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The Journal of Rfalconcam

Falcon Identification 101 – How to tell Mariah from Kaver

Here’s a popular question that we get asked all the time: “How can you tell which one is Mariah, and which is Kaver?”

The answer is easy– they look different. Just like no two people look exactly alike, no two Peregrines do either. At first glance (or even second and third glance) it might not be easy to see the differences, but we’re here to help with that, so read on!

First, let’s compare Mariah and Kaver side by side:
Mariah and Kaver Comparison

In this picture, Mariah is on the left, and Kaver is on the right. The very first thing you’ll notice is the difference in size between the two Peregrines. Mariah is a much larger bird than Kaver. In fact, in most birds of prey including falcons, hawks, eagles and owls, the female is larger than the male. When one sex is larger than the other, scientists call it sexual dimorphism. Many animals exhibit sexual dimorphism inlcuding humans, but for us it is the males who are generally larger. In raptors, the female is larger. This difference in size even influences what we call male and female falcons. Only the female Peregrine is called a falcon. The male peregrine is called a tiercel. Tiercel comes from the latin word tertius, which means “one-third”, because the male is typically 1/3 smaller than the female.

When Mariah and Kaver are side by side it’s easy to tell who’s who by their size. When they’re alone, it’s a little harder, but not too much. If you can see them on the Falconcam’s high resolution Main Camera, you’ll notice some differences in their features that can help.

After her size, the next thing to notice about Mariah is the white stripe that runs between her eyes, just above the yellow part of her bill. That part is called the cere, and among other things, its where her nostrils are. Most times if you’re looking at Mariah’s face you’ll be able to see the white feathers above her cere. Kaver doesn’t have a stripe above his cere, so that’s a pretty easy way to tell them apart.

Next is the shape of the head. The top of Mariah’s head is a bit flatter than Kaver’s. One of the distinctive features of falcons is their head coloring. Peregrines have a dark “hood” and malar stripes. The malar stripes are the dark patches on their cheeks that resemble sideburns. The combination of dark hood and malar stripes makes it look like the Peregrine is wearing a helmet. Mariah’s malar stripes are longer than Kaver’s.

It’s hard to tell in our picture above, but Kaver’s helmet is darker than Mariah’s. In brighter light Kaver’s helmet looks almost black, while Mariah’s almost always appears slate gray, with white highlights.

Mariah in Flight

If you come to Rochester to watch the falcons, you’ll rarely get close enough to see their faces. Good binoculars or a spotting scope can help, but even if you don’t have those, all hope is not lost. That’s because Mariah and Kaver often look different in flight, and that difference can be used to tell them apart. Mariah, in particular, often flies with the first couple of feathers on her right wing (called “primary” flight feathers) split from the others. The picture above is a good example. Her wings often have a broad, rounded shape, especially when she’s soaring. And since she’s a larger bird, sometimes her size alone is enough to identify her.

Kaver in Flight

In contrast, Kaver’s wings often have a more pointed shape. His smaller size also gives him a sleeker look. When he flaps his wings, his wingbeats are more frequent than Mariah’s, and not as powerful. Believe it or not, it’s pretty easy to pick up on these differences after watching them for a while.

So there you go– Size, facial markings, coloration, wing shape and flight differences are the clues you need to tell Mariah from Kaver. Keep watching the Rochester Falconcam and you’ll be an identification expert in no time.


20 Responses to “Falcon Identification 101 – How to tell Mariah from Kaver”

  1. Robin Says:

    I do not see the picture you refer to. Was it removed, or is there something else I need installed to be able to view the picture?
    Thank you!

  2. Silas (8 yrs old) (London UK) Says:

    Hello – my Gran has introduced me to the wonderful world of Kaver & Mariah. I have read your articles with great interest, as my Gran insists I must learn by observing, and reading as much as I can about the subjects/s. Thank you so much.

    My Gran has approved of my message!!!!

  3. Jess Says:

    @Silas– Your Gran is pretty smart, Silas! Observation is one of the very best ways to learn new things. That’s how I learned almost everything I know about Peregrine falcons!

  4. Audrey (London UK) Says:

    Jess: Thank you for your reply to my Grandson, I will make sure he sees it tomorrow (Tuesday). Methinks he is going to drive me mad, in the nicest possible way!!

  5. California Sharon Says:

    Jess, what a great resource you are providing to the online falcon community! This “how do you tell them apart” description will be extremely helpful to newbies. I even learned something today–what a “cere” is! Thank you for your posts!

  6. Jess in NC Says:


    Thank you so much! I’ve been reading/watching for years and that really made it obvious.

    Thanks you to the whole team for making this year’s cam even more amazing than ever!
    Jess in NC

  7. Mrs. Place and the third grade Says:

    Thank you for providing another year of great falcon watching. This is the 5th year I have been watching the falcons with my 3rd graders. They are already hooked on checking the cam from home and announced to me this morning that an egg had been laid. We will read the postings and information provided. What a great resource this is for everyone to enjoy.

    Betsy Place

  8. Carol Says:

    This is great this year can’t wait for all the exciting watches to happen. Love hearing from all over Kudos to // Jess thanks Glad someone took this over

  9. Pick Says:

    I’m probably not the first to notice, but Camera 2 at 11:30 PM on Wed. night shows Mariah on two eggs! Way to Go Mariah!

  10. Makinley Ingram Says:

    How do you know it is Kaver and Mariah? How did you put the camras up in the sky skraper? Mariah and Kaver are good parents. THANK YOU FOR EVERYTHING

  11. AJ Says:

    Well, I was feeling good for Kaver this year. Thought he wouldn’t have such a hard time covering the eggs. Poor Mariah, she must be tired of laying and sitting already. How boring for her.

  12. kalea Says:

    oh how glad i am to find you. quite a brood brewing !! this is wonderful. i am here many many times a day…i even watched as mariah delivered egg number two!….and now there’s five……thi isgreat.

  13. egon firl Says:


    please explain the stones in the nest every yr.it hard to sit on the eggs
    now stones tooooooooooo

  14. charlene Says:

    Thank you for taking the time out to explain all to everyone. I am so glad that the falcon cam is still a part of Rochester. There are so many people who love our Falcons her and world wide.
    Keep up the good work.

  15. Kindergarten teacher Says:

    Thank you so much for bringing our falcons back again! We were so disappointed when we thought the website would not return. Watching Mariah and Kaver has become one of the highlights of kindergarten at our school each year. The new site is fantastic – very informative! Keep up the great work! It is VERY much appreciated!

  16. Rose DeNeve Says:

    Kaver and Mariah’s offspring are always referred to as eyasses. I’ve never seen an explanation of this term on the site. I have always understood an eyas to be a young bird being trained in falconry. My dictionary gives this definition, too. Now I’m confused. Has the term taken on an expanded meaning?

  17. Tia Van Camp Says:

    I grew up and lived in Rochester NY for 27 years. My sister-in-law introduced me to this website. I “love” watching Mariah and Kaver and their offspring. Thank you so much for the opportunity to view the birds, and also see the sky over Rochester. Thank you too, for all the knowledge that you share, helping me with my fascination with birds, especially falcons. Now I know that the male peregrine is called a Tiercel!

  18. Michael Says:

    Thanks for the webcam. My friends and I have been enjoying it for the last couple of years. We were curious if the identification points you gave are the same for all Peregrine Falcons (minus the spread primaries for Mariah in flight). Thank you again for this wonderful experience.


  19. Robert Clark Says:

    I’m a member of ‘Friends of Brockley & Ladywell Cemeteries’ Lewisham, London. These are twinned cemeteries in South London with a ‘nature reserve’ title added even though the cemeteries still operate for burials.

    A pair of ‘hawks’ have taken up residence of late amongst the limes and tall poplars; being parent and young as far as I can make out. There is quiet a bit of high pitched ‘monosyllabic screeching’ between the two with a raise of tone at the end of the call. Most times the hawks are out of sight high in the wavering trees gusted by present windy conditions.

    Today the parent was more evident to closer scrutiny as ‘she’ wheeled lower seeming ‘on the chase’ through the cemetery groves with the younger remained sat tight high up continuing to call. At times I saw them float above the trees as a pair. Then; I was able to obtain a closer view as the parent hawk glided down and out of sight close to me. I crept up and had the pleasure of noting the hawk dabbling in a largish puddle.

    While in flight the hawks seemed generally grey, sleek in flight with slim rounded wings and with a fan of a tail that was not over-pronounced I was able to note the detail of faun, almost pinkish hue, of the hawk’s breast feathers as she waded in the puddle. She was, therefore, not a Peregrine, neither was she a kestrel of which I am very familiar. This bird was larger than a kestrel.

    I would be grateful if you might lead me toward identifying this hawk.

    Thank you,
    Bob Clark

  20. Terry Leary Says:

    yesterday someone brought me a baby, 6 months old, falcon. It is very sweet but I want to release it. There are no other falcons in this country, I live in Nicaragua, I hear this bird came from Honduras. What do you think can the bird survive in the wild, it’s wings are not clipped but he has always lived in captivity. Best, Terry

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