Peregrine Falcon Watch
Spring 2003

Falcon Facts


What we already know ~

Questions we have ~

  • Peregrine Falcons are Raptors
  • They are the fastest birds
  • They were endangered
  • They return to the same nest every year
  • They are related to hawks
  • When mom leaves the nest, dad will sit on the eggs
  • They have pointed wings and curved beaks
  • Their eyes are black
  • They don't have webbed feet
  • They have very sharp toenails
  • They hunt for food
  • They use their talons to catch food
  • They eat meat
  • When were falcons discovered and who discovered them?
  • Why are they called raptors?   
  • Why are they endangered? 
  • Are they nocturnal?    
  • Where do they nest? 
  • How many eggs does a female lay? 
  • What color are the eggs?  Are they speckled or have any other markings?  Are they large or small? 
  • Does the male leave and find another mate after the eggs are laid? 
  • How long does it take for the eggs to hatch? 
  • Once the babies are born, does the mother take care of them?    
  • How long do the babies stay in the nest? 
  • What are the babies called? 
  • How high can falcons fly?
  • Do the fly/nest in flocks?
  • What do they eat in the winter?
  • How fast do they go at top speed? 
  • How long do they live? 
  • Are they a state bird for any state?
  • Do the eggs hatch in a certain order ... last one laid / first to hatch?
  • Is there a pattern to the number of eggs a female lays - same number every year?
  • Does the female sit on the eggs when it is colder and the male when it is warmer outside?
  • Do Peregrine Falcons have a natural predator, other than man? 

   What we have learned ~

General Characteristics:
  • Scientific Name comes from the Latin word, "Falco Peregrinus" which means wandering falcon, traveler, or foreigner.
  • There are 39 species of falcon - the Peregrine is one of five commonly found in Canada.
  • There are 3 subspecies of Peregrines ~ American, Artic and Peale's.
  • 5 types of falcons live in the U.S. ~ gyrfalcon, peregrine, merlin, American kestrel, and prairie falcon
  • Peregrines are the most well known of the falcons.
  • Peregrines adapt to their environment and live on every continent except Antarctica.
  • They can live in the mountains, deserts, forests, on sea cliffs, in cities and large urban areas.
  • They vary in size depending on where they live ~ the biggest are in Alaska.
  • Some like to migrate south to Latin America in the winter.  They can migrate as far as 10,000 miles ~ farther than other birds. 
  • Peregrines can live up to 17 years.
  • They are raptors (Latin meaning "to seize") - birds of prey / carnivores - and eat other birds ~ sparrows, starlings, gulls, ducks, and their favorite, pigeons.  In fact, during WWII they were often shot in England to keep them from eating the pigeons that were carrying important messages to the forces.
  • Falcons are the swiftest birds of prey and are very muscular. In level flight the travel about 50 kilometers (31 miles) an hour.  In a dive, called a "stoop" they reach speeds over 300 kilometers (186.33 miles) an hour!
  • They have a unique way of hunting for food ~ they dive at their prey so fast that they overtake it by surprise, catching it in mid-air, and the speed kills the prey instantly.  They are diurnal - they hunt during the day.  The capture takes less than 2 minutes! 
  • An adult eats about 70 grams (2 1/4 oz.) of food a day ~ that equals about 2 blackbirds.
  • In the city it has been observed that falcons don't like to land on the ground ~ even if their meal falls to the ground, they won't go get it.  In fact, they don't usually fly lower than the level of their nest.
  • They are at the top of the food chain, so adult peregrines have no natural predators.  They do however, face many threats from humans ~ use of pesticides, altering of landscape and habitats, egg collecting, hunting, and taking of the young for falconry.  Baby falcons (eyases) are a tasty meal for owls, racoons, and mountail cats.  
  • They have very good eye sight ~ they can spot a meal up to a mile away.
  • Their wings are thin and pointed, and span about 40 inches.
  • The female is called a falcon, the male is called a tiercel.
  • Slim birds with a small head.  The male is about 1/3 the size of the female.  Their bodies average 15 - 21 inches long and weigh about 2 pounds.  The female will weigh about 10.6 ounces more than the male.
  • Adult Peregrines have blue-gray wings, backs, and heads, with white undersides marked with black bars going across the chest.  There faces are white under their chin.  They have large, dark eyes and very sharp beaks and yellow talons (feet).
  • Peregrines make a "kek-kek-kek" noise, especially when angry or aggressive.


  • Use of the pesticide DDT (Dichloro-Diphenyl-Tricholor-Ethane) was the primary cause for the Peregrine population to begin to decline and be placed on the endangered list in the early 1970s depending on the state.  Peregrines ate birds that had eaten seeds that had been soaked in the pesticide.  This caused the Peregrine to stop laying eggs, or lay eggs with very this shells.  When the birds tried to incubated the eggs, the shells were so thin they broke.  Pesticide residues become more concentrated as they work their way up the food chain (called "bioaccumulation") and can stay in the environment for years.
  • When DDT was banned from use in the US the Peregrine Falcon's population began to rise again.  The use of pesticides is controlled in Canada and the U.S., but not in Latin America where some of the birds go for the winter.
  • In Canada and the U.S. it is illegal to kill or disturb Peregrine Falcons in their nests.
  • Peregrine Falcons were removed from the federal endangered species list in August of 1999, however the falcon population is being closely monitored by state wildlife departments especially in Ohio and California.
  • Several agencies bred peregrines in captivity and release the young by "hacking".  Birds that are about a month old are placed in a hack box that has been placed on a cliff or ledge of a building.  Food is fed to them through a tube so they do not see the human.  Once they can fly and hunt on their own (several weeks later), the box is left open for them to leave.

Nesting / Eggs / Hatching:

  • Peregrines are ready to start a family when they are about 2 years old.
  • They mate for life and return to the same nesting site every year.
  • Their range is about 30 miles with their nest in the center of their range.  They do not like other falcons within 3 miles of their nest site.
  • Their favorite spot for a nest is on the edge of a cliff.  They are known to substituted tall sky scrapers in downtown urban areas for cliffs as well.  Their nesting ledge is called an "aerie".
  • They don't use a lot of nesting material.  Peregrines prepare a saucer shaped indentation in lose soil, sand, or grass called "scrape".
  • The tiercel (male) arrives at the nesting site and begins a lot of fancy aerial displays to attract his mate in early Spring.  Sometimes the male will select several locations for a nest and the female makes the final decision.  The female is the boss of the house, and the male is cautious around her.
  • 3 to 5 eggs (with an average of 4) are laid at 2-3 day intervals.  The group of eggs are called a "clutch".
  • Eggs can range in color from a soft pink to reddish-brown, sometimes with little speckles, bigger than a chicken and about the size of a duck egg.
  • The male and female share the responsibility of sitting on (incubating) the eggs.  The eggs need to stay at a constant warm temperature and dry, or the embryo will not survive.  If the air temperature is warm, the parents will leave the eggs briefly to hunt.
  • The eggs also need to be turned, which we've observed occurs as the birds shift around on the nest.  There are times that it looks like the birds are actually rolling the eggs with their mouth or feet (see picture page and observation log).
  • Eggs are incubated for 33 days.
  • "Pipping" the shell is when the "eyases" (babies) begin to hatch out.  They do this from the inside with an "egg tooth" (a tiny sharp point) on the end of their beak.  The egg tooth disappears almost immediately.  This process can take up to 2 days!


  • Eyases weigh 1 1/2 ounce when first hatched.
  • Newly hatched, they are wet and covered with a white fuzz called "down".  By 3 - 5 weeks the fuzz has been replaced by brown feathers. 
  • Males develop faster than females, females are larger and more powerful when fully grown.
  • In 3 weeks they are 10 times their birth weight; in 6 weeks they are full grown; and at 9-12 weeks they begin to hunt and care for themselves.
  • Their first prey is small game ~ dragonflies and butterflies.
  • The first few days of learning to fly is dangerous to the young falcons, especially in urban areas.  Wind changes can slam the birds into the ground and mirrored or illuminated windows are another hazard. Unfortunately statistics are not on their side, only one out of two manage to survive the first year.


Site Map
Introduction to Project

APK Falcon Cam
APK Falcon Forums
Falcon Facts
Observation Log Pages
1, 2, 3, 4, 5, 6, 7, 8, 9 ...
Weather Log
Pictures 1, 2
Baby Album 1, 2, 3, 4 ...
Meet The RH Nest Monitor Team
Our Related Activities:
Fertile Egg Dissection
Sky Hunters Fundraiser
       Our Visit
2, 3, 4
Frightful's Mountain
Student Research Projects
Reflections Index


Links & Resources

Sign our Guest Book 

View our Guest Log   

Class Home Page 


2003 by Lynne Harvey
Rolling Hills Elementary
Poway Unified School District
San Diego, CA.

You are visitor    since March 26, 2003