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Scinax ruber (Brown Tree )

Family: (Tree ) Order: Anura (Frogs and Toads) Class: Amphibia ()

Fig. 1. Brown tree frog, ruber. [https://stricollections.org/portal/imagelib/imgdetails.php?imgid=21822 downloaded 2 February 2017]

TRAITS. The brown tree frog is also known as the red-snouted tree frog or ranita listada (Spanish). They are medium sized tree frogs, males can reach up to 41mm in snout-vent length (SVL) and females reach 44mm SVL. The dorsal (back) ground colour varies depending on the light intensity, ranging from cream, tan or even grey to dark brown, usually with broad dark brown dorsolateral (back) stripes and distinct lumbar (lower back) spots (Fig. 1). Yellowish or orange blotches on a dark background are present on the groin and hidden surface of the thighs. The skin on the dorsum (back) and ventral (underside) is smooth to weakly granular. Toes I-III webbing is reduced and the fingers are unwebbed (Lescure and Marty, 2001). The iris is bronze with irregular black vermiculation (surface patterns).

DISTRIBUTION. Scinax ruber is widespread in South American countries such as northern , from through the French , , , , and UWI The Online Guide to the Animals of Trinidad and Tobago Ecology

Trinidad and Tobago (Fig. 2). They were introduced to , and as an invasive species (IUCN, 2017).

HABITAT AND ACTIVITY. The brown tree frog habitat is tremendously variable, they thrive in terrestrial and fresh water areas, which are open to moist, disturbed habitats such as gardens and parks (Duellman, 1978). In Trinidad and Tobago Scinax ruber is found along road sides with shallow water, grasses, and urban habitats with standing water (Murphy, 2017). These frogs are nocturnal (active at night) creatures (Fig. 3). The males use a yellow camouflage when they call which makes them difficult to spot (Murphy, 2017).

FOOD AND FEEDING. A limited amount of research has been published with respect to Scinax ruber’s food and feeding patterns, however generally adult tree frogs are insectivores (feed on insects). Their diet consists of small insects which includes ants, beetles, crickets, flies among other tiny insects (Funk, 2017). They hunt at night for their prey (small insects) by patiently waiting while camouflaged for any small insect that is in striking range (Funk, 2017). When an insect is close enough they quickly stick out their glue-like tongues and pull them into their mouth. However, they weren’t insectivores during their whole life cycle. At the tadpole stage, they begin their lives as herbivores (plant eating) but as they mature they become carnivorous (flesh eating) creatures.

POPULATION ECOLOGY. During its adulthood Scinax ruber are solitary (existing alone) amphibians. Both male and female only unites during the mating season. There has been no research publish thus far pertaining the age and longevity of the brown tree frog. This species is quite abundant since there is a large, increasing population in South America, moreover they can easily adapt to the environment which makes them a stable population (IUCN, 2017).

REPRODUCTION. Scinax ruber are seasonal breeders since they only mate and produce offspring during the rainy season. They usually lay their eggs in small temporary pools (Duellman, 1997). This frog’s egg clutch can contain up to 590 eggs which then develop into tadpoles (Linsay, 2012). No parental care occurs by this frog. Tadpoles begin to mature into frogs a couple of months after the eggs are initially laid into the body of water.

BEHAVIOUR. Like any other tree frog Scinax ruber camouflages itself to protect them from predators. They use the brown coloration to its advantage by blending in with the terrestrial environment from both ground- dwelling and aerial predators. They communicate by calling a series of low or high pitch notes additionally they also produce a chuckle call (Ibanez et al., 1999).

APPLIED ECOLOGY. The IUCN assesses Scinax ruber as of Least Concern because of its wide distribution, large population, and the broad range of habitats. There are no conservation threats since they are a very adaptable species (IUCN 2017).

REFERENCES Duellman, W.E. (1978). The biology of an equatorial herpetofauna in Amazonian . University of Kansas Museum of Natural History 65:1-352 Duellman, W.E. (1997). Amphibians of La Escalera region, Southeast Venezuela: , Ecology. Scientific papers of the Natural History Museum of the University of Kanas 2: 1-52

UWI The Online Guide to the Animals of Trinidad and Tobago Ecology

Funk C. (2017). Tree frogs. National Wildlife Federation. http://www.nwf.org/Wildlife/Wildlife- Library/Amphibians-Reptiles-and-Fish/Tree-Frogs.aspx Ibanez, R., Rand, S. and Jaramillo, C.A (1999). The amphibians of the Barro Colorado Natural Monument, Soberania National Park and adjacent areas. IUCN. (2017). Scinax ruber. The IUCU Red List of Threatened Species. http://www.iucnredlist.org/details/biblio/55994/0 Lescure, J. and Marty, C.A, (2001). Atlas of the Amphibians of Guyana. Natural Heritage Sites ,Paris Linsay, W. (2012) Just making myself at home: The rescue organization, Panama. http://amphibianrescue.org/tag/scinax-ruber/ Murphy, J. (2017). The Lesser Brown Tree frog, Scinax ruber : The Herpetology of Trinidad and Tobago. http://herpetologytt.blogspot.com/2017/01/lesser-brown-treefrog-scinax-rubra.html

Author: Anil Bahall Posted online: 2017

Fig. 2. The brown tree frog geographic distribution. [http://biogeodb.stri.si.edu/amphibians/es/species/196/, downloaded 3 March 2017]

UWI The Online Guide to the Animals of Trinidad and Tobago Ecology

Fig. 3. The brown tree frog at night. [http://www.bio.fsu.edu/chorusfrog/research_SAm.html, downloaded 3 March 2017]

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