In Central Amazon, Brazil, the tabanid
Phorcotabanus cinereus
(Wiedemann) was recorded attacking the native duck
Cairina moschata
(Linnaeus) (Anseriformes, Anatidae). The flight and behavior of the tabanid
during the attacks and the host's defenses were videotaped and analyzed
in slow motion. The tabanid was recorded flying rapidly around the heads
of the ducks before landing. Landing always took place on the beak, and
then the tabanid walked to the fleshy caruncle on the basal part of the
beak to bite and feed. Firstly the duck defends itself through lateral harsh
head movements, and then, when it is being bitten, it defends itself by
rubbing its head on the body, or dipping the head into water, when swimming.
If disturbed, the fly resumed the same pattern of flight as before and would
generally try to land again on the same host and bite in the same place.
This feeding activity was observed predominantly between 9:30 am and 4:30
pm and always in open areas, near aquatic environments, from June 1996 to
January 1997, the dry season in Central Amazon. To test the attractiveness
of other animals to
P. cinereus
, mammals, caimans and domestic and wild birds were placed in suitable habitat
and the response of
P. cinereus
observed.
P. cinereus
did not attack these animals, suggesting that this species has a preference
for ducks, which are plentiful in the region.
