Distinguishing between juvenile light morph harlani and kriderii can be difficult. The two are extremely similar, being overall quite pale with high contrast markings. They also interbreed, causing individuals that are intermediate in plumage.

As with any bird identification, it is best not to not focus on one trait alone. Instead, it is better to make a holistic assessment of plumage characters and come to a well-reasoned and conservative assessment. Below is an outline of plumage features to aid in distinguishing the two that together with the plate above should provide a helpful guide. 

Tail pattern

The upperside of the tail is very helpful trait for differentiating the two juvenal plumages. Although both tend to be lighter in their base color and quite high contrast, kriderii generally average much thinner in their tail bands and many decrease in markings towards the base of the tail. This contrasts with the often irregular and thicker bands on harlani tails that are on average against a darker base color. 

Uppertail coverts

Much like adult kriderii, juveniles can have limited to no markings in their upper tail coverts, enhancing the pale tail base appearance. In contrast, harlani tend to have white uppertail coverts with relative thick bands that contrast with the somewhat darker tail coloration. In general, this creates  prominent uppertail coverts instead of the seemingly hidden or blended uppertail coverts in kriderii. 

Wings

Like tail markings, kriderii have secondary and primary banding that is relatively thin and less distinct. The primary panels on kriderii are also quite pale, and the banding in the inner primaries is a unique thin web-like pattern. Unlike most harlani that have noticeable banding to the tip of the outer primaries, most kriderii have darker outer primaries where the banding to the tip is not as distinct. Together with a very limited and sparse patagium, largely unmarked underwing and unmarked greater underwing coverts, the entire underwing of kriderii averages much paler than harlani. 

Head pattern

The main difference in head pattern between these taxa is the organization of markings. On average, harlani is much more heavily marked in the head but more importantly the markings are spread throughout the head and nape causing a messier appearance. Contrastingly, kriderii generally have more organized markings restricted to particular patches on the head including a prominent dark posterior eyeline, limited crown markings, variable amounts of markings on the nape, and variable amounts of markings on the malar. 

Bellyband

While the bellyband averages sparse and less marked on kriderii, there is considerable variation in this trait. Because of overlap between the two taxa, reliance on this trait alone can be misleading.

Below are examples of these features in a selection of photos from the Macaulay Library. Each photo is numbered corresponding to the links listed below, from which the eBird checklist housing other photos of each link can be accessed.

harlani

Underside

1. https://macaulaylibrary.org/asset/520147291

2. https://macaulaylibrary.org/asset/24203713

3. https://macaulaylibrary.org/asset/109270341

4. https://macaulaylibrary.org/asset/386042981

5. https://macaulaylibrary.org/asset/616692248

Topside

1. https://macaulaylibrary.org/asset/408065021

2. https://macaulaylibrary.org/asset/194793571

3. https://macaulaylibrary.org/asset/613774344

4. https://macaulaylibrary.org/asset/536978231

5. https://macaulaylibrary.org/asset/631370651

6. https://macaulaylibrary.org/asset/610842959

kriderii

Underside

1. https://macaulaylibrary.org/asset/398433951

2. https://macaulaylibrary.org/asset/321975961

3. https://macaulaylibrary.org/asset/311507201

4. https://macaulaylibrary.org/asset/398688251

5. https://macaulaylibrary.org/asset/624394052

6. https://macaulaylibrary.org/asset/629764870

Topside 

1. https://macaulaylibrary.org/asset/610679464

2. https://macaulaylibrary.org/asset/297803081

3. https://macaulaylibrary.org/asset/76574721

4. https://macaulaylibrary.org/asset/629874406

5. https://macaulaylibrary.org/asset/181737021

We recently wrapped up a very successful field trip deploying 19 new GPS transmitters for the project. This time we set our sights on the Mississippi River Valley region, hoping to fill gaps in our knowledge of abieticola breeding in the central Boreal forest region. Here, we also sought to expand our distribution of winter sampling and learn more about this fascinating region!

Starting in Tennessee, we explored parts of Mississippi, Louisiana, Arkansas, Missouri and Illinois in search of Red-tailed Hawks with heavy bellybands and markings suggesting that they are of migrant, northern origins. We captured a fabulous variety light morph birds, and even a couple of dark morphs! Additionally, we were lucky to find and deploy transmitters on a few awesome birds displaying harlani traits, and one lovely kriderii individual.

To see all of the places we went and all of the birds (even non-hawks!) that we found, you can check out our eBird Trip Report here.

As we watch these birds embark on their northbound journeys, we’re always excitedly speculating where we think these birds might go to breed. This year, we’d like to invite everyone to join us in this exciting guessing game! Click the link here to make your guesses on where you think each of these birds might go this summer.

Stay tuned for the answers and updates on these birds later this year!

A 19-year-old recaptured Red-tailed Hawk has been fitted with a GPS transmitter by The Red-tailed Hawk Project, creating an exceptional opportunity to track the movements of a long-surviving individual!

Meet ‘Maxine”, originally banded as a juvenile on September 25, 2007 by volunteers at the HawkWatch International Chelan Ridge raptor migration site in Washington state. Red-tailed Hawk Project Researcher Neil Paprocki captured Maxine in central Washington and outfitted her with a GPS transmitter on March 6, 2026 — making her nearly 19 years old! If you are wondering, the longevity record for Red-tailed Hawk according to the USGS Bird Banding Lab is 30 years and 8 months. Maxine has another 10+ years to go if she hopes to break that record!

Thanks to detailed records kept by HawkWatch International biologists, we have a unique opportunity to compare Maxine’s morphology between 2007 and 2026. She has always been a larger bird, weighing 1,399 grams and 1,483 grams in 2007 and 2026, respectively (around 3 pounds). Like many other Buteos, her tail was significantly longer and wings shorter as a juvenile. Longer tails and shorter wings in juvenile Buteos likely function to increase control and maneuverability as young birds learn to fly.

We rarely get the chance to track the movements of known aged individuals this old because it is difficult to age unmarked birds at capture past ~4 years of age and tracking devices placed on younger birds may only last until the birds are 5-years old (or up to 10 years in rare cases). We are excited for this a golden opportunity to learn about the ecology of a Red-tailed Hawk in her golden years!

Thanks to project collaborators HawkWatch International for originally banding Maxine and Kidd Biological, Inc. for sponsoring this transmitter!

Our transmitter efforts in 2025 focused primarily on expanding our knowledge of movement and plumage variation among Red-tailed Hawks in western North America. Our sampling predominately occurred during winter throughout the desert southwest of California, Arizona, and New Mexico and resulted in breeding origins from British Columbia, Washington, Oregon, Idaho, Montana, Wyoming, and a few resident (non-migratory) southwestern individuals. Desert southwest winter captures are numbered 5–20 in the above map. We also sampled wintering individuals from the Pacific Northwest (numbered 1–4 in the above map) resulting in two more harlani from Alaska and two non-harlani from British Columbia.

Genomic work is still pending, but we are particularly excited about our sampling of breeding locations from British Columbia where the breeding ranges of at least four subspecies meet: harlani, alascensis, calurus, and abieticola. British Columbia certainly represents an exciting frontier of genomic and plumage discovery, and we look forward to sharing future updates with everyone!

Thanks to the Holdfast Collective, Kidd Biological, Inc., Cornell Lab of Ornithology, and University of Idaho for supporting our transmitter efforts in 2025.

We are excited to share a new research article now published in Movement Ecology! In this paper we investigate how atmospheric conditions influenced the timing of water crossing for Red-tailed Hawks at the Straits of Mackinac in Michigan during spring migration. Specifically, we investigated the availability of over-water uplift and its effect on crossing behavior, which has only previously been assessed in the Eastern hemisphere during autumn migration. We also looked at the effects of wind speed, wind support and Julian day on the probability of crossing.

We found that over-water uplift was available in spring and that it positively affected the probability of crossing, and that low wind speeds and wind support increased the probability of crossing. Julian day was also an important predictor as hawks were more likely to cross earlier in the spring. We also saw that there was substantial variation in crossing behavior among individuals despite the general effects of over-water uplift and wind.

This paper is the first to highlight that over-water uplift is available to soaring migrants at a water barrier in the Western Hemisphere during spring migration. We also show that like other soaring raptors, low winds and wind support are important predictors influencing the decision to cross open water. Overall, we found that Red-tailed Hawks are flexible and can use varying conditions to cross open water. Our findings add to the growing body of research on how soaring raptors overcome water barriers during migration.

This work was a collaborative effort between the Mackinac Straits Raptor Watch, Michigan State University and the Cornell Lab of Ornithology.

You can download a PDF of the full open-access paper via this link: https://rdcu.be/eIXXH

We are excited to announce the publication of a new research article for an upcoming movement ecology issue in the Journal of Raptor Research. In this paper, we detail the migratory behavior and plumage variation of GPS-tracked adult Red-tailed Hawks (Buteo jamaicensis) that summered in Alaska, USA.

We found significant levels of migratory connectivity among Alaska’s Red-tailed Hawks. Individuals that spent the breeding season in northern Alaska were more likely to migrate longer distances to overwintering locations in the Great Plains, USA, while individuals that spent the breeding season in southern Alaska were more likely to migrate shorter distances to overwintering locations in southwestern Canada and the western USA. We also noted significant differences in migratory routing between the two regions.

In addition, the standardized photographs for the 22 adults in this study strengthen our understanding of the plumage diversity present in Alaska. While we mostly tracked individuals with predominately B. j. harlani phenotypes, we also sampled several individuals that did not match the typical description of B. j. harlani and may represent gene flow from neighboring subspecies.

This paper was a collaborative effort among the University of Idaho, Cornell Lab of Ornithology, Michigan State University, University of Kansas, HawkWatch International, and the U.S. Fish and Wildlife Service. You can download a PDF of the full paper here: https://rapt.kglmeridian.com/view/journals/rapt/aop/article-10.3356-jrr2513/article-10.3356-jrr2513.xml

Also, be sure to check out our new publications page for links to our published research!

We’ve just completed a new plate that details harlani identification. This is the first plate of many that we hope to make available for how to distinguish between all subspecies. You can download a high resolution version of this plate by clicking on the image below. Stay tuned for more!

We are extremely excited to share that the Spring 2025 issue of the Cornell Lab of Ornithology’s Living Bird Magazine dons a spectacular photo of an adult Harlan’s Red-tailed Hawk (Buteo jamaicensis harlani) taken by Brian Sullivan, and includes a feature article focused on the work of the Red-tailed Hawk Project, written by the talented Scott Weidensaul!

The article is full of great images that bring much of the concepts that are the focus of our work to life. It’s well worth a read for those that know little about the species, and for those that know a lot and might enjoy considering all of the topics Scott discusses.

Be sure to read the article, and if aren’t already, become a member of the Cornell Lab and subscribe to Living Bird!

We’ve posted a new subspecies account for B. j. fuertesi, led by Brian Sullivan! – https://redtailedhawkproject.org/buteo-jamaicensis-fuertesi/

We continue to work on subspecies overviews for all described Red-tailed Hawk subspecies, so keep checking back for information on your favorite subspecies including the identification, taxonomic history, distribution, status, and our assessment of the current knowledge on the taxon. 

Since we plan to treat these accounts in a version type format where we conduct an annual review and update each account accordingly, we hope that these will represent the most up to date and correct information for understanding diversity within the Red-tailed Hawk (see this example of the type of information that might justify a revision – https://redtailedhawkproject.org/2024/09/12/published-in-the-journal-of-biogeography-a-revision-to-the-distribution-of-plumage-polymorphism-in-the-red-tailed-hawk-buteo-jamaicensis/).