Wednesday, February 08, 2017Register
 Species Spotlight

Mountain Bluebird (Sialia currucoides), courtesy of US Fish and Wildlife
[Photo: US Fish and Wildlife]

Mountain Bluebird
Sialia currucoides

Description: The mountain bluebird is a medium-sized songbird in the Turdidae, or thrush family. The mountain bluebird has a chunky body, large head, and medium length tail. It is 6.5-8 inches (16.5-20 cm) long and weighs, on average, 1.1 ounces (31 g). The plumage color of the mountain bluebird is sexually dimporphic with the male's body a brighter sky blue and the female a much duller, gray-blue color with bright patches on the rump, wings, and tail. Females also have a white eye ring and some have a faint malar streak (streak below the eye). A mountain bluebird can be distinguished from the closely related western bluebird (Sialia mexicana) by the prominent rusty patch on the chest and shoulders of the western bluebird. The mountain bluebird call consists of two songs: a short, loud song similar to the American robin and sung in the morning; and a soft, musical warble common throughout the rest of the day.

Life History: The mountain bluebird has a five year life span. It is a migratory bird, leaving breeding areas in the later summer and early fall and returning in the late winter and early spring. Breeding occurs in the early spring and females produce 1-2 broods per year. Males attract females by choosing desirable nest sites. Pair bonds are seasonally monogamous and males engage in guarding behavior of females after pair formation, through nest building, until hatching. Females lay eggs from May through July with earlier egg laying occurring further south. Females lay one egg per day until 4-6 pale blue eggs have been laid. The chicks hatch after 20 days and leave the nest in 3 or 4 weeks. The mountain bluebird forages diurnally and perches on power lines or fences, from where it darts to catch prey. It is mostly carnivorous, with 92% of its diet consisting of insects and the remaining food comprised of seeds and fruit such as grapes, currants, and elderberries. Adults are preyed upon by other birds such as the American kestrel, Cooper's hawks and American crows. Nestlings are preyed upon by ants, flies and chipmunks.

Habitat: The primary habitats of the mountain bluebird are orchards, farmland and open mountain meadows near trees. It prefers habitat with short grasses, a few shrubs, and nearby trees. The mountain bluebird occupies similar habitat during breeding and non-breeding season, but lives at higher elevations during breeding periods. The mountain bluebird is a cavity nester, building its nest in tree cavities or nest boxes. Nests are built by females and are woven from grasses, soft bark, hair and feathers.

Distribution: The breeding range ofSialia currucoides is found throughout the Rocky Mountains, stretching from Colorado to Alaska, and spanning from Nebraska in the east to Nevada in the west. The non-breeding range reaches from Oregon down to southern Mexico, from the Great Plains west to the California coast.

Status: The mountain bluebird has benefited from management practices such as nest box building and logging. It also benefits from practices like grazing and prescribed burning, which clears long understory grasses. There is a stable amount of existing habitat for the mountain bluebird, thus the population remains secure throughout the breeding range. Loss of populations has occurred in places where trees are not large enough to support nest cavities.


Birds of North America Online

Colorado Division of Wildlife

 Western Cordillera

Western Cordillera Level 4 Ecoregion Map [Figure: Houston Advanced Research Center using USEPA data]Western Cordillera Level 4 Ecoregion Map Legend [Figure: Houston Advanced Research Center using USEPA data] Western Cordillera Level 4 Ecoregion Map [Figure: Houston Advanced Research Center using USEPA data]

The Western Cordillera ecoregion is comprised of the Southern Rocky Mountains in Colorado stretching down to northern New Mexico, and the Wasatch and Uinta Mountains running the length of central Utah. This ecoregion is known for its rugged beauty and is home to 30 of the highest peaks in the Rocky Mountains.

Climate & Topography

The topography of the Western Cordillera is characterized by high, rugged, forested mountains and deep, intermontane depressions interspersed with open, park-like meadows. In Utah, high-elevation dissected plateaus can also be seen. Elevation ranges from 4,800 to 14,400 feet (1,460-4,390 m), with local relief between 3,000 and 7,000 feet (900-2,100 m). In the Southern Rocky Mountains the underlying geology is composed of granitic, volcanic and sedimentary rocks; in the Wasatch and Unita Mountains, sedimentary and igneous rocks predominate. In the mountainous areas, soils are those typical of forested ecosystems (shallow and fertile), but may be heavily eroded and depleted along steep slopes. In the valleys (or "park" areas) deeper, more organic soils are present. Consistent with the moderately dry climate, most soils have a dry to moderately dry moisture regime. Streams are often perennial and maintained by snowmelt. Glacial lakes also provide important sources of water at high elevations. Average annual rainfall at the base of the mountains ranges from 10-20 inches (25-50 cm) and at higher elevations precipitation increases to 40 inches (100 cm) of largely snowfall per year. Temperatures vary widely with elevation, with average annual temperatures ranging from 25-52 degrees F (-4 to 11 deg C). The growing season ranges from less than 25 days at extreme elevations to 200 days in low valleys.

Vegetation & Wildlife

These rugged mountain ranges exhibit distinct vegetation bands with valley, montane, subalpine and alpine communities present. At lower elevations (below 8,500 feet), in the valleys and foothills, several species of grass (e.g. blue grama, Junegrass and western wheatgrass), sagebrush, antelope bitterbrush, mountain mahogany, scrub oak species, ponderosa pine, pinyon and Utah juniper are present. Above this zone is the montane zone (7,000-9,000 feet), where ponderosa pine, aspen, and Douglas-fir predominate. The sub-alpine zone (8,500-12,000 feet) is above the montane zone, and is dominated by Engelmann spruce, lodgepole pine, aspen and subalpine fir. Alpine tundra is the highest vegetation zone (above 11,000 feet) and located above the tree-line, such that grasses, cushion plants, wildflowers, sedges and lichens comprise the vegetation. Because of the many vegetation zones present in this ecoregion, there is an abundance of wildlife, including species such as the grizzly bear, black bear, elk, lynx, black-tailed deer, shrew mole, golden eagle, blue heron, blue jay, salmon, mountain bluebird, and the Uncompahgre fritillary butterfly.

Land Use & Environmental Impacts

The major land uses in this area are mining, forestry, grazing, tourism and recreation with a large amount of land reserved as National Parks and forests. The major threats to this region's ecosystems are fire suppression, overgrazing of lowland riparian areas, increasing residential development, and the introduction and spread of non-native species. Non-native species that threaten the Western Cordillera ecoregion include leafy spurge, common burdock, mountain goats, and the northern pike.

 Invasive Spotlight

[Photo: D. Osmundson, US Fish and Wildlife]
[Photo: D. Osmundson, US Fish and Wildlife]

Northern Pike
Esox lucius

Description: The northern pike is a large member of the Esocidae or pike family. This fish can reach lengths of 60 inches (150 cm), but averages around 20-30 inches (50-75 cm). It averages around 2-3 pounds (.9-1.4 kg) but large specimens can weigh over 40 pounds (18 kg). The northern pike has a long, tube-like body with a flattened, duckbill snout and is known for its extraordinary number of large, sharp teeth. The head and upper body are a light to dark green color with bean-shaped spots running along the body. The dorsal and anal fins are set back (posterior) on the body, close to the caudal (tail) fin. The northern pike has a white underbelly and yellowish-orange, striped fins.

Life History: The northern pike lives an average of seven years, but can live up to 25 years in the wild and 75 years in captivity. Sexual maturity for both males and females occurs from 1-2 years of age. Spawning takes place in the spring, after ice melt, at water temperatures of 45-60 degrees F (7-16 deg C). The northern pike spawns on vegetation mats, preferably in marshes, and has a high rate of fecundity, producing up to 100,000 eggs during one spawning session. Only 1 percent of eggs will survive, due to predation by insects and by cannibalistic northern pike. Eggs hatch in 12-14 days and the fry (newly hatched larval fish) feed on zooplankton and then invertebrates until they reach fingerling size (1-3 inches [2.5-7.5 cm]), after which they feed on darters, minnows, and bass and perch juveniles. Northern pike grow rapidly, and require 5-6 pounds of food for every one pound of growth. They are opportunistic carnivores, eating a wide variety of prey items such as fish (including smaller northern pike), frogs, crayfish, ducklings, and others. The northern pike feeds by using sight and will eat almost anything that it encounters.

Habitat: The northern pike lives in shallow, cool waters in lakes, backwater pools, and small to large rivers. It is highly tolerant of low temperature and low dissolved oxygen conditions, thus it survives winter conditions quite well. The northern pike requires shallow (less than 12 inches or 30 cm deep), vegetated areas for spawning and rearing.

Distribution: Esox lucius is native to the northern latitudes of North America, Europe and Asia. In the United States, the northern pike is native to the upper Midwest, but is also distributed in many non-native watersheds, where it was historically stocked as sport fish. Northern pike has non-indigenous occurrences in 39 states in the United States, including many states in the West, where it is considered a nuisance species.

Status: The northern pike was heavily stocked in the 1940s and 1950s and has rapidly spread throughout many tributaries and lakes. Northern pike now has non-indigenous occurrences in 39 states. The northern trout is at the top of the aquatic food chain and is a voracious eater, severely impacting native fish populations. In some invaded habitats, the northern pike is the only remaining fish species and adults rely solely on cannibalism to survive. In many western fisheries, northern pike predation on trout has been recognized as a serious fisheries management problem. The northern pike carries parasites including the broad tapeworm which can infect humans and another parasite which affects lake whitefish (Coregonus clupeaformis). The northern trout is also capable of hybridizing with the native muskellunge.


Colorado State, Northern Pike in selected Colorado Trout Reservoirs

FishBase, Esox lucius

USGS, Non-indigenous Aquatic Species

 Endangered Spotlight

[Photo: Creed Clayton, US Fish and Wildlife]
[Photo: Creed Clayton, US Fish and Wildlife]

Uncompahgre Fritillary Butterfly
Boloria acrocnema

Description: The Uncompahgre fritillary butterfly (UCB) is a small butterfly of the Nymphalidae family in the order Lepidoptera (moths and butterflies). It has a 1-1.2 inch (2-3 cm) wingspan. The body of the UCB is a brownish color, with the dorsal (backside) portion of the wings a dull orange-brown color, criss-crossed with black bars and indistinct markings. The ventral (underside) consists of a light brown forewing and a hind wing which is red on the inner wing and purplish-gray on the outer wing. The inner and outer part of the wing is divided in half by a white jagged bar.

Life History: Due to the short growing seasons at the extreme altitudes where it lives (~13,000 feet), the UCB requires two years to complete its life cycle. The UCB lays its eggs on the stems of snow willows (Salix nivalis). The UCB larvae hatch late in the summer, and the larvae, or caterpillars, eat the leaves of the willow during the first summer and fall. The caterpillars hibernate over winter, continue to grow the following summer and fall, hibernate over winter a second time, and then emerge as adults the following summer. Adult UCBs feed on nectar from nearby flowering plants.

Habitat: The butterfly is restricted to alpine meadows from 12,100-13,500 feet (3,688-4,115 m) in the San Juan mountains of Colorado. They are associated with patches of snow willows, utilizing this tree for egg-laying and larval food. Snow willows are found on northeast facing slopes, which provide a wetter, cooler microhabitat than other areas of the San Juan mountains.

Distribution: Boloria acrocnema is found in the San Juan mountains of southwestern Colorado. When it was discovered in 1978, there were only two known colonies: Mt. Uncomphagre and Redcloud Peak in the San Juan mountains. As of 2009, 11 confirmed colonies of UCBs exist at Mt. Uncomphagre and Redcloud Peak.

Status: The UCB was listed as a federally endangered species in 1991 because of its narrow geographic range and small, declining population. There is a recovery plan in place for this species (1994). This species does not have a critical habitat designation, but all UCB populations currently reside on federally managed lands. At the time of its listing, the population of UCBs was estimated at 1,000 and now ranges from 3,400-23,000 (with significant yearly population fluxes). Major threats to this species at the time of listing included overcollection and threats to habitat from recreational hiking and sheep grazing. An emerging threat to the population, due to its small population size, is the reduction in habitat from climate change; warming temperatures may cause the butterfly to retreat even higher into shrinking alpine habitat.


The Butterfly Conservation Initiative

USFWS, UCB 5-Year Review

USFWS, UCB Recovery Plan

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