Can hawks make purple martins shun a house they used for years?

[wpakalka]

For the past several years, I have had purple martins fill a 12-unit purple martin house I have on the top of a fifteen-foot pole in my back yard in Houston. And I always battled English sparrows. But once in the summer of 2015 and once again in the summer of 2016, I happened to look up and see a hawk hovering outside the martin house, and it then stuck its leg into the entrance of one of the units and grabbed an adult martin in its talons and flew off with it. I can only guess that one or more hawks have made a habit of doing their grocery shopping in my martin house. In 2017 and again this year, I have seen no martins (and no sparrows) anywhere near my martin house. Have they all learned it is not a safe place for smaller birds to reside? Has anyone heard of this phenomenon and does anyone have any suggestions on how to remedy the problem?

[Dale D]

Normally Hawk attacks on a colony won't cause abandonment but, from what you describe you witnessed I would not be surprised if they abandoned the house. Having successful attacks reaching in a Hawk would become relentless. Your Martin's no longer had a safe place to get away from the Hawks. It may take you some time to rebuild that colony with new birds. Reduce your compartments from 12 to 6 making them deeper and impossible for a Hawk to reach in.

[Dale D]

Normally Hawk attacks on a colony won't cause abandonment but, from what you describe you witnessed I would not be surprised if they abandoned the house. Having successful attacks reaching in a Hawk would become relentless. Your Martin's no longer had a safe place to get away from the Hawks. It may take you some time to rebuild that colony with new birds. Reduce your compartments from 12 to 6 making them deeper and impossible for a Hawk to reach in.

[JMcM]

For the past several years, I have had purple martins fill a 12-unit purple martin house I have on the top of a fifteen-foot pole in my back yard in Houston. And I always battled English sparrows. But once in the summer of 2015 and once again in the summer of 2016, I happened to look up and see a hawk hovering outside the martin house, and it then stuck its leg into the entrance of one of the units and grabbed an adult martin in its talons and flew off with it. I can only guess that one or more hawks have made a habit of doing their grocery shopping in my martin house. In 2017 and again this year, I have seen no martins (and no sparrows) anywhere near my martin house. Have they all learned it is not a safe place for smaller birds to reside? Has anyone heard of this phenomenon and does anyone have any suggestions on how to remedy the problem?

My father in law seen a hawk take one of his martins away a few years back. He had a nice colony of birds at the time but hasn’t had Martins since. I know he hasn’t had PM’s for the past couple years.

I can understand if something caused the PM’s to abandon their site but what’s keeps younger and other PM’s from establishing there again?

[Dale D]

For the past several years, I have had purple martins fill a 12-unit purple martin house I have on the top of a fifteen-foot pole in my back yard in Houston. And I always battled English sparrows. But once in the summer of 2015 and once again in the summer of 2016, I happened to look up and see a hawk hovering outside the martin house, and it then stuck its leg into the entrance of one of the units and grabbed an adult martin in its talons and flew off with it. I can only guess that one or more hawks have made a habit of doing their grocery shopping in my martin house. In 2017 and again this year, I have seen no martins (and no sparrows) anywhere near my martin house. Have they all learned it is not a safe place for smaller birds to reside? Has anyone heard of this phenomenon and does anyone have any suggestions on how to remedy the problem?

My father in law seen a hawk take one of his martins away a few years back. He had a nice colony of birds at the time but hasn’t had Martins since. I know he hasn’t had PM’s for the past couple years.

I can understand if something caused the PM’s to abandon their site but what’s keeps younger and other PM’s from establishing there again?

New Purple Martin's have no idea there were Hawk attacks in the shallow cavities prior to their arriving there. That is why it is important to correct the problem before new Martin's decide to take residence.

[John Miller]

When there is predation of most of the young, martins sometimes abandon sites for many seasons. I agree it makes sense that new martins would not know the history, but from what I've read of people's experiences after abandonment, somehow the site gets blacklisted for some period of time. But maybe it just seems that way because one is essentially starting from scratch and any new site sometimes takes several seasons to attract nesting martins. As said however, consider renovating the housing to deeper compartments. Short of that, some kind of fencing guard may help. And if you have the budget, just switching to a rack of gourds may help, both because it's "different" housing and because deep gourds offer pretty good protection from aerial predators reaching in.

[eyeamtheman]

Y E S

[wpakalka]

Thank you to all who commented.

[Ransom Graham]

This is the perfect argument for why the new supergourds are the perfect Martin Housing. With the excluder entrance holes and guards it is impossible for a hawk to reach in and remove a Martin. Also the gourds move when the hawk lands on it increasing the difficulty. The entrance hole also eliminates any starling problems.

[Lizzie]

from what I've read of people's experiences after abandonment, somehow the site gets blacklisted for some period of time. But maybe it just seems that way because one is essentially starting from scratch and any new site sometimes takes several seasons to attract nesting martins..

My experience exactly.
The first colony took me at least 10 years to establish.
After owl attacks and subsequent abandonment, it took another 9-10 year to get a single breeding pair last summer.
If your colony site doesn't happen to be in a high visibility area which is frequented by martins, and the conditions are not ideal, it can take quite awhile to have martins come to stay.

[Keith]

It is quite possible that your Martins will abandon this site. We can hope that your birds will just be arriving late. The remedy one could do is to put tunnels on your houses or gourds with starling resistant entries. I put tunnels with the Clinger entrance on my 100 compartments and they seem well protected. Years ago I lost 18 pairs to raccoons and had no birds for two years even with other colonies nearby. Maybe these birds communicate, who knows?
Keith

[KathyF]

For the past several years, I have had purple martins fill a 12-unit purple martin house I have on the top of a fifteen-foot pole in my back yard in Houston. And I always battled English sparrows. But once in the summer of 2015 and once again in the summer of 2016, I happened to look up and see a hawk hovering outside the martin house, and it then stuck its leg into the entrance of one of the units and grabbed an adult martin in its talons and flew off with it. I can only guess that one or more hawks have made a habit of doing their grocery shopping in my martin house. In 2017 and again this year, I have seen no martins (and no sparrows) anywhere near my martin house. Have they all learned it is not a safe place for smaller birds to reside? Has anyone heard of this phenomenon and does anyone have any suggestions on how to remedy the problem?

As others have mentioned, a change in housing may help - but these attacks would have had to have happened a LOT more frequently than 2x in the last 2 years to cause abandonment. And if it was happening more frequently, you would have witnessed it a lot more than twice in the last 2 years.
So, I would also ask - did you have predator guards on your pole to keep snakes and raccoons from climbing the pole? Ground predator attacks are more common and often the main cause of abandonment in my experience, followed closely by owl attacks. Were the 2 hawk attacks the only signs you ever saw of predation - no feathers in your yard, blood or anything?
While changing out your housing, you might also take a look at your yard and determine if you can cut down more trees to open up flyways and help with hawk attacks.

[wpakalka]

Thanks again to all who have supplied ideas. I do not think anything is getting up the pole, as it is a fairly high metal pole leading to the flat metal bottom of the PM apartments, and I have not seen any evidence of attacks on the ground near the pole--no blood, no feathers. It's all very frustrating as I keep the apartments clean after the PMs leave, and I put the door plugs in until they return. The first year I had it up, all the apartments were filled with PMs, and we had an extraordinary phenomenon when the fledglings came out on the balconies and were trying to learn how to fly. We look out one afternoon and saw more than 100 adult PMs lining a nearby telephone line, watching the goings on. It was like an old Alfred Hitchcock movie. The second year, sparrows tried to take over. I emptied their nests twice a week (easy to distinguish from the martin's neat twig floors--the sparrows packed the units with grass, leaving just a small tennis ball sized hole for themselves). Then, for a few years that pattern repeated itself and the PMs managed to rear some babies, but then we saw the hawks. I agree that although we only saw 2 attacks in two years, we were not home all the time and there were surely more. And to make matters worse, my neighbors closest to my PM house have their own similar one, and I do not think they do anything to service it, yet they have plenty of martins.

I guess it's time to switch to gourds. Do they need to be cleaned out after the PMs leave at the end of the Texas summer, or can I just leave them unattended? And do sparrows try to take over gourds?

[Louise Chambers]

If you don't have a good baffle/guard on the pole, and netting above that - you might have had snake predation. Snakes climb metal or wooden poles with ease, and clean out martin houses, eating eggs, nestlings, and adults - you won't even know it happened until one year no martins return.

House Sparrows will nest in gourds, and gourds and houses do not have to be cleaned out at end of season, but it's a good idea to do it anyway. Get rid of nest parasites (mites, fleas, etc) and decaying nest material.

[Emil Pampell-Tx]

I would bet all my money that you had a snake attack, or possible a raccoon but most likely a snake. You need a good predator guard as snakes can easily clime a metal pole. You also need to enlarge your rooms to 6x12inches

[Roymg]

My experience to your question is every year I have, it seems, a resident hawk that after my birds first arrive and get established this hawk will take some. This year I know I lost three for sure. But these birds do not ever leave. They just adapt their tactics in dealing with this hawk by staying away during the day and only returning late in the evening. They waste no time in getting into their apartments. This goes on until the hawk moves on, after a month or so, and the birds behavior returns to normal. I do think it delayed nesting procedures but they have now begun to get their nest ready.

I've never lost my colony due to hawks and now all seems to be good.

[Matt F.]

I Maybe these birds communicate, who knows?

Keith,
I think there's some definite credence in that theory.
We know Martins' sense of smell is almost non-existent, and we know they have excellent memories.
The situations that others like wpakalka and Lizzy have observed at their sites, points to Martins in a particular area that fled a site due to predation, not only of course remembering to not nest there themselves ever again, but also warning other investigating Martins about that site by such things as alarm calls, and refusing to land on that housing at all. This behavior would no doubt make the new Martins leery.

All landlords trying to rebuild from an attack can really do, is to bring their "A" game when it comes to their site, and making improvements if possible.
Clear area (trees cut way back - even more than's probably needed), two-stage predator guards - using both stovepipe style and netting, safe and house sparrow and starling free housing.

[KathyF]

@Matt, I'm pretty sure they send it out in the newsletter too.....

[Matt F.]

@Matt, I'm pretty sure they send it out in the newsletter too.....

[JimmyP]

I always get a little ticked when I drive by someone's place and see a martin house pole's without predator guards on it !! Snakes and predators do their dirty work after dark so be assured you're losing eggs and birds. I learned this as a kid living on a farm snakes would eat all our chickens egg's not sure how they do it but a snake can smell an egg a mile away. USE PREDATOR GUARDS !!!