Terms and Definitions:

Peregrine falcon:  Falco peregrinus  One of the species of falcons

Diurnal raptor:  Diurnal raptors are birds of prey, with sharp talons and hooked beaks for grasping and tearing prey.

Falcon:  A species from the family Falconidae. This term is also used for female falcons.

Tiercel:  Male falcons.

Eyas (eyass):  The young of the peregrine falcon.

Eyrie (aerie):  The nest site.

Scrape:  The ‘nest’.  Peregrines do not construct nests but will scrape in dirt or gravel on a natural or man-made structure.  They will also use abandoned nests of other species such as ravens without improving them.

Copulation/Mating:  The female leans forward and moves her tail to one side.  The male lands on her back, resting his tarsi on her back, flapping his wings, and presses his tail underneath the female’s.  Copulations are often accompanied by wailing, e-chupping and chittering.

Caching:  Storing food for later retrieval.

Casting/Pellet:  A piece of indigestible material coughed up by mouth.

Courtship Display:  A series of behaviors to attract a mate and affirm the pair bond. These behaviors include aerial displays, head bows, scraping, and beaking.

Clutch:  The eggs.

Incubation:  Brooding of eggs.  Partial incubation can start with the laying of the first egg and consists of laying on the eggs for minutes or hours.  Hard (constant) incubation usually starts with the next-to-last egg and is a constant brooding, either by the falcon or by the tiercel.  Incubation in California usually starts in mid March (later at higher elevations or in northern locations).

Lethargy:  Just before and during the period of egg laying, the female may become lethargic.  She might spend considerable time in the nest by herself.  After an egg is laid, she may have more active periods.

Tarsus:  The heel/ankle of the bird

Band/ring:  A metal or plastic band that attaches to a bird’s leg. Each metal band has a unique series of numbers that can be used to determine where a bird was banded. Some bands are more than one color. If you find a bird band, you can report it here!

VID (Visual Identification) band/Color band:  These bands usually have 2 or 3 characters (numbers or letters) that are meant to be read at a distance by binocular or scope. VID bands are often one or more colors and can be used to much more easily identify birds.

Hacking/Hack Site:  “Hack” is an old English word for a type of wagon used to carry falcons to a hilltop release site.  During the breeding and re-introduction period in the 1970’s and 80’s, breeders adopted the hacking technique of falconers so that falcons and other raptors could become independent once released into the wild.  Young fledglings  are put into a hack box before they are able to fly and are fed through hole in the back or top of the hack box so they don’t become dependent on humans to feed them.  When the front of the box is opened, the young falcons will fly when ready.  They do not need to be encouraged to fly by their parents or taught to hunt.  This is something they learn on their own.

Adult:  A bird past its first molt.

Molt:  The loss of feathers.  Peregrine feathers are lost in a specific order during molt.  Molt occurs during and after the breeding period in the spring and summer.  Feathers can be lost to injury or disease at other times.

Yearling:  Yearling peregrines can appear to be blond rather than brown or grey, with ‘bleached’ looking worn feathers.

Floater:  A non-breeding adult.  Floaters may be looking for breeding territories and may stay in or around a breeding territory.  Floaters are frequently driven off, sometimes gently escorted away by a breeding adult.

Streaks/bars:  The fledgling has vertical streaking (dark markings) on the belly and breast.  The adult has horizontal barring on the belly.  The breast can be white or buffy with some dark barring.

Subspecies: There are at least 19 distinct subspecies of Peregrine Falcons. Subspecies can vary in size, coloration, and habitat. There are three subspecies we usually see on the west coast (two in migration, one resident).

Anatum:  Our local subspecies. They are characterized by a white or buffy breast.

Tundrius/Tundra:  Subspecies that breeds in the arctic in Alaska and Canada. They are characterized by a white breast and pale coloring.

Peales/Pealei: The largest Peregrine subspecies. It is characterized by an overall dark coloration, including on the breast. Occurs as a breeder in the northwest from the Aleutian chain to coastal British Columbia.