hawk resistant swallow boxes

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ken buker
Posts: 71
Joined: Thu Nov 20, 2003 9:51 pm
Location: Washington/Silver Lake
Martin Colony History: Started backyard colony at Silver lake in June 2004 with single pair of SY martins. Built a nest, no eggs, they left by late July. Returned 2005 and colony grew to three pair successfully raising and fledging 15 healthy young. In 2018 this colony was 110 pair strong and thriving. Managed a small colony along the lower Columbia river west of Longview, WA for a few years prior to starting my colony at Silver Lake.

Hi Everyone,
My name's Ken Buker from Silverlake, WA. I'm an active martin enthusiast with a purple martin colony at my Silver lake home. My colony started in 2004 from a single pair of SY birds and has grown to over 110 pairs of martins during the 2018 and 2019 seasons fledging nearly 400 young martins each of those years year. I learned long ago about the need for owl guards and all of my cavities are equipped with owl protection, though not totally foolproof, I experience few losses from owls, but do experience some aerial predation from hawks.

My question for anyone willing to share information is, Do you have any experience with box design or hawk protection for Swallow boxes.
I have over 30 swallow boxes around the perimeter of my property. This year and last the swallows have been seriously harassed by a resident hawk, so much so that many have abandoned their boxes and some caught leaving a nest of young to perish. I have fabricated 3/4 cages around some but it's too late for many at least this year. I'm looking to make modifications for next years arrivals, so any suggestions or ideas would be greatly appreciated.

Thanks, Ken Buker
Silver Lake, WA.
Posts: 623
Joined: Thu Jan 19, 2017 11:15 pm
Location: Plano, Texas
Martin Colony History: See Signature


Not sure what you can do with regards to barriers and such to prevent hawk attacks and also not sure how much you have read prior to posting so I apologize in advance if I state the obvious.

I personally do not have a problem with owls but I did attract a good many coopers hawks this year with the increase of activity at my sight. To combat the hawks I placed Martin decoys close to the gourd racks to give the hawk an obvious slow target. My martins have learned to swoop by these decoys on their way out of the gourds. I witnessed many times the hawk coming in and hitting the decoy as the Martins scrambled. The hawks hit the decoys so many times that they decreased the number of times they visit my colony. In fact, just two days ago I saw a hawk on my decoys for the first time in three weeks or so. Knowing the Martins like to dip down after leaving their gourds, I placed the decoys in what I believed to be their exiting path. It has worked so well that I have not lost a Martin all season to a hawk.

I think providing a slower target for the hawks will help your birds escape as they are leaving. Some have stated that they didn't want to use decoys as they may attract hawks however some of us believe its the activity and noise of the many live birds that attracts predators.

Good luck to you.

2016 - late to put up, many visitors
2017 - 1 pair, 3 fledged
2018- 2 pair, 12 fledged
2019 - 4 pair, 21 fledged
2020 - 15 pair, 67 fledged
Posts: 319
Joined: Mon May 12, 2014 1:02 pm
Location: Western KY
Martin Colony History:

Tried to attract PMs since 2004; began a more ernest attempt in 2014.

2018 — 3 pairs: 1 ASY pair & 1 SY pair in the Trio; 1 SY pair in a supergourd on the gourd multi-rack.

2019 — 6 pairs

2020 — In progress

Current housing consists of two modified Trio M12Ks at 20' and a round gourd rack at 20'.

We've also provided housing for bluebirds, Carolina wrens, house wrens, Carolina chickadees, tufted titmice, great-crested flycatchers and northern flickers for ~15 years.

Are the boxes out in the open or near some trees? Do you know what kind of hawk or can you describe its relative size or behavior?

TreeSwallowProjects.com has a lot of good info and you may find the "Predator Protection" page helpful.

Sialis.org has good info about bluebirds though some of it is applicable to tree swallows as well. Regarding hawk predation from the website, "Measure entrance hole (1-1/2 - 1- 9/16" round or 1.375" x 2.250" oval hole), put hole restrictor on if enlarged. Add wooden block over hole, or... use deeper boxes (8.5" from bottom of hole to floor) with kerfs on interior to enable fledging, or lower nests to 4.5"+ below entrance hole. Place boxes away from known hawk nesting sites, and from power lines or other perch/divebombing spots. Replace nestboxes with sturdier ones."

I use the xbox design for bluebirds and built an altered one for tree swallows — it has an enlarged floor plan of 5"x5" and a perch on top. (Unfortunately, we have a very small tree swallow population in my area so bluebirds frequently use it instead). I also increase the roof overhang a few inches to help restrict larger birds' access to the entrance hole. You can read more about this design at http://nestboxbuilder.com/nestbox-article-xbox.html .
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