Monday, March 1, 2010

Telling the difference between Mom and Dad

As we watch the increasingly busy activity at the nest, perhaps the most frequent questions are, "Is that Mom?", "Is that Dad?", and "Which is which?"

John Blakeman, our Ohio expert on all things hawk, encouraged us last year to use the correct terminology for the hawks. John is a licensed Master Falconer, a former federal bander of raptors, and also an advisor to Marie Winn and others in New York regarding Pale Male and his nesting exploits there.

John told us, "The male, the father, is the 'tiercel,' pronounced 'TEAR-cel.' He's a bit smaller than his mate. A female hawk is properly called a 'formel.' The parents - the tiercel and the formel - as full adults are properly said to be 'haggards.' In the case of hawks, a haggard is not a scruffy, raggedy old individual. Quite the opposite. A haggard hawk is a full adult, thereby possessing all the knowledge and experiences needed to survive. The 'babies' are neither 'chicks' nor 'babies.' Chicks are little chickens, and these birds are NOT chickens. The proper name for a hatchling hawk is an 'eyass,' pronounced EYE-ess."

So, now that we know how to name them, how do we tell them apart? Kay and I were down at the nest early Saturday and Sundays morning this weekend, and these pictures clearly show the difference in feather color and markings.

The tiercel/dad has a much lighter beak and chin area.

Right under his beak is a white bib that runs into his lovely cream chest, which has just a few scattered spots, almost like a delicate necklace.

The formel/mom, on the other hand, has a much darker bib under her beak - dark chocolate brown in color.

The spots on the formel's chest are more pronounced, almost in lines, and start much higher up.

When you see both birds together, the differences in their coloring are quite obvious. The problem right now is that they rarely turn their faces to the camera, so we don't often see their beak area.

In full flight, the pale coloring and delicate chest speckles of the tiercel are very clear.

Both hawks are now busy bringing materials to line the bowl of the nest. We discovered that some of the pine greenery is coming from a tree
behind the Franklin Institute, when we caught a glimpse of the tiercel caught in the act of pulling off a twig!

The tiercel also flew in with what looked like a pile of leaves from a gutter! Note his cool reflection in the window.

After all the nest activity, both hawks flew off to nearby trees. We saw the formel swoop for a mouse alongside the Vine Street exit ramp.She took her snack atop one of their favorite perching spots - the python-neck lamp posts that are so prevalent in the down-town area of Philadelphia.

The hawks are almost always in sight of their nest at the Franklin Institute. They sited it very effectively when they chose that top floor corner window ledge. In this picture, the hawks' window is the sixth window on the top floor counting to the right from the pillared portico of the Franklin Institute. You can see the tiercel perched on the lamp pole.

Surrounding our hawks are the skyscrapers of downtown Philadelphia. It is magical to watch how beautifully they have adapted to their urban terrain, choosing once more to build their nest here, and hopefully raise their young again, to our great delight!


  1. Fabulous Della- hope everyone who keeps asking the same questions sees the link to this blog- you and Kay are doing such a great job explaining everything to us, with John's help- fascinating.

    Gosh, if I am spending so much time watching an empty nest, what will the spring and summer be like!


  2. Brilliant, so helpful, thank you both...

  3. I think this needs to become a book!

  4. perfect timing you two. Re set my vocabulary and f/t ID IQ.
    can better inform others now. blog first,

  5. Fabulous! Thanks so much for these updates!