Makarora Braided River Birds – Spring/ Summer 2018

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.

Male wrybill (6+ years old) with metal leg band (right tibia) photo credit 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.

Makarora braided river habitat and wrybill migration route (bottom left) from wintering site in the north island to breeding site in the South.
New Zealand Bird Banding Scheme Record

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.

Female wrybill with two eggs

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.

Adult black-fronted tern. Photo credit Nick Beckwith
Black-fronted tern nest site

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!

Immature banded dotterel (pre-fledgling)

Southern black-backed gull population control 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.

Fig 1: Summary results of Makarora 2018 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.

South Island pied oystercatcher age 8+ years (Makarora Braided River). Photo credit Nick Beckwith.

 

 

Endangered bird life of the Crucible Basin, Siberia Valley

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.

Kea (juvenile male) at Lake Crucible looking towards the Gillespie Pass, Makarora

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.

A pair of rock wren below photographed during their diagnostic bouncing display on their long legs with occasional emissions of characteristic sharp tweet calls http://nzbirdsonline.org.nz/species/rock-wren#bird-sounds.

Male rock wren
Female rock wren

ABT are collaborating with DoC to extend current mammalian trapping efforts for rock wren within the alpine environment of the Makarora catchment.

Kea fledgling (2017/ 2018) Lake Crucible

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.

Young kea looking up at overhead drone – Lake Crucible