The 2018 braided river bird survey for the Makarora River commenced on the 18 October over a period of three days. The survey area begins at Boiler Flat, includes the lower Willkin and finishes at the Makarora delta where the river meets Lake Wanaka. Endangered braided river birds; wrybill, black-fronted tern, black-billed gull, banded dotterel and South Island pied oyster catcher have returned to breed on the braided river again.
This years survey found six pairs of endemic wrybill (the only bird in the world with a bill that bends to the right) two on nests with eggs and one with two new chicks. During the survey one of the male wrybills was identified with a metal leg band and its unique code was identified thanks to the help of an amazing photo taken by volunteer surveyor Nick Beckwith.
The wrybill was originally banded as a juvenile at Miranda (Firth of Thames) and now as a six year old is found breeding over 900 km away. This bird has probably made the return journey at least five times. A wrybill female was also recorded with a metal band last year and she was found to have been banded on the same day as the male (as an adult) at Miranda during November 2012.
Key nest site monitoring is ongoing throughout the breeding season. Two wrybill chicks hatched on 6 Nov after 30 day incubation period; mainly by the female.
The black fronted terns had formed a number of nesting colonies with eggs at many nest sites along the length of the river. Unfortunately most nests have been lost to high level flooding over the last weekend but signs of re-nesting has already been observed.
Despite the Makarora River flooded “bank to bank” last Friday the adaptation of endemic braided river birds is such that a flightless braid island bound banded dotterel chick somehow survived an extreme natural weather event (image below). Nature never fails to amaze!
Southern black-backed gull populationcontrol commenced this season on the Makarora River and also on a more national scale for Canterbury braided rivers. The numbers of SBBG’s have significantly increased on the Makarora River and on a national scale due primarily to changes in landuse. They are a known predator of braided river bird eggs and chicks, particularly in relation to black-fronted terns. This is evident from trial camera footage at several nesting sites. Invasive avian predator control complements the existing invasive mammal predator control programme for the Makarora River. Similar control measures over time have been shown to increase fledgling success for black fronted terns on the Tasman River.
Fig 1, below summarises this years braided river bird walkover survey.
Other interesting records include a banded and flagged South Island pied oystercatcher. This bird was originally banded at Sand Island near Nelson Airport as an adult during January 2010. This is an interesting record as little is currently know about the migrational movements of this species.
In the news, ABT are delighted to feature in the latest Otago Regional Council (ORC) Eco Fund promotional video (above screenshot of the Makarora River with the Wilkin valley in the background) and were asked to supply threatened species survey images from last season (top left and top right below) which have been used to feature in the new promotional brochure. The video provides a short clip on a number of valuable environmental projects happening across Otago. There is nice drone footage of the Makarora braided river habitat. The video aims to encourage projects that protect and enhance the environment and the community.
Makarora Catchment Threatened Species Programmes
We may have been quite but behind the scenes ABT are busy implementing and progressing Makarora threatened species programmes for endemic braided river birds, rock wren, blue duck / whio and forest birds. This also includes biodiversity education an integral part of connecting people with nature.
Invasive mammalian catch effort on the Makarora braided river has removed a number of stoats, hedgehogs, rats and mice in preparation for the spring bird breeding season. Feral cats and the Southern black-backed gull (an avian predator of endemic braided river bird chicks) are also part of the braided river bird restoration programme and will be addressed this coming season. Volunteer help has been essential to this progress.
The implementation of ABT’s Makarora Braided River Bird Invasive Predator Control Strategy commenced this weekend (7-8 April). A team of amazing volunteers helped deploy a number of invasive mammal traps along 15 km of the Makarora River. Trap locations and deployment was informed by previous braided river bird monitoring undertaken during the 2017/2018 survey season and existing information on the movement of invasive mammalian predators (capable of decimating indigenous bird life) such as stoat, rat and hedgehog.
Volunteers keen to help indigenous wildlife included local Makarora residents, members of Makarora School and nearby residents of Lake Hawea.
The day began with loading up of traps on two boats, one a jet boat with an experienced captain Rod Elliott and partner Jos Mclean. Following a jet boat ride to the far side of the river, volunteers were loaded up with traps for particular designated areas and equipped with a GPS. Traps were then securely staked, marked with coloured triangles and numbered to aid future maintenance.
Following a trap setting demonstration and health and safety talk, traps were baited and sett according to recognised best practice.
The installation and maintenance of the Makarora braided river trapping network aims to help control invasive mammalian predator numbers so that endangered braided river birds such as wrybill, black-fronted tern, banded dotterel and black-billed gull can nest and successfully raise their chicks without being predated. In the longer term a noticeable increase in braided river bird restoration is desired.
Further traps are to be deployed and monthly trap maintenance will be ongoing during the non-breeding season with more frequent checks during the bird nesting season (spring/summer). Volunteers welcome!
Thanks go to all our volunteers. ORC. Also, BRaid for DoC 200 trap supply and production, bait donations from Hawea Flat egg suppliers, discounted radios from Hunting and Fishing Central Otago, waratahs from DoC Wanaka and support from Wilkin River Jets and Mt Albert Station.
ABT’s rock wren transect survey monitoring programme for the 2017/2018 survey season includes the Crucible Basin situated within the Siberia Valley. Monitoring surveys aim to provide an updated baseline on threatened species and allow repeatable monitoring for rock wren within the Makarora catchment to help guide appropriate future conservation management in relation to invasive mammalian predators.
A number of rock wren pairs were recorded present within the bolder-field and moraine habitat and evidence of adults foraging invertebrates for nestlings was noted. During rock wren surveys the Crucible Basin was also noted as an important site for kea as well as rock wren. On both survey occasions seven kea were observed, mainly this years juveniles with their characteristic yellow ceres, eyelids and pale crowns. Kea parents were observed feeding young fledglings regurgitated food and a rock bivi frequented by kea was found close to Lake Crucible.
ABT are collaborating with DoC to extend current mammalian trapping efforts for rock wren within the alpine environment of the Makarora catchment.
All kea records in relation to ABT’s survey and monitoring have been forwarded to the Kea Conservation Trust to help inform a national kea database.
Generally our time at Crucible Basin was positive however, we did note an aerial drone trying to film kea and artificial feeding by visitors. These are two national issues where continued awareness raising is crucial for New Zealand’s threatened species. Image below shows a hunkered down kea looking up at the drone buzzing above whilst others disappeared beneath boulder habitat.
The Aspiring Biodiversity Trust are pleased to report the confirmed presence of rock wren at the north branch of the Wilkin River following the undertaking and setting up of a recent (Jan 2018) transect monitoring survey.
Rock wren Xenicus gilviventris is the only true alpine New Zealand bird species and is currently classed as globally endangered under the International Union for the Conservation of Nature (IUCN). Peter Child’s (1980) work was the first comprehensive bird survey of Mt Aspiring National Park for rock wren.
The main threat to this species is predation from invasive mammals such as stoats and rats now known to be present within alpine environments. The results of the survey will help inform and guide existing and future conservation management for rock wren. Monitoring transects will also be repeated in subsequent years to allow more informed decisions to be made in relation to this indigenous alpine specialist.