T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Heron (White heron) Egretta alba modesta

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Pelecaniformes
Family: Ardeidae
Genus: Egretta
Species: E. alba
Sub Species binomial name: Egretta alba modesta, Ardea alba modesta.
Common name: Kotuku, White heron, Great Egret.

E. alba is a cosmopolitan bird found worldwide in tropical and temperate regions. There are four subspecies in various parts of the world, which differ very little. Differences are in the coloration during the breeding season and their size.

The species are:
Egretta alba alba (Europe) Ardea alba alba
Egretta alba egretta (Americas) Ardea alba egretta
Egretta alba melanorhynchos (Africa) Ardea alba melanorhynchos
Egretta alba modesta (India, Southeast Asia, and Oceania) Ardea alba modesta

The largest subspecies is Egretta alba modesta is found in India, China, Japan, Australia and New Zealand. E. a. modesta is thought by some taxonomists to be a full species, the Eastern Great Egret (Ardea modesta).

Egretta alba modesta in New Zealand it is a rare bird restricted to one breeding location. The species was almost exterminated to satisfy the demand for feathers for women’s hats after its only breeding site on the banks of the Waitangiroto Stream, near Okarito in South Westland was discovered in 1865. By 1941 there were only four nests left when it was declared a reserve and patrolled at breeding time. The bird’s numbers have now stabilised with a permanent population of around 100 to 120. It is not known when this breeding site became established from birds carried by a favourable wind from Australia.
It is not known exactly when the only heronry in New Zealand became established, but it is presumed that a few hundred years ago a favourable wind carried some birds over from Australia. This migration sometimes still occurs, in the winter of 1957 about 150 trans-Tasman strays appeared in Northland, Waikato, the Bay of Plenty, Canterbury and Otago.
Outside of the breeding season these birds disperse widely throughout the country, frequenting shallow waters along the margins of rivers, inland lakes, swamps and coastal estuaries. It has been recorded in Taranaki.

Egretta alba modesta is an elegant white heron with a long, slender neck, yellow bill and thin black legs and feet. They grow to 92 cm in length and weigh about 900 grams. During breeding their bill darkens and a veil of fine feathers of loose texture lie over the back, wings and the long white tail feathers extend like a bridal train.
Its long legs are bare of feathers well above the ankle joint. It has long spreading toes suitable for wading on muddy bottoms. They are solitary feeders. Their food consists of mainly small fishes, eels, frogs, tadpoles, insects and even birds.
They will stand in water remaining perfectly still until a fish comes within reach, then with lightning like rapidity it strikes and at once swallows its prey. At night when not feeding they roost in trees.

In August and September white herons arrive at New Zealand only heronry (Waitangiroto colony) to nest in kāmahi, māhoe and kōwhai trees and in the crowns of tree ferns. Females lay three to five pale blue-green eggs and both sexes share incubation and the feeding of the chicks. The chicks fledge at around 42 days and leave the colony three weeks later. Egretta alba modesta can live up to 22 years.

 

The veil of fine feathers of loose texture which lie over the back, wings 

A White heron  standing on a car in Nelson.
  

In flight their long neck is held kinked. 

Thanks to Wikipedia for text and information http://creativecommons.org/licenses/by-sa/3.0/