Acris crepitans

From Wikipedia, the free encyclopedia

iNorthern Cricket Frog

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Anura
Family:	Hylidae
Genus:	Acris
Species:	A. crepitans

Binomial name

Acris crepitans
Baird, 1854

The Northern Cricket Frog (Acris crepitans) is a species of small Hylid frog native to the United States and northeastern Mexico. Despite being members of the tree frog family, they are not arboreal. There are three recognized subspecies.

1 Description
2 Behavior & diet
3 Reproduction
4 Habitat
5 Subspecies
6 Geographic distribution
7 Conservation status
- 7.1 Effects of UV radiation
8 References

[edit] Description

Northern cricket frogs are small frogs, between 0.75 and 1.5 inches (19–38 mm) long. Their dorsal coloration varies widely, and includes greys, greens, browns, often in irregular blotching patterns. Typically there is dark banding on the legs and a white bar from the eye to base of foreleg. The skin has a bumpy texture. It is very similar to the Southern Cricket Frog, Acris gryllus, found in the US Southeastern Coastal Plain, though there is some overlap along the fall line. The Southern Cricket Frog has longer legs, with less webbing on the hind feet, and a more pointed snout. The line on the back of its thigh is more sharply defined than the similar mark of the Northern Cricket Frog (Conant et al. 1998, Martof et al. 1980).

[edit] Behavior & diet

Northern cricket frogs are diurnal and generally active much of the year, except in mid-winter in northern areas when the water is frozen. Their primary diet is small insects, including mosquitos. They in turn are predated upon by a number of species, including birds, fish, and other frogs. To escape predators, they are capable of leaping more than three feet in a single jump and are excellent swimmers.

[edit] Reproduction

Breeding generally occurs from April through May. The males call from standing bodies of water with a high pitched, short call which is repeated. It sounds somewhat like the click of hitting small stones together, or like a metallic cricket, which is the source of their common name. One egg is laid at a time and generally attached to a piece of vegetation or scattered along the bottom within a pool of water. The 0.5 inch (14 mm) tadpoles hatch in only a few days and undergo metamorphosis in early fall. Maturity is usually reached in less than a year.

[edit] Habitat

Cricket frogs prefer the edges of slow moving, permanent bodies of water. Large groups of them can often be found together along the muddy banks of shallow streams.

[edit] Subspecies

Blanchard's Cricket Frog, Acris crepitans blanchardi (Harper, 1947)
Eastern Cricket Frog, Acris crepitans crepitans (Baird, 1854)
Coastal Cricket Frog, Acris crepitans paludicola (Burger, Smith and Smith, 1949)

[edit] Geographic distribution

A. c. crepitans - from New York, south to Florida and west along the gulf coast states to Texas.
A. c. paludicola - southwestern Louisiana to eastern Texas.
A. c. blanchardii - Michigan and Ohio, south through to most of Texas and Mexico. Has been recorded in Minnesota and Colorado.

[edit] Conservation status

Frogs like the cricket frog are very important to humans as an indicator of water and general environmental quality in the areas they inhabit. Since the 1970s, populations of all amphibians have been in decline, which is largely believed to be attributable to the increase in use of fertilizers and pesticides. A. c. blanchardi is listed as a species of concern in the state of Michigan. Acris crepitans is listed as an endangered species in New York.

[edit] Effects of UV radiation

It has been shown that frog development is often impaired by exposure to ultraviolet radiation, particularly UV-B. Studies have shown that UV-B radiation has had a significant impact on cricket frog populations, causing local extirpations and a reduction in range of 70 miles from their previous northern extreme. Four factors are believed to contribute to the decline of cricket frogs due to UV-B radiation:

They are affected most by UV-B radiation in lab settings in comparison to other frog species.
They are less protected from UV-B than other frogs because their eggs are laid closer to the surface of the water (.75cm compared to 6cm)
Since they are not laid in large egg masses, they do not gain the benefit of the top eggs sheltering the lower eggs.
Eggs are laid later in the season, when days are longer, subjecting them to increased levels of UV-B.

[edit] References

Hammerson et al (2004). Acris crepitans. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 12 May 2006. Database entry includes a range map and justification for why this species is of least concern