Wednesday 7 November 2012



Start Description of the Black Robin

The Black Robin is a small,sparrow-sized bird measuring 10–15 cm high. Its plumage is almost entirely brownish-black, with a black bill and brownish-black yellow-soled feet.
Females are usually slightly smaller than males. Male songs are a simple phrase of 5 to 7 notes. Its call is a high pitched single note. Their eyes are dark brown. The birds will moult between December and March.


Adaptations
Key Adaptations

Some of the obvious adaptations of the Black Robin are;
  • Finds worms by keen eyesight (not by hearing!)
  • They have a beautiful song
  • Females are usually smaller than the male
  • They have a good eyesight to see in the dark
  • Feathers are very black and grow between 10 and 15 centimetres high
  • Its plumage is almost entirely brownish-black, with a black bill and brownish-black yellow-soled feet.
There are also a few more which are not so obvious.

Importance

These adaptations are important to the bird because if they weren't there the black robin it wouldn't have this name. The birds rely's on its eyesight a lot more than us humans so if the bird was blind it would need to be looked after because it will not survive in the wild.


Community
Habitat


Black robins currently live on Rangatira (South East) Island and Mangere Island in the Chatham Islands group. Attempts made to establish another population in a fenced convenant on Pitt Island have failed, possibly due to competition for food with introduced mice.


These birds like foraging for insects in the deeper layers of litter, which are found on flat areas of the forest floor. They spend a lot of  time in the lower branches of the forests in order to shelter from strong winds the the Chatham Islands bring. Black Robins live in woody vegetation, beneath the canopy of trees.

The Chatham islands form a complex group that have been isolated for 80 million years. This is long enough to develop many plants that are seen nowhere else. Plants like forest trees, giant herbs and seaweed are known to live here. Even the local flax (Phormium “Chathams”) is different. Of 388 indigenous terrestrial plant species, 47 (about one-eighth) are endemic to the Chatham Islands.

The most well known to the Chatham Islands, out of the endemic is the forget-me-not, rautini, Chatham Islands kakaha and the soft speargrass. Plants of the Chathams show a much higher proportion of coloured flowers than in mainland New Zealand. Examples are Chatham Island forget-me-not which is a bright blue colour (picture below).

Environment

The Chatham Islands, 800 kilometres off the east-coast of the South of New Zealand can be described having very strong winds, wild seas that batter the islands. The average temparture at the Islands would be about the same as Christchurch and the rainfall would be the same as Nelson - changeable, windy and rarely any frosts.

Relationships

The Black Robin has no natural predators but in the 1900 the Maori introduced more predators of the Robin.The predators that got introduced in 1900 have affected it's population because by 1980 there were only 5 left with only one being a female. The introduced predators of the black robin included the cat that caught the robin and the rat that ate their eggs and caught their chicks. Don Merton of the Wildlife Service came up with a plan to save the black robin. It involved using another species of bird as foster parents to the black robin eggs (hatching and raising them as their own chicks), so that the only black robin breeding pair would be encouraged to lay more eggs.

The reason they were saved from extinction is because of the last breeding pair named Old Yellow and Old Blue. 'Old Blue' was the last remaining female in 1980 and she was one of the longest-lived robins known, reaching 14 years of age. She herself raised 11 chicks.

The bird forages for food in the leaf litter on the ground. They usually eat grubs, cockroaches, wetas and worms. So if the Black Robin did become extinct all these insects/ animals would be better off because it they wouldn't have one of their predators to worry about. But the predators of the Robin would suffer because they would no longer have one of their food sources to survive off

Why it has succeeded

I think my organism has succeeded in this community because it has faith and this bird is very strong and will do anything to survive. Without Don Merton's great idea the Black Robin would have been extinct by now but this bird is so well known around the Chatham Islands and 'Old Blue' will always be remembered as the wonderful bird who saved their community.

Endangered New Zealand


Indigenous and Introduced Predators 

The Black Robin has got no indigenous predators but when the people arrived at the Chatham Islands they introduced cats and rats which were predators of the Robin. By 1980 their numbers had dropped to only the five. This effected their community and population.

Human Practices

Us humans have introduced more and more animals and this effects the food chain because someones food source could be lost or habitats could be ruined.

Food Webs



References:

I would like to thank the following websites for the information on this blog;