Merlin (bird)

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Merlin
Male prairie merlin (F. c. richardsoni) with prey in Alberta (Canada)

Least Concern  (IUCN 3.1)[1]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Falconiformes
Family: Falconidae
Genus: Falco
Species:
F. columbarius
Binomial name
Falco columbarius
Subspecies

3–9 subspecies (see text)

Range of F. columbarius
  Summer only range
  Year-round range
  Winter only range
Synonyms

Aesalon columbarius (Linnaeus, 1758)
Falco aesalon Tunstall, 1771 (but see text)

For the app used to identify birds, see
Merlin Bird ID
.

The merlin (Falco columbarius) is a small

tropical regions in winter. Males typically have wingspans of 53–58 centimetres (21–23 in), 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 quail. The merlin has for centuries been well regarded as a falconry
bird. 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.

Nomenclature

The merlin was described and illustrated by the English naturalist

scientific name F. aesalon.[8][9]

The name "merlin" is derived from

Old Icelandic smyrill.[10] Wycliffe's Bible, around 1382, mentions An Egle, & agriffyn, & a merlyon.[10] The species was once known as 'pigeon hawk' in North America.[11]

Although the merlin shares its name with the wizard

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

phenetic similarity, but this is not considered likely today.[8][9][13][14][15]

European subspecies aesalon. Adult male (front) and female (behind)

In that regard, a

UMMP V29107) and some tarsometatarsus, tibiotarsus and humerus 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, ancient merlins would have spread to Eurasia again, with gene flow being interrupted as the Beringia and Greenland regions became icebound in the Quaternary glaciation.[9][13][17]

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. Arguably, they might be considered distinct species, with gene flow having ceased at least a million years ago, but probably more.[9]

By and large, color variation in either group independently follows

Pacific temperate rain forest subspecies suckleyi's males are almost uniformly black on the upperside and have heavy black blotches on the belly, whereas those of the lightest subspecies, pallidus, have little non-dilute melanin altogether, with grey upperside and reddish underside pattern.[8]

Anchorage (Alaska
, United States)

American group[8]

  • Falco columbarius columbarius (Linnaeus, 1758) – taiga merlin, boreal merlin, tundra merlin
Guyanas to the northern Andes foothills. Rarely winters in the northern USA.[11][18]
Great Plains from Alberta to Wyoming. Resident (some winter dispersal).
  • Falco columbarius suckleyi (Ridgway, 1873) – black merlin, coastal forest merlin
Pacific coast of North America, from S Alaska to N Washington
state. Resident (some altitudinal movements).

Eurasian group[8]

  • Falco columbarius/aesalon aesalon (Tunstall, 1771) – Eurasian merlin
Northern Eurasia from
Mediterranean region to about Iran
.
Male (presumably F. c./a. pallidus) wintering in Little Rann of Kutch (Gujarat, India)
  • Falco columbarius/aesalon subaesalon
    Icelandic
    )
Iceland and Faroe Islands. Latter population has some gene flow with aesalon. Resident (some winter dispersal).
  • Falco columbarius/aesalon pallidus (Sushkin, 1900) – pallid merlin, steppe merlin
Asian
Altay Mountains. Migratory, winters in S Central Asia and N South Asia
.
  • Falco columbarius/aesalon insignis (Clark, 1907) – East Siberian merlin
Siberia between
Kolyma Rivers. Migratory, winters in continental East Asia
.
Mountains of eastern Kazakhstan and surrounding countries. Short-distance migrant.
  • Falco columbarius/aesalon pacificus (Stegmann, 1929) – Pacific merlin
Russian Far East to Sakhalin. Migratory, winters in Japan, Korea and nearby.

Description

Juvenile, F. c. columbarius

The merlin is 24–33 cm (9.4–13.0 in) long with a 50–73 cm (20–29 in) wingspan.

prey animals and decreases the territory size needed to feed a mated pair.[8][21]

The male merlin has a blue-grey back, ranging from almost black to

Nestlings are covered in pale buff down feathers, shading to whitish on the belly.[21]

Upperside pattern of male (presumably F. c./a. pallidus) wintering in Little Rann of Kutch, Gujarat, India

The

cere. The feet are also yellow, with black claws.[21]

Light American males may resemble the American kestrel (F. sparverius, not a typical kestrel), but merlin males have a grey 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 South Asia, 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.[21]

Ecology

Merlins inhabit fairly open country, such as

arid regions. During migration however, they will utilize almost any habitat.[8]

Most of its populations are migratory, wintering in warmer regions. Northern European birds move to southern

maritime parts of its breeding range, such as Great Britain, the Pacific Northwest and western Iceland, as well as in Central Asia, 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 and southern Russia 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, just south of the breeding range, F. c. columbarius is typically recorded as a southbound migrant as late as September/October.[8][18] In Europe, merlins will roost communally in winter, often with hen harriers (Circus cyaneus). In North America, communal roosting
is rare.

northern blue jay (Cyanocitta cristata bromia), Mount Auburn Cemetery, Massachusetts
, United States

Merlins rely on speed and agility to hunt their prey. They often hunt by flying fast and low, typically less than 1 m (3.3 ft) 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 (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.[8][22]

The merlin will readily take prey that is flushed by other causes, and can for example be seen tagging along

ornithologists. 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.[8][23]

In particular during the breeding season, most of the prey are smallish birds weighing 10–40 g (0.35–1.41 oz). Almost any such

heart attack or stroke, without being physically harmed, when a merlin went at them and they could not escape.[23]

Larger birds (e.g.

butterflies and beetles[30][31]), small mammals, (especially bats,[32] shrews,[33] rabbits,[30] voles, lemmings[34] and other small rodents[35]) reptiles (such as lizards and snakes)[24] and amphibians[36]—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, while small birds are certainly the breeding merlin's staple food, exceptional breeding success seems to require an abundance of Microtus voles.[8]

carnivorous 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,[37]
"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

Falco columbarius egg
MHNT
Nestlings

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

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.[8]

Three to six (usually 4 or 5) eggs are laid. The rusty brown eggs average at about 40 mm × 31.5 mm (1.57 in × 1.24 in).[

Incubation is performed by the female to about 90%; the male instead hunts to feed the family. Hatchlings weigh about 13 g (0.46 oz). The young fledge 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 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.[8][38]

Relationship with humans

A male smyril is featured on this Faroese stamp by Edward Fuglø

Robert Havell's London workshops. The original watercolor by Audubon was purchased by the New York History Society,[39]
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

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.[40] 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.[40] 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.[41] 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."[40]

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."[42] 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

Georgia SSR
, November 1979

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

CITES Appendix II and on a local level protected as other birds of prey; while some countries allow to capture merlins, e.g. for falconry, international trade requires an export permit.[1][8]

By far the most serious long-term threat to these birds is habitat destruction, especially in their breeding areas. Ground-nesting populations in moorland 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).[8]

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

temperate climes. Also, it may be that the number of merlins wintering in the northern USA has increased during the 20th century.[11][8][18]

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 Canada—due to eggshell thinning and subsequent brood failure, and compromising the immune system 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.[8]

See also

References

  1. ^
    doi:10.2305/IUCN.UK.2016-3.RLTS.T22696453A93562971.en
    . Retrieved 12 November 2021.
  2. ^ "Merlin Overview, All About Birds, Cornell Lab of Ornithology". www.allaboutbirds.org. Retrieved 2020-01-29.
  3. ^ Catesby, Mark (1729–1732). The natural history of Carolina, Florida and the Bahama Islands (in English and French). Vol. 1. London: W. Innys and R. Manby. p. 3, plate 3.
  4. ^ "Merlin". Audubon. 2014-11-13. Retrieved 2020-01-27.
  5. ^ Linnaeus, Carl (1758). Systema Naturæ per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (in Latin). Vol. 1 (10th ed.). Holmiae (Stockholm): Laurentii Salvii. p. 90.
  6. ISBN 978-0199206872
    .
  7. ISBN 978-1-4081-2501-4
    .
  8. ^
    ISBN 84-87334-15-6
    .
  9. ^ a b c d Wink, Michael; Seibold, I.; Lotfikhah, F.; Bednarek, W. (1998). Chancellor, R.D.; Meyburg, B.-U.; Ferrero, J.J. (eds.). Molecular systematics of holarctic raptors (Order Falconiformes) (PDF). Holarctic Birds of Prey. Adenex & WWGBP. pp. 29–48.
  10. ^ a b "merlin". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  11. ^
    Wilson Bulletin
    . 18 (2): 47–60.
  12. ^ "Bird of The Week: Merlin". Kern Audubon Society. February 28, 2021. Retrieved 2022-10-14.
  13. ^ a b Helbig, A.J.; Seibold, I.; Bednarek, W.; Brüning, H.; Gaucher, P.; Ristow, D.; Scharlau, W.; Schmidl, D.; Wink, Michael (1994). Meyburg, B.-U.; Chancellor, R.D. (eds.). Phylogenetic relationships among falcon species (genus Falco) according to DNA sequence variation of the cytochrome b gene (PDF). Raptor conservation today. pp. 593–599.
  14. JSTOR 4089459
    .
  15. PMID 12414309
    .
  16. ^ Martin, R.A.; Honey, J.G.; Pelaez-Campomanes, P. (2000). "The Meade Basin Rodent Project; a progress report. Kansas Geological Survey Open-file Report 2000-61". Paludicola. 3 (1): 1–32.
  17. JSTOR 4083714
    .
  18. ^ a b c "Annotated Ohio state checklist" (PDF). Ohio Ornithological Society (OOS). 2004. Archived from the original (PDF) on 18 July 2004. Retrieved 29 October 2009.
  19. ^
    ISBN 0-618-12762-3
    .
  20. ^ Davis, Kate (2002). Falcons of North America. Mountain Press Publishing Company.
  21. ^
    ISBN 84-87334-15-6
    .
  22. ISBN 84-87334-20-2
    .
  23. ^ a b Olson, Storrs L.; James, Helen F.; Meister, Charles A. (1981). "Winter field notes and specimen weights of Cayman Island Birds" (PDF). Bulletin of the British Ornithologists' Club. 101 (3): 339–346.
  24. ^ a b c d "Falco columbarius (Merlin)". Animal Diversity Web.
  25. ^ Ferguson-Lees, J. & Christie, D.A. & Franklin, K. & Mead, D. & Burton, P.. (2001). Raptors of the world. Helm Identification Guides.
  26. ^ "Merlin". Carolina Raptor Center. Archived from the original on 27 July 2010.
  27. ^ Ferguson-Lees, J. & Christie, D.A. & Franklin, K. & Mead, D. & Burton, P.. (2001). Raptors of the world. Helm Identification Guides.
  28. ^ Ferguson-Lees, J. & Christie, D.A. & Franklin, K. & Mead, D. & Burton, P.. (2001). Raptors of the world. Helm Identification Guides.
  29. JSTOR 4162530
    .
  30. ^
    UWI St. Augustine
    . Retrieved 2023-12-16.
  31. ^ Ferguson-Lees, J. & Christie, D.A. & Franklin, K. & Mead, D. & Burton, P.. (2001). Raptors of the world. Helm Identification Guides.
  32. doi:10.1111/mam.12060
    .
  33. ^ Ferguson-Lees, J. & Christie, D.A. & Franklin, K. & Mead, D. & Burton, P.. (2001). Raptors of the world. Helm Identification Guides.
  34. ^ Ferguson-Lees, J. & Christie, D.A. & Franklin, K. & Mead, D. & Burton, P.. (2001). Raptors of the world. Helm Identification Guides.
  35. ^ "Merlin". The Peregrine Fund. Retrieved 2023-12-16.
  36. ^ Ferguson-Lees, J. & Christie, D.A. & Franklin, K. & Mead, D. & Burton, P.. (2001). Raptors of the world. Helm Identification Guides.
  37. ^ Dunn, Pete (2012). Hawks in Flight (Second ed.). Houghton Mifflin Harcourt.
  38. ^ "Falco columbarius life history data". AnAge]. 2009.
  39. ^ "Audubon's Watercolors: The Complete Avian Collection: The New-York Historical Society Edition". Archived from the original on 14 July 2014. Retrieved 19 June 2014.
  40. ^
    ISBN 0-88839-978-2
    .
  41. ^ "Merlin | Hawk Mountain Sanctuary: Learn Visit Join". www.hawkmountain.org. Retrieved May 18, 2016.
  42. ^ "Merlin Falconry by Eric Edwards". www.merlinfalconry.com. Retrieved May 20, 2016.

External links

Wikimedia Commons has media related to Falco columbarius.
Wikispecies has information related to Falco columbarius.
Wikisource has the text of a 1920 Encyclopedia Americana article about Merlin or Stone-falcon.
Wikisource has original text related to this article:

Historical material

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