Objectives for Ornithology
First Field Trip
1. What are the rules of birding etiquette?
2. What methods can you use to identify a bird which you've never seen
3. How (and why) do you document a rare encounter?
1. Who was Roger Tory Peterson?
1. How many species of birds are there in the world? Nesting in North
America? In Pennsylvania? How many species have been recorded from PA?
What is the most common nesting species in North America?
2. What characters do all birds share? What character is unique to
How and Why Birds are Studied
1. Some terms or people to be familiar with:
John James Audubon
American Ornithological Union American Birding
2. Give a variety of reasons why birds are worth studying. Why should
we care about birds?
3. The American Museum of Natural History has the largest collection
of bird skins in North America, numbering over 900,000 specimens. If you
divide that number by the total number of bird species in the world, that
means that there are, on average, about 100 specimens of each species.
And there are several more million skins in other research museums. Why?
Why is it important to have large numbers of specimens?
4. By the end of the semester, be sure that you have looked at several
ornithological periodicals like The Auk, American Birds,
and The Wilson Bulletin. Dr. Skinner subscribes to all of these
and can show you examples.
Origin, Evolution and Speciation
lumpers and splitters
1. Why are bird fossils relatively scarce?
2. What group are birds descended (evolved) from? Approximately how
long ago did birds make their first appearance on earth?
3. What is the significance of the fossil species, Archaeopteryx
lithographica? In 1986, fossils were found which were given the name
What is the significance of this find?
4. Describe briefly how bird species develop. Darwin's finches make
a good example, although there are others.
5. All creatures have a common name and a scientific name.
Why are scientific names given in two or three parts, and in Latin? For
example, why are robins which breed in PA known officially as Turdus
6. Give the classification of any species of bird of your choice (except
for the robin), beginning with the level of Kingdom and progressing to
the species level.
7. How many families of birds are there in the world? What ending do
all scientific names of bird families share?
8. Some terms to know:
Feathers and Flight
wing loading aspect ratio
4. Discuss how and why certain species are adapted for certain types of
flight, e.g. gliding and soaring vs. powerful sustained flight.
1. What functions does flight serve?
2. What are the adaptations birds have made which allow them to fly?
These can be grouped into weight-saving and power-promoting categories.
3. Be familiar with the basic physics of flight. This would include:
5. What adaptations would you expect flightless birds to have compared
to flying species?
6. Some terms to know:
camouflage by disruptive pattern camouflage
by countershading sexual dimorphism
7. Be able to discuss the structure of a feather (rachis, barb,
and the structure and function of the various types of feathers (down,
8. Besides flight, what other functions do feathers have?
9. Be able to identify the major feather regions of a wing (primaries,
10. Have a general understanding of feather tracts, or pterylae.
11. Why do birds molt their feathers?
12. Be able to discuss the basic stages of molt (basic plumage,
alternate plumage, eclipse, etc.).
13. Be able to discuss the pigment and structural color.
14. What is the significance of the different shapes of wings?
Food, Feeding Habits, and Digestion
1. To say that someone "eats like a bird" is a misconception. In reality,
they eat at a much greater rate than you do. Why do birds eat so much (or
2. Why are most birds meat-eaters (carnivores) rather than plant-eaters
(herbivores)? Why are seed eaters an exception to this generalization?
3. What special adaptations does a bird's digestive system have compared
to yours? Be sure you can discuss structures they possess that you do not
4. Terms to be familiar with: insectivore
omnivore piscivore granivore
5. How might several species of birds that feed in the same habitat
divide up the available food resources? (The example I gave in class dealt
with shorebirds feeding on the beach.)
6. Some birds have the problem of getting rid of large amounts of salt.
How do these birds gain this extra salt? How do they get rid of it?
7. Explain the differences that exist between your urinary system and
a bird's (e.g., why is their excreta semisolid and mostly white, while
yours is partly yellow liquid and partly brown and smelly?)
8. Discuss adaptations of bills and feet for different feeding techniques.
binocular vs. monocular vision nictitating
membrane rods and cones
14. If a sound is at 15,000 cycles per second (cps), what does this mean?
1. What are the major functions of a bird's skeleton?
2. What important differences are there between a bird's skeleton and
yours? (Most of these are adaptations allowing a bird to fly).
3. What differences would you expect to find between the skeleton of
a flying bird and an one which can't fly, like an ostrich?
4. Why do birds have 'light meat' and 'dark meat'?
5. What are the important muscles for flight?
6. What are the major functions of a bird's circulatory system?
7. Why do birds have a 4-chambered heart like you? Why do they beat
8. Why do some birds, including our local chickadees, sometimes become
torpid on cold winter nights?
9. What are the major functions of a bird's respiratory system?
10. A bird's respiratory system differs quite a bit from yours. Briefly,
how and why?
11. What functions do the air sacs perform?
Nervous system and Senses
12. Most birds have very keen sight and hearing, but poor olfaction
and taste sensations. Why?
13. Some terms to know:
15. Some birds have especially acute vision from a distance, while
others have the ability to see 'in the dark'. What special modifications
do these birds have?
1. Describe the difference between a song and a call.
What are the functions of each?
2. What determines which sex sings?
3. What function does song serve for birds? (There are many.)
4. Describe the location and general anatomy of the syrinx.
5. What allows the voices of different species to be different?
6. Distinguish between vocal and non-vocal noises in birds.
Give an example of each.
7. Specifically, why do birds sing in the spring and early summer but
much less frequently during the rest of the year? Another way to think
abut this is, why don't birds sing the rest of the year?
8. Birds of grasslands will fly up into the air to deliver their songs
when a perch is not available. Propose a reason why.
9. Propose a reason for the remarkable ability of the Northern Mockingbird
to mimic other birds.
10. Describe how a parabolic microphone is used to record
bird songs and produce audio-spectrograms (=sonograms), and of what
use these analyses have.
The Breeding Cycle: Territory, Courtship, Nest,
1. Describe what is meant by a 'reproductive strategy'.
2. Why do some birds begin breeding when they are only 10 months old
(e.g., most warblers, chickadees, etc.) while others (e.g., bald eagles)
may not breed until they are 5 years old?
3. Distinguish between home range and territory.
4. Why do birds gain by protecting territories? (There are many possibilities).
5. Discuss possible costs and benefits a bird (or any other organism)
faces when evolutionarily 'deciding' whether to be colonial or solitary
6. Why are females "choosy" while males are "eager" when selecting
7. We formerly through most birds are monogamous (during any
single breeding season). Under what kinds of conditions would you expect
this kind of mating system to develop? Under what kinds of conditions would
you expect to see polygyny? Polyandry?
8. What is a lek? A clutch? An indeterminate layer?
9. Be able to describe the general process of copulation and egg laying.
10. Why do eggs have different shapes, sizes, patterns, and colors?
11. What is a brood patch? Which sex develops them?
12. What is the purpose of ritualized breeding behaviors?
13. Describe some variations in nests between species.
14. Why do different species lay different numbers of eggs?
The Breeding Cycle: Hatching and Development of
pipping egg tooth
precocial altricial nestling
2. What are 'helpers at the nest'.
1. Terms to be familiar with:
3. Brown-headed cowbirds are very frequent brood parasites
of many passerines in eastern North America. How do they do it?
What are the advantages and disadvantages? How do host species respond
1. What is migration? How does it differ from dispersal?
2. Why do birds migrate?
3. What are flyways? Which is the closest to us?
4. How do migrating birds find their way?
1. What are the causes of bird extinctions?
2. Name three extinct species of birds. Name three endangered
3. Describe briefly techniques used to protect puffins and Dark-rumped
1. What types of research are yet to be done?
1. Have a general idea of how the process of bird banding is carried
2. What should you do if you find a banded bird?
3. What are some reasons for banding (or marking birds in other ways)?
Describe an example.
DON'T FORGET TO RETURN ALL BORROWED MATERIALS AT THE FINAL. GRADES WILL
NOT BE ISSUED UNTIL I HAVE EVERYTHING. WE WILL BE GOING OUT INTO
THE FIELD AS PART OF THE FINAL--BRING BINOCULARS, FIELD GUIDES, AND BE
PREPARED FOR THE WEATHER (EXCEPT RAIN).