1/2 Cup Nest at Box 3
Inspite of almost daily rain here most of the female Tree Swallows possessing boxes continue to gather nest material. Box 3, above, has reached what I call the 1/2 cup stage, with a substantial ring of grasses around the outside of the box bottom but quite a bit of bare floor still showing. Boxes 1 and 2 females are adding to their 1/4 cup nests, but at a rather slow rate. Box 4 seems to have stalled temporarily, but the Box 8 female has finally begun. Reading this, I wouldn’t blame you if you wondered if all the responsibilities seems to be falling on the females right now. Don’t the males share in the work?
A Male Tree Swallow Sits On Its Box
Although they’re not doing the building, male Tree Swallows do have a role during the nest building. It’s pretty much the same one they’ve been playing since they first claimed their boxes – using calls, physical displays, and chases to defend their box against intruders – and here at Salmon Creek there certainly is an abundance of intruding floaters this spring.
There's No Shortage Of Floaters Here This Year
A male that successfully prevents floaters from interrupting makes it easier for a female to devote her time and energy to gathering nest material. I think it’s no coincidence that at the Salmon Creek grid this year the boxes where nest building has lagged, Boxes 5, 6, and 7, are the same boxes where floaters are concentrating their takeover efforts. Along the east row, box defense, and nest building, have both been more effective.
Nest Defense Has Indirectly Helped Nest Building At Box 2
Males also act as though they are genuinely “interested” in the females’ nest building activities. Males frequently peek in the entrances as if to monitor progress, sometimes getting in the way.
Get Out Of The Way And Let A Working Female Through!
Males often give a soft, gurgling “Contact Call” as the female returns with vegetation, and may peek in the entrance and gurgle to her as she arranges things inside. It’s been suggested that this helps cement the “pair bond” between the two, and may “encourage” the female to keep up the good work, or at least to keep working. Sounds reasonable. To hear a YouTube video of this call click here: Contact Call or Gurgle.
And lest you think male Tree Swallows never contribute anything to the nest building effort, we should mention that males are the primary gatherers of one important nest component, feathers. And the first nest feathers at the grid appeared way back on 4/28, most likely brought in by the Box 1 male. We’ll have much more to say about feathering Tree Swallow nests in days to come.
White Feathers, Probably Gathered By The Male Swallow At Box 1
We have a purple martin house at the end of our dock. Last year and now again this year we identified house swallows and they are nesting in the house. My concern is that it’s located at the end of the dock on tidal water. The pole is pretty high up. We have no concerns regarding racoons, etc. My worry is that the babies will fall in the water. Should we move the house?
I wouldn’t worry too much about the babies falling into the water. One of the Tree Swallow’s most typical natural nest sites is in old woodpecker cavities located in dead trees standing in water, and a great many still use these situations, especially in the more northern and wilder parts of its nesting range in the US and Canada. When the swallow nestlings fledge they should be physically developed enough to fly strongly to safe perches (unless they are frightened into fledging prematurely). But if you feel you have a safer alternative spot nearby you could move the house, and it would be better to do it now rather than later.
On another note, I’m probably misinterpreting your note, but a high pole won’t stop a determined raccoon. They are extremely good climbers, and can clamber up even thin smooth poles with remarkable ease. Just want to make sure you and anyone else reading this is aware of this danger.