The black-billed magpie (''Pica hudsonia''), also known as the American magpie, is a bird in the corvid family found in the western half of North America. It is black and white, with black areas on the wings and tail showing iridescent hints of blue or blue-green. It is one of only four North American songbirds whose tail makes up half or more of the total body length (the others being the yellow-billed magpie, the

scissor-tailed flycatcher The scissor-tailed flycatcher (''Tyrannus forficatus''), also known as the Texas bird-of-paradise and swallow-tailed flycatcher, is a long-tailed bird of the genus ''Tyrannus'', whose members are collectively referred to as kingbirds. The kingbi ...

, and the

fork-tailed flycatcher The fork-tailed flycatcher (''Tyrannus savana'') is a passerine bird of the tyrant flycatcher family, and is the member of a genus typically referred to as kingbirds. Named for their distinguishingly long, forked tail, fork-tailed flycatchers are ...

). This species prefers generally open habitats with clumps of trees. It can therefore be found in farmlands and suburban areas, where it comes into regular contact with people. Where persecuted it becomes very wary, but otherwise it is fairly tolerant of human presence. Historically associated with bison herds, it now lands on the backs of cattle to glean ticks and insects from them. Large predators such as wolves are commonly followed by black-billed magpies, who scavenge from their kills. The species also walks or hops on the ground, where it obtains food items such as beetles, grasshoppers, worms, and small rodents. The black-billed magpie is one of the few North American birds that build a domed nest, which is made up of twigs and sits near the top of trees, usually housing 6–7 eggs. Incubation, by the female only, starts when the clutch is complete, and lasts 16–21 days. The nestling period is 3–4 weeks.

Taxonomy and systematics

Externally, the black-billed magpie is almost identical to the Eurasian magpie (''Pica pica''), and is considered

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organis ...

by many sources. The American Ornithologists' Union, however, splits it as a separate species (''P. hudsonia''), on the grounds that its

mtDNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA ...

sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is calle ...

is closer to that of California's yellow-billed magpie (''Pica nuttalli'') than to the Eurasian magpie. If this view is correct, the Korean subspecies of the European magpie, ''Pica pica sericea'', should also be considered a separate species. It appears that after the ancestral magpie spread over

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...

, the Korean population became isolated, at which point the species crossed the Bering Land Bridge and colonized North America, where the two American magpies then differentiated. Fossil evidence indicates that the ancestral North American magpie had arrived in its current range around the mid-

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58mya) and that the yellow-billed magpie lineage split off rather soon thereafter due to the Sierra Nevada uplift and the beginning

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...

s. A comparatively low genetic difference, however, suggests that some gene flow between the black-billed and yellow-billed magpies still occurred during interglacial periods until the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

Description

The black-billed magpie is a mid-sized bird that measures from tip to tail. The tail is made up of long, layered feathers, the middle pair of which protrude farthest of all. The beak is oblong and weakly curved toward the tip. Unlike other members of the

Corvidae Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers. In colloquial English, they are known as the crow family or corvids. Cu ...

family, the black-billed magpie is dimorphic in size and weight, though there can be overlap between the sexes. Males are, on average, six to nine percent larger and sixteen to twenty-four percent heavier than females, at , a wingspan of , and tail lengths of . Females weigh between , have wingspans of , and tail lengths of . The black-billed magpie can be distinguished from the similar yellow-billed magpie by its longer tail and by the colour of the beak.

Vocalizations

The vocalizations of the black-billed magpie consist of a number of calls variously described as tweets, coos, purrs, shrills and squawks, but the most common is an alarm call, called a chatter, and described as a ''ka-ka-ka-ka'', sometimes preceded with a ''skah-skah''. This call is very different from that of the Eurasian magpie, and is similar to that of the yellow-billed magpie.

Distribution and habitat

The species is non-migratory. It ranges from coastal southern Alaska, southwest Yukon Territory, central British Columbia, Alberta, Saskatchewan, and Manitoba in the north, through the Rocky Mountains down south to all the Rocky Mountain states including New Mexico, Colorado, Utah, Wyoming, Idaho, and some bordering states as well. The range can extend as far east as northern Minnesota and Iowa, with casual records in northern Wisconsin and upper Michigan, but is thought to be limited further east and south by high temperature and humidity. The species is absent in California west of the Cascades and Sierra Nevada ranges, where it is replaced by the yellow-billed magpie. During the breeding season the preferred habitat is riparian areas with thickets. The predilection for open habitats with clumps of trees means that the species also breeds in some meadows and suburbs. Outside the breeding season, magpies can be found in their breeding habitat but also near feedlots, grain elevators, landfills, and around barns and houses.

Behavior

Breeding and nesting

Adult black-billed magpie pairs stay together year-round and often for life unless one dies, in which case the remaining magpie may find another mate. Divorces are possible: one South Dakota study found low rates of divorce (8%) but one 7-year study in Alberta found divorce rates up to 63%. Black-billed magpies nest individually, frequently toward the top of trees. Only the nest tree and its immediate surroundings are defended, and so it is possible for nests to be somewhat clumped in a location. When this happens (usually in areas with a limited number of trees or with abundant food resources), a diffuse colony is formed. In this, the black-billed magpie is intermediate between the Eurasian magpie, whose nests are much more spread out because a large territory is defended around each nest, and the yellow-billed magpie, which is always loosely colonial. Nests are loose but large accumulations of branches, twigs, grass, rootlets, bark strips, vines, needles, and other materials, with branches and twigs constituting the base and framework, while mud is used as anchor and in the nest cup. The nest cup is lined with fine rootlets, grass, and other soft material. Nests almost always include a hood or dome of loosely assembled twigs and branches, and usually have one or more side entrances. Nests are built by both sexes over 40–50 days, starting in February (though later in northern parts of the range). Old nests can be repaired and used, or a new nest can be built on top, with older nests thus reaching 120 cm high by 100 cm wide (48 inches high by 40 inches wide). Other bird species, including small hawks and owls, often use old magpie nests. The breeding season for magpies is generally from late March to early July. They nest once a year, but may re-nest if their first attempt fails early. The female lays up to thirteen eggs, but the usual

clutch size __NOTOC__ A clutch of egg (biology), eggs is the group of eggs produced by birds, amphibians, or reptiles, often at a single time, particularly those laid in a nest. In birds, destruction of a clutch by predators (or removal by humans, for exam ...

is six or seven. The eggs are greenish grey, marked with browns, and 33 mm (about 1.3 inch) long. Only the female incubates, for 16–21 days. The male feeds the female throughout incubation. Hatching is often asynchronous. Hatched young are

altricial In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...

, brooded by the female but fed by both sexes. They fly 3–4 weeks after hatching, feed with adults for about two months, and then fly off to join other juvenile magpies.

Fledging Fledging is the stage in a flying animal's life between hatching or birth and becoming capable of flight. This term is most frequently applied to birds, but is also used for bats. For altricial birds, those that spend more time in vulnerable c ...

success (usually 3–4 young per nest) is lower than clutch size; this is not an unusual state of affairs in species with asynchronous hatching, as some nestlings often die of starvation. Black-billed magpies reach sexual maturity at one or two years of age. The lifespan of the species in the wild is about four to six years.

Feeding

The black-billed magpie is an opportunistic omnivore, eating many types of insects, carrion, seeds, rodents, berries, nuts, eggs, and also garbage and food from pets that are fed outside. Chicks are fed animal matter almost exclusively. Magpies typically forage on the ground, usually walking, sometimes hopping, and sometimes scratching with their feet to turn over ground litter. They sometimes land on large mammals, such as moose or cattle, to pick at the ticks that often plague these animals. They often follow large predators, such as wolves, to scavenge or steal from their kills. Black-billed magpies are also known to make food caches in the ground, in scatter-hoarding fashion. To make a cache, the bird pushes or hammers its bill into the ground (or snow), forming a small hole into which it deposits the food items it was holding in a small pouch under its tongue. It may, however, then move the food to another location, particularly if other magpies are in the vicinity, watching. Cache robbing is fairly common, so a magpie often makes several false caches before a real one. The final cache is covered with grass, leaves, or twigs. After this, the bird cocks its head and stares at the cache, possibly to commit the site to memory. Such hoards are short-term; the food is usually recovered within several days, or the bird never returns. The bird relocates its caches by sight and also by smell; during cache robbing, smell is probably the primary cue.

Social interactions

Black-billed magpies often form loose flocks outside of the breeding season. Dominance hierarchies typically develop within such flocks, more linearly among males than among females. Dominants can steal food from subordinates. Aggressive interactions also occur at point sources of food. Surprisingly, young males appear dominant over adult males, though this may simply reflect the adults' better overall condition and consequent lack of motivation to engage in fights. Fights are rare and involve jumps and kicks. Dominance is more generally established through displays, such as stretching the body laterally with the bill raised and the nictitating membrane of the eye flashing (only on the side of the opponent). Magpies often gather excitedly in trees near the body of a dead magpie, calling loudly, a poorly-understood behaviour called a funeral. Some individuals may approach the body and peck at its wings or tail.

Roosting

Magpies tend to roost communally in winter. Every evening they fly, often in groups and sometimes over long distances, to reach safe roosting sites such as dense trees or shrubs that impede predator movement, or, at higher latitudes, dense conifers that afford good wind protection. In Canada, they arrive at the roosting site earlier in the evening and leave later in the morning on colder days. At the roosting site, they tend to occupy trees singly; they do not huddle. They sleep with the bill tucked under the scapular (shoulder) and back feathers, adopting this position sooner on colder nights. During the night, they may also regurgitate in the form of pellets the undigested parts of what they ate during the day. Such pellets can be found on the ground and then used to determine at least part of the birds' diet.

Flight

Level flight appears slow and labored. As measured in wind tunnels, minimum and maximum sustained flight speeds are 14.5 km/h and 50 km/h (9 mph and 31 mph), respectively. Flight is commonly interrupted by nonflapping phases. Descents from heights consist of repeated J-shaped swoops with the wings nearly closed.

Relationship with humans

When Lewis and Clark first encountered black-billed magpies in 1804 in South Dakota, they reported the birds as being very bold, entering tents and taking food from the hand. Magpies formerly followed

American bison The American bison (''Bison bison'') is a species of bison native to North America. Sometimes colloquially referred to as American buffalo or simply Bubalina, buffalo (a different clade of bovine), it is one of two extant species of bison, alongs ...

herds (from which they gleaned ticks and insects), as well as the bands of Plains Indians that hunted the bison so they could scavenge carcasses. When the bison herds were devastated in the 1870s, magpies switched to cattle, and by the 1960s, they had also moved into the emerging towns and cities of the West. Today, black-billed magpies remain relatively tame in areas where they are not hunted. However, they become very wary in areas where they are often shot at or disturbed. During the first half of the 20th century, black-billed magpies were considered detrimental to game-bird populations (due to them sometimes stealing bird eggs) and domestic stock (pecking at sores on cattle), and were systematically trapped or shot. Bounties of one cent per egg or two cents per head were offered in many states. In Idaho, the death toll eventually amounted to an estimated 150,000. In 1933, 1,033 magpies were shot in Washington's Okanogan valley by two teams of bounty hunters. Many magpies also died from eating poison set out for coyotes and other predators. If regularly disturbed at the nest, magpie pairs will eventually either move the eggs or abandon the clutch altogether, but in the first instance they will defend the nest aggressively. Biologists who have climbed nest trees to measure magpie eggs have reported that the parents recognized them personally on subsequent days and started to

mob Mob or MOB may refer to: Behavioral phenomena * Crowd * Smart mob, a temporary self-structuring social organization, coordinated through telecommunication Crime and law enforcement * American Mafia, also known as the Mob * Irish Mob, a US crimin ...

them, overlooking other people in the vicinity. Many suburban songbird lovers dislike magpies because of their reputation for stealing eggs, but studies have shown that eggs make up only a small proportion of what magpies feed on during the reproductive season, and that songbird populations do not fare worse in the presence of magpies. A common misconception about magpies in general is that they like to steal bright or shiny things. This reputation belongs to the Eurasian magpie (''Pica pica'') rather than the black-billed magpie, and at any rate an experiment conducted at Exeter University has shown that the reputation is undeserved: Eurasian magpies displayed caution around shiny objects rather than being attracted to them.

Status

Because of its wide range and generally stable population, the black-billed magpie is rated as a species of

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of nat ...

. In the United States, black-billed magpies are protected under the

Migratory Bird Treaty Act The Migratory Bird Treaty Act of 1918 (MBTA), codified at (although §709 is omitted), is a United States federal law, first enacted in 1918 to implement the convention for the protection of migratory birds between the United States and Canada . ...

, but " Federal permit shall not be required to control ... agpieswhen found committing or about to commit depredations upon ornamental or shade trees, agricultural crops, livestock, or wildlife, or when concentrated in such numbers and manner as to constitute a health hazard or other nuisance". State or local regulations may limit or prohibit killing these birds as well. The species is not threatened, and in some areas, it has benefited from forest fragmentation and agricultural developments. Like many corvids, however, it is susceptible to

West Nile virus West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family '' Flaviviridae'', from the genus '' Flavivirus'', which also contains the Zika virus, dengue virus, and yellow fever virus. The v ...

. In Canada, however, black-billed magpies do not appear on the list of birds protected by the

Migratory Birds Convention Act The Migratory Birds Convention Act (also MBCA) is a Canadian law established in 1917 and significantly updated in June 1994 which contains regulations to protect migratory birds, their eggs, and their nests from destruction by wood harvesting, hunti ...

. Provincial laws also apply, but in Alberta, magpies may be hunted and trapped without a license.Alberta Wildlife Act, Schedule 4, Part 6 Non‑licence Animals
qp.alberta.ca A detriment to the overall black-billed magpie population is toxic chemicals, particularly topical pesticides applied on the backs of livestock. Because black-billed magpies sometimes glean ticks off the backs of cattle, this proves a problem.

References

External links

* {{Taxonbar, from=Q254057 black-billed magpie Native birds of Alaska Birds of the Aleutian Islands Native birds of the Canadian Prairies Native birds of Western Canada Native birds of the Plains-Midwest (United States) Native birds of the Northwestern United States Native birds of the Western United States black-billed magpie Taxa named by Joseph Sabine