Habitats and Ecological Values of the Hokianga ... - MarineNZ.org.nz

R.J. DAVIDSON: V. KERR
HABITATS AND ECOLOGICAL VALUES OF HOKIANGA HARBOUR
2.2.3 Areas of Particular Importance to Birds
As part of the present study, areas important to birds were identified and described. A variety of
wildlife habitats are known from Hokianga Harbour. Each habitat is utilised by a variety of bird
communities.
The range of habitats have been summarised as follows:
• open tidally flooded mud and sand flats;
• beaches;
• sand dunes;
• cobble, boulder and rock;
• native rush-lands and peripheral shrubs;
• Spartina grassland;
• permanent water;
• shallow water (< 0.5 m depth);
• deep water (> 0.5 m depth);
• peripheral trees;
• tidal freshwater vegetation;
• native herb-field;
• artificial structures; and
• islands.
Open tidally flooded mud and sand flats
This feeding habitat is utilised by a variety of wading bird species including regularly observed
species such as banded dotterel, pied stilt, godwit and ducks and less frequent visitors such as lesser
knot and wrybill. These mud and sand flat areas support invertebrates including shellfish (e.g.
cockles), snails, crabs and worms that provide a staple food for many different wader bird species.
Large areas of sand flat occur in the lower Harbour (i.e. Onoke to the entrance), while large areas of
mudflat occur in the central and upper Harbour. According to Davis and Bellingham (1984) some
separation in species utilisation between sand flats of the lower Harbour and the mudflats in the
central and upper Harbour occur. For example, waders excluding stilts and herons tended to utilise
the sand flats of the lower Harbour.
Beaches
Relatively large areas of beach habitat is located between the northern entrance to Waitapu. These
areas are import to roosting waders such as New Zealand dotterel, wrybill and banded dotterel.
Sand dunes
Extensive dune areas are located at the north head of the Harbour. These areas are used as breeding
sites by variable oystercatcher, black-backed gull and New Zealand dotterel.
PAGE 11 3/06/2005 DAVIDSON ENVIRONMENTAL LTD 389/2001