Fall is almost here and unexpected bird sightings make these days exciting for birders. We’ll start with an amazing sighting from Piscataquis County.

On Aug. 27, Dan Furbish and Dennis Peacock were birding in Dover-Foxcroft and saw a pink bird perched on a tree around the margin of a farm pond. It was a roseate spoonbill, a record for birders in Maine.

As the name suggests, spoonbills have an unusual bill that is adapted for filtering small animals from the water. A spoonbill moves the open bill from side to side to capture small fish, crustaceans, insects and snails. Sensitive touch receptors on the bill facilitate efficient feeding.

The small shrimp and other crustaceans that spoonbills consume make a living by eating the microscopic algae in the water. These algae produce red pigments called carotenoids for photosynthesis. The pink color of spoonbill feathers results from the movement of the carotenoids up the food chain – algae to shrimp to spoonbill.

In North America, roseate spoonbills typically are found in coastal marshes in Florida and Texas. One would imagine that a wayward spoonbill in Maine would be found in a place like Scarborough Marsh. The appearance in a farm pond well away from the coast boggles the mind.

The roseate spoonbill was still present in Maine as of last weekend. It is a young bird, born in 2018.

This remarkable record is not unique for this fall migration. The first Quebec record appeared in Saint-Martin-de-Beauce in August. Other spoonbills have appeared in the past three weeks in Minnesota, Iowa, Illinois, Ohio, Pennsylvania and New York as well as in southern states that are closer to their breeding range.

Other unexpected bird records this fall include the first reddish egret in Ontario as well as records of a neotropical cormorant and a wood stork in New Hampshire. A western kingbird recently appeared in Wells.

Why do birds show up in unexpected places? A common hypothesis is birds have been carried off-course by winds and storms. Actually that explanation doesn’t hold water. Many species of birds hunker down during storms and rarely are carried far. Open ocean birds like storm-petrels and shearwaters may be carried inland. I think storms have nothing to do with the spate of spoonbills records this August and September.

Errors in navigation and orientation can provide an explanation. In other words, birds get lost. One might expect that young birds would be likely to err during migration.

I think the explanation for the spoonbill records is a phenomenon called post-breeding dispersal. Herons, egrets, ibises and spoonbills (including juvenile birds) commonly fly north of their breeding range after nesting is complete rather than migrating south.

Many ornithologists believe this post-breeding dispersal is a type of prospecting for new breeding grounds. Such birds are often first-year birds, obviously with no prior breeding experience.

A general pattern is that birds do not typically return to the area of their birth to nest in subsequent years but do show a strong tendency to return to their first nesting site. Nesting site fidelity is stronger than natal site fidelity.

Glossy ibises staged a large population increase in the 1970s and expanded their breeding range northward. Post-breeding dispersal is commonly observed in this species. One can see how such prospecting trips might facilitate the northward extension of the breeding range in subsequent years.

I suspect most of these post-breeding excursions fail to result in the adoption of an area as a breeding site next year. I certainly don’t expect roseate spoonbills will be breeding in Piscataquis County soon. But if you see a yellow-crowned night-heron, rufous hummingbird or a lark sparrow this fall, it’s likely not a lost bird but a bold post-breeding explorer.

Herb Wilson teaches ornithology and other biology courses at Colby College. He welcomes reader comments and questions at

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