At the Project:
Nesting is over. Your project is empty. The swallows have all left, but you
still have things to do like box cleaning, data treatment, finalizing records,
reporting results, etc. And you may find yourself wondering where your
swallows are and what's next in their lives?
Concepts:
What should you do with the old nests?
- Old nests should be removed from the boxes.
- Wear disposable gloves if you can. Used nests can be messy.
- Remove nests from boxes, put them in a trash bag, seal and dispose.
- Exception: if there has been a major blowfly infestation, take the bag
of nests elsewhere, empty them on the ground and leave them. This
allows tiny wasps that parasitize blowflies to mature inside blowfly
pupae that remain in the nest. Big parasites often have little parasites
of their own!
Box Care:
- If you are concerned about vandalism you may want to take boxes and
poles down.
- If land owners need to mow the field remove boxes and poles.
- Boxes that are removed can be hosed and scrubbed. Wearing gloves,
rinse boxes with a dilute bleach solution, then rinse again with water.
- Store boxes and poles out of the elements. They'll last longer.
Where have the swallows gone and what are they doing?
- The swallows are trying to keep themselves alive so they'll have a
chance to reproduce next year. That's really what a songbird's life all
about.
- Most Tree Swallows move to large marshes after nesting.
- They now become very social, forming flocks of tens of thousands to
hundreds of thousands. Flocks of millions have been reported from
coastal areas on migration and on wintering grounds.
- By day the swallows spread over neighboring areas searching for food.
- Food is usually insects, but unlike other swallows Tree Swallows eat
small berries, fruit and seeds. Bird guides state they resort to these in
bad weather, but in truth they consume suitable vegetable food
whenever they find it. Here in NY we've often watched flocks eating
berries of red-osier dogwood and arrowwood viburnun on hot August
days. Individual berries are grasped in a swallow's mouth, plucked with
a twisting motion of the bird's head, then gulped down.
- Tree Swallows are especially fond of bayberries and waxmyrtle berries,
and have special enzymes that allow them to digest their waxy outer
coating. (Below left: bayberries in winter; center: hundreds of
swallows descending on bayberry bushes in summer; right: 28 bayberry
seeds dissected from a single road-killed swallow's digestive tract).
- When not foraging they sun themselves and preen.
- In evenings the swallow flocks return to marshes to roost. Thousands
swirl about high overhead as dusk falls. Then, forming a funnel the
flock rushes into the marsh vegetation in waves. This can be an
awesome spectacle. You can even take cruises in September and
October to watch hundreds of thousands of Tree Swallows going to
roost on Connecticut coastal islands (ctriverexpeditions.org).
Eventually Tree Swallows from across their wide nesting range move south to
their wintering grounds in Florida, the U.S. Gulf Coast, Mexico, Central
America, and the larger Catibbean islands. As you might expect large
wetlands support the highest concentrations of wintering Tree Swallows. A
few hardy ones try to tough it out in coastal wetlands as far north as New
England in the east and up the Pacific coast to Washington State.
Some of your swallows, both adults who nested and young that fledged from
your boxes, will make the trip south successfully and winter there. And with
luck many survivors will return next spring for another nesting season with
you at your project.
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Learn About Birds at Tree Swallow Nest Box Projects