Saturday, November 12, 2022

The Tree Swallows (Tachycineta bicolor) on Middleton Island in 2022



2022 was the 14th year of the Middleton Island Tree Swallow (TRES) project. ISRC-crew members cleaned out the nest boxes in spring. After 5 additional boxes were installed last year, replacing some of the ones that were gone, another old wooden box (Box #1) didn't survive the winter, leaving 16 nest boxes available to the TRES this year. By the end of the summer, on August 7, al boxes were inspected again, cleaned out and photographed. Somewhat disappointingly; in 2022 only one pair of TRES nested on Middleton; the lowest number in the projects' history.


7-August-2022
Swallow boxes check
Box 1: No Box
Box 2: No Box
Box 3: Good shape! Missing a nail, empty
Box 4: Good shape, missing nail, empty
Box 5: Perfect condition, full nest, poop inside nest
Box 6: Good condition, empty
Box 7: Good shape, missing nail, empty.
Box 8: Okay condition but rotting. Should be replaced in the nest 2 seasons. Empty.
Box 9: Perfect condition, empty.
Box 10: Broken, needs to be replaced.
Box 11: Perfect condition, empty.
Box 12: Good condition, slightly rotten, empty.
Box 13: Good condition, back corner rotten but box feels sturdy. Empty.
Box 14: Perfect condition, a few pieces of grass and 1 feather.
Box 15: Good condition, starting to rot a little bit in the back and bottom. Empty.
Box 16: No box. Needs new one.
Box 17: Good condition! Empty
Box 18: Perfect condition! Empty
Box 19: Good condition. Post slightly angled. Empty
Box 20: Good condition. Empty




Remarkably, the only nest built this year, was found in box # 5; a green and relatively small prefabricated box, made from recycled plastic boards and 4 wooden blocks giving some strength to the structure. These are sold in Europe and are intented for House Sparrows Passer domesticus. Only the nest box entrance was enlarged to suit the TRES. 
 











With the ongoing decay of the wooden boxes, the search for the most "durable" nest box design continues. Here the remains of the first generation wooden box # 10. 




Two of the three new "Dutch-built partially recycled" nest boxes contained a bit of bird poop, but whether this came from a TRES or a migrant of a different species remains unknown.









The other one of the two green prefabicrated recycled nest boxes installed last year (box # 14) was still in perfect condition. It also appeared to have had the swallow's (short) interest, as it contained a few pieces of grass and a feather. Not enough to count as a nesting attempt, but perhaps an indication that the TRES has a preference for this model. More swallows will be needed to proof this. Hopefully next year a few more will make it to the island again.


I thank ISRC-members Shannon, Stella, Sierra and Scott for monitoring the TRES on Middleton this year!