Danger In the Nest: Osprey and Baling Twine

For the last six years, an adult Osprey pair – “Charlotte” and “Charlie” - have delighted viewers around the world as they build a nest and attempt to raise a family each year on the nesting platform in Charlo, MT. Charlotte and Charlie have successfully raised 11 chicks since 2016.

This year, Charlotte and Charlie first appeared in mid-April, when they migrated thousands of miles back to Montana from Central or South America where they spend the winter. After spending some time bonding and getting their nest into tip-top condition, Charlotte laid two eggs. They kept the eggs warm by incubating them for over 5 weeks. Those eggs hatched around June 13 and 16. Right around the same time, Charlie brought baling twine into the nest.

Two osprey chicks in a nest. One is badly tangled in baling twine.
A picture of the two osprey chicks in the nest, before the twine was removed the first time. The younger, smaller chick is at the edge of the nest near the top of the image. The older, larger chick is in the center of the image entangled in orange baling twine. They are less than two weeks old and still completely reliant on their parents for survival.

What is baling twine? How do Osprey get it?

Baling twine is a strong, thin rope that is used to hold together bales of hay. Today, it is most commonly made of many fine strands of polypropylene, a plastic polymer. Polypropylene baling twine can take half a century (or longer) to break down- much longer than the natural lifespan of an Osprey. When discarded baling twine is left in a field or pasture, Osprey will pick it up to use as nesting material, lining the nest and building it up. This can have devastating consequences for the birds.