Morley Nelson Snake River Birds of Prey
Guide to Raptors at Morley Nelson Snake River Birds of Prey National Conservation Area (NCA) in Idaho. Published by the Bureau of Land Management (BLM).
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Morley Nelson Snake River Birds of Prey National Conservation Area American Kestrel (Falco sparverius) Description/Size Wing span: 20-24 inches Length: 8-11 inches Weight: 3.4 to 5.3 ounces The smallest falcon in North America. Like all falcons, kestrels have large heads, notched beaks, and “heavy shouldered” streamlined bodies. There is a difference in the plumage of each sex. In both sexes the back is reddish brown sparsely barred with black, the crown is blue-gray with variable amounts of rufous, the face and throat are white with a black malar (vertical stripe) below the dark eyes and another behind the cheek, the beak is blue-black and the legs and feet are yellow. Male kestrels have blue-gray wings, while females have reddish-brown wings with black barring. Males have rufous tails with one wide, black sub-terminal band and a white tip. Females have rufous tails and many black bars. The light-colored under parts of females typically are heavily streaked with brown; those of males are white to buffy orange with variable amounts of dark spotting or streaking. This adult plumage is attained at 1 year. Both sexes are slightly larger than robins but females are 10-15% larger than males. Similar Species Merlin – similar sized falcon but not as colorful; both sexes have narrow pale bands on a dark tail. Habitat/Range North America, the Bahamas and Antilles, Central America, and South America. Frequents open and partially open countryside including agriculture lands, transportation corridors such as freeways and highways, meadows, prairies, plains, and deserts. Food/Diet Primarily a sit and wait perch hunter-most prey is caught on the ground but some are to the back of the head. They capture a variety of prey but insects are the primary prey followed by small mammals, birds, small reptiles and some amphibians. Insects wrens, and starlings. Reptiles include small lizards and snakes. Foods only rarely taken include centipedes, scorpions, spiders, snails, and earthworms. Occasionally Voice The American kestrel has three basic vocalizations. A shrill, clear screaming kli kli kli kli kli kli, kli kli is used when upset or excited. A whine is used during courtship feeding and copulation. A chitter is the most frequent vocalization in male/female interactions. Behavior !! " # $ Raptor Information Sheet - American Kestrel The American kestrel is often seen hovering or perched on wires in open areas, hunting insects and small mammals. When perched, it commonly bobs its tail up and down. It is the only North American falcon to hunt by hovering. Northern populations in North America are more migratory than those breeding farther south. This results in a leap-frog pattern of migration in which northern birds winter south of southern birds. Some northern populations move as far south as Central America, while many southern populations are sedentary. Most American kestrels breeding in North America overwinter in the US. American kestrels form strong pair bonds and some pairs remain together across years. Requires a cavity, natural or manmade, for nesting, and will nest in bird boxes, holes in trees (made by other birds or natural), cliffs and the crevices of buildings. Generally Clutch size: 4 to 6 eggs & ' requires a few prominent elevated perches for hunting nearby. Will vigorously defend shades; elliptical, 1.3 x 1 inches ! " * +* Incubation: 28-29 days Fledge: 28-31 days Disperse: 2-4 weeks Reproduction/Nesting Raptor Information Sheet - American Kestrel Life Span Longest recorded – 14 years 8 months Conservation Status Not on the US Fish and Wildlife’s Endangered or Threatened Species List. However it is protected by the Migratory Bird Treaty Act. Idaho Fish & Game lists the American kestrel as a protected non game species for which it is illegal to collect, harm or otherwise remove from its natural habitat. American kestrels are considered to be abundant through most of its North American range. The southeastern race, Falco sparverius paulus, is in serious decline due to habitat loss and has been listed by the Florida Fish and Wildlife Conservation Commission as “threatened”. In Georgia it is listed as a <= * and windows; illegal shooting, predation by larger raptors, pesticide poisoning, being trapped in chimneys, drowning in water tanks, electrocution on power lines, and being trapped in fresh tar on a resurfaced road. Viewing in the NCA Seen in the NCA and Treasure Valley year round. Look for them perched on telephone wires and poles. Interesting Facts >? * @falx meaning “scythe”, referring to the shape of the wing and shape of the talons and sparverius meaning “pertaining to a hedge sparrow”. - Formerly know as Sparrow Hawk >$ 'JKQ&KQ@ - Outward pointed, cone shaped projections in the center of the round nostrils slow X Spanish name: Cernicalo chitero, Cernicalo americano Sources YZ+J[$<> \] Bird Banding Lab - www.pwrc.usgs.gov/bbl/homepage/long2890.htm Carolina Raptor Center - www.carolinaraptorcenter.org/am_kestrel.php Hogle Zoo - www.hoglezoo.org/animals/view.php?id=106 Q<K> || |}~ Z > '||* !|| | National Audubon Society The Sibley Guide to Birds The Peregrine Fund - www.peregrinefund.org/Explore_Raptors/falcons/amkestrl.html "+!+ '|| ||| Endangered-Threatened-Special-Concern-2004.pdf Georgia Dept of Natural Resources, Wildlife Resources Division http://georgiawildlife.dnr.state.ga.us/content/specialconcernanimals.asp US Fish and Wildlife Service - http://migratorybirds.fws.gov/intrnltr/mbta/mbtandx.html#h Illustration: courtesy Alberta Sustainable Resource Development Map: The Peregrine Fund Photography: David Ellis Raptor Information Sheet - American Kestrel American Kestrel (Falco sparverius) Male Female ] ' \]+J[$< Raptor Information Sheet - American Kestrel Morley Nelson Snake River Birds of Prey National Conservation Area Barn Owl (Tyto alba) Description/Size Wing span: 42-47 inches Length: 12.5-20 inches Weight: 11-22 ounces North America’s only member of the owl family, Tytonidae. Pale tawny and white plumage, and heart-shaped facial disk are distinctive. Large head lacks ear tufts. Heart-shaped facial disk is white with brown to orange brown border. Long beak is off white; cere pinkish white. Eyes relatively small for an owl. Iris is dark brown to black. Upperparts gold to buff; heavily marked with white, black and gray. Underparts are white with spotting. Females tend to have more and larger spotting on wings and breast than males. Some males are unmarked and some females are dark buff heavily spotted with black. Wings long and rounded. Tail short and square. Legs relatively long. Feathering on lower legs may be sparse. Toes light gray, talons dark gray. Feet Thirty-two subspecies of barn owls recognized across the world and measurements vary greatly throughout its range. Only one subspecies, T.a. pratincola, is recognized in North America; found from sw British Columbia south and east through most of the U.S. (except some of the northern-central states), Mexico, south to e. Nicaragua and Hispaniola; also Bermuda. This subspecies is also the largest; nearly twice the mass of the smallest subspecies (T.a. punctatissima; Galápagos Is.) Similar Species Ashy-faced Owl (Tyto glaucops) – only found on the island of Hispaniola; has much darker plumage and darker silvery-gray facial disc. Habitat/Range The barn owl is one of the most widespread of all owls and, indeed, is among the most widely distributed of all land birds – living in North, Central and South America; Europe, Africa, India, SE Asia, and Australia. This owl occupies a broad range of open habitats with some trees, urban to rural, favoring lower elevations in most of its range. Not found in most mountainous or heavily forested areas. Its northern range limit is determined by the severity of winter conditions and availability of prey. Breeding numbers seem limited by the availability of nest cavities in proximity to adequate densities of small mammals. The species is generally resident except that northernmost populations in North America are reported to be partly migratory. Food/Diet Diet is primarily small mammals: voles, shrews, moles, mice, lemmings, kangaroo rats, hares and rabbits. Birds are usually eaten only in small numbers; most are small ! ! " # ## $ piecemeal. Excess prey cached in the nest site during incubation and early brooding. Voice More vocal during breeding season. Calls can be categorized as screams, snores, hisses, or chirrups/twitters. Screams used to advertise, to warn and given in distress. Hisses used in defensive situations. Snores are non aggressive, self advertising calls given mostly by nestlings and females. Chirrups and twitters include feeding calls, discomfort calls, and greeting and conversational twitters. Common call year-round is simply a long hissing shriek csssssshhH. Courtship call of male is a shrill repetitive twittering. Adults returning to nest may give low, frog-like croak. Non vocal sounds: Billsnap is a defensive sound made when threatened or closely approached by a human Raptor Information Sheet - Barn Owl or other large predator; usually associated with hissing and sometimes the distress call. % & $ single clap but occasionally a loud clap followed by a softer one. Behavior Although highly nocturnal, can be observed hunting in daylight. Most hunting done in # # '* # perches. Often follows a favorite course or returns to favorite hunting areas. Hunts mostly at night, beginning about one hour after sunset and ending about one hour before sunrise. Prey is captured with the feet and usually nipped through the back of the skull with the beak. Can discriminate sounds of appropriate prey by memorizing prey noises. Ability to locate prey by sound is the most accurate of any animal tested, allowing capture of prey hidden by vegetation or snow. In North America, barn owls produce one to two pellets per day. Minimum interval between eating and casting is +* 6 $ ## < # speeds of 50 mph. Not considered highly maneuverable but can make turns on small radius. Low wing loading permits heavy prey to be carried at slow speeds. Walks on ground with an awkward-looking side-to-side lurch. Runs rapidly, often with aid of # # = #$ > # # ? # # @ of migration in this species remains unresolved. Reports of migratory movement in ns of northern northe hern some regions JK disperse in all directions al site; these from the natal movements of up to 1180 e mistaken mistake ken miles may be n. Individuals for migration. se the same habitually use ting owls roost. Roosting etimes soundly, sleep, sometimes h head hunched standing with down, eyes closed, and elaxed. Barn facial disk relaxed. owls often mobbed by other ularly crows/ravens/ birds, particularly # y ight. The owl’s most yl roosts in daylight. action is to escape its common reaction tormentors. Reproduction/Nesting tship, males may circle During courtship, te, giving short screeches near nest site, ng calls. Sexual chases and chattering e male pursues female follow where reeching. Also used in with both screeching. && hovers with feet dangling in front of perched female for several seconds. Nests ests in natural natu ural cavities in trees, cliffs, fs, s, and caves or or in man-made structures like n nest est boxes, barns, s, chimneys, and other structures. ures. Nest is a scrape lined with pellets ellets or other debris. Typically nest st at the same site as long as theyy live. Occasionally, change nestt sites but do not move Clutch size: 4-7 eggs Eggs: subelliptical, white, 1.3 x 1.7 inches Incubation: 29-34 days Fledge: 7-9 weeks Disperse: 7–8 weeks Raptor Information mation Sheet - Barn Owl long distances to do so. Two broods common. Pair may lay a second clutch of eggs #! = # permits. Generally monogamous, it is sometimes polygamous. Pairs usually remain together as long as both live, but either sex will readily re-mate if its mate disappears. Solitary or in pairs when not breeding. Most individuals appear to breed at one year of age. Life Span Longest recorded – 15 years 5 months. Conservation Status Not on the US Fish and Wildlife’s Endangered or Threatened Species List. However it is protected by the Migratory Bird Treaty Act. Idaho Fish & Game lists the barn owl as a protected non game species for which it is illegal to collect, harm or otherwise remove from its natural habitat. Several states have the barn owl on their threatened or endangered species list or list it as a species of special concern. It is declining in many areas of North America and Europe. Several factors have been implicated: pesticides pose a secondary poisoning threat; reduced availability of nest sites including demolition or alternation of old buildings; loss of foraging areas and/or prey populations due to urban sprawl and changing agricultural practices. Collisions with vehicles are a major cause of mortality. Illegal shooting and electrocution are minor causes. Viewing in the NCA Seen in the NCA year round. Interesting Facts &V ! X# tyto which refers to an owl, and alba the Latin word for white. - Common name refers to the owl’s use of man-made structures, like barns, as roosts and nest sites. - Other names: monkey-faced owl, white owl, ghost owl, and golden owl. &K # # # ! # # - Ear openings are at slightly different levels on the head and set at different angles. This gives the barn owl very sensitive and directional hearing; it can catch prey in complete darkness. - Barn owls have been associated with omens, witchcraft and death. Spanish name: Lechuza de campanario Sources Bird Banding Lab - www.pwrc.usgs.gov/bbl/homepage/long3120.cfm Idaho Fish&Game&YZZ! Z# Z Z Z cfm National Audubon Society - The Sibley Guide to Birds Owling.com - http://www.owling.com/Barn.htm The Owl Pages - http://www.owlpages.com/ The Peregrine Fund – www.peregrinefund.org/Explore_Raptors/owls/barnowl.html Birds of North America Online - http://bna.birds.cornell.edu/BNA/account/Barn_Owl/ US Fish and Wildlife Service – http://ecos.fws.gov/tess_public/pub/listedAnimals.jsp and www.fws.gov/migratorybirds/regulationspolicies/mbta/mbtintro.html Illustration: courtesy Alberta Sustainable Resource Development Map: The Peregrine Fund Raptor Information Sheet - Barn Owl Barn Owl (Tyto alba) Adult Nestlings Photos: Know Your Owls, Axia CD ROM Raptor Information Sheet - Barn Owl Burrowing Owl (Athene cunicularia) Description/Size Wing span: 20-24 inches Length: 7.5-11 inches Weight: 4.5-9 ounces A small owl that lacks ear tufts; has relatively long, narrow wings, short tail and long legs. Adults – upperparts evenly barred, spotted pale brown and buffy. Spots are smaller and more numerous on the crown and larger on the back, upper wings and hind neck. Sandy colored on the head, back and upperparts of the wings. Tail short with buffy white bands. Distinct oval facial ruff, framed by bold white eyebrows extending above and along side of the beak. Has a prominent white chin stripe. Under parts are buffy white with broad brown barring/spots except the under tail coverts are white. Lower chest white; band of dark brown (mottled with white) between white throat and chest. Eyes usually bright lemon yellow. Beak is cream colored. Cere and eyelids grayish. Gape pinkish. Bristle-like feathers on legs and feet are white to beige. Skin dark gray, except undersides of feet sometimes yellowish in juveniles. Unlike most owls, the male is slightly heavier and has a longer wingspan than the female. Males tend to be lighter colored, more grayish brown and not as heavily barred below. Females are usually darker than males. Juveniles – Brown on head, back and wings. Under parts lack barring and are dull white except for upper chest that is dark brown. Crown marked with fine buffy-white streaks. Up to 18 subspecies currently recognized. Two subspecies in North America: A.c. hypugaea found from e Texas north to s. Manitoba and west across s. Canada and all of the western US south to El Salvador, and A.c. floridana restricted to Florida and the Bahamas. Similar Species None. Habitat/Range Open, well-drained grasslands, steppes, deserts, and prairies, often associated with burrowing mammals. Also agricultural lands, and golf courses, cemeteries, airports, vacant lots and other open areas within cities. Extends from southwestern Canada, western US and Florida, throughout Central America, and most of South America except the Amazon River basin. Also on Cuba, Hispaniola, n. Lesser Antilles, Bahamas, and several islands off the west coast of Mexico. Nests in dry level open terrain with low height vegetation for foraging and available perches such as fences, utility poles and raised rodent mounds. The abundance of available burrows seems to be a critical habitat requirement. Favored locations are those in relatively sandy sites, areas with low vegetation around burrows, holes at the bottom of vertical cuts with a slight downward slope from the entrance and slightly elevated locations to avoid flooding. Winter range is much the same as breeding range, except that most apparently vacate northern areas of the Great Plains and Great Basin. Raptor Information Sheet - Burrowing Owl Food/Diet Opportunistic hunters taking insects, small mammals and birds but will also eat reptiles and amphibians. Insects include grasshoppers, scorpions, large beetles, moths, and crickets. Mammals include mice, rats, voles, gophers, and bats. During breeding season, food is cached within nest burrows and tunnels. Also found scattered within 100 feet of the nest burrow. Voice Thirteen vocalizations of adults and three of young have been identified. Adult vocalizations include a Primary Song, a two–note call coo coooo, given exclusively by the male. Other sounds associated with copulation, nest defense and food begging: rasp, chuck, chatter, and scream. Most vocalizations given near the nest burrow. Juveniles give an intense prolonged rasp when severely distressed; mimics a rattlesnake rattle and deters potential predators from entering nest burrows. Non vocal sounds: Bill snaps most often heard in defense of nest site, but given whenever severely threatened; accompanied by threat display and vocalizations. Behavior Only small owl likely to be seen perched in the open in daylight; often on the ground or on fence posts. Bobbing “deep knee bend” motion of agitated birds is distinctive. Hunts while walking, hopping, or running across the ground; also hovers in mid air and swoops down; glides silently from a perch; or catches insects in the air. Hunting style varies with type and activity of prey pursued, time of day, and vegetation. Prey is caught with feet and carried by the beak. Is crepuscular - hunts mainly at dawn and at dusk but will hunt any time during a 24 hour period. Tends to hunt insects in day and small mammals at night. It has been suggested that these owls may be capable of fasting for several days. Flies with irregular, jerky wingbeats and frequently makes long glides, interspersed with rapid wingbeats. May flap wings asynchronously (not up and down together). Birds in the northern part of the range are migratory. Banding recoveries show that Canadian owls migrate further south than those banded in the US, suggesting a “leap-frog” migration. Compared with other birds, these owls show a significantly higher tolerance for carbon dioxide, apparently a response to nesting in burrows. Mammalian predators elicit aerial attacks during the nesting season. Avian predators elicit escape behavior, often into burrows. Reproduction/Nesting Courtship displays include rising quickly to 100 feet, hovering for 5-10 seconds then dropping to 50 feet. Repeated many times. Circular flights of approximately 130 feet also occur; performed mainly by males. Usually monogamous but occasionally polygynous (one male and two females). Pair bond may or may not be retained from year to year. Nests and roosts in abandoned animal burrows or other crevices. If soil conditions allow they will dig their own burrows. Also use manmade burrows (containers placed underground with entrance tunnel). May nest alone or in a group with other nesting burrowing owls. Prefer nesting areas with high density of burrows available; this may provide extra escape burrows for young owls before independence. Adults return to same burrow or nearby area each year. Both adults renovate and maintain burrows. Often line the nest with a variety of dry materials including dung. Continue to maintain their burrow throughout most of the breeding season. In nonmigratory populations, use and maintain burrows year-round; in winter, burrows provide protection from avian predators. Burrow dimensions vary; nest cavity is roughly circular, approximately 10 inches wide and 4-5 inches high. Tunnel slants approximately 15° downward from the entrance. Young owls begin to use satellite burrows at 7-8 weeks. No known record of second broods; renesting may occur if the first nest is destroyed early in the breeding season. Sexually mature at one year of age. Clutch size: 6-9 eggs Eggs: round-ovate, white, 1.3 x 1.0 inches Incubation: 28-30 days Fledge: 44 days Disperse: little information available. Life Span Longest recorded – 8 years 8 months. Conservation Status Not on the US Fish and Wildlife’s Endangered or Threatened Species List. However it is protected by the Migratory Bird Treaty Act. Idaho Fish & Game lists the western burrowing owl as a protected non game species for which it is illegal to collect, harm or otherwise remove from its natural habitat. The BLM considers this a Sensitive Species Raptor Information Sheet - Burrowing Owl in Idaho – the viability of the species is at risk across all or a significant portion of its range. Listed as endangered, threatened, or a species of special concern in most states where they occur. In Canada it is Endangered. Intensive cultivation and urban development of grasslands and native prairies has long been recognized as a cause of declining burrowing owl populations: results in loss of burrows, loss of foraging habitat, creation of suboptimal nesting habitat, and increases in vulnerability to predation; may also reduce the chance that unpaired owls will be able to find mates. Human activities which cause the reduction of burrowing mammals also impact these owls through the loss of burrows for nests. Pesticides used in farming can result in direct mortality, or indirectly due to loss of prey base or due to contaminated prey. This owl is vulnerable to many different predators. Mammals, particularly badgers, are major predators. Domestic cats, dogs, opossums, weasels, and skunks feed on eggs and young. Hawks, falcons, larger owls and crows are also predators of adult and young burrowing owls. Collisions with vehicles are often a serious cause of mortality; the owls habitually sit and hunt on roads at night. Severe spring and summer weather known to kill both adults and young in burrows. It is not known if illegal shooting is a local or widespread problem. Viewing in the NCA The western burrowing owl is seen in the NCA from March through August. Interesting Facts - The scientific name comes from the Greek word athene referring to Athena the Greek goddess of wisdom whose favorite bird was an owl and the Latin word cunicularia meaning mine or miner, referring to its nesting under ground. - Common name refers to its nesting in burrows. - Other names: ground owl, long-legged owl, prairie dog owl. - Burrowing owls are crepuscular – hunting mainly at dawn and at dusk. - The Zuni Indians called this owl the “priest of the prairie dogs” because it frequently nests and roosts in empty prairie dog burrows. - Early European settlers were convinced that rattlesnakes often shared its nests. Spanish name: Lechuza llanera, Chicuate Sources Bird Banding Lab - www.pwrc.usgs.gov/bbl/homepage/ long3120.cfm Idaho Fish&Game - http://fishandgame.idaho.gov/wildlife/ nongame/birds/birdspecies.cfm National Audubon Society - The Sibley Guide to Birds The Peregrine Fund – www.peregrinefund.org/Explore_ Raptors/owls/burrwowl.htm Owling.com - www.owling.com/Burrowing.htm The Owl Pages – www.owlpages.com Birds of North America Online - http://bna.birds.cornell.edu/ BNA/account/Burrowing_Owl/ US BLM – http://www.blm.gov/id/st/en/prog/wildlife.html US Fish and Wildlife Service – http://ecos.fws.gov/tess_ public/pub/listedAnimals.jsp Illustration: courtesy Alberta Sustainable Resource Development / Map: The Peregrine Fund Photography: David Martorelli Burrowing Owl (Athene cunicularia) Adult Immature Photos: Know Your Owls, Axia CD ROM Raptor Information Sheet - Burrowing Owl Morley Nelson Snake River Birds of Prey National Conservation Area Cooper’s Hawk (Accipiter cooperii) Description/Size Wing span: 27 - 35 inches Length: 15 -18 inches Weight: 12 - 19 ounces. Medium sized accipiter with relatively large head; holds wings straight when soaring. crown contrasts with pale nape and blue gray dorsal area. Short rounded wings are ! " ! # $ % adults. Females are about one third larger than males. Sexes similar in plumage, but ! ! & vertically streaked with brown and white on chest and belly; their wings and tails are barred. Bill gray with pale yellow cere. No color morphs or subspecies. Similar Species Sharp-shinned hawk' ( ! % wrist; square tipped tail with thin white terminal band. Northern goshawk juvenile – ( ( ** ( undertail coverts streaked. Habitat/Range !+ ! / " 0 1 treed urban areas. Breeds throughout southern Canada, US, and northern Mexico. # urban settings. Urban sites have included isolated trees in residential neighborhoods. Forest edge breeding birds and may serve as primary hunting 2 34 2 + 5 " 0 ( casually to Costa Rica and possibly Panama. Food/Diet Mainly small to medium sized birds and mammals such as jays, robins, woodpeckers, small owls, rabbits, squirrels, chipmunks and 6 0 ! !7 ! 8 ! 9 ' ! quail, and pigeons. Will cache uneaten prey on horizontal branches during the breeding season. Raptor Information Sheet - Cooper’s Hawk Voice Usually silent except during breeding season. Mates likely communicate mainly by 0!cak cak cak, 2 kik K kik call when trying to locate the male. Females give whaaa + * Behavior Wingbeats are described 4 rapid wingbeats alternate with 8 4 maneuverability in dense cover. 38 or below tree canopy when hunting or approaching and departing nest. Cooper’s hawks are sit-and-wait predators that perch in concealed place, then dash out quickly to capture prey. 9 !8 low, alternating rapid wingbeats and glides, through open conceal its approach. Also soars ! 8 9 !8 rapidly, then glides last 12-15 X with talons, usually killing the prey on impact or grasping and relaxing grip on prey repeatedly until the prey is dead. Will also drown prey in water, holding it under until it ceases to move. Occasionally runs or walks on ground to pursue or retrieve prey. Prey is carried to a perch where it is plucked and torn into pieces. Cooper’s hawks are solitary migrants. Avoids the X 6 " Z / 0 and s. U.S.; those in the west winter in central and s. Mexico. Some populations are resident. Mobbed by smaller birds, especially when carrying prey. Reproduction/Nesting Clutch size: 3-5 eggs Eggs: elliptical, bluish white, 1.9 x 1.5 inches, 7 GHIHJ K GOQHI Disperse: 7 weeks " 2 ! 8 ! 6 4 8 8 + / +