The merlin (''Falco columbarius'') is a small

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

falcon Falcons () are birds of prey in the genus ''Falco'', which includes about 40 species. Some small species of falcons with long, narrow wings are called hobbies, and some that hover while hunting are called kestrels. Falcons are widely distrib ...

from the

Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...

, with numerous subspecies throughout North America and

Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...

. A

bird of prey Birds of prey or predatory birds, also known as (although not the same as) raptors, are hypercarnivorous bird species that actively predation, hunt and feed on other vertebrates (mainly mammals, reptiles and smaller birds). In addition to speed ...

, the merlin breeds in the northern

Holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical reg ...

; some migrate to

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

and northern

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

regions in winter. Males typically have wingspans of , with females being slightly larger. They are swift fliers and skilled hunters which specialize in preying on small birds in the size range of sparrows to doves and medium-sized

shorebirds FIle:Vadare - Ystad-2021.jpg, 245px, A flock of Dunlins and Red knots Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflats in order to foraging, forage for food c ...

. In recent decades merlin populations in North America have been significantly increasing, with some merlins becoming so well adapted to city life that they forgo migration; in Europe, populations increased up to about 2000 but have been steady subsequently. The merlin has for centuries been well regarded as a

falconry Falconry is the hunting of wild animals in their natural state and habitat by means of a trained bird of prey. Small animals are hunted; squirrels and rabbits often fall prey to these birds. Two traditional terms are used to describe a person ...

bird.

Nomenclature

The merlin was described and illustrated by the English naturalist

Mark Catesby Mark Catesby (24 March 1683 – 23 December 1749) was an English natural history, naturalist who studied the flora and fauna of the New World. Between 1729 and 1747, Catesby published his ''Natural History of Carolina, Florida and the Bahama ...

(as the "pigeon hawk") in his ''Natural history of Carolina, Florida and the Bahama Islands'' published in 1729–1732. Based on this description, in 1758

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

included the species in the tenth edition of his ''

Systema Naturae ' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the syste ...

'' and introduced the present

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, altho ...

''Falco columbarius'' with the type locality as "America". The genus name is

Late Latin Late Latin is the scholarly name for the form of Literary Latin of late antiquity.Roberts (1996), p. 537. English dictionary definitions of Late Latin date this period from the 3rd to 6th centuries CE, and continuing into the 7th century in ...

; ''falco'' derives from ''falx'', ''falcis'', a

sickle A sickle, bagging hook, reaping-hook or grasshook is a single-handed agricultural tool designed with variously curved blades and typically used for harvesting or reaping grain crops, or cutting Succulent plant, succulent forage chiefly for feedi ...

, referring to the claws of the bird. The species name ''columbarius'' is

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

for "of doves" from "columba", "dove". Thirteen years after Linnaeus's description

Marmaduke Tunstall Marmaduke Tunstall (1743 – 11 October 1790) was an England, English ornithologist and collector. He was the author of ''Ornithologia Britannica'' (1771), probably the first British work to use binomial nomenclature. Tunstall was born at Burto ...

recognized the Eurasian birds as a distinct

taxon In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

''Falco aesalon'' in his ''Ornithologica Britannica''. If two species of merlins are recognized, the

Old World The "Old World" () is a term for Afro-Eurasia coined by Europeans after 1493, when they became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia in the Eastern Hemisphere, previously ...

birds would thus bear the

scientific name In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''F. aesalon''. The name "merlin" is derived from

Old French Old French (, , ; ) was the language spoken in most of the northern half of France approximately between the late 8th Anglo-Norman ''merilun'' or ''meriliun''. There are related Germanic words derived through older forms such as Middle Dutch">Anglo-Norman language">Anglo-Norman ''merilun'' or ''meriliun''. There are related Germanic words derived through older forms such as Middle Dutch ''smeerle'', Old High German ''smerle'' and Old Icelandic ''smyrill''. Wycliffe's Bible, around 1382, mentions ''An Egle, & agriffyn, & a merlyon''. The species was once known as "pigeon hawk" in North America. Although the merlin's name looks and sounds like the name of the wizard

Merlin The Multi-Element Radio Linked Interferometer Network (MERLIN) is an interferometer array of radio telescopes spread across England. The array is run from Jodrell Bank Observatory in Cheshire by the University of Manchester on behalf of UK Re ...

prominent in Arthurian legend, the bird is not named after the wizard. The wizard's name is an English cognate of the Welsh name " Myrddin" and is unrelated to the name of the bird.

Systematics

The relationships of the merlin are not resolved to satisfaction. In size, shape and coloration, it is fairly distinct among living falcons. The red-necked falcon is sometimes considered more closely related to the merlin than other falcons, but this seems to be a coincidence due to similar hunting habits; it could not be confirmed in more recent studies. Indeed, the merlin seems to represent a lineage distinct from other living falcons since at least the

Early Pliocene Early may refer to: Places in the United States * Early, Iowa, a city * Early, Texas, a city * Early Branch, a stream in Missouri * Early County, Georgia * Fort Early, Georgia, an early 19th century fort Music * Early B, stage name of Jamaican d ...

, some 5 Ma (

million years ago Million years ago, abbreviated as Mya, Myr (megayear) or Ma (megaannum), is a unit of time equal to (i.e. years), or approximately 31.6 teraseconds. Usage Myr is in common use in fields such as Earth science and cosmology. Myr is also used w ...

). As suggested by

biogeography Biogeography is the study of the species distribution, distribution of species and ecosystems in geography, geographic space and through evolutionary history of life, geological time. Organisms and biological community (ecology), communities o ...

and

DNA sequence A nucleic acid sequence is a succession of bases within the nucleotides forming alleles within a DNA (using GACT) or RNA (GACU) molecule. This succession is denoted by a series of a set of five different letters that indicate the order of the nu ...

data, it might be part of an ancient non-

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. This includes: * ''electromagnetic radiation'' consisting of photons, such as radio waves, microwaves, infr ...

of ''Falco'' species from Europe to

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, alongside the ancestors of forms such as the American kestrel (''F. sparvierus''), and the aplomado falcon (''F. femoralis'') and its relatives. A relationship with the red-necked falcon (''F. chicquera'') was once proposed based on their phenetic similarity, but this is not considered likely today. More recently, a genetic link to two tropical African species, grey kestrel ''Falco ardosiaceus'' and dickinson's kestrel ''F. dickinsoni'' has been found. In that regard, a

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

falcon from the Early

Blancan The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 4,750,000 to 1,806,000 years BP, a period of .Rexroad Formation of

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

. Known from an almost complete right

coracoid A coracoid is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is present as part of the scapula, but this is n ...

(specimen UMMP V29107) and some

tarsometatarsus The tarsometatarsus is a bone that is only found in the lower leg of birds and some non-avian dinosaurs. It is formed from the fusion of several bird bones found in other types of animals, and homologous to the mammalian tarsus (ankle bones) a ...

tibiotarsus The tibiotarsus is the large bone between the femur and the tarsometatarsus in the leg of a bird. It is the fusion of the proximal part of the tarsus with the tibia. A similar structure also occurred in the Mesozoic Heterodontosauridae. These ...

and

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

pieces (V27159, V57508-V57510, V57513-V57514), this prehistoric falcon was slightly smaller than a merlin and apparently a bit more stout-footed, but otherwise quite similar. It was part of the Fox Canyon and Rexroad Local Faunas, and may have been the ancestor of the living merlins or its close relative. With its age quite certainly pre-dating the split between the Eurasian and North American merlins, the fossil falcon supports the idea of the merlin lineage originating in North America, or rather the colonization thereof. After adapting to its

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of Resource (biology), resources an ...

, ancient merlins would have spread to Eurasia again, with

gene flow In population genetics, gene flow (also known as migration and allele flow) is the transfer of genetic variation, genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent ...

being interrupted as the

Beringia Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 70th parallel north, 72° north latitude in the Chukchi Sea; and on the south ...

and

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

regions became icebound in the

Quaternary glaciation The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial period, glacial and interglacial, interglacial periods during the Quaternary period that began 2.58 Year#SI prefix multipliers, Ma (million ...

Subspecies

That the merlin has a long-standing presence on both sides of the Atlantic is evidenced by the degree of genetic distinctness between Eurasian and North American populations. They are probably best considered distinct species, with

having ceased at least a million years ago, but probably more; but more study is required, particularly in the less-sampled subspecies, before a formal split can be made. By and large, color variation in either group independently follows Gloger's Rule. The Pacific temperate rain forest subspecies ''F. c. suckleyi'' males are almost uniformly black on the upperside and have heavy black blotches on the belly, whereas those of the lightest

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

, ''F. c. pallidus'', have little non-dilute

melanin Melanin (; ) is a family of biomolecules organized as oligomers or polymers, which among other functions provide the pigments of many organisms. Melanin pigments are produced in a specialized group of cells known as melanocytes. There are ...

altogether, with gray upperside and reddish underside pattern. Nine subspecies are currently accepted: American group (''Falco columbarius'' sensu stricto) * ''Falco columbarius columbarius'' (Linnaeus, 1758) – taiga merlin, boreal merlin, tundra merlin :

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

and northernmost United States east of

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

, except

Great Plains The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include th ...

. Migratory, winters in S North America,

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

, the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

, and N

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

from the Guyanas to the northern

Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

foothills. Rarely winters in the northern USA. * ''Falco columbarius richardsonii'' (Ridgway, 1871) – prairie merlin :Great Plains from

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

Wyoming Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...

. Resident (some winter dispersal). Paler than ''F. c. columbarius''. * ''Falco columbarius suckleyi'' (Ridgway, 1873) – black merlin, coastal forest merlin :

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

coast of North America, from S

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

to N Washington state. Resident (some altitudinal movements). Eurasian group (''Falco aesalon'' if split) * ''Falco columbarius/aesalon subaesalon'' (C.L. Brehm, 1827) – Icelandic merlin :

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

and

Faroe Islands The Faroe Islands ( ) (alt. the Faroes) are an archipelago in the North Atlantic Ocean and an autonomous territory of the Danish Realm, Kingdom of Denmark. Located between Iceland, Norway, and the United Kingdom, the islands have a populat ...

. The Faroese population has some gene flow with ''F. c. aesalon''. Resident or some winter dispersal to coasts. * ''Falco columbarius/aesalon aesalon'' (Tunstall, 1771) – Eurasian merlin :Northern Eurasia from

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

through

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

to central

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

. Population of northern

Britain Britain most often refers to: * Great Britain, a large island comprising the countries of England, Scotland and Wales * The United Kingdom of Great Britain and Northern Ireland, a sovereign state in Europe comprising Great Britain and the north-eas ...

shows evidence of

from ''F. c. subaesalon''. British Isles population resident or short-distance movement from moors to coasts, rest migratory; winters in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

and the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

region to about

Iran Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...

. * ''Falco columbarius/aesalon pallidus'' (Sushkin, 1900) – pallid merlin, steppe merlin :Asian

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without closed forests except near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the tropical and subtropica ...

s between

Aral Sea The Aral Sea () was an endorheic lake lying between Kazakhstan to its north and Uzbekistan to its south, which began shrinking in the 1960s and had largely dried up into desert by the 2010s. It was in the Aktobe and Kyzylorda regions of Kazakhst ...

and

Altay Mountains The Altai Mountains (), also spelled Altay Mountains, are a mountain range in Central and East Asia, where Russia, China, Mongolia, and Kazakhstan converge, and where the rivers Irtysh and Ob have their headwaters. The massif merges with th ...

. Migratory, winters in S

Central Asia Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...

and N

South Asia South Asia is the southern Subregion#Asia, subregion of Asia that is defined in both geographical and Ethnicity, ethnic-Culture, cultural terms. South Asia, with a population of 2.04 billion, contains a quarter (25%) of the world's populatio ...

. * ''Falco columbarius/aesalon insignis'' (Clark, 1907) – East Siberian merlin :Siberia between Yenisei and

Kolyma River The Kolyma (, ; ) is a river in northeastern Siberia, whose basin covers parts of the Sakha Republic, Chukotka Autonomous Okrug, and Magadan Oblast of Russia. The Kolyma is frozen to depths of several metres for about 250 days each year, b ...

s. Migratory, winters in continental

East Asia East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of Economy of China, China, Economy of Ja ...

. * ''Falco columbarius/aesalon lymani'' (Bangs, 1913) – Central Asian merlin :Mountains of eastern

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

and surrounding countries. Short-distance migrant. * ''Falco columbarius/aesalon pacificus'' (Stegmann, 1929) – Pacific merlin :

Russian Far East The Russian Far East ( rus, Дальний Восток России, p=ˈdalʲnʲɪj vɐˈstok rɐˈsʲiɪ) is a region in North Asia. It is the easternmost part of Russia and the Asia, Asian continent, and is coextensive with the Far Easte ...

to Sakhalin. Migratory, winters in

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

Korea Korea is a peninsular region in East Asia consisting of the Korean Peninsula, Jeju Island, and smaller islands. Since the end of World War II in 1945, it has been politically Division of Korea, divided at or near the 38th parallel north, 3 ...

and nearby.

Description

The merlin is long with a wingspan. Compared with most other small

s, it is more robust and heavily built. Males average at about and females are typically about . There is considerable variation, however, throughout the birds' range and—in particular in migratory populations—over the course of a year. Thus, adult males may weigh , and females . Each wing measures , the tail measures and the tarsus measures . Such

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

is common among raptors; it allows males and females to hunt different

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

animals and decreases the

territory A territory is an area of land, sea, or space, belonging or connected to a particular country, person, or animal. In international politics, a territory is usually a geographic area which has not been granted the powers of self-government, ...

size needed to feed a mated pair. The male merlin has a blue-gray back, ranging from almost black to

silver Silver is a chemical element; it has Symbol (chemistry), symbol Ag () and atomic number 47. A soft, whitish-gray, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. ...

-gray in different

. Its underparts are buff- to orange-tinted and more or less heavily streaked with black to reddish brown. The female and immature are brownish-gray to dark brown above, and whitish buff spotted with brown below. Besides a weak whitish supercilium and the faint dark malar stripe—which are barely recognizable in both the palest and the darkest birds—the face of the merlin is less strongly patterned than in most other falcons. Nestlings are covered in pale buff

down feather The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and p ...

s, shading to whitish on the belly. The

remiges Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the ta ...

are blackish, and the tail usually has some three to four wide, blackish bands, too. Very light males only have faint and narrow medium-gray bands, while in the darkest birds the bands are very wide, so that the tail appears to have narrow lighter bands instead. In all of them, however, the tail tip is black with a narrow white band at the very end, a pattern possibly

plesiomorphic In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, an ...

for all falcons. Altogether, the tail pattern is quite distinct though, resembling only that of the aplomado falcon (''F. berigora'') and (in light merlins) some typical

kestrel The term kestrel (from , derivative from , i.e. ratchet) is the common name given to several species of predatory birds from the falcon genus ''Falco''. Kestrels are most easily distinguished by their typical hunting behaviour which is to hover ...

s. The eye and

beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for pecking, grasping, and holding (in probing for food, eating, manipulating and ...

are dark, the latter with a yellow

cere The beak, bill, or Rostrum (anatomy), rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for pecking, wikt:grasp#Verb, grasping, and holding (in wikt:probe ...

. The feet are also yellow, with black claws. Light American males may resemble the American kestrel (''F. sparverius'', not a typical kestrel), but merlin males have a gray back and tail rather than the reddish-brown of the kestrels. Light European males can be distinguished from kestrels by their mainly brown wings. In the north of

, wintering males may be confused with the red-necked falcon (''F. chicquera'') if they fly away from the observer and the head (red on top in ''F. chicquera'') and underside (finely barred with black in ''F. chicquera'') are not visible.

Ecology

Merlins inhabit fairly open country, such as

willow Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known ...

birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech- oak family Fagaceae. The genus ''Betula'' contains 3 ...

scrub,

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally o ...

, but also

taiga Taiga or tayga ( ; , ), also known as boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruces, and larches. The taiga, or boreal forest, is the world's largest land biome. In North A ...

forest,

park A park is an area of natural, semi-natural or planted space set aside for human enjoyment and recreation or for the protection of wildlife or natural habitats. Urban parks are urban green space, green spaces set aside for recreation inside t ...

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

such as

and

prairie Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...

s, or

moorland Moorland or moor is a type of Habitat (ecology), habitat found in upland (geology), upland areas in temperate grasslands, savannas, and shrublands and the biomes of montane grasslands and shrublands, characterised by low-growing vegetation on So ...

. They are not very

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

-specific and can be found from

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

to the

treeline The tree line is the edge of a habitat at which trees are capable of growing and beyond which they are not. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually low ...

. In general, they prefer a mix of low and medium-height vegetation with some trees, and avoid dense forests as well as treeless

arid Aridity is the condition of geographical regions which make up approximately 43% of total global available land area, characterized by low annual precipitation, increased temperatures, and limited water availability.Perez-Aguilar, L. Y., Plata ...

regions. During

migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

however, they will utilize almost any habitat. Most of its populations are migratory, wintering in warmer regions. Northern European birds move to southern

and

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

, and North American populations to the southern United States to northern

. In the milder maritime parts of its breeding range, such as

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

, the

Pacific Northwest The Pacific Northwest (PNW; ) is a geographic region in Western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though no official boundary exists, the most common ...

and western

, as well as in

, it will merely desert higher ground and move to coasts and lowland during winter. The migration to the breeding grounds starts in late February, with most birds passing through the US,

Central Europe Central Europe is a geographical region of Europe between Eastern Europe, Eastern, Southern Europe, Southern, Western Europe, Western and Northern Europe, Northern Europe. Central Europe is known for its cultural diversity; however, countries in ...

and southern

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

in March and April, and the last stragglers arriving in the breeding range towards the end of May. Migration to winter quarters at least in Eurasia peaks in August/September, while e.g. in

Ohio Ohio ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Erie to the north, Pennsylvania to the east, West Virginia to the southeast, Kentucky to the southwest, Indiana to the ...

, just south of the breeding range, ''F. c. columbarius'' is typically recorded as a southbound migrant as late as September/October. In Europe, merlins will roost communally in winter, often with hen harriers (''Circus cyaneus''). In North America, communal roosting is rare. MerlinchasingBlueJay08

Merlins rely on speed and agility to hunt their prey. They often hunt by flying fast and low, typically less than above the ground, using trees and large shrubs to take prey by surprise. But they actually capture most prey in the air, and will "tail-chase" startled birds. Throughout its native range, the merlin is one of the most able aerial predators of small to mid-sized birds, more versatile if anything than the larger

hobbies A hobby is considered to be a regular activity that is done for enjoyment, typically during one's leisure time. Hobbies include collecting themed items and objects, engaging in creative and artistic pursuits, playing sports, or pursuing other ...

(which prefer to attack in mid-air) and the more nimble sparrowhawks (which usually go for birds resting or sleeping in dense growth). Breeding pairs will frequently hunt cooperatively, with one bird flushing the prey toward its mate. The merlin will readily take prey that is flushed by other causes, and can for example be seen tagging along sharp-shinned hawks (''Accipiter striatus'') to catch birds that escape from this ambush predator into the open air. It is quite unafraid, and will readily attack anything that moves conspicuously. Merlins have even been observed trying to "catch"

automobile A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, peopl ...

s and

train A train (from Old French , from Latin">-4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ... , from Latin , "to pull, to draw") is a series of connected vehicles th ...

s, and to feed on captive birds such as those snared in the mist nets used by

ornithologist Ornithology, from Ancient Greek ὄρνις (''órnis''), meaning "bird", and -logy from λόγος (''lógos''), meaning "study", is a branch of zoology dedicated to the study of birds. Several aspects of ornithology differ from related discip ...

s. Even under adverse conditions, one in 20 targets is usually caught, and under good conditions almost every other attack will be successful. Sometimes, merlins cache food to eat it later. In particular during the breeding season, most of the prey are smallish birds weighing . Almost any such

will be taken, with local preferences for whatever is most abundant—be it

lark Larks are passerine birds of the family Alaudidae. Larks have a cosmopolitan distribution with the largest number of species occurring in Africa. Only a single species, the horned lark, occurs in North America, and only Horsfield's bush lark occ ...

s (Alaudidae), pipits (''Anthus''), finches (Fringillidae),

house sparrow The house sparrow (''Passer domesticus'') is a bird of the Old World sparrow, sparrow family Passeridae, found in most parts of the world. It is a small bird that has a typical length of and a mass of . Females and young birds are coloured pa ...

s (''Passer domesticus''), other

Old World sparrow Old World sparrows are a group of small passerine birds forming the family (biology), family Passeridae. They are also known as true sparrows, a name also used for a particular genus of the family, ''Passer''. They are distinct from both the New ...

s (Passeridae), northern wheatears (''Oenanthe oenanthe''), thrushes (''Turdus''), kinglets (Regulidae) or buntings (''Emberiza'')—and inexperienced yearlings always a favorite. Smaller birds will generally avoid a hunting merlin if possible. In the

Cayman Islands The Cayman Islands () is a self-governing British Overseas Territories, British Overseas Territory, and the largest by population. The territory comprises the three islands of Grand Cayman, Cayman Brac and Little Cayman, which are located so ...

(where it only occurs in winter), bananaquits were noted to die of an apparent

heart attack A myocardial infarction (MI), commonly known as a heart attack, occurs when Ischemia, blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction (tissue death) to the heart muscle. The most common symptom ...

stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...

, without being physically harmed, when a merlin went at them and they could not escape. Larger birds (e.g. sandpipers, flickers, other

woodpecker Woodpeckers are part of the bird family (biology), family Picidae, which also includes the piculets, wrynecks and sapsuckers. Members of this family are found worldwide, except for Australia, New Guinea, New Zealand, Madagascar and the extreme ...

s, ptarmigan, other

grouse Grouse are a group of birds from the order (biology), order Galliformes, in the family (biology), family Phasianidae. Grouse are presently assigned to the Tribe (biology), tribe Tetraonini (formerly the subfamily Tetraoninae and the family Tetr ...

ducks Duck is the common name for numerous species of waterfowl in the family (biology), family Anatidae. Ducks are generally smaller and shorter-necked than swans and goose, geese, which are members of the same family. Divided among several subfam ...

and even

rock dove The rock dove (''Columba livia''), also sometimes known as "rock pigeon" or "common pigeon", is a member of the bird family Columbidae (doves and pigeons). In common usage, it is often simply referred to as the "pigeon", although the rock dov ...

s as heavy as the merlin itself) and other animals—

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s (especially

dragonflies A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threate ...

moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...

grasshopper Grasshoppers are a group of insects belonging to the suborder Caelifera. They are amongst what are possibly the most ancient living groups of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grassh ...

butterflies Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...

and

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

s), small

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s, (especially

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

shrew Shrews ( family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to dif ...

rabbit Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated ...

vole Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of lo ...

lemming A lemming is a small rodent, usually found in or near the Arctic in tundra biomes. Lemmings form the subfamily Arvicolinae (also known as Microtinae) together with voles and muskrats, which form part of the superfamily Muroidea, which also inclu ...

s and other small

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

s (such as

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

s and

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

s) and

amphibian Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

s—complement its diet. These are more important outside the breeding season, when they can make up a considerable part of the merlin's diet. But for example in

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

, while small birds are certainly the breeding merlin's staple food, exceptional breeding success seems to require an abundance of ''

Microtus ''Microtus'' is a genus of voles found in North America, Europe and northern Asia. The genus name refers to the small ears of these animals. They are stout rodents with short ears, legs and tails. They eat green vegetation such as grasses and se ...

'' voles.

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

s are the primary threat to eggs and nestlings. Adult merlins may be preyed on by larger raptors, especially

peregrine falcon The peregrine falcon (''Falco peregrinus''), also known simply as the peregrine, is a Cosmopolitan distribution, cosmopolitan bird of prey (raptor) in the family (biology), family Falconidae renowned for its speed. A large, Corvus (genus), cro ...

s (''F. peregrinus''), eagle-owls (e.g.,

great horned owl The great horned owl (''Bubo virginianus''), also known as the tiger owl (originally derived from early naturalists' description as the "winged tiger" or "tiger of the air") or the hoot owl, is a large owl native to the Americas. It is an extreme ...

, ''Bubo virginianus''), and larger '' Accipiter''

hawk Hawks are birds of prey of the family Accipitridae. They are very widely distributed and are found on all continents, except Antarctica. The subfamily Accipitrinae includes goshawks, sparrowhawks, sharp-shinned hawks, and others. This ...

s (e.g., northern goshawk, ''A. gentilis''). In general however,

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose nutrition and energy requirements are met by consumption of animal tissues (mainly mu ...

birds avoid merlins due to their aggressiveness and agility. Their desire to drive larger raptors away from their territory is so pronounced that it is an identifying characteristic. Quoting from one popular raptor watching reference, "An observer may use this aggressive tendency for identification purposes and as a means of detection. High-flying merlins often betray themselves and distinguish themselves because they are vigorously harassing another raptor (even ones as large as the Golden Eagle)."

Reproduction

Breeding occurs typically in May/June. Though the pairs are

monogamous Monogamy ( ) is a relationship of two individuals in which they form a mutual and exclusive intimate partnership. Having only one partner at any one time, whether for life or serial monogamy, contrasts with various forms of non-monogamy (e.g. ...

at least for a breeding season, extra-pair copulations have been recorded. Most nest sites have dense vegetative or rocky cover; the merlin does not build a proper nest of its own. Most will use abandoned

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

(particularly '' Corvus'' crow and '' Pica'' magpie) or

nests which are in

conifer Conifers () are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sin ...

or mixed tree stands. In

—particularly in the UK—the female will usually make a shallow scrape in dense heather to use as a nest. Others nest in crevices on cliff-faces and on the ground, and some may even use buildings. Three to six (usually 4 or 5) eggs are laid. The rusty brown eggs average at about . The incubation period is 28 to 32 days. Incubation is performed by the female to about 90%; the male instead hunts to feed the family. Hatchlings weigh about . The young

fledge Fledging is the stage in a flying animal's life between egg, 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 vulnera ...

after another 30 days or so, and are dependent on their parents for up to 4 more weeks. Sometimes first-year merlins (especially males) will serve as a "nest helper" for an adult pair. More than half—often all or almost all—eggs of a

clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

survive to hatching, and at least two-thirds of the hatched young fledge. However, as noted above, in years with little supplementary food only 1 young in 3 may survive to fledging. The merlin becomes sexually mature at one year of age and usually attempts to breed right away. The oldest wild bird known as of 2009 was recorded in its 13th winter.

Relationship with humans

John James Audubon John James Audubon (born Jean-Jacques Rabin, April 26, 1785 – January 27, 1851) was a French-American Autodidacticism, self-trained artist, natural history, naturalist, and ornithology, ornithologist. His combined interests in art and ornitho ...

illustrated the merlin in the second edition of '' Birds of America'' (published in London, 1827–38) as Plate 75, under the title, "Le Petit Caporal – ''Falco temerarius''". The image was engraved and colored by Robert Havell's London workshops. The original watercolor by Audubon was purchased by the New York History Society, where it remains as of January 2009. William Lewin illustrates the merlin as Plate 22 in volume 1 of his ''Birds of Great Britain and their Eggs'', published 1789 in London.

Use in falconry

In medieval Europe, merlins were popular in

: the Book of St. Albans listed it as "the falcon for a lady", where it was noted for classic "ringing" (circling rapidly upward) pursuits of the English skylark. Though the merlin is only slightly larger than the American kestrel in dimensions, it averages about one third to one half larger by weight, with this weight mostly being extra muscle that gives it greater speed and endurance than the kestrel. Like the American kestrel, the merlin offers the modern falconer the ability to hunt year round against sparrows and starlings, in urban settings not requiring large tracts of land or hunting dogs, with the additional advantage of being able to reliably take small game birds such as dove and quail during hunting season. A large and exceptionally aggressive female merlin may take prey as large as pigeons and occasionally even small ducks. They also offer an exciting style of flight, generally at closer range than large falcons where it may be more clearly witnessed and enjoyed by the falconer. In addition to horizontal tail-chases in the manner of American kestrels, they will also "ring up" in pursuit of prey that seeks to escape by out-climbing them, and perform high speed diving stoops on prey beneath them in the manner of larger falcons. Quoting from one popular falconry book on the eagerness of merlins to chase a swung lure, "Every stoop, outrun, dodge, and aerial maneuver of a hard flight to real quarry can be duplicated with no risk of loss of the falcon. Merlins regularly flown to the lure take most field quarries with such ease and such assurance as to make the field flight the less interesting and exciting of the two." Quoting expert falconer Matthew Mullenix, author of the book "American Kestrels in Modern Falconry", in an article comparing the American kestrel to the merlin he states "What a merlin gives you is raw power: lots of it. It brings an ability to negate wind as a factor, to stay airborne at a tremendous clip then gear down further at any time for more performance. One merlin can dominate an entire flock of frightened birds, directing its fate as a whole. The flock responds like bait fish to a barracuda and for precisely the same reason. Merlins demonstrate total mastery of their element." Concerning suitable game for these two species, he states "To snipe, dove, quail and open-country sparrows, merlins are best suited. For most blackbirds (Icteridea), either falcon can prove effective. Starlings in close are extremely vulnerable to kestrels; but in the open are best prey for merlins."

Status and conservation

Altogether, the merlin is not particularly rare, and due to this and its wide range it is considered a species of

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

by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

. Its numbers are—except in the

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

n part of its range, where the situation is less well determined—regularly censused. In about every major country it inhabits, many hundreds to many thousands are found, ranging from a "mere" 250–300 pairs in

Belarus Belarus, officially the Republic of Belarus, is a landlocked country in Eastern Europe. It is bordered by Russia to the east and northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Belarus spans an a ...

to perhaps as many as 30,000 pairs of ''aesalon'' in

European Russia European Russia is the western and most populated part of the Russia, Russian Federation. It is geographically situated in Europe, as opposed to the country's sparsely populated and vastly larger eastern part, Siberia, which is situated in Asia ...

as determined in 1993. It is listed on

CITES Appendix II CITES (shorter acronym for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of inte ...

and on a local level protected as other

birds of prey Birds of prey or predatory birds, also known as (although not the same as) raptors, are hypercarnivorous bird species that actively predation, hunt and feed on other vertebrates (mainly mammals, reptiles and smaller birds). In addition to speed ...

; while some countries allow to capture merlins, e.g. for falconry, international trade requires an export permit. By far the most serious long-term threat to these birds is

habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

, especially in their breeding areas. Ground-nesting populations in

have a preference for tall heather, and are thus susceptible to overmanagement by burning vast tracts instead of creating a habitat mosaic containing old and new growth. Still, the merlin is rather euryoecious (adaptable to various conditions) and will even live in settled areas, provided they have the proper mix of low and high vegetation, as well as sufficient prey (which is usually the case) and nesting sites (which is a common limiting factor). In North America, the species seems to have been more widespread in the past, or perhaps its range has shifted northwards: ''F. c. columbarius'' was an uncommon breeding bird in

before the 20th century, but in Seneca County, as early as the 1900s even single adults were rarely seen in the breeding season. It is encountered in Ohio as a passage migrant and rarely as a winter guest, though two recent nestings have been confirmed. Changing land-use in Ohio mainly turned forest into

agricultural Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created f ...

land and thus is not very likely to have rendered the region inhospitable to the merlin;

global warming Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...

on the other hand cannot be dismissed as a reason, given that the merlin is essentially a

subarctic The subarctic zone is a region in the Northern Hemisphere immediately south of the true Arctic, north of hemiboreal regions and covering much of Alaska, Canada, Iceland, the north of Fennoscandia, Northwestern Russia, Siberia, and the Cair ...

species that barely ranges even into

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

climes. Also, it may be that the number of merlins wintering in the northern USA has increased during the 20th century. Perhaps the most frequent cause of accidental death for individuals is collision with man-made objects, particularly during attacks. This may account for almost half of all premature deaths of merlins. In the 1960s and 1970s, organochlorine pesticides were responsible for declines—particularly in

—due to eggshell thinning and subsequent brood failure, and compromising the

immune system The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic ...

of adults. This has since been remedied with restrictions on the use of DDT and similar chemicals, and numbers have rebounded. Overall, merlin stocks appear globally stable; while they may decline temporarily in places, they will usually increase again eventually, suggesting that this phenomenon is due to the fluctuations of supplementary food stocks discussed above.

References

External links

Merlin Species Account
– Cornell Lab of Ornithology

- USGS Patuxent Bird Identification InfoCenter

* ttp://www.oiseaux.net/birds/photos/merlin.html Merlin photosa
Oiseaux.net

Ageing and sexing (PDF; 5.3) by Javier Blasco-Zumeta & Gerd-Michael Heinze
*

Canadian Peregrine Foundation * *

Merlin Falcon Foundation

Historical material

*
The Merlin, called in Latine ''Æsalon''.
Page 85 in ''The Ornithology of Francis Willughby'', translated by John Ray (1678)
Engraving
of a perched merlin, tableaux III. *
''Falco columbarius'', Pigeon Hawk
; from ''American Ornithology'' 2nd edition, volume 1 (1828) by Alexander Wilson and George Ord

from 1st edition by A. Wilson. *
The Pigeon Hawk
and
Le Petit Caporal
, John James Audubon, ''Ornithological Biography'' volume 1 (1831). A
Pigeon Hawk; Petit Caporal
in the appendix to ''Ornithological Biography'' volume 5 (1839), Audubon notes that his ''Falco temerarius'' of volume 1 was a small male merlin, and that this was brought to his attention by Charles Lucien Bonaparte, Charles Bonaparte, nephew of "the little corporal"
Illustration
from ''Birds of America'' octavo edition, 1840. {{Taxonbar, from=Q131918 Falco (genus) Holarctic birds Birds described in 1758 Taxa named by Carl Linnaeus Birds of the Dominican Republic