1 BIRD SPECIES SEEN AT SCOTTSDALE COMMUNITY COLLEGE INDEX OF 74 SPECIES References at end. Text written by staff. Photos by Roy Barnes, Emma Olsen and Dr. John Weser. Abert's Towhee American Kestrel Anna's Hummingbird Ash-throated Flycatcher Bewick's Wren Black Phoebe Black-chinned Hummingbird Black-crowned Night Heron Black-headed Grosbeak Brewer's Blackbird Brewer's Sparrow Brown-headed Cowbird Burrowing Owl Cactus Wren Canada Goose Canyon Wren Cattle Egret Cliff Swallow Common Raven Cooper's Hawk Costa's Hummingbird Curve-billed Thrasher European Starling Gambel's Quail Gila Woodpecker Great Blue Heron Great Horned Owl Great-tailed Grackle Greater Roadrunner Green Heron Green-tailed Towhee Harris's Hawk Hooded Oriole Horned Lark House Finch House Sparrow Inca Dove Killdeer Lesser Goldfinch Loggerhead Shrike Lucy's Warbler MacGillivray's Warbler Mallard Marsh Wren Mourning Dove Northern Flicker Northern Harrier (Marsh Hawk) Northern Mockingbird Northern Rough-winged Swallow Orange-crowned Warbler Osprey Peach-faced Lovebird Prairie Falcon Red-tailed Hawk Red-winged Blackbird Rock Pigeon Rock Wren Ruby-crowned Kinglet Savannah Sparrow Say's Phoebe Sharp-shinned Hawk Snow Goose Song Sparrow Verdin Violet-green Swallow Warbling Vireo Water Pipit Western Kingbird Western Meadowlark White-crowned Sparrow White-throated Swift White-winged Dove Wilson's Warbler Yellow-rumped Warbler
2 ABERT'S TOWHEE (PIPILO ABERTI) Scientific Name: Pipilo aberti Residency: Year-round in western, central and southern Arizona. Diet: Feeds on insects year round. Forages on leaf litter seeds. Predators: Hawks and mammals. Nesting: Nests in shrubs. Abert's Towhees may place nests as high as 15 to 20 feet from the ground. Nests are constructed from cones, non-woody vegetation such as grasses or weed stems. Nest lining consists of animal hair, fine roots, and thinner grasses. Eggs are laid in clutches of five to six, or more. Color ranges from white, bluish, or tan, with little or heavy blotching. Notes: The Abert's Towhee is on the National Audubon's Society's WatchList, which monitors species that some fear may be approaching Threatened or Endangered status. The Abert's Towhee is on the list due to threats against its habitat, rather than observed population decline. There is a strong correlation between damage to riparian areas due to the presence of livestock, and threats to the survival of the Abert's Towhee, a riparian specialist. Photo: Photo above was taken at the Riparian Preserve at the Gilbert Water Ranch on February 18, Scottsdale Community College: Riparian Preserve at Gilbert Water Ranch:
3 AMERICAN KESTREL (FALCO SPARVERIUS) Scientific Name: Falco sparverius Residency: Year-round throughout Arizona. Diet: Insects (many grasshoppers), small mammals (including voles and mice), small birds (like sparrows), amphibians, and reptiles. Hunts by perching or hovering (often hovers near roads, in tall tress or on telephone poles), then diving down to catch prey. Predators: Fire ants and yellow rat snakes prey upon eggs and young. Red-tailed Hawk, Sharp-shinned Hawk, and Cooper's Hawk prey upon adults. "Eye spots" on back of head serve to confuse would-be predators. Nesting: Builds a cavity nest with no lining material. Lays 1 brood per year consisting of 4-5 eggs, white with dark/brown markings. Adapts quickly to a wooden nesting box. May also use woodpecker hole in cactus or tree, or cliff nook. Notes: Formerly called Sparrow Hawk (hence the Latin name Falco sparverius) owing to its small size (10 inches total length). However, despite its small size, it will defend its nest against almost any intruder. The American Kestrel is the most common falcon in North America, with habitats as diverse as towns and wild lands. The male does all the hunting during the breeding period (8-12 weeks duration), while the female stays at the nest. Photo: Photo above was taken at Scottsdale Community College on September 16, Scottsdale Community College:
4 ANNA'S HUMMINGBIRD (CALYPTE ANNA) Scientific Name: Calypte anna Residency: Year-round resident, central/southern Arizona. Also a year-round resident along the entire West Coast. Anna's Hummingbird is considered to be a crescent invader from California, a winter resident. Diet: Nectar and invertebrates such as fruit flies, gnats, mosquitoes, thrips, aphids, spiders, maggots, caterpillars, ants, and insect eggs. Predators: Larger birds, including the Western Scrub-jays, American Kestrel, Greater Roadrunner, and the Curve-billed Thrasher. Nesting: Breeding occurs in Spring. Nests are constructed from soft materials such as hair, feathers, and fine strips of bark. Spider webs are used as an adhesive. Anna's Hummingbirds rarely reuse old nests, preferring to construct new ones. Eggs are bean size. Coon Bluff and Scottsdale Community College. Notes: The Anna's Hummingbird has grown in number since the 1950's, and has expanded its range further south and east. This species' ability to adapt well to an ever-growing suburban environment, and the accessibility and availability of hummingbird feeders and flowers utilized in many suburban areas, has led to the growth in population numbers of this bird. Photo: Taken at Scottsdale Community College on February 23, Watt Preserve: Scottsdale Community College: Riparian Preserve at Gilbert Water Ranch:
5 ASH-THROATED FLYCATCHER (MYIARCHUS CINERASCENS) Scientific Name: Myiarchus cinerascens Residency: Summers throughout most of Arizona. Yearround in southwest corner of the state. Diet: Catches aerial insects. Predators: Red-tailed Hawk and American Kestrel. Nesting: Natural cavity, woodpecker holes (for example, in Saguaro cactus), or nest box, lined with stems, chips of manure, hair and sometimes snake skins. Eggs: 4-5 per clutch, whitish with darker marks. One brood per year. Notes: May nest in mailboxes, drain pipes or fence posts. Photo: Taken at Coon Bluff on March 25, Watt Preserve: Coon Bluff:
6 BEWICK'S WREN (THRYOMANES BEWICKII) Scientific Name: Thryomanes bewickii Residency: A winter resident in southwestern Arizona; resides year-round in northern and southeastern Arizona. Diet: Insects and spiders (97%), seeds (3%). Picks up insects from leaves and lower branches of shrubs. Predators: Sharp-shinned Hawk, Greater Roadrunner, and rattelsnakes prey upon adults. Eggs are preyed upon by snakes. House Wren may remove eggs from cavities, contributing to the decline of Bewick's Wren. Nesting: Female and male build nest in a wide variety of cavities (wood-pecker hole, mailbox, fencepost, nest box, tin can, crevice in a wall). Nest made of twigs, hair, leaves and grasses lined with feathers and grasses. Lays 3-8 eggs, white with brown markings. Produces 2-3 brood per year. Coon Bluff. Notes: A common wren of backyards and gardens. Explores every crevice and competes with House Wren for the nesting cavities. Photo: Taken at Coon Bluff in 2009.
7 BLACK PHOEBE (SAYORNIS NIGRICANS) Scientific Name: Sayornis nigricans Residency: Year-round in southern and western Arizona. Diet: Aerial insects. Feeds mostly on insects near the surface of water. In winter, it feeds on insects near the ground. Occasionally eats tiny fish such as minnows, and some small berries. Predators: Few observations, but may include Cooper's Hawks, Northern Harriers, and American Kestrels. Potential nest predators include: American Kestrels, other corvids, Loggerhead Shrikes, and sometimes terrestrial predators (such as red fox, coyotes, and California ground squirrels). Scrub Jays are known to take eggs. Nesting: The female builds a mud-based cup mixed with hair and grasses, lined with finer materials. The nest is stuck to vertical surface with some overhanging protection, for example a cliff, wooden or concrete wall, or bridge. May nest near human activity. Lays 1-6 white eggs. One-two broods per year. Notes: Often uses the same nest or location for several years. Almost always found near water, therefore affected by human destruction of riparian habitats and diversion of water. Photo: Photo above was taken at Coon Bluff on January 7, Coon Bluff:
8 BLACK-CHINNED HUMMINGBIRD (ARCHILOCHUS ALEXANDRI) Scientific Name: Archilochus alexandri Residency: Summers are spent throughout the state. Diet: Nectar; will also consume insects and spiders, especially the female when laying her eggs. Predators: There have been sporadic reports of predation by the greater roadrunner, the brown-crested flycatchers and the Mexican jay. Snakes eat eggs and fletchlings. Nesting: Breeding occurs from April through July. The nest is a small cup constructed from soft plant down or seeds and mosses; it is held together on top of a branch with spider webbing. The nest is usually lined with hair or feathers. Two bean-sized eggs are laid. Notes: The black-chinned hummingbird is the most common hummingbird in the western United States, and population numbers have remained stable within the Sonoran Desert for decades. This population stability exists presumably because this bird visits over 90 species of plants in addition to artificial feeders for nectar, rendering this species much less threatened than other species by the growing urbanization throughout its range. Photo: Photo above was taken at Scottsdale Community College on July 23, Scottsdale Community College:
9 BLACK-CROWNED NIGHT HERON (NYCTICORAX NYCTICORAX) Scientific Name: Nycticorax nycticorax Residency: Lives year-round in central and western Arizona. In the northeast corner of Arizona, it is a winter resident only. Diet: Fish, aquatic insects, amphibians, lizards, snakes, rodents, and small mammals. Eats the young of other bird species such as terns, herons, and ibises. Predators: Observed or suspected predators of eggs and young include: raccoons and muskrats, Great Horned Owl, and Ring-billed Gulls. Species which eat the eggs include: Fish Crows, Boat-tailed Grackles, Common Crows, and Blue Jays. Response to predators: occasionally Black-crowned Night-Herons chase and mob crows. Nesting: Singly or in small colonies (there may be up to 12 nests in one tree). Nest is placed in reeds, shrubs, cattails, a tree, or against a tussock. Nest made of coarse twigs, reeds and finer material. Lays 3-5 eggs (light-blue/greenish/pale blue-green). One brood per year. Notes: Most active near dawn and dusk (crepuscular); roosts in trees during the day. Hunts alone, feeding mostly at night or at dusk. The adults apparently do not distinguish between their own young and those from other nests, and will brood chicks not their own. Photo: Photo above was taken at the Riparian Preserve at the Gilbert Water Ranch on November 18, Riparian Institute at Gilbert Water Ranch:
10 BLACK-HEADED GROSBEAK (PHEUCTICUS MELANOCEPHALUS) Scientific Name: Pheucticus melanocephalus Residency: Resides throughout most of Arizona in the summertime, except for the very southwest corner of the state which is a migration zone. Diet: Feeds on insects, berries and seeds, including spiders and snails. Also able to feed on monarch butterflies. Predators: Steller's Jay and Scrub Jay prey upon nests. Nesting: The female makes the nest from twigs, pine needles, weeds, and rootlets; the lining is made out of materials such as animal hair and thin grass. It is cup shaped and bulky and can usually be found in trees or large shrubs. Pale blue-green eggs with red to brown spots are laid two to five at a time. Notes: The Black-headed Grosbeak is now able to hybridize with the Rose-breasted Grosbeak, its eastern counterpart, because the treeless prairies of the Central Plains that formerly served as a natural barrier between the two has become settled with towns and homesteads, providing a suitable habitat for each species. Photo: To be added.
11 BREWER'S BLACKBIRD (EUPHAGUS CYANOCEPHALUS) Scientific Name: Euphagus cyanocephalus Residency: Year-round in northern Arizona. Winter in southern Arizona. Diet: Feeds on the ground, primarily on insects, weed seeds, grain, and small fruits. Predators: Coyote, Bobcat, Great Horned Owl, and Bull Snakes prey upon nests. Sharpshinned Hawk, American Kestrel and Great Horned Owl prey upon adults. Nesting: The female builds a cup nest, either just above the ground (in a shrub or small tree) or directly on the ground. She lays 1-2 broods per year, 3-7 eggs each. The eggs are gray with brown markings. Brewer's blackbirds often nest in small colonies of up to twenty pairs. Notes: Often associates with other blackbirds, starlings, and Brown-headed Cowbirds, forming huge winter migration flocks. Taking advantage of human modifications, the Brewer's Blackbird is common in agricultural environments and urban parks. Photo: To be added.
12 BREWER'S SPARROW (SPIZELLA BREWERI) Scientific Name: Spizella breweri Residency: Winters are spent in South half of the state, and sumers are spent in the North. Diet: Seeds and insects. Predators: Nest predators include, Gopher Snakes and other snakes. Adults are preyed upon American Kestrel and Prairie Falcon. Nesting: The nest is constructed of grass on or near the ground. Three to five bluish, brownspotted eggs are laid. There are two distinct nesting populations, one is located in the alpine meadows of the Rocky Mountains of the Yukon, and the other is in the sagebrush deserts. Notes: In areas where habitat destruction and/or fragmentation have occurred due to range management/grazing, population numbers of the Brewer's Sparrow have decreased significantly. When heavy grazing occurs, this often causes the invasion of non-native species of plants, especially grasses that are more prone to fires, resulting in the destruction of sagebrush habitat, so vital to this species. Photo: To be added.
13 BROWN-HEADED COWBIRD (MOLOTHRUS ATER) Scientific Name: Molothrus ater Residency: Year-round in southeastern Arizona. In winter: only in southwestern Arizona. In summer: will reside all the way in the northern part of the state. Diet: Insects, grain, grass and weed seeds. Feeds off the ground, but will also visit seed feeders. In the past, cowbirds used to feed on the bugs on bison. Today they often feed alongside horses and cows. Predators: Direct predators of the fledglings include: black racers, black rat snake, and Blue Jays. Eggs are also destroyed by host species, since the cowbird lays all her eggs in the nests of other species. Host species may reject the cowbird egg in one of several ways: ejecting them from the nest, burying them, or deserting the nest entirely. The following species almost always reject cowbird eggs: Western Kingbird, Eastern Kingbird, Blue Jay, American Robin, Gray Catbird, Brown Thrasher, Cedar Waxwing, and Northern Oriole. Most other hosts reject less frequently. Nesting: Has no nest of its own, but instead lays her eggs in the nests of other species (parasitism: see predators section above, and notes section below). She lays 5-7 eggs per breeding session, but usually only one egg per host nest. The eggs are white with dark markings (brown or gray). Notes: A member of the Blackbird family, the Brown-headed Cowbird is one of the only two parasitic bird species in Arizona, and the only brood parasite common across North America. The female will lay her eggs in the nests of other bird species (known to parasite more than 200 species), which reduces the reproductive success of the other species. Most of these host species (called "acceptors") will incubate the cowbird eggs and raise the young, even at the exclusion of their own young. The remaining species (known as the "rejectors") will reject the cowbird eggs most of the time. Photo: Photo above was taken at Scottsdale Community College on May 23, Riparian Institute at Gilbert Water Ranch:
14 BURROWING OWL (ATHENE CUNICULARIA) Scientific Name: Athene cunicularia (sometimes considered its own genus with the scientific name of Speotyto cunicularia) Residency: Year-round in southern Arizona. In the summer, they reside throughout the state. The Burrowing Owl is a complete migrator to southern Arizona and Mexico. Diet: Insects, scorpions, small mammals, amphibians, lizards and birds. The Burrowing Owl places horse and cow dung around the burrow to attract dung beetles. Predators: Mammals, particularly badgers, are major predators. Domestic cats make up a smaller portion of the predators. Avian predators of both adult and young Burrowing Owls include: Swainson's Hawks, Ferruginous Hawks, Merlins, Prairie Falcons, Peregrine Falcons, Great Horned Owls, Red-tailed Hawks, Cooper's Hawks, and American Crows have all been seen or suspected as predators of adult and young Burrowing Owls. Opossums, weasels, skunks and dogs feed on eggs and young. Nesting: Nests in cavities or burrows in the ground; may use former den of a mammal, or man-made boxes. Lays one brood per year; the number of white eggs ranges from 2 to 12 per clutch. Scottsdale Community College. Notes: When faced with a mammalian predator during the nesting season, the Burrowing Owl attacks aerially. When faced with an avian predator, they usually escape into burrows. It is interesting to note that Burrowing Owls catch food with their feet. This species is diurnal, hunting both at night and during the day (catches more insects during daytime, and more mammals during night-time). The Burrowing Owl may dig its own burrow, or take over one previously made by prairie dogs, skunks, armadillos, or tortoises (the latter is considered a desert keystone species, since its burrows provide homes to several other desert species). This owl may be found in almost any open environment, including pastures, golf courses, backyards, airports, open lots, cemeteries, and university campuses. A major cause of death is collision with cars. This owl is considered an endangered or threatened species in some states. Photo: Taken at Scottsdale Community College on February 9, Scottsdale Community College:
15 CACTUS WREN (CAMPYLORHYNCHUS BRUNNEICAPILLUS) Scientific Name: Campylorhynchus brunneicapillus Residency: Southwestern Arizona, year-round. Diet: Insects (beetles, ants, wasps, grasshoppers). Predators: Snakes, including Red Racer. Nesting: Pairs normally build a bulky woven nest in natural fortresses such as clumps of cholla cactus or spiny shrubs. However, Cactus Wrens make nests for other uses than breeding; one nest within a territory is used as a nursery, while others serve as sleeping quarters for their parents or decoys to fool predators. They also make individual roosting nests, which they use year round. Scottsdale Community College, Coon Bluff, Brown's Ranch, Watt Preserve, and the Riparian Preserve at the Gilbert Water Ranch. Notes: The Cactus Wren is the largest wren in North America and is, in fact, Arizona's state bird. Although no North American wren species is considered threatened or endangered, the cactus wren may be declining, according to Breeding Bird Survey data. Photo: Photo above was taken at Scottsdale Community College on April 16, Brown's Ranch: Scottsdale Community College:
16 CANADA GOOSE (BRANTA CANADENSIS) Scientific Name: Branta canadensis Residency: A winter resident in western, northern, and northeastern Arizona. Occurs in several localities, mainly in the high country, but also including a few low elevation sites such as Roosevelt Lake. Diet: Entirely herbivorous. Eats submergent vegetation (aquatic plants), seeds, berries, grasses, sedges, winter wheat, clovers, and waste grain, especially corn. Feeds on the ground and in the water. Predators: Humans are among the most common predators. The adults are not often preyed upon by other species, owing to their large size and aggressiveness. However, coyotes, gray wolves, Snowy Owls, Golden Eagles, and Bald Eagles have been observed taking adults. Goslings are preyed upon by gulls, foxes, and occasionally Bald Eagles. Most important egg predators are foxes (arctic and red), Herring, gulls (Glaucous, Iceland and Glaucous-winged), and jaegers (Long-tailed and Parasitic). Less important are Common Raven, American Crow, and brown and black bears. Nesting: Platform-type nest, or large open cup: made of sticks, mosses, lichens, and grasses lined with down and some body feathers. Nests on the ground at edges of ponds, lakes, or swamps, on rocks or grass hammocks out in the water. Lays 2-10 creamy-white eggs. One brood per year. Notes: The most widespread and commonly seen goose. Some birds no longer migrate during winter owing to food provided at local ponds by humans. Increased residency can be a nuisance to humans. Adults molt their primary flight feathers while raising young, rendering family groups flightless at the same time. Photo: Photo above was taken at the Riparian Preserve at the Gilbert Water Ranch on February 18, Scottsdale Community College:
17 CANYON WREN (CATHERPES MEXICANUS) Scientifc Name: Catherpes mexicanus Residency: Year-round resident throughout Arizona. Diet: Insects and spiders. The Canyon Wren is not known to drink water; it is possible that it obtains all the water it needs from its insect prey. Predators: Potential predators include; snakes, corvids, hawks, and falcons. Nesting: Male and female build nest of twigs and mosses inside narrow crevice of canyon, rock wall, boulder pile, or building. Nest is lined with spider's silk, feathers, fur, webs, wool, lichens, plant down (soft plant material). May reuse nest from year to year. Lays 3-7 eggs (white with small, faint reddish-brown dots). One-two broods per year. Notes: The Canyon Wren spends its entire life among rocks and cliffs, preferring steep-sided canyons. It can climb up, down, and across rocks. This bird has a unique anatomy, giving it a competitive advantage when foraging for food. Its vertebral column is attached higher on the skull than it is on most other bird species, and the skull is slightly flattened. These modifications allow the Canyon Wren to thrust its bill into tight crevices without bumping its head. Photo: Photo above was taken at Coon Bluff on November 9, 2006.
18 CATTLE EGRET (BUBULCUS IBIS) Scientific Name: Bubulcus ibis Residency: Year-round in southwestern Arizona. In summer, resides throughout the state. Diet: Insects (grasshoppers, crickets, spiders, flies, moths), frogs, reptiles, mollusks, and occasionally birds. Forages in flocks, in both terrestrial and aquatic habitats. Often observed in fields, catching insects that are stirred up by tractors, cattle, horses and other large farm animals. Predators: Eggs are taken by Great-tailed Grackle, American, and Fish Crows. Young and adults are taken by Cooper's Hawk, Harris' Hawk, Peregrine Falcon and Great Horned Owl. Nesting: May nest in colonies, either with other Cattle Egrets (intra-species), or other heron species (inter-species). It builds a platform-type nest in a shrub or tree, and lays 2-6 bluish-white eggs once per year (clutch size ranges from 1 to 9 eggs). Notes: The Cattle Egret has benefited from agricultural developments, since this bird thrives in open areas, lawns, pastures fields, and along roadsides. One of the most abundant herons, this species is widespread across the Unites States. It has bred in almost all states and populations are increasing. Photo: Taken at the Riparian Preserve at the Gilbert Water Ranch on February 17, 2007.
19 CLIFF SWALLOW (PETROCHELIDON PYRRHONOTA) Scientific Name: Petrochelidon pyrrhonota Residency: A common and widespread swallow species in Arizona during summer and migration; seen in southwestern Arizona (including Maricopa County) during migration. In summertime, it is seen in the remainder of the state (northern, eastern and central areas). Diet: Mainly flying insects; rarely berries. Feeds in close-knit flocks. Predators: American Kestrels, Great Horned Owls, Sharp-shinned Hawks, Black-billed Magpies, Loggerhead Shrikes, Common Grackles and Bull snakes. Nesting: Male and female build a gourd-shaped nest with narrow entrance tunnel. Nest made of mud pellets, and lined with grass and feathers. Lays 1-6 eggs, white with brown speckling. One to three broods per year. May even have two broods in the same season. Notes: Colonial, with many nests lined up beneath eaves of buildings or cliff overhangs (up to 3,700 nests in one spot!). Nests are sometimes built under bridges or in culverts. Members of colony may return to the same nest sites each year. Within a colony birds try to steal mud and grass from each other's nests. A female may carry her eggs in her bill over to another swallow's nest, or even lay her eggs directly in another's nest. Photo: Taken by E.N. Olsen at the Riparian Institute at Gilbert Water Ranch on April 7, 2009.
20 COMMON RAVEN (CORVUS CORAX) Scientific Name: Corvus corax Residency: Year-round throughout Arizona. Diet: Omnivorous: eats insects, shellfish, seeds, fruit, small animals (rodents), bird eggs and nestlings, carrion and food scraps. Ravens are scavengers, able to exploit multiple food sources. Increasing populations of this bird species can have a significant negative impact on certain prey species, such as the Desert Tortoise and Least Tern. Predators: Peregrine Falcon, Golden Eagle, and Coyote. Nesting: Both the male and female participate in building the platform-type nest, mostly on cliffs, but also large trees and buildings. Made of sticks, twigs and vine; a depression within the nest is lined with moss, hair and/or grass. They breed once per year, laying 3-8 eggs (pale green with brown markings). This species tends to use the same nest site for many years. Coon Bluff. Notes: It is interesting to note that this species follows wolf packs to scavenge carrion. The Common Raven is also known to scavenge alongside crows and gulls. The Common Raven is highly intelligent and adaptable, able to survive in extreme ranges of climate from Artic to desert. It is therefore one of the most widespread bird species in the world. From , raven populations increased dramatically within the Sonoran Desert, but since 1993 have leveled off. This population increase is a major concern for some biologists who maintain that ravens sometimes predate animals within the Sonoran Desert who are considered threatened or of "special concern" status, such as the Desert Tortoise or the Chuckwalla lizard. These species suffer from dwindling population numbers from many factors usually associated with habitat loss, and raven predation may be an added threat to species already vulnerable. It s interesting to note, however, that ravens are often closely associated with human activities, and have even been indicators in some studies of the level to which humans have affected an area This close relationship with human activities seems to indicate that the rise in raven populations and the inverse decline of other native species may be more directly due to the human population explosion that has occurred in the Sonoran Desert within the last few decades. Photo: Taken at Coon Bluff on April 3, 2007.
21 COOPER'S HAWK (ACCIPITER COOPERII) Scientific Name: Accipiter cooperii Residency: Year-round resident throughout Arizona, except for the southwestern corner of the state, where it only spends the winter. Diet: Small mammals and birds. Predators: Great Horned Owl and Red-tailed Hawk. Nesting: The male builds a platform nest out of sticks lined with bark; the female lays three to five bluish-white eggs. Notes: The Cooper's Hawk is a prime example of how human introduction of agents like pesticides into the natural environment can affect the survival of native wildlife. The introduction of DDT in the 1940 s and 1950's has been linked to the dramatic decline in population numbers of this bird, though their population began to increase again in the 1960's. Although the Cooper's Hawk is listed as threatened or of special concern in many states, this species has shown the ability to adapt to breeding in urban environments, which may help to further increase their population. Photo: Taken at Scottsdale Community College on March 9, Scottsdale Community College: Robbins Butte:
22 COSTA'S HUMMINGBIRD (CALYPTE COSTAE) Scientific Name: Calypte costae Residency: Resides year-round along the southwestern edge of Arizona. During the summer, resides throughout western and southern parts of the state. Resides in desert habitat, except during the hottest days of summer when it moves to chaparral, scrub or woodland habitats. Diet: Flower nectar, small insects, hummingbird feeders (some will stay the winter if a consistent food source is available, such as a hummingbird feeder). Predators: Snakes, Loggerhead Shrike, Cactus Wren, Common Raven, Scrub Jays, and Gray Thrashers. Nesting: The small cup-shaped nest is placed in a low protected area in a tree, shrub, cactus, sage, or yucca stalk. Lays 2-3 white, bean-sized eggs per clutch (one brood per year). Notes: The Costa's Hummingbird is currently on the National Audubon Society's Watchlist due to severe declines in its populations over the last few decades. These declines have been attributed to many factors affecting habitat loss, such as urban and agricultural development, cattle grazing, and the planting of buffel grass for cattle - a plant that fuels fires, thus destroying native plants that aren t fire resistant, but which are vital to this species for food and nesting sites. Photo: To be added.
23 CURVE-BILLED THRASHER (TOXOSTOMA CURVIROSTRE) Scientific Name: Toxostoma curvirostre Residency: Year-round in central and southern Arizona. Diet: Forages on the ground for insects, fruit, berries, seeds (digs holes in the soil with its curved bill). Will visit ground seed feeders and bird-baths. Predators: Egg predators: coachwhips, striped whipsnakes, gopher snakes, common kingsnake, desert spiny lizard, ants, Greater Roadrunner, round-tailed ground squirrel, and Harris antelope ground squirrel. A Harris' Hawk has been observed taking a fledgling. A Mexican boa has been observed constricting an adult. Nesting: Both the female and male build the nest - a bulky loose stick bowl, often in a thorny shrub, in the arms of a chain cholla cactus, or Buckhorn Cholla, or in a small tree. She lays 1-5 pale blue-green eggs with many brown spots. The pair often remains together for an entire year, and raises one to three broods in that year. The nest may be repaired and reused. Scottsdale Community College, Brown's Ranch, and Watt Preserve. Notes: The Curve-billed Thrasher is the best known of the six thrashers residing in Arizona. It is the most widespread of the western thrashers. Like other thrashers, it spends as much time scurrying around on the ground as it spends flying. It is most common in cholla-rich desertscrub, but also resides in brush thickets in riparian and urban habitats. It competes with Cactus Wrens, driving the latter out of its territory. Conservation status: populations are decreasing in some areas owing to development by humans. Photo: Photo above was taken at Scottsdale Community College on April 21, Scottsdale Community College: Riparian Preserve at Gilbert Water Ranch: