By Alessandra Kite
This is the first blog post of the Identification (ID) series where we will cover key identification features of bird species that many birders can find challenging in the field. Because we are discussing a more holistic identification (using as many features as we can to identify and age the birds), we understand that some concepts might be new to a novice birder. Going forward we will mark each section with a colour that will let you know how simple or complex a concept might be!
The three levels we will use are:
• Beginner: This is useful information for everyone and especially birders who are new to identification who have not seen a majority of expected birds yet in the field, or those who have seen and can identify few of the discussed species but do not have a lot of comparative experience. Beginner pointers will highlight the most obvious identification features that can be seen in the field for a quick and easy analysis, or key features about its habitat or behaviour.
• Intermediate: Birders who have seen and can identify a majority of expected bird species in the field but have little comparative experience. Intermediate pointers will highlight slightly more nuanced and variable identification features that can be seen in the field, such as shape or flight style.
• Experienced: Birders who have seen and can identify all expected bird species in the field and have a lot of comparative experience. Experienced pointers will highlight fine details in identification dealing with moult patterns and terminology, and, in some cases, flight style.
One of the amazing things about studying birds is that there is always more to learn no matter how experienced you are! So if you ever find yourself discouraged about an ID or find that you are comparing yourself to more experienced birders, reflect on how far YOU have come since you started birding, and think about your most positive experiences with the birds and environments you love. It is really easy to start comparing yourself to those around you when learning something new, but remember that even experienced birders make mistakes and have more to learn. Each individual person learns differently and has different skill sets, and, at the end of the day, birding is supposed to be fun!
So with that, let’s get into the ID!
• Accipiter Habitat and Range Overview
Accipiter refers to a taxonomic family of hawks called Accipitridae. There are three species of Accipiter that can be seen in Ontario: the Cooper’s Hawk (aka. Coop, COHA), the Sharp-shinned Hawk (aka. Sharpie, SSHA), and the American Goshawk (aka. Gos, formerly known as the Northern Goshawk, AGOS). The Coop and the Sharpie are most commonly seen in forested, semi-forested, or Urban habitats, and mainly eat birds and small mammals. You may hear them referred to as the broader colloquial term sparrow hawk, (not to be confused with the European species of Accipiter called the Sparrow Hawk ;) because these birds are often seen in neighbourhoods and at backyard feeders chasing after the sparrows and small songbirds. The Sharpie has a much more extensive range than the Coop in summer, breeding as far north as James Bay across to Manitoba, while Coops tend to only breed as far North in Ontario as Marathon. However, Sharpies have a much smaller wintering range in Ontario than Coops, only remaining in Southern Ontario and in the East to Ottawa, picking off feeder birds in Urban environments. Coopers may range slightly further than Sharpies in the winter, and can be seen hunting more broadly in forests, fields, and cities.
Sharp-shinned Hawk range map. eBird Status and Trends - eBird Science
Cooper's Hawk range map. eBird Status and Trends - eBird Science
The American Goshawk can be much more elusive because it doesn’t tend to venture as frequently into Urban environments, hunting and breeding primarily in large, heavily forested areas. Goshawks can be found nearly all across Ontario, venturing North through Manitoba and into southern Nunavut. They are less often found breeding in Southern Ontario due to lack of appropriate forested habitat, but can be seen infrequently soaring overhead during migration. Goshawks can overwinter across Southern Ontario and across most of Northern Ontario, but can be more scarce in the James Bay and Hudson Bay region.
American Goshawk range map. eBird Status and Trends - eBird Science
• Habitat and range during the time of year can be a very useful tool in narrowing down which species of Accipiter you might be seeing. For example, if you are in Hamilton during the winter and you see a small Accipiter chasing sparrows at your feeder, you are most likely looking at a Sharpie or potentially a Coop. If you are in Simcoe County and you see a larger Accipiter chasing pigeons in the countryside, you are likely seeing a Coop or potentially a Gos.
Accipiter Plumage Features
Sharpies and Coops: Generally, Sharpies and Coops look very similar to one another in the field, as both juveniles and adults. The general plumage impression of juvenile birds of both species, meaning individuals up to a year old, is brown on their wings and back, with brown streaking across cream underparts. The general plumage of adults of both species is blueish-grey back and wings, with a dark barred pattern across reddish-orange underparts. Both juvenile species also have light grey-yellow eyes, and they change from orange to a deep red colour with age. It is understandable why these two species are some of the most difficult raptors to distinguish in Ontario! Despite this, the two species do have notable plumage differences, that when combined with shape, size, and behaviour, can be identified with certainty most of the time.
Adult Sharpie (left) and adult Coop (right). Images retrieved from Flickr, taken by Alan Schmierer.
• The main two plumage differences that are generally the most easily seen in the field are the tail shape, and the colouration on the top of their head (aka. crown).
• The pattern of the tail in Sharpies and Coops is generally the same at any age, the difference lies in the shape. When perched or gliding, Sharpies tend to show a very rectangular shaped tail; this is because the tail feathers of a Sharpie are all around the same length, giving the tail tip a very squared-off, cornered, or flat appearance. In Coops, the outer tail feathers tend to be shorter than the innermost tail feathers, giving the tail a rounded appearance when perched or gliding, and fan-like when the tail is spread. Although this is one of the best ways to tell the difference between the two species quickly in the field, it is always better to consider multiple ID features before coming to a conclusion. • In some cases, identifying the bird by only tail shape can be more deceiving than helpful. For example, when a Sharpie spreads its tail feathers, it can look very similar to the fan-like shape of the Cooper’s. The outer tail feathers of a Sharpie are generally more angular then a Coop’s, and they often retain a more squared off or angled shape even when the tail is spread, however if the tail feathers are particularly old or worn out the tail can appear a lot more rounded. In other cases, if a Sharpie is moulting and growing in new tail feathers the shape of the tail might not be typically characteristic, and could result in a more rounded appearance as the outer tail feathers grow in.
• Another key distinguishing plumage feature between the Sharpie and the Coop, is the crown: the feather colouration on the top of their head to the top of their neck. This difference can only be seen once birds grow in adult plumage. Adult Coops always have a dark grey, almost black crown, that cuts off sharply to lighter greyish blue at the back of their head. Sharpies also have a dark crown, averaging lighter than Coops, however it does not cut off at the back of their head but instead fades down their neck all the way to their back. This plumage feature is very helpful for identification only if you get a good look at the bird (generally perched because it is harder to see in flight), and if it is an adult. Unfortunately, getting a good look at accipiters is relatively uncommon due to several reasons: 1. If they are perched they are most often in forests or thickets with dense branches in the way of good viewing, or 2. They are zipping past you or soaring over you, and are either silhouetted, a blur, or you can only see their underparts.
Adult Sharpie (left) and adult Coop (right). Compare the head and neck colour and tail shape of each species. Images retrieved from Flickr, taken by Alan Schmierer and Kaaren Perry respectively.
• The main takeaway is that if you are lucky enough to see an accipiter in good light and with not many obstructions, take good note of its tail and crown and you have a good chance of identifying it!
Goshawks: Adult Goshawks look very different from adult Sharpies and Coops, so there is not much confusion in the field. They have a distinct black-dark grey head with a very bold white eyebrow and throat. They have slate grey-bluish back and wings, with darker flight feathers, and a stark white belly with faint grey barring. When they are young, Goshawks have a pale grey-yellow eye that transitions to orange and then a deep red colour with age.
Adult American Goshawks. Images retrieved from Flickr, taken by Andrey Gulivanov and kblomster respectively.
Now, let's talk about the plumage differences between Accipiters, juvenile edition! Juvenile Coop’s and Sharpies can be a lot harder to differentiate because you can’t rely on the crown colouration, and the tail feathers can be worn or moulting. • Along with tail colouration in some cases, the pattern of the body plumage can be a helpful hint when distinguishing juvenile Coop’s and Sharpies. Juvenile Goshawks are similar to the other two, but generally have more distinct differences than Coops and Sharpies share. Overall, all three species as juveniles look almost identical at a quick glance.
• The amount of white on the tip of a juvenile accipiter’s tail can be helpful for identification but only use this with caution along with other features. Generally, a Coop with fresh tail feathers will have broader white tips on the end of their tail feathers than Sharpies. This feature can differ depending on how much the feathers are worn down (there will appear to be less white on the tip of the tail the more the worn the feathers are) and when viewed from below this feature is very hard to distinguish because juvenile Sharpies have a pale band at the end of their tail that can appear broader when bright sunlight passes through. • From late fall through to spring this feature is not likely to be reliable because the tail feathers are likely too worn out to distinguish a difference. The amount of white on the tip of a Goshawks tail is somewhere in between a Sharpie’s and a Coop’s so it is not very reliable. • However, juvenile Goshawks have a much different banding pattern on the tail. The dark stripes on each feather are shaped more like a “V” than a stripe, so when the tail is spread each dark band looks more like a zigzag pattern, rather than a stripe that you’d see on Coops or Sharpies. This difference isn’t noticeable from below if the tail is not spread, and • all three species might show an irregular banding pattern depending on if the feathers are moulting/growing in.
• The pattern of the breast (chest and belly) can also help to identify juvenile Accipiters. Coops tend to have a paler breast (more white) with very dark brown-black thin streaking. Sharpies tend to have buffier breasts (more blurry creamy coloured) than Coops, and the streaks tend to be paler reddish-brown with a more broad or tear-drop shape that extends further down the belly than Coop’s. Breast colouration as an identification feature should be used with caution because there is a lot of variation in streaking within the two species and some Coops can have broader lighter streaking that extends further down the belly just as common as some Sharpies can have darker, thinner streaking that doesn’t extend as far. Goshawks have dark and defined streaking, like Coops, although it tends to extend much further down the body and can appear as heavy spots on the sides and leg feathers. Juvenile Goshawks also almost always show dark spots or streaking on the undertail coverts, while Coops may show very few, and Sharpies none at all.
• The pattern of the back can sometimes be helpful in identifying between juvenile Accipiters, however the difference between Sharpies and Coops is very small and both species are variable, so it is important to consider this feature with other field marks. Juvenile Coop’s tend to have paler feather edgings or “scaling” on their backs, with white patches being more apparent. Juvenile Sharpies tend to have darker or more rufous coloured edging on their back feathers, and their back seems more uniform overall compared to Coop’s. Juvenile Goshawks tend to have paler backs with edging that is more variable in colour (white, rufous, light brown) than both Sharpies and Coop’s.
Juvenile Sharpie (top left), Coop (top right), and Gos (bottom). Take note of the breast and tail pattern, as well as the amount of white on the tip of the tail. Images retrieved from Flickr, taken by patrick pearce, Kristin "Shoe" Shoemaker, and Rhonda respectively.
• The main takeaway is that all three species look very similar as juveniles so if you are lucky enough to see a juvenile accipiter in good light and with not many obstructions, take good note of its tail, breast, and back pattern. • With juvenile accipiters, overall shape and impression, as well as flight style, may help with a more conclusive ID.
Shape Size and Impression
Shape, size, and impression can be a huge help to identifying very similar looking species, especially accipiters. Plumage details are great to look at when you are lucky enough to have a really good look at a bird, however most of the time accipiters are viewed briefly or details can be obscured by the environment or lighting. In general, it is more helpful to use as many features as you can to identify a bird to come to a more conclusive and accurate ID.
• Overall Size: There is generally quite a significant difference in size between each species of Accipiter found in Ontario. In each species, the female types are generally larger than the male types in both weight and length. There is nearly no overlap in size between each species. Some of the larger female Sharpies could have similar Wing lengths to the smaller male Coops, but the Coops will still have longer tails and larger heads than any Sharpie.
Here is a table of min and max recorded measurements for weight (g), wingspan (mm), and tail length (mm) for each species ranked lowest to highest. The data was taken from The U.S. Geological Survey's North American Bird Banding Program.
Species/ Sex | Male Sharpie | Female Sharpie | Male Coop | Female Coop | Male Goshawk | Female Goshawk |
Tail Length (mm) | 124-142 | 148-165 | 171-205 | 197-235 | 207-260 | 242-299 |
Wingspan (mm) | 160-180 | 188-210 | 215-248 | 244-283 | 302-346 | 336-387 |
Weight (g) | 75-140 | 128-232 | 272-457 | 349-666 | 607-1075 | 734–1301 |
• Size can be a useful feature to consider when dealing with birds in-hand or extremes in the field, however a majority of the time size can be hard to judge in the field, even with experience. There are other comparative features to look for when separating these tricky species by shape:
• Leg Thickness: This ID can be helpful when the bird is perched or otherwise when the legs are visible. Sharpies have very thin, pencil-like legs; this can make Sharpies appear longer legged. Coops have legs that are almost twice as thick as a Sharpie, giving them a shorter-legged appearance. Goshawks have very thick legs, giving them a short-legged appearance. This difference can be tricky for birders with low comparative experience, but the impression of the leg width can be helpful with comparing other ID features.
• Head Shape: Separating accipiter species by head shape can be challenging when perched, however it can be a good feature to look for when differentiating Coops and Sharpies. Cooper’s Hawks have larger heads than Sharpies and tend to have a blockier or squared appearance in profile. Sharpies on the other hand have smaller heads with a more rounded crown. Sharpies also appear to have larger or “buggier” eyes that are placed more centrally on the face whereas Coops appear to have smaller eyes that are pushed further forward, due to their large heads and crowns.
In flight, head size and extension from the body can be a very useful tool in separating accipiter species. When soaring, Sharpies tend to hold their wrists farther forward than the other two species, giving the head a very shrunken appearance that usually does not extend past the wings. Conversely, Coops tend to hold their wings straighter and perpendicular to their body, and their head appears larger extending well past the wings. An important note for Sharpie ID is that when their crop is very full they will stick their head out further in flight, giving the appearance of a larger head. Goshawks tend to hold their wings similar to Sharpies in a glide, so their head doesn’t usually extend past their wings. The important feature to consider in Goshawks when comparing with Sharpies, is that no matter the apparent head size, their wings and tail will always appear evidently larger and broader in flight, almost comparable to larger raptors such as Red-tailed Hawks when soaring. Even in a glide or when soaring, these wing positions can change so this field mark is better used for prolonged and consistent views. Next we’ll get into flight styles that, along with size and shape, can help determine a more conclusive ID for accipiters in flight.
Flight Style
Accipiters generally have a very direct flight path when hunting or on breeding grounds. They do not fly very high above the trees, instead weaving through obstacles or skimming the treetops. Accipiters frequently rely on powered flight (continuous flapping) but they will also take advantage of hot rising air (thermals) to gain lift when searching for prey or migrating. If the lift is sufficient, they may glide or soar for long periods of time without flapping. Incorporating the wingbeat, as well as the shape of the bird when soaring, can be very helpful in identifying these species, even when backlit or distant.
• Wing beat: Generally, smaller birds fly with much quicker wingbeats than larger birds. This is especially noticeable in Sharpies, being the smallest of the accipiters. Sharpies in sustained flight flap with weak, shallow, rapid beats that give the appearance that they are always fighting to stay in the air and that they could be blown away at any moment. Sharpies often appear nervous in flight and have a more erratic wingbeat pattern (not very consistent). Even when flapping aggressively, they don’t seem to move very quickly when migrating, however, they do have the ability to dart very fast when hunting. Coops and Goshawks on the other hand have a much stronger or forceful wingbeat with consistency and no hesitation. Coops tend to have shallow wing beats similar to a Sharpie but their flight style is more deliberate and forceful. Goshawks have a heavier wingbeat and flap much deeper than the Sharpie or the Coop. The flight style of a Goshawk is direct, powerful and effortless; they don’t need to move their wrists as much to gain lift as a Sharpie or Coop does. When flying in strong winds, any raptor can give the impression of an erratic wing beat, so it is best to use this feature in conjunction with others and in context.
• Soaring: When soaring, Sharpies and Goshawks tend to hold their wings in line with their body, and may show a slight dihedral (holding wings at an upward angle) when banking or adjusting. Coops almost always soar on a dihedral. Sharpies are very light and small, so they will rise much quicker in a thermal than the other two species, soaring in tight circles at low altitudes and slightly larger circles at higher altitudes. They are also much more affected by wind speeds and direction than the larger, more sturdy Coops and Goshawks, so they make much sharper adjustments and more unstable movements in flight. Sharpies have short stocky wings with a visible secondary bulge, and tend to bend their wings forward in flight. Sharpies also have a shorter tail with a much thinner base in comparison to the other two species. Coops always tend to soar at a relaxed pace in wider circles, rising more steadily with fewer adjustments, and Goshawks even more so, appearing more like a Buteo (ex: Red-tailed hawk) than other Accipiters. When soaring, Coops have very smooth straight looking wings because they don’t bend their wings forward and they don’t have a pronounced secondary bulge. Their tails are much longer and have a wider base than Sharpies, giving them the impression of a flying cross. Goshawks have incredibly broad wings, with the most pronounced secondary bulge out of the accipiters. They also have very long primaries giving the appearance of long drooping “fingers”. Concerning body shape, Sharpies have a very short and stocky body that seems broader at the chest, sharply tapering to the tail, Coops have relatively slim bodies that are very long and only taper briefly near the tail, and Goshawks have very broad bodies overall.
Adult Sharpie (top left), Coop (top right) and Gos (Bottom) in a soaring flight position. Pictures by Kiah Jasper.
• Gliding: This can be the one of the more challenging flight positions from which to identify accipiters because wing position can change frequently and when birds are gliding they are usually flying very fast in one direction only offering short views. There is more room for confusion when identifying accipiters during a glide. Sharpies generally glide for short periods of time, either very quickly when gaining lift in strong winds near a cliff face or ridge or after they have maintained sufficient lift during migration. Sharpies can appear very small and almost robin-like in a glide or with tucked wings, but they still give a long tailed appearance, and the small head shape is very evident in this position. Coops can be slightly more confusing because they can often give the impression of Sharpies during a glide. Because their wrists are positioned more forward, it can give the impression of a smaller head shape. Sharpies always have shorter and stockier bodies and wings than a Coop, while Coops have a longer primary projection as well as a longer body and tail. Goshawks have the longest primary projection out of the accipiters, and very narrow or tapered, and droopy primary feathers. Goshawks also have the broadest wings out of the accipiters, however the smaller male goshawks have slightly slimmer wings and can most often give the impression of a falcon in a glide, due to the very tapered primary feathers (pointy wings). Since identifying accipiters in a glide can be tricky, we recommend also taking wing beat into consideration; ultimately it is the easiest to identify accipiters in flight while soaring due to prolonged views and consistent flight style.
Juvenile Sharpie (top left), adult Coop (top right) and juv male Gos (Bottom) in a gliding flight position. Pictures by Kiah Jasper.
• Head on or Flying away: If you are observing an accipiter head on or flying away, they are most likely in a gliding position, which is often used when they are darting through the forest, hunting in a city, or migrating along a ridge. It is very tricky to identify accipiters from these angles, but some of the best characteristics to look for is the depth of the chest, wing beat, and the droop of the wings. All accipiters glide with a slight droop to their wings but Goshawks appear to have the most pronounced droop due to their long primary feathers. This characteristic makes Goshawks (especially males) look a lot like Falcons when viewed head on. Sharpies appear to have the least pronounced droop because their wings are short and stocky. Sharpies and Goshawks are very deep chested and show a more pronounced body bulge, while Coops tend to have a wider, more shallow body (remember that if the crop is full the body shape impression will be different). Goshawks and Coops however have a very pronounced and broad back, compared to Sharpies which have narrow backs.
Juv Sharpie (top left), adult Sharpie (top right), , juv Coops (middle), and adult Gos (bottom) in flight. Pictures by Kiah Jasper.
• Now that we have thoroughly explored the identification of the Sharp-shinned Hawk, the Cooper’s Hawk, and the American Goshawk, let’s do some practice! Here is an image of various sized silhouettes of accipiters in flight numbered 1-9. Try to see how many birds you can identify correctly!
Comment your answers if you want :)
Highlight/select the white blanks to discover the answer: 1: American Goshawk, 2: Cooper's Hawk, 3: Cooper's Hawk, 4: Cooper's Hawk, 5: American Goshawk, 6: American Goshawk, 7: Sharp-shinned Hawk, 8: American Goshawk, 9: Sharp-shinned Hawk.