In a recent art project with 4th grade children, their assignment was to draw a winter bird, along with some kind of tree branch or tree. They sketched in pencil, then colored the picture with crayons.
There were some printed pages they could look at, to see different types of winter birds and basic bird shapes.
Here is what the birds shapes page looks like; I made these drawings by looking at bird photographs:
And here are the photo pages we used:
Using these pages as a reference, the children made a variety of bird pictures with various backgrounds, such as a city scene (Central Park in New York, including the Statue of Liberty off in the distance), birds in a yard, bird perched on an evergreen bush, etc.
If you would like to download these bird drawing reference pages, they are available on Gentle Shepherd's website on the Arts and Crafts Freebies page-- www.gentleshepcurr.com/arts-and-crafts-freebies
Here are some example drawings; the bird on the left is an imaginary type; the ones on the right are wrens.