Regularity: Regularly occurring
Type of Residency: Year-round
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Range includes large areas of Canada and the western and north-central United States from the Great Bear Lake in Canada's Northwest Territories to northern Ontario, southward to Arizona, New Mexico, northern Oklahoma, Missouri (possibly northern Arkansas), and Illinois; disjunctly also in southern Ontario, southern Quebec, northern New York, and northwestern Vermont (Conant and Collins 1991, Stebbins 2003, Lemmon et al. 2007). Elevational range extends to above 12,000 feet (3,670 meters) in Colorado and Utah (Hammerson 1999, Stebbins 2003).
Montana Valley and Foothill Grasslands Habitat
This taxon can be found in the Montana valley and foothill grasslands ecoregions, along with some other North American ecoregions. This ecoregion occupies high valleys and foothill regions in the central Rocky Mountains of Montana in the USA and Alberta, Canada. The ecoregion the uppermost flatland reaches of the Missouri River drainage involving part of the Yellowstone River basin, and extends into the Clark Fork-Bitterroot drainage of the Columbia River system. The ecoregion, consisting of three chief disjunctive units, also extends marginally into a small portion of northern Wyoming. Having moderate vertebrate species richness, 321 different vertebrate taxa have been recorded here.
The dominant vegetation type of this ecoregion consists chiefly of wheatgrass (Agropyron spp.) and fescue (Festuca spp.). Certain valleys, notably the upper Madison, Ruby, and Red Rock drainages of southwestern Montana, are distinguished by extensive sagebrush (Artemisia spp.) communities as well. This is a reflection of semi-arid conditions caused by pronounced rain shadow effects and high elevation. Thus, near the Continental Divide in southwestern Montana, the ecoregion closely resembles the nearby Snake/Columbia shrub steppe.
A number of mammalian species are found in the ecoregion, including: American Pika (Ochotona princeps), a herbivore preferring talus habitat; Bighorn Sheep (Ovis canadensis), Black-tailed Prairie Dog (Cynomys ludovicianus), who live in underground towns that may occupy vast areas; Brown Bear (Ursos arctos); Hoary Marmot (Marmota caligata), a species who selects treeless meadows and talus as habitat; and the Northern River Otter (Lontra canadensis), a species that can tolerate fresh or brackish water and builds its den in the disused burrows of other animals.
There are six distinct anuran species that can be found in the Montana valleys and foothills grasslands, including: Canadian Toad (Anaxyrus hemiophrys); Western Toad (Anaxyrus boreas); Northern Leopard Frog (Lithobates pipiens); Plains Spadefoot Toad (Spea bombifrons); Columbia Spotted Frog (Rana luteiventris), an anuran that typically breeds in shallow quiet ponds; and the Boreal Chorus Frog (Pseudacris maculata).
Exactly two amphibian taxa occurr in the ecoregion: Long-toed Salamander (Ambystoma macrodactylum), a species who prefers lentic waters and spends most of its life hidden under bark or soil; Tiger Salamander (Ambystoma tigrinum).
Reptilian species within the ecoregion are: Milk Snake (Lampropeltis triangulum), an adaptable taxon that can be found on rocky slopes, prairie and near streambeds; Painted Turtle (Chrysemys picta); Western Plains Garter Snake (Thamnophis radix), a taxon that can hibernate in the burrows of rodents or crayfish or even hibernate underwater; Yellow-bellied Racer (Coluber constrictor); Spiny Softshell Turtle (Apalone spinifera); Western Terrestrial Garter Snake (Thamnophis elegans); Rubber Boa (Charina bottae); Western Skink (Plestiodon skiltonianus); and the Western Rattlesnake (Crotalis viridis).
The ecoregion supports endemic and relict fisheries: Westslope Cutthroat Trout (Oncorhynchus clarki lewisi), Yellowstone Cutthroat Trout (Oncorhynchus clarkii bouvieri), and fluvial Arctic Grayling (Thymallus arcticus), a relict species from past glaciation.
- C. Michael Hogan & World Wildlife Fund. 2014."Montana Valley and Foothill Grasslands". Encyclopedia of Earth, National Council for Science and the Environment, Washington DC ed.Mark McGinley.
- Matthew Jaeger, Ken Frazer, Clark Nelson, Mike Vaughn, Brad Schmitz, Jim Darling. 2005. Movements and habitat use of Yellowstone native fishes and reptiles and nesting distributions of native birds. T2-25-2 Report. Montana Department of Fish, Wildlife and Parks. Miles City, MT
Habitat and Ecology
Comments: Habitat is mostly the vicinity of quiet bodies of water and associated wetlands and meadows; sometimes these frogs cross up to a few hundred meters of upland habitat between wetlands, and they may overwinter in upland sites adjacent to wetlands; periods of inactivity may be spent in water, among thick wetland vegetation, under objects on the ground, or in rodent burrows (Hammerson 1999). Chorus frogs breed in marshes, rain pools, pools formed by melting snow, bog ponds, glacial kettle ponds, beaver ponds, marshy edges of lakes and reservoirs, flooded areas, and other bodies of water with little or no current (Hammerson 1999). Both permanent and temporary waters are used, and eggs commonly are laid in ponds that dry up before the tadpoles metamorphose. Eggs usually are attached to vegetation in shallow water.
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 to >300
Comments: This species is represented by a very large number of occurrences (subpopulations).
Comments: Total adult population size is unknown but certainly exceeds 100,000 and presumably exceeds 1,000,000.
Tiny clams sometimes have been found attached to the toes of boreal chorus frogs. The frogs may serve as dispersal agents for the clams, which are restricted to waters and cannot move very far on their own. The frogs might even rarely move the clams from one body of water to another.
Life History and Behavior
Comments: Emergence from wintering sites typically occurs in March in lowland areas. Activity extends into September and October, and some individuals remain active into November, even after cold spells. In general, these frogs tend to be relatively inconspicuous in lowland areas in summer. Spring emergence in the mountains may not occur until May. Chorus frogs at high elevations sometimes remain active even after September snowstorms but in other places or years may disappear by mid-September even if warm weather continues. In the mountains, most activity occurs between late morning and mid-afternoon, though calling activity may extend late into the night during the breeding season. Activity in lowland areas tends to be diurnal in early spring and fall, nocturnal or crepuscular during warm spring and summer weather.
In lowland areas, males usually begin calling in late March or April, usually when air temperature is above 10?C. Chorusing continues through spring and early summer. By early to late June calling may come to a temporary halt, only to begin again in June, July, or even August after heavy rains or when fields are flooded with irrigation water. In the Great Plains region of Colorado, most egg laying occurs in April, May, and June. At high elevations, breeding begins immediately after the spring thaw in late May or early June and may continue into July. Calling (but not egg laying) commonly occurs through late August at high mountain breeding sites and in adjacent meadows. Some of the males calling in August appear to be young of the year.
Each female may lay several egg clusters. Hatching may occur within a few days or up to about a week after laying.
Metamorphosis occurs as early as early June in lowland areas and primarily during July and August, sometimes as late as early September, in the mountains. Young usually leave the water before the tail is fully resorbed.
Breeding populations at low elevations are composed only of individuals that hatched the previous year. At higher elevations males do not breed until they are about two years old, females not until three years old.
Molecular Biology and Genetics
Statistics of barcoding coverage: Pseudacris maculata
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Total adult population size is unknown but certainly exceeds 100,000 and presumably exceeds 1,000,000.
Area of occupany, number of subpopulations, and population size probably have declined somewhat over the long term, especially in the southeastern portion of the range where habitat change has been most extensive, but the extent of decline may not exceed 25 percent.
Current trend is not well documented, but area of occupany, number of subpopulations, and population size probably are declining at a rate of less than 10 percent over 10 years or three generations.
Global Short Term Trend: Relatively stable (=10% change)
Comments: Current trend is not well documented, but area of occupany, number of subpopulations, and population size probably are declining at a rate of less than 10 percent over 10 years or three generations.
Global Long Term Trend: Increase of 10-25% to decline of 30%
Comments: Area of occupany, number of subpopulations, and population size probably have declined somewhat over the long term, especially in the southeastern portion of the range where habitat change has been most extensive, but the extent of decline may not exceed 25 percent.
Degree of Threat: Low
Comments: No major threats are known, but locally some populations probably are declining as a result of conversion of habitat to intensive human uses.
Global Protection: Very many (>40) occurrences appropriately protected and managed
Comments: Many occurrences are in national parks and other protected areas.
Boreal chorus frog
The boreal chorus frog (Pseudacris maculata) is a species of chorus frog native to Canada from the west of Lake Superior to western Alberta and north to the Northwest Territories. It occurs in the USA throughout Montana, northwestern Wisconsin, northeastern Arizona, northern New Mexico, and southwestern Utah.
This small species of frog reaches about 30 mm in length. It is highly variable, but is normally brown, and can be green on the dorsal surface, with three broken dorsal stripes; these stripes can be very distinct to quite faint. A dark band is present from the snout, across the eye, and continuing down the side. It has slightly enlarged toe pads to help in climbing small grasses and vegetation. This species is very similar to the western chorus frog (Pseudacris triseriata). It can be distinguished from this species by having shorter legs.
Ecology and behaviour
This species can be found around permanent water bodies in cleared land and forest. Males make a "reeeek" call from grasses, vegetation, or ground around the water body from April through to September. This is normally one of the first species of amphibian to emerge in spring, it is often found while snow and ice are still present.
Names and Taxonomy
Comments: A molecular phylogeny of Pseudacris based on mtDNA data (Moriarty and Cannatella 2004) revealed four strongly supported clades within Pseudacris: (1) A West Coast Clade containing regilla and cadaverina, (2) a Fat Frog Clade including ornata, streckeri, and illinoensis, (3) a Crucifer Clade consisting of crucifer and ocularis, and (4) a Trilling Frog Clade containing all other Pseudacris. Within the Trilling Frog Clade, brimleyi and brachyphona form the sister group to the Nigrita Clade: nigrita, feriarum, triseriata, kalmi, clarkii, and maculata. The Nigrita Clade shows geographic division into three clades: (1) populations of maculata and triseriata west of the Mississippi River and Canadian populations, (2) southeastern United States populations of feriarum and nigrita, and (3) northeastern United States populations of feriarum, kalmi, and triseriata. Moriarty and Cannatella (2004) found that subspecific epithets for crucifer (crucifer and bartramiana) and nigrita (nigrita and verrucosa) are uninformative, and they therefore discouraged recognition of these subspecies. They concluded that further study is needed to determine if illinoensis warrants status as a distinct species. Molecular data were consistent with retention of regilla, cadaverina, ocularis, and crucifer in the genus Pseudacris.
Using mtDNA samples from a large number of localities throughout North America, Lemmon et al. (2007) elucidated the phylogenetic relationships and established the geographic ranges of the trilling chorus frogs (Pseudacris). They redefined the ranges of several taxa, including P. maculata, P. triseriata, and P. feriarum; found strong evidence for recognizing P. kalmi as a distinct species; and discovered a previously undetected species in the south-central United States (to be described in a forthcoming publication). Based on mtDNA data, Pseudacris maculata and P. clarkii did not emerge as distinct, monophyletic lineages but, given the degree of morphological and behavioral divergence between the taxa, Lemmon et al. (2007) chose to recognize them as separate species, until further data suggest otherwise.