applications and supplying reports. Hence, it is satisfying to record that for the last 4 years, the Group has been able to survive on its own fund-raising projects, plus donations. The generosity of the latter is due to our improved public profile.
Looking into the near future, the major challenges involve maintaining/improving the control of predators, controlling weeds and improving bird nesting habitat (probably by the creation of raised, weed-free islands), and banding more adult birds (particularly wrybills). With water being the new ‘gold’ in Canterbury, a close watch must also be kept on river flows, how/if they are changing due to abstraction or climate change, and how such changes might be affecting bird numbers and breeding. To these challenges and opportunities can be added the ever-present challenge of maintaining public interest, and the involvement of the local community in bird management on the Ashley-Rakahuri River. This not only enhances fund raising opportunities, but also helps to reduce human disturbance in the riverbed during the breeding season.
All photos by ARRG members - Lynley Cook, John Dowding and Nick Ledgard