ARRG Chair report, 2017
Welcome everyone to this AGM. The Ashley-RakahuriRivercare Group was formed in 1999, and became an Incorporated Society in 2005. This report is largely an adaptation of the summary from our 13th annual report, which was for the 2016-17 season.
Activities over the past year were focussed as usual on management to assist the breeding of threatened bird species in the river. To this end, the main actions undertaken involved on-going bird population surveys, monitoring, predator control, habitat enhancement and improving awareness through advocacy to the public and river management decision-makers.
Funding. After many years of relying on funding from outside agencies, it is pleasing to report that the Group has been self-funded for a few years now. Our major sources of finances are a trap making / selling project and donations. Very recently, we have obtained additional funds for weed clearance activities from the WZC’s Immediate Steps fund and the Rata Foundation, plus we have had promotional sponsorship from the Canterbury Water Management programme and Karikaas cheeses.
Bird surveys. After years of bird populations trending upwards, the 2016 survey confirmed a recent decline. Total bird numbers were 30% lower than the 17-year average and the lowest since 2008. This was the second year of decline since the peak numbers between 2011 and 2014. Most of the major species were affected. Wrybill numbers equalled the long-term average, but were the lowest since 2009. Black-fronted tern and banded dotterel numbers were just above the long-term average, while black-billed gulls were well below. The biggest drop amongst the key species was for pied stilts, where numbers were 56% down on last season. A likely reason for this decline is the loss of bare gravel areas due to weed invasion. Early indications for this 2017-18 season are that bird numbers have not improved from last season.
Predator control. This season saw an increase in trap numbers from 118 last year to 139. In total, 52 potential predators were trapped in 15,114 trap-nights, the second highest ever. The overall summer trap-catch rate was 0.34 predators per 100 trap nights - the lowest annual rate recorded to date. Hedgehogs remain the most trapped predator, followed by cats and rats (highest ever). Eleven mustelids were caught, just over half the number of the previous season, but very similar to the season before. As usual, more predators were caught in the autumn/winter period, with a notable increase in stoats (18 compared to just 2 in 2016) and rats. The winter trap-catch rate was 0.57. This year we will be reviewing our trapping programme, relative to increasing our target area coverage in order to cater for a possible kaki release in 2019.
Monitoring of breeding birds. As with population numbers, breeding attempts declined in the 2016-17 season. Eight pairs of wrybills attempted to nest in the study area – two less than in the previous season. A minimum of 3 chicks were raised, for a productivity of 0.38 chicks fledged per pair, well below the 13-year average of 0.77. Just 10 pairs of black-fronted terns nested in the 2016-17 season, the lowest number since 2005. Productivity was between 0.4 and 0.6, which although close to the long-term average of 0.41, is rather meaningless with so few pairs nesting. For the third year running, no gull colony established – in fact, not a single pair nested on the river in 2016-17. As with the wrybills and terns, there appears to be a link between the poor nesting and the loss of bare gravel areas. This probably encouraged the gulls to set up a good colony close to the river on a cultivated dairy farm just south of the SH1 road bridge. The eventual productivity of between 1.17 and 1.70 is amongst the best ever recorded in the country. This success could be explained by the main riverbed threats (floods, predators, weed invasion and human disturbance) being largely absent or considerably less on a managed farm site. Breeding success or productivity of other species was not recorded, but signs of successful breeding were noted at many sites. As with bird populations, the early indications for the 2017/18 season is that breeding attempts may well be lower than previously.
Habitat enhancement. Habitat threats from predators and human disturbance have not changed recently, but weed invasion has advanced considerably. Vegetation mapping in early 2017 showed that the total area of bare gravel had declined by 85% since January 2014 – from almost 200ha down to around 30ha. This decline has occurred over the same period as the recent decline in annual bird numbers. A good flood on April 6, 2017, doubled the area of bare shingle, and this was enhanced further by another major flood (1-in-10 year event) in mid-July, followed by good floods on Sept 19 and Oct 9. Despite the floods, planned clearance of remnant weeds by bulldozer went ahead on August 28/29, utilising about 20% of the funds granted for such work. The end result is significant areas of clear shingle at the most preferred bird breeding sites. Spare funds will be utilised to maintain these as clean sites into the future.
Awareness / education. During 2016/17 there were many opportunities to improve awareness of the Group’s activities. Twelve articles appeared in local papers. Powerpoint presentations were given to five schools, four service clubs, plus a well-attended braided river seminar (150 present) on June 26, 2017. Riverbed visits during the breeding season proved to be popular with the public, with over 30 attending in early November. Also popular and appearing in many sites throughout Canterbury, were flocks of cut-out birds. ‘The Flock’ was successful in drawing attention to the arrival of riverbed birds for the summer breeding season, with hundreds of colourfully decorated bird silhouettes made by schools and community groups.More recently, we have contracted Tony Benny, a local film maker, to make a video showing Group activities occurring during a typical year, plus there has been a Screen Vista created for use in the local cinema through to the end of January. Our website ( was maintained by the District Council’s VisitWaimakariri office, while Steve Attwood ran our Facebook page ( One awareness topic in which we must see improvements is in the area of field interpretation – so that the general public has easy access to on-site signs describing the unique riverbed birds and habitats which we are dedicated to preserving and improving.
The Group remained closely associated with staff from DOC, the Waimakariri District Council and local Zone Committee, Environment Canterbury (ECan) and the Ashley-Rakahuri Regional Park. We are actively involved with BRaid Inc., which aims to improve the ecological welfare of all braided rivers in Canterbury.
Conclusion. Relative to the future success of rare and endangered shorebird species breeding in the Ashley-Rakahuririver, it appears that the rising bird population trend up to 2014 is now declining. Populations of all species are either lower than in the previous 2 years, or at best only matching the long-term average. The breeding of the key study species, wrybill, black-fronted tern and black-billed gull, shows the same trend. The major reason for the decline in bird numbers appears to have been a surge of weed invasion of the riverbed between 2014 and early 2017. Although recent floods and clearance by bulldozer has led to major increases in the bare gravel areas needed for breeding, the timing of the most recent floods may well have impacted negatively on current breeding activity. Looking into the near future, the major challenges involve on-going control of weeds,improving the control of predators, plus banding more adult birds (particularly wrybills) to determine long-term survival trends. To these targets and opportunities must 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.
Last but never least, my heartfelt thanks go to all members of the Group for the work they have put in over the past year. I don’t like picking out individuals, but there are four I must mention: Joan Miles for her work as Secretary, Sue Mardon for her excellent work as Treasurer, Geoff Swailes for his organisation of trapping and the trap making/selling team, and Grant Davey for his mapping and record-keeping skills. Steve Attwood also deserves special mention for his willing help and success in the promotion area. Ongoing thanks are always due to the likes of ECan and their Regional Park staff, the Waimak DC and DOC. We might be the body which makes passionate pleas on behalf of the public, but without their professional support it would be very hard to make meaningful progress.
Nick Ledgard
ARRG ChairOctober, 2017