| ©The Raptor Center
State
Goals for Environmental Education (as per the Minnesota State Plan for
Environmental Education, Greenprint, 1993)
Students will:
- Understand
ecological systems.
- Provide
experiences to assist citizens to increase their sensitivity and
stewardship for the environment.
- Provide
the information citizens need to make informed decisions about actions to
take on environmental issues.
Learning
Objectives
Students will:
- Describe
the nests of three common birds.
- Build
a specific type of bird nest, using the same materials a bird would use.
- Build
a nest platform to attract a nesting pair of osprey.
- Observe,
record, and submit data on nesting osprey in Minnesota to The Raptor
Center.
Vocabulary
Words
- adaptation
- artificial
- fledging
- habitat
- tropical
- temperate
Materials
- National
Wildlife Federation House Hunting Copy Cat Page bird research books
- slips
of paper
- pencils
- nesting
materials
- Minnesota
Non-game Wildlife Platform Materials
Background
Ospreys return to Minnesota from Central and South
America to begin the nesting season anytime between the third week in March and
the first week in May. They are quite conspicuous; once you learn to recognize
them, you'll see them fairly often while driving around our state's abundant
lakes. Ospreys are a black and white bird of prey with a black eye stripe,
often seen hovering above the water looking for a meal of fish. Their wings
look slightly different than most hawks, they have "elbows." This is
often a tell tale sign.
Hovering Osprey
The osprey nest can be found on the ground or even
up to 60 feet high on live trees, dead trees, utility poles, duck blinds, fishing
shacks, storage tanks, aerials, cranes, power line transmission towers,
billboards, chimneys, windmills, fences, channel buoys, and even on artificial
platforms built by humans. Most nests vary in size, between one foot wide and
up to ten feet wide, with the exterior composed of small and large sticks and
an inside lining constructed of inner bark, sod, grasses, vines, and many other
items that the osprey are able to carry away from the ground. Large nests may
reach up to 400 lbs., and are often used in successive years! Noted author,
John Steinbeck, and others have even noted the strange and interesting items
found in the interior of these large nests.
Anatomy of an Osprey
Nest
The building of a nest, for any bird, is quite a
task. Some birds adapt and build their nest anywhere and with anything they
find. Other birds are less adaptable and build nests only in specific places,
using specific materials. Generally, bird nests can be in trees, on the ground,
plastered to a wall, or even floating on water! Think of all the different
types of nests and where you can find them. Ospreys are somewhat tolerant of
people and often nest in areas with human activity. They are quite adaptable in
nest site location, so long as it meets certain needs. These needs include an
open sky above the nest, a 360 degree view, close proximity (3 - 5 km.) to
water with a food source, and the availability of nesting material.
(Researchers would probably add many more factors and requirements to this list
of osprey nesting needs, but for our purposes, this general list is
sufficiently accurate and complete.) It is also important to understand that
all animals prefer to be in proximity with other animals of like kind, so one
can not put up a nesting platform in an area where the osprey population is low
and expect to attract a nesting pair. Ospreys have to be already nesting in the
area in order to attract them to an artificial nesting platform.
People who wish to attract a nesting pair of osprey
to an artificial platform should consult with biologists in their area who work
for the Minnesota Department of Natural Resources, United States Fish and
Wildlife Service, or other similar organizations. Listed below are the contact
names for each Minnesota Department of Natural Resources Non-Game Wildlife
Program regional office and phone number. The United States Fish and Wildlife
Service (Department of the Interior) has a Web site for more general
information and manages several refuges in Minnesota. Phone numbers for those
refuges and a link to the Web site are also listed below.
Minnesota Department of Natural Resources
Non-Game Wildlife Program
General
Information - 612-297-4966
Northwest
Region, Katie Haws - 218-755-2976
Northeast
Region, Jack Monty - 218-327-4421
Central
Region, Pam Perry - 218-828-2228
Southwest
Region, John Schladweiler - 507-354-2196
Southeast
Region, Bonnie Erpelding - 507-285-7435
Metro
Region, Joan Galli - 612-297-4966
United States Fish and Wildlife
Service (Department of the Interior)
Regional
Office - General Information - 612-725-3502
Migratory
Bird Office - 612-725-3313
Agassiz
National Wildlife Refuge - 218-449-4115
Big
Stone National Wildlife Refuge - 612-839-3700
Crane
Meadows National Wildlife Refuge - 612-632-1575
Hamden
Slough National Wildlife Refuge - 218-439-6319
Minnesota
Valley National Wildlife Refuge - 612-335-2299
Rice
Lake National Wildlife Refuge - 218-768-2402
Rydell
National Wildlife Refuge - 218-687-2229
Sherburne
National Wildlife Refuge - 612-389-3323
Tamarac
National Wildlife Refuge - 218-847-2641
**Please note: If your school or family erects a
platform, there is no guarantee that you will attract a nesting pair of
osprey.****
The activities are designed to be done in
progression. The first activity discusses the idea of home, the second activity
explores bird nests in general, and the third is a comprehensive plan to
construct an osprey nesting platform.
Activity
1. Discuss the idea of a home. Have your
students lived in one home all their life? How many have moved? Do any students
vacation in a specific place each summer? Do birds live in specific places in
the forest just like people do? [In general, yes.] Why might birds choose
specific places in the forest or specific types of forest? [Adaptations
enable birds to live in certain habitats. If that habitat is damaged or
disappears, then birds must compete for resources in new habitats where other
birds already have the advantages.]
2. There are many different designs for
constructing an osprey platform. We recommend the use of the Minnesota Non-Game
Wildlife Program's Design. If it is possible to "offset" the platform
on the pole, please do so. This will aid biologists who may wish to band birds
for scientific study. (To "offset" the platform on the pole, simply
do not install lag screws from the center of the platform into the pole.
Install lag screws closer to one of the sides of the platform. This will also require
the metal strapping to be custom cut, slightly different from the design plans
provided, but easy to do.)
We recommend that you try to defray costs by
contacting local lumber yards about donations and contact your local power
company about cost share programs and/or assistance in erecting an old utility
pole. (These companies are very cooperative.) It is easy to ask a utility
company to bring a pole to the school yard, then return when the platform is
attached and the pole is ready for installation into the ground. Most lumber
yards and power companies are eager to get involved for the publicity. Whoever
helps you, it is important to take pictures and write a short article for the
local paper to assist them with publicity.
Minnesota Non-Game
Wildlife Program's Osprey Platform
3. Whether or not you choose to build a nesting
platform, a great exercise in nature observation is to watch a nest and
complete a survey form about the activities found at that particular nest site.
Please remember to keep your distance from the nest and use binoculars and or a
spotting scope to observe. You would not want your class activity to jepordize
the successful hatching of the eggs. It is also illegal to disturb migratory
bird nests!
Osprey Nest Survey
Form Directions
Osprey Nest
Survey Form
Discussion
1. Discuss why birds prefer specific habitats. What
do birds obtain from specific habitats? For instance, the osprey lives near
water and feeds mainly on fish. Why might it need to live 3 - 5 km. from a
water source? [It would burn up lots of energy if it lived further than 5
km. from water and it would not be worth it to fly that far for a meal. There
may be exceptions to this, but this is generally true.]
2. Discuss why certain birds migrate between
tropical and temperate habitats, while others live year round in these places.
Why do birds leave North American habitats in the fall? [They leave because of
cold weather, lack of insects and fruit or a combination of these reasons.] Why
do they leave the tropics in the spring? [They need territory with abundant
food for nesting and longer days to find food.]
3. Discuss the important factors that biologists
need to know about nesting ospreys, such as date of arrival at the nest, egg
laying dates, number of young in the nest, number of young fledged, and date of
fledging. Why would this information be important? [All of this information
is important over a long period of study to determine the life cycle and habits
of osprey.]
Extensions
1. One of the reasons that ospreys have difficulty
finding suitable nesting trees is because of the lack of "super canopy
trees." Super canopy trees are those very large trees that "poke
above" most trees in the forest. Do you think that increased cabin
construction on our lakes and rivers has had an impact on the decline of these
super canopy trees? Chose a position and defend it
.2. Construct another wildlife home from the book "Woodworking
for Wildlife." Erect this second home and keep a record of activity.
Compare the time of arrival at the nest, the number of adults, etc. with your
osprey platform. Are there similarities? Are there differences?
Book
Resources
A Field Guide to Birds of Eastern and Central North
America, Roger Tory Peterson, Haughton Mifflin Co., Boston, 1980
Ospreys: Their Natural and Unnatural History, Alan
F. Poole Cambridge University Press, Cambridge, United Kingdom, 1989
Encyclopedia of North American Birds, John K.
Terres, North American Audubon Society, Alfred Knopf et al.
The
Life of Birds, Joe Carl Welty, CBS College Press, Philadelphia, PA, Third
Edition,1982 |