This is the third post in a series about ageing and determining color-type of Swainson’s Hawks, the first post focused on telling age, the second post focused on telling color-type and sex of adults and this post will focus on determining color-type of juveniles.
Unlike adult birds, juvenile Swainson’s Hawks cannot be sexed in the field by plumage characteristics. However, juveniles can easily be separated into particular color-types. in my opinion, there are three main color-types worth knowing when talking about juveniles; these are the light type, light-intermediate type, and dark type. These three types are the ones most commonly encountered (from my experience). There are officially five different color types in total, however.
As I mentioned in earlier posts, lighter birds make up about 90% of the population for Swainson’s. Of that 90%, pure light-types are the most abundant, and what most birders are used to seeing, so I will start with discussing the light type juveniles, but first I should point out a few general juvenile traits. Many juvenile birds show a very light-colored head in their fresh, right-out-of-the-nest plumage, and by late spring and summer later that year, they may be very, very worn-looking and so even lighter heads and duller plumage as they begin to transition into subadult plumage. This should be taken into account, when trying to determine color-type since a bird could become so faded and bleached, that it may, at first glance, resemble a color-type that it is not. Also, remember from my first post, that juveniles birds lack ‘bibs’, lack a very defined black trailing edge to the wing, and lack a wide subterminal band; the subterminal band on juveniles is rarely wider than any other band on the tail. Juvenile birds also have light yellow eyes, whereas adult have darker, almost black eyes. Juvenile birds almost always show feathers on their upper side heavily edged with tawny coloration.
Light type Juvenile:
So, the light-type juvenile Swainson’s Hawk show a very pale, usually almost white head with a few darker markings, especially dark malar marks. Sometimes like in the photo below, they can have slightly browner heads. These malar marks usually run down and form markings around the sides of the throat and then continue down to form weak streaking throughout the belly. The underwing coverts are typically completely unmarked, and just appear white. Sometimes, the underwing coverts will show a very narrow string of small dots extending from the body, outward, about midway through the coverts. The leg feathers are white, with no markings.
Dark type Juvenile:
The second color-type is the dark type. This type is overall a dark grayish-brown or sometimes black. The head is very dark. The breast and belly is heavily marked with dark feathers throughout. The underwing coverts are very heavily marked, but variable from very dark to some with a decent amount of lighter feathers. The upper side is the same color as the underside. The undertail coverts are typically lighter in color than the rest of the body.
Light-intermediate type Juvenile:
The final color-type that is most often encountered on juveniles is the light-intermediate. This type is very, very similar to the light type but shows more markings on the breast and belly, extending farther down. The leg feathers are lightly marked. The upperside of the bird looks almost identical to the upperside of light types.
Those are the three color types that I have encountered most often in the field, however, like I mentioned, there are a few other types the juvenile birds can come in. The other types (intermediate, dark-intermediate, rufous) are just get more and more heavily marked versions until you reach the birds that are considered dark types. If you have any questions about this post, please contact me by leaving a comment or emailing me (firstname.lastname@example.org).
All photos on this post were taken by myself and cannot be used without my permission.