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Bellbird without a tail

Posted: Sun Nov 05, 2017 9:36 pm
by nzsam
Hi. How usual is it for a male bellbird to have no tail? I have had two contacts near Te Anau who have seen one (possibly the same bird).
I have just added 2 photos - one taken by each person in their separate gardens.

Re: Bellbird without a tail

Posted: Mon Nov 06, 2017 10:51 am
by Jim Kirker
Hey Glenda, at first I thought it must be a birth defect then did a quick search and found that at least one study showed that "the frequency of birds with tail loss increased strongly with susceptibility to cat predation. Male birds were disproportionately preyed upon, especially if having song posts low in the vegetation, and if having short flight distances when singing. Colonially breeding species were less susceptible to predation than solitary species."
This bird looks more male than female to my eye, which would fit with escaping from a cat. It's feeding and flying between gardens OK and could still be a tailless mutant and possible forerunner of a new subspecies :)
The article is in Chinese Birds 2010 1(2) Causes of interspecific variation in susceptibilty to cat predation on birds. Moller AP, Erritzoe J, Nielsen JT.
Hopefully the attached link will open.
Cheers, Jim
http://www.birdresearch.dk/unilang/Moel ... B_2010.pdf

Re: Bellbird without a tail

Posted: Mon Nov 06, 2017 12:12 pm
by Liam Ballard
Wait so just to clarify Jim, do you think this bird is tail-less because of a beneficial mutation (i.e. harder for cats to catch birds with no tail) or that the bird has lost a tail due to an attempted attack by a cat?

Cheers

Re: Bellbird without a tail

Posted: Mon Nov 06, 2017 8:02 pm
by Jim Kirker
I'd favour an attempted attack, probably by a cat, but maybe it was born tailless and if it was it might have a survival advantage, such as the one you mentioned and not needing to eat the protein required to grow the tail and the energy needed to preen it, move it around, keep it steady, fan it etc. It might put a prospective mate off though :(

Re: Bellbird without a tail

Posted: Fri Nov 17, 2017 11:03 am
by andrewcrossland
An escape from a cat or a person who caught it do somehow and held it by the tail. Anyone must netting on the area?

Re: Bellbird without a tail

Posted: Fri Nov 17, 2017 8:53 pm
by nzsam
Actually there was a mist netting workshop held nearby at the Birds NZ conference this year. Both the people who have seen this bird live near to that site.

Re: Bellbird without a tail

Posted: Sat Nov 18, 2017 5:11 pm
by andrewcrossland
........so........... anybody pull a bellbird ou of a net and hold its tail instead of irs head and body........?

Re: Bellbird without a tail

Posted: Sun Nov 19, 2017 8:48 pm
by Oscar Thomas
I extracted and banded a bellbird properly so don’t look at me.. released without harm.