Advice needed: Should we boot tree swallows even after purple martin migration is done?

nvbirdalliance · Tue May 27, 2025 12:52 pm

Hello all, looking for some advice. Our colony is in Four Mile Run Wetlands Park in Alexandria, VA.

This was our second year with the colony up with no purple martins moving in. We did have an issue with the hole size so our amazing on-site partner filed the holes to be large enough around April 8. I don't know if this caused us to miss them this year or if they were uninterested in our site for other reasons.

I assume that migration is mostly done now and that if we were going to get some second year birds moving in, they would have already - correct?

Ok current situation is that there is one pair of tree swallows that just started nest building there within a week or so ago. No eggs yet. Should we block the gourds so they can't nest in there? It feels mean to exclude them since we missed the PMs this year and no one is gonna be using those gourds anyway. But we really want to get PMs next year. Does allowing tree swallows to nest there this year mean that we will be less likely to get PMs next year? Please advise.

Another problem we are having is that we are getting wasps in some of the gourds building nests! Oh no! Our once again, amazing local on-site partner, had to remove some of these last year and applied soap to the entrances to try to deter them. What else can we do to deter them that would be safe for the birds?

Thanks so much!!!
-Tina from NVBA

scottfreidhof · Wed May 28, 2025 9:04 pm

It is still possible for martins to find and claim the gourd rack as their own this spring. Would it be possible to set up a separate bird house for the tree swallows right away? Then you could block the entrance to that particular gourd assuming no eggs yet. If egg laying has begun since the last check then probably best to allow the tree swallows to complete their nesting cycle. Proactive step for next March is to have several tree swallow nest boxes nearby to attract the swallows away from the gourd rack.

flyin-lowe · Fri May 30, 2025 9:42 am

Once you have established martins you don't have to worry about the tree swallows, but until then you should not allow them to take up residence in your martin housing. If it were me I would block off all entrances (since you don't have martins currently) and put up a gourd about 30-50 feet away. If you happen to see martins visiting you can open a few cavities but until then, the tree swallows will take every chance they can to use a gourd on a martin pole.

nvbirdalliance · Fri May 30, 2025 10:23 am

UPDATE: 3 PMs spotted on our gourds, yesterday! Wow! Can they win over the tree swallow pair?

Can anyone tell if a female is among this group? https://ebird.org/checklist/S244337469

My partner is going over now to look and will take out the tree swallow nest.

We can get up nest boxes for tree swallows next Spring but not this year, we need to get park approval first.

WOW!

nvbirdalliance · Fri May 30, 2025 10:57 am

The tree swallow pair has a nest with eggs. :( so we can't move it. Does that mean we won't get purple martins to nest there this year?

scottfreidhof · Fri May 30, 2025 4:41 pm

That is great news about the martins! Looks like you have one female, one second year male, and one after second year male. If the tree swallows are not constantly trying to drive the martins away, then you might very well be successful in establishing a colony this year.

flyin-lowe · Sat May 31, 2025 8:28 pm

We have huge TS populations in my area. Years ago I had documented on here I had 2 pair of tree swallows nesting in the same gourd rack with martins as well. In that situation I already had martins established. My guess would be the TS will pester the martins enough they will leave but hopefully they are pre occupied enough with their nest that they leave them alone.

SE Wisc hopefull · Mon Jun 02, 2025 3:52 pm

For what it's worth ... I had PMs for the first time last year ... 3 pairs for sub adults. By God's grace they have all returned as ASY and took up residence in same house/gourds with more sub adults showing up each day this year.

Last year I had the same issue with Tree Swallows and tried moving them to separate housing. I went out of town for a few days and in that time the Tree Swallows started laying eggs in a gourd so I thought that would be the end of chances on PMs. Turns out a young male showed up and sat all day at the entrance to the Tree Swallow gourd. No matter how much they buzzed him and pestered him, he sat like a statue. After several days the Tree Swallows gave up and moved on. When I lowered the gourds, the eggs were gone so I assume he ate them. Anyways, he did find a mate raised 3 to fledge in the same gourd.