Lice — all birds have them

Press, Volume CXV, Issue 33869, 14 June 1975, Page 11

Lice — all birds have them

/Contributed by Canterbury Museum) Never have the museum’s study collections of birds been subjected to such close scrutiny as occurred recently when they were examined by Mr Ricardo Palma, formerly of Argentina and Chile, a zoologist whose particular interest is studying bird lice.

These minute insects live amongst the feathers of birds. Bird lice are small (from Imm to 10mm — less than half an •. inch long) — tough "skinned”, flat, and wingless. Their stout legs and hooked claws enable them to grip their hosts. Lice are categorised as ectoparasites — that is. they are adapted to live on the outside of the host’s body, as distinct from endoparasites which live inside their host.

Unlike some parasites which kill their host — for example, hydatids — lice are “true” or nonfatal parasites. Their hosts have developed a biological tolerance to their presence and do not die from their presence. Lice are commonly confused with fleas, woodlice, fishlice, booklice and plant lice but these animals are not truly lice. Jaws adapted Whereas lice which live on mammals pierce the hosts skin and suck blood for their food (the sucking lice) birds are parasitised by lice which

chew feathers — the chewing lice. The jaws of chewing lice are adapted to cut feathers and occasionally skin debris or dandruff into fragments which the insect then eats. Although a few of the species of chewing Ijce live on mammals, for example, red and Virginia deer, thar and guinea pigs, most of the 3000 species known to science occur on birds. Characteristic As is characteristic of parasites, lice are usually host-specific, each species of lice only occurring on only one particular species of bird. The number of lice on an individual bird may range from one or two to several hundred. Usually these numbers comprise two or three species. On some birds — for example, the giant petrel — up to 12 species of chewing lice have been recorded. In Christchurch Mr Palma is working in the zoology department, University of Canterbury, under the direction of Professor R. Pilgrim, an expert on ectoparasites. Their aim is to identify and assemble a collection of lice from New Zealand’s birds and mammals.

Before leaving South America about 15 months ago Mr Palma completed a degree on bird lice at the University of Buenos Aires.

The museum’s extensive collections of birds provided this young South American parasitologist with an excellent opportunity to “hunt” for lice.

As well as recovering dozens of dead lice from the native and introduced birds we hold in deep freeze, Mr Palma also found dead but well preserved lice on many of our mounted birds. Extinct birds Most exciting of all he found lice on some of our extinct birds — one was the Huia — some specimens of which have been in our collections for 80 to 90 years.

It is remarkable that some of these lice and even their minute eggs, still attached to the feathers. had to be gentlyprized loose from their hosts with forceps. This demonstrates how well adapted these tiny ecto parasites are to clinging to the feathers of their hosts. Much handling In view of the somewhat rigorous treatment which mounted birds must necessarily undergo and the countless times such birds must have been handled by curators and scientists it is incredible that these parasites had not become dislodged from their hosts. If these lice had dropped off their very existence may never have been made known to science. — G.A.T.