No Orioles Yet!
Last spring, the first migration reports of Orioles arrived from Texas on the 13th of April.. If you live in Texas, we hope you're on the look-out! Where ever you are, we ask your help in reporting "leaf-out" of your deciduous trees. Here's why: For many songbird species, the timing of spring migration may be related to leaf-out. This is because when leaves emerge many insects that eat leaves also emerge. With your help, we'd like to test whether these spring events are inter-related.

How to Report Leaf-Out and Oriole (Baltimore & Bullock's) Migration Sightings:
On the left-hand side of this page you'll see a blue owl button. Simply press the button and a FIELD DATA FORM will appear. If you have any trouble using this system, send a message to our feedback form We'd be happy to help you!

Alan Davenport, UFWS Office of Migratory Bird Management

Where Are the Orioles Now?
This map was made from bird-banding data. It shows data from Orioles that were banded during the breeding season (May-July) and recovered (found) during the wintering months (November-February). The blue lines connecting the points do not show the migratory route. Rather, the lines connect data points for each individual bird. By looking at this map, you can see where Orioles from your state or province might spend the winter. These data were not easy to collect! Of the 92,010 Orioles banded only 959 have been recovered. Even fewer banding recoveries are shown on this map, since we are only looking only at those records dates described above. Special thanks to Alan Davenport of the USFWS Office of Migratory Bird Management for providing this map.

Challenge Question # 1
"What is the rate of recovery for banded Orioles? At this rate, how many Orioles must be banded for one Oriole band to be found again?" "

To respond to this Challenge Question please follow the instructions at the end of this report.

Jim Gilbert

# Sightings	Elevation	Habitat
0	Above 10,500'	Subalpine/Rain Paramo
0	7,500'-10,500'	Montane/Wet or Rain
3	4,200'- 7,800'	Lower Montane (includes cloud forest)
7	1,800'- 4,500'	Subtropical (Pre-montane) Forests
10	Sea level to 1,800'	Tropical (Lowland) Forests

According to Henderson's records, what habitat-type do orioles seem to prefer? These observations are important. They remind us that habitat-use on the wintering grounds is very specific. Therefore, when certain types of forest are cleared for human use, the birds that depend on that forest type will be effected. Forests in tropical countries at low elevations have already been utilized. Now forests at higher and higher elevations being cleared, as human populations swell.

Jim Gilbert

The immense biodiversity of Costa Rica might seem surprising. Can you think of reasons why? Scientists believe it is due to the fact that Costa Rica (and Panama) lie right in between North and South America. Being this close to both continents made Costa Rica something like a bridge which plants and animals could migrate across over the centuries. The result of this is that Costa Rica has been left with one of the most diverse collections of plant life anywhere on the planet--and as a result, the neotropical migrants have one of the most diverse food sources on earth!

This richness means there are many things for orioles to feed on. The Northern Oriole is believed to feed on the following while in Costa Rica: Nectar from trees (Erythrina, Inga, and Calliandra), vines, and the many different types of epiphytes (plants that grow on other plants, such as orchids); it also eats bananas and other fruits, as well as the insects found on branches and leaves. After hearing about this rich variety of food doesn't this question come to mind?

Challenge Question # 2
"Why do you think orioles and other neotropical migratory birds leave the neotropics and come to North America?"

Biodiversity & the Seasons
Close your eyes and imagine the dead of winter. Feel the cold, picture the darkness, and listen to the silence. Now fill you mind with thoughts of spring-- birds singing, frogs calling, flowers blooming and sunshine greeting you in the morning. When you contrast the number of bird species in your region during winter with the number in summer, the results can be impressive. The arrival of migratory songbirds increases the species richness of the region. Scientists believe that the stability of ecosystems depends on the rich interaction between species, and that these natural systems sustain all life, including our own.

Try This!
How does avian biodiversity change with the season in your part of the world?

1. Look at a field guide to birds of North America. Using the range maps in the guide. count the number of bird species that are found in your region in the winter months.
2. Now count the number of species in your region during the breeding season.
3. Then answer Challenge Question # 3:

Challenge Question # 3:
"How does the avian biodiversity of your region change with the seasons? How many bird species do you have during the winter months? How many species do you have during the breeding season?"

How to Respond to Journey North Oriole Challenge Question # 1

1. Address an e-mail message to: jn-challenge-oriole@learner.org
2. In the Subject Line of your message write: Challenge Question # 1
3. In the body of the message, give your answer to this question:

Challenge Question # 1
"What is the rate of recovery for banded Orioles? At this rate, how many Orioles must be banded for one Oriole band to be found again?" "

How to Respond to Journey North Oriole Challenge Question # 2

1. Address an e-mail message to: jn-challenge-oriole@learner.org
2. In the Subject Line of your message write: Challenge Question # 2
3. In the body of the message, give your answer to this question:

Challenge Question # 2
"Why do you think orioles and other neotropical migratory birds leave the neotropics and come to North America?"

How to Respond to Journey North Oriole Challenge Question # 3

1. Address an e-mail message to: jn-challenge-oriole@learner.org
2. In the Subject Line of your message write: Challenge Question # 3
3. In the body of the message, give your answer to this question:

Challenge Question # 3:
"How does the avian biodiversity of your region change with the seasons? How many bird species do you have during the winter months? How many species do you have during the breeding season?"

Don't Forget!
Please include the name of your school and your location so we can credit you properly for your answers.

The Next Oriole Update Will be Posted on April 3, 1997.