In the tropics, what appears at first to be a leaf may
be a katydid; a twig may turn out to be a walkingstick
or a mantis; a thorn may be a treehopper; a dead leaf
may be a frog; bark may be a butterfly or moth; and a
tree stump may be a bird. A bird? Yes. The Neotropical
potoos (Nyctibiidae), a group consisting of seven
species, are large nocturnal birds that feed on flying
insects at night (chapter 15). When perched, they
appear to be a combination of owl and nightjar. By day
they sit very still atop a tree snag in plain sight, with
the body positioned in such a manner as to closely
resemble a branch (plate 11- 17). In some species,
if the tree snag sways with wind the potoo sways in
synchrony with it.
In many species cryptic coloration serves to reduce
detection by predators, but in predators it acts to
reduce detection by their prey (plate 11- 18).
Tropical cats also demonstrate cryptic coloration.
The spotting and/or banding patterns of an Ocelot
(Leopardus pardalis) or Jaguar (Panthera onca), so
obvious when the animals are observed in zoos, aid
in concealing the animals in nature (plates 11- 19– 20).
Plate 11- 17. This is a Common Potoo (Nyctibius griseus)
perched atop a tree snag, looking much like an extension
of the snag. That’s the basic idea. All potoos exhibit such
behavior during the day. They feed at night by capturing large
insects in flight. Photo by John Kricher.
Plate 11- 18. This mantis (family Mantidae) is a predator of
insects and is normally cryptically positioned as it sits and
waits for a potential prey insect. Photo by Dennis Paulson.Plate 11- 19. This Jaguar, photographed in the Pantanal of Brazil,
demonstrates the cryptic nature of the animal’s coloration in
the complex light and shade of forest. Photo by John Kricher.Plate 11- 20. When Jaguars are not hunting and are out in the
open they still appear fairly cryptic. Take note of the second
Jaguar sleeping in the shade to the left of the obvious one
sunning on a riverbank. Photo by John Kricher.184 chapter 11 evolutionary arms races: more coevolution, more complexity