Travel Reference
In-Depth Information
Grey Lourie or go-away bird that I surprised in Botswana (see Figure 25).
The DNA evidence is equivocal. The relationships between the hoatzins and
other present-day branches of the avian family tree are extremely distant,
making the exact ai nities of the hoatzins dii cult to decide.
5
Even though all their close relatives have disappeared, hoatzins are
quite common birds. Luckily for them they taste rather awful and are not
hunted by the local tribes. One of the reasons for their foul taste is that they
dine almost exclusively on the shoots and leaves of about fi fty dif erent
plants. Their bodies are loaded with breakdown products of the tannins
and cardiac glycosides that the plants secrete to repel insect and animal
predators.
The hoatzins must eat a wide variety of plants in order to keep the vari-
ous toxins at manageable levels. This mush of dif erent plant tissues, each
quite indigestible by the hoatzins themselves, is transformed into nourishing
compounds inside their foreguts by a process of fermentation.
Figure 25
This grey turaco or grey lourie (
Corythaixoides concolor
) is known as the go-
away bird because its song sounds like it is demanding that you leave immediately. I photo-
graphed it in Botswana's Okavango Delta. It may be one of the closest living relatives of the
hoatzin, but close is a relative term, for hoatzins and turacos occupy distinct branches of the
avian evolutionary tree.
