The Merlin falcon and sharp-shinned hawk are two small species of raptors found throughout much of North America. Both are skilled aerial hunters that prey primarily on small birds. There are some key differences between these two species in terms of size, plumage, habitat, hunting behavior, diet, and more. This article will provide an in-depth look at how to distinguish a Merlin from a sharp-shinned hawk.
Size Difference
One of the most noticeable differences between a Merlin and a sharp-shinned hawk is their size. The Merlin is the smallest falcon species in North America, with males averaging 9-12 inches in length and weighing 5-8 ounces. Females are slightly larger at 10-13 inches in length and weighing 7-11 ounces.
In comparison, sharp-shinned hawks are larger overall. Male sharpies average 11-13 inches in length and weigh 4-8 ounces, while females range from 13-16 inches in length and weigh 7-14 ounces. So while there is some overlap in size, male Merlins are smaller than even the smallest male sharp-shinned hawks. Female Merlins are distinctly smaller and more petite than female sharpies.
When seen together, the size difference is quite apparent. The Merlin has a very small, compact body shape compared to the longer-tailed, fuller-chested build of the sharp-shinned.
Plumage Differences
In addition to size, there are some key differences in plumage that can help distinguish a Merlin from a sharp-shinned hawk:
– Merlin: Dark slate gray upperparts, lighter underparts with dark streaking. Distinctive vertical white bands (“mustaches”) along the sides of the face. Tail finely barred with black bands.
– Sharp-shinned hawk: Blue-gray upperparts, lighter underparts with rufous barring. Thinner barring on the tail. No strong facial markings.
Male Merlins tend to have more uniform, solid gray upperparts while male sharpies are more brownish gray. Females of both species are browner on the back. The bold black mustache marks on the male Merlin are distinctive from any facial pattern on the sharp-shinned.
The Merlin’s tail is more narrowly barred compared to the sharpie’s tail. When seen head on in flight, the broad white bands on the tail are an excellent identification mark for the Merlin.
Habitat Preferences
Merlins and sharp-shinned hawks frequent some different habitats:
– Merlins prefer open country. They are most often found in grasslands, meadows, shorelines, and wetland edges. Also found in open woodlands.
– Sharp-shinned hawks most often hunt in forests. They excel at maneuvering through dense, cluttered woods. Also found along wooded edges and in parks or residential areas with mature trees.
So a Merlin is more likely to be spotted hovering over an open marsh or field while a sharpie is more likely to be cruising through dense forest. However, there is some habitat overlap in semi-open woodlands.
Hunting Behavior
These species have some similar hunting strategies but also some key differences:
Merlin hunting behavior:
– Frequently hunts by hovering in place high overhead and scanning for prey below.
– Will also hunt from a perch or on the wing.
– Pursues prey in fast, direct flight. Catches prey mid-air or picks off prey on the ground.
– Hunts mostly in early morning and late afternoon.
Sharp-shinned hawk hunting behavior:
– Still-hunts by perching and scanning the landscape for prey.
– Also hunts on the wing, using vegetation as cover.
– Uses swift maneuvers and surprise ambush attacks to take prey by surprise.
– Hunts throughout the day and will return to plucking perches with prey.
So Merlins rely more on speed and fast pursuit in the open while sharp-shinned hawks use greater maneuverability and surprise to ambush prey in dense habitat.
Diet
There is considerable overlap in the diets of Merlins and sharp-shinned hawks, as both specialize in hunting small birds. However, some key dietary differences include:
Merlins
– Eat mostly small songbirds like sparrows, finches, larks.
– Also take insects, small rodents, bats.
– Occasionally hunt shorebirds.
Sharp-shinned hawks
– Prey mostly on small woodland birds like chickadees, nuthatches, warblers.
– Also take mourning doves, woodpeckers, jays.
– Less likely to hunt shorebirds or insects.
So while both dine on small birds, Merlins take more open country species while sharpies focus on woodland species. Merlins also consume a wider variety of non-bird prey.
Geographic Range
Merlins have a more northern distribution overall compared to sharp-shinned hawks:
Merlin range:
– Breeds across northern North America from Alaska to Labrador. Winters as far south as the southern U.S. and Mexico.
– Uncommon to rare year-round in the lower 48 states.
Sharp-shinned hawk range:
– Breeds across much of Canada and the northern and western U.S. Winters across the southern U.S and Mexico.
– Common to fairly common year-round in much of the lower 48 states.
So Merlins are more likely to be seen during migration and winter in the U.S, while sharp-shinned hawks maintain higher breeding populations in the lower 48 states. However, ranges overlap broadly during winter months.
Nesting
Some key differences in nesting habits:
Merlins
– Do not build their own nests. Use abandoned songbird or corvid nests.
– Nest on the ground on rocky outcrops, in trees or on human structures.
– Lay 3-6 eggs. Incubation lasts around 30 days.
Sharp-shinned hawks
– Build nests high in dense coniferous or mixed forests.
– Nest is a large stick platform lined with bark strips.
– Lay 3-5 eggs. Incubation lasts 30-35 days.
So sharpies construct more substantial nests in forest trees while Merlins opportunistically use old nests in a wider variety of sites. But clutch size and incubation periods are fairly similar.
Vocalizations
The calls of Merlins and sharp-shinned hawks are very distinct:
Merlin:
– Common call is a rapid series of high-pitched “kik-kik-kik”.
– Male’s territorial advertising call is a repetitive “killy-killy”.
Sharp-shinned hawk:
– Call is a thin, whistled “pew-pew-pew”
– Alarm call is a louder “keeyu”.
So Merlins have higher-pitched, more rapid vocalizations compared to the whistled, thinner calls of sharpies. Becoming familiar with these vocal differences helps identify them while hidden in foliage.
Distinguishing Perched Birds
When seen perched, here are some tips for identification:
Merlin
– Very small, squat appearance. Large headed.
– Long wings relative to stubby tail. Wings nearly reach tail tip.
– Vertical white “mustache” marks on males. Finely barred tail.
Sharp-shinned hawk
– Larger with longer tail and smaller head.
– Wings shorter relative to tail length. Wing tips fall short of tail tip.
– No strong facial markings. Broader tail bars.
The Merlin’s compact body, mustache marks, longer wings, and finely barred tail are key perched identification features. Sharpies appear larger-bodied, longer-tailed, and lack distinctive facial patterns.
Distinguishing in Flight
In flight, focus on these characteristics:
Merlin:
– Fast, direct flight on quick wingbeats.
– Pointed wings.
– White tail bands visible from beneath.
Sharp-shinned hawk:
– Swift flight with some buoyant glides.
– Short, rounded wings.
– Broader, less distinct tail bands.
The Merlin’s straight and sleek flight profile contrasts with the sharpie’s more undulating, accipiter-like flight. The bold tail bands are the best mark for identifying a Merlin in flight.
Juveniles and Polymorphism
Identifying juveniles and color morphs takes some specialized knowledge:
– Juvenile Merlins have heavy brown streaking overall with a buffy tint. Still show some facial markings.
– Sharp-shinned juveniles are also heavily streaked but lack strong facial patterns.
– Dark morph Merlins lack the contrasting facial patterns. Use tail banding instead.
– Some dark morph sharpies can look superficially similar to Merlins. Check tail and wing proportions.
So plumage clues like streaking, patterns, and proportions are essential for identifying young birds and dark color morphs accurately.
Key Identification Tips
In summary, these clues are most helpful for distinguishing Merlins from sharp-shinned hawks:
– Size – Merlins are significantly smaller and more compact.
– Plumage – Bold “mustache” marks on male Merlins. Finely barred tail.
– Habitat – Merlins prefer open country, sharpies forest.
– Hunting – Merlins hunt more by hovering, sharpies by ambushing.
– Prey – Merlins take more open country birds, sharpies woodland species.
– Range – Merlins more northern, sharpies range farther south.
– Flight – Merlins fly fast and straight, sharpies are more maneuverable.
– Tail – Broad white bands are the best mark of a Merlin in flight.
So by getting to know the right size, plumage clues, habitat, hunting style, geographic range, prey, and flight profiles you can confidently distinguish a Merlin from a sharp-shinned hawk.
Conclusion
In summary, the Merlin and sharp-shinned hawk have some superficial similarities as small raptors that hunt other birds, but they have many key differences in size, plumage, habitat preferences, hunting styles, vocalizations, geographic ranges, flight profile and other characteristics. By learning the right field marks, behaviors, and vocalizations you can positively identify a Merlin versus a sharp-shinned hawk. This guide covers all the major comparison points between these two small falcon and hawk species to allow accurate identification.
