This has been recorded in the Red Wattlebird in Australia (see abstract
below). I remember talking to David Paton back in the 1980s about this
research and he thought that, in winter, Red Wattlebirds were feeding on the
nectar and fruits of exotic plants in parklands and gardens of Melbourne, in
preference to the their natural diet. His conclusion was that these exotic
plants were deficient in thiamine, compared with levels in their natural
diet.
I've also seen Red Wattlebirds in Canberra convulsing in winter, so similar
environmental conditions presumably occur there too.
Stephen Ambrose
Ryde, NSW
Thiamine Deficiency and Winter Mortality in Red Wattlebirds, Anthochaera
carunculata (Aves:Meliphagidae) in Surburban Melbourne.
DC Paton, DF Dorward and P Fell
Abstract
Red wattlebirds are found in convulsions during winter in south-eastern
suburbs of Melbourne, and eventually die. We suggest that the birds suffer
from a thiamine deficiency. The symptoms of the sick birds-head retraction,
convulsions and anorexia-are similar to those described for animals with a
thiamine deficiency, and the diet of wattlebirds is likely to be low in
thiamine, particularly in winter. Furthermore, thiamine levels in the blood
of convulsing birds were significantly lower than those in healthy birds and
similar to levels that induce clinical symptoms in humans. Thiamine levels
of healthy birds showed a seasonal pattern and were lowest in winter,
suggesting a thiamine shortage during winter. However, we were unable to
induce the symptoms when caged birds were fed on a thiamine-deficient diet.
The high ambient temperatures used during these feeding trials may have
prevented clinical symptoms from developing. Further work is needed before
firm conclusions can be made about the role of thiamine deficiency in the
winter mortality of red wattlebirds.
Australian Journal of Zoology 31(2) 147 - 154
Full text doi:10.1071/ZO9830147
C CSIRO 1983
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