Crypturellus

Etymology

Crypturellus is formed from the Greek words κρυπτός (kruptós), "covered" or "hidden", οὐρά (ourá), "tail", and -ellus, a Latin diminutive suffix. The genus name Crypturellus therefore means "small hidden tail".

Description

Crypturellus members, like other tinamous, have a cryptic color scheme dominated by browns, buffs, yellows, and greys. Unlike the rest of the family, these birds show some sexual dimorphism: the females are more heavily barred than the males and are also a bit brighter and larger.

Range

The majority of species occupy forests or rain forests, preferring lower elevations. They range from Uruguay to Mexico. However, the earliest known occurrence of the genus is a fossil humerus, described as Crypturellus reai, from the Early Miocene Santa Cruz Formation of Patagonia.

Vocalization

Crypturellus are a very loud group of birds with melodious calls. They tend to use lower frequency when they call than other members of the Tinamou. Males and females have different calls and each species also has different calls. Normally each sex will have a long and a short phrase call. The genus can be grouped into two partial groups based on the similarity of their calls.

Some, like the slaty-breasted tinamou are quiet and hide during the middle of the day, choosing this time to take naps and conserve energy. The slaty-breasted tinamous also have a unique call amongst themeselves, so much so that individual birds can be recognized by their calls. Most members of the genus have a variation in their calls, within the species, based on their geographical location. They also are known to use regular calling sites.

Feeding

Similar to other forest tinamou, the members of this genus prefer to eat fleshy fruit; however like tinamous in general they are opportunistic and will eat a variety of foods including insects, which they have been known to leap 1 metre (39 in) high to obtain

Breeding

Courtship technique for the members of Crypturellus consists of the male lowering his breast to the ground, stretching his neck forward and raising his posterior vertically. This will cause the male to appear larger and longer than normal, which not only impresses the female but also benefits the male in that it scares away competitors.

Females outnumber the males with some of the species, such as the variegated tinamou, having a 4:1 female-to-male ratio. They also only have a 2-egg clutch, which would explain why they are one of the species that have multiple clutches.

Once copulation has taken place, the female will choose a nest site that is typically a depression covered with leaves next to a tree trunk, usually between a couple of buttresses. Members of the genus that are savanna style birds such as the small-billed tinamou will instead lay their eggs in a cavity near a clump of grass. The eggs are oval or elliptical on the smaller birds and near spherical in the larger birds, such as the undulated tinamou and the Brazilian tinamou. The colorings of the eggs are varied, but in general are brightly colored with no splotches or spots; the colors fade over time and usually will change to a less overt color midway through the incubation period. The predominate colors are chocolate or red wine with the eggs of yellow-legged tinamou, undulated tinamou, little tinamou, and red-legged tinamou using different color schemes.

Clutch size can be upwards of 9-16 eggs, however these larger clutches are the products of multiple females. The male will incubate and care for the young. Incubation takes about 16 days. If he dies, the female will take over. When the chicks cross cleared areas, they will run like the chicks of rails. Some members of the genus mature rapidly, like the slaty-breasted tinamou which can gain adult size (not weight) by 20 days.

Species