Environmental Engineering Reference
In-Depth Information
shall record reasons. The consent holder shall forthwith forward in writing the
final survey design together with any comment made on the draft survey
design by the Ecology Peer Review Panel, and the survey author's comments
in response, to the Waikato District Council Group Manager Regulatory for
endorsement, acting in a technical certification capacity. The final survey
design shall be put in to effect and completed in full.
6.27 Subject to (c) below,
“Breeding Success Rates”
shall be calculated on the
following basis:
(a)
(SIPO After Productivity Rate - SIPO Before Productivity Rate) × Number
of SIPO pairs in the Upper Rangitata Predator Control Area× 40 %
(SIPO survival rate).
(b) (
Wrybill After Productivity Rate - Wrybill Before Productivity Rate) ×
Number of wrybill pairs in the Upper Rangitata Predator Control Area ×
60 % (wrybill survival rate).
(c) These figures, including the SIPO survival rate and the wrybill survival
rate, shall be reviewed and if necessary updated under condition 6.30(a)
below.
Interim Productivity Monitoring Results
Migration southward past the proposed HMR wind farm occurs mainly in July and
August. After a short stay at coastal feeding areas, some of the birds migrate inland
to the Upper Rangitata Valley - the chosen mitigation site. SIPO typically arrive
from August whereas wrybill arrive later, some not appearing until September. The
birds typically begin breeding soon after arrival.
The Rangitata is a large braided river where the water flows in a number of chan-
nels. During major flood events, these largely coalesce although some of the larger
islands remain above water levels. SIPO tend to nest both on adjacent farmland and
on the edges of the river, whereas wrybill nest in clean gravels adjacent to river
channels. In floods, wrybill often lose their nests whereas even in the larger floods,
most SIPO nests remain above water levels. Introduced predators especially cats,
stoats, weasels, hedgehogs and rats are readily seen and native black-backed gulls
Larus dominicanus
and Australasian harriers
Circus approximans
also prey on eggs
and chicks of both species.
The first season of “before” monitoring occurred in 2011-2012 spring and early
summer. Thirty pairs of each species were chosen randomly and at least one mem-
ber of each pair was banded with large alpha-numeric bands and numbered metal
bands while nesting. Pairs were followed approximately every 3 days and chicks
were banded when large enough to hold adult bands.
SIPO laid two or three eggs with a mean (±s.e.) clutch size of 2.3 ± 0.10. Predation
was the overwhelming source of egg and chick loss and the 30 pairs produced a total
of 32 independent fledglings through the season. Eleven of the pairs did not produce
any young, whereas the most successful pair produced three.
