Allobates femoralis (common name brilliant-thighed poison frog, brilliant-thighed poison-arrow frog) is a species of frog in the family Aromobatidae. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, and Suriname. Its natural habitat is tropical lowland forests.
Description
Allobates femoralis is a small frog, the males growing to in length and the females being marginally larger. The coloration on the back is dark brown or black and the limbs are colored dark brown. The throat is black and the belly is white, marked with black. A pale brown dorso-lateral stripe runs from the snout to the base of the legs and an intermittent white ventro-lateral line runs from the snout to the arm and onwards to the leg. There is an orange-yellow patch behind the arm and a half-moon shaped orange patch on the outside of the thigh. A. femoralis resembles Lithodytes lineatus in general appearance, but L. lineatus has a dorso-lateral line encircling the back, legs barred with dark and light bands of colour, and two or more orange patches on each thigh.
Habitat and distribution
Allobates femoralis is distributed in the Amazon basin and tropical eastern South America. Its geographical range includes Guyana, Suriname, French Guiana and Brazil, and the eastern parts of Colombia, Ecuador, Peru and Bolivia. A single reported sighting in Venezuela may have referred to Ameerega picta. It is found on the forest floor, usually at elevations below 300 m (1,000 ft), but in Colombia and Ecuador occurs at altitudes of up to 1,000 m (3,300 ft).
Biology
Allobates femoralis is a terrestrial frog species. It is active during the day, and it feeds on small insects such as beetles, crickets, roaches and ants; the juveniles largely feed on springtails. Breeding takes place between November and April, peaking in January or February. The males are territorial and court females for two to three days before a clutch of eight to seventeen eggs is laid in a nest among fallen leaves. The male guards the eggs, and after they have hatched, he carries the tadpoles to pools of water on his back.
Mating and reproduction
Courtship behavior
Pair formation is initiated when the male Allobates femoralis detects the presence of a female A. femoralis. He then leads her to the oviposition site, which is always covered, and the female lays clutches of eggs between dead leaves or beneath a log. The leaves or the log thus form a roof over the clutch. This behavior known as the "courtship march" refers to when the male initiates the courtship and the female follows him to the oviposition site.
Although courtship components vary across species of poison frogs, A. femoralis is known to have the longest courtship duration among its species. Females rarely reject males and their gesture of courtship, and females also do not evaluate male quality/fitness during courtship. However, females sometimes demand prolonged courtship for the following reasons: verification of male's territory ownership, ovulation stimulation, and benefit of spatial learning and finding clutches in case of mate loss.
Polygyny
Male A. femoralis can court more than one female A. femoralis. When the male courts two females, he marches alternately with each female, and while the male courts one female, the other female stays in the spot where the male conducted her before moving on to his current courtship interaction. And the females sharing courtship with the same male do not interact aggressively with each other.
Male/male interactions
Unlike females that do not show aggression under polygyny, A. femoralis males interact aggressively with other males when it comes to territorial defense. During the 'courtship march' when an A. femoralis male searches for an ovipostion site, the female can be intercepted by a competing male, which the female will start following. This leads to physical aggression between males that can last about 15 minutes, where eventually, one of the males will leave the oviposition site. It is suggested that visual signals play an important role in male-male aggression.
Reproductive behavioral divergence
Behavioral divergence is observed within the range of A. femoralis from different localities. The divergence is observed in various factors, including the number of notes of A. femoralis call, the presence of cephalic amplexus, and the presence of visual components of the courtship behavior (throat display, limb lifting, circling, leg stretching). Researchers suggest that the process of diversification may be understood in depth through geographic variation in sexual signals.