Wing entrapment in SREH and some possible wing "guards&

[John Miller]

Wing Entrapment, Possible “Wing Guard” Solutions

As a colony grows to near full occupancy, intense fighting often ensues among martins for available compartments. A major risk to martins at this time is wing entrapment in entrances. I experienced this recently at our thriving colony in Forest Park, St. Louis.

I found a dead male tightly wedged on its side in an aluminum crescent hole -- both wings and one foot out, his head, body, tail and other foot inside. I found this in time – probably no more than 12 hrs – to set free the male “victor” who was trapped inside.

Entrapment probably occurs more often in aluminum crescents because of the restrictive nature of these holes and the unnatural aspect of having a hole in a thin flat surface. The trapped martin I found was in a Trendsetter House, but is not unique to this house or to crescent openings. Wing entrapment is described in a PMCA archived article, “martin mishaps,” in a Trio round keyhole and in the triple railing porch guard used on some Trio housing. http://www.purplemartin.org/update/10(1)mishaps.html

Many landlords now round out the corners of their crescents to make wing entrapment less likely; however, this may help only with a single wing. SREH variations such as WDC holes also may help prevent single wings getting stuck at the bird’s “shoulder,” but would not have helped my guy, who appeared to have rolled over on his side in battle -- his back to the hole -- and somehow popped both wings out.



I am now working on some modifications – essentially “wing guards” -- to my interior crescent holes to help prevent entrapment. Although I have not used these, the photo shows two approaches:

In the nest tray, I have attached a small “arch” or wing-guard directly to the tray, the guard made out of one half of a one-inch wide PVC, thin-wall, three-inch diameter drain pipe. This is simply a version of the successful tunnel entrances used in gourds, in which to my knowledge no one has experienced wing entrapment.

Here the arch is set to the side of the tray because Trendsetter entrances are set into the sides of the compartments, with martins entering and making left or right turns into the nesting area.

The wing-guard concept hopefully will hold a martin in battle out from the hole, and force it to right itself before exiting, creating a safer “ boxing” ring.

This arch needs must be carefully placed to be flush with the wall or one might create a new entrapment hazard, and it also must be seated on the board so that it fits around the crescent and does not obstruct it at the corners.

I have added a one-eighth inch plank on the back side of the tray to make the sides flush with the compartment. The arch – one half of a three-inch pipe – leaves about one-eighth inch of clearance over the crescent hole at the top. I’ve measured and cut two slots in the tray for the arch to set into, then glued it with construction adhesive. I cut the slots about 3 & 3/16” apart, to pull the sides out about 1/16” beyond the crescent hole corners. The “arch” concept works for crescents, but would obstruct the sides of WDC openings positioned as shown.

The second approach shown in the photo (right) is simply a Trio crescent door with one-inch-long blocks glued at the interior sides and top. A variation of this was suggested previously on the Forum. These blocks are made of one-half inch thick quarter round molding (plastic or wood), with the rounded side turned toward the hole.

I spoke with Louise of the PMCA about the block concept and she suggested maybe replacing the blocks, which have blunt ends (wing bruising risk) with a ring of foam, hot glued around the hole.

One does need to do be careful with any modification not to create new places where wing entrapment might occur, and to make sure that function – such doors closing securely and ability to slide trays in and out -- is not comprised.

We all know that SREH entries are saving many martins and allowing new landlords to establish colonies in areas where starlings are numerous. I hope fellow landlords will report here what problems they are seeing with entrapment in various types of SREH, including different materials, and join me in exploring ways we can make all SREH entries safer.

John Miller

[klcretired]

John,
Thanks for the Head's up article and help...Personally i haven't ever had that problem yet at My Site on either my LS Goliad House w/ all sreh entrance's nor my LS Gourd Rack w/ all sreh's....but Being retired i do keep a constant watch on everything for stuff such just as that especially during all this fighting & Bickering over nest rights.
Thanks again,
this is what it's all about PM Landlord's helping PM Landlord's.

[Peggy Riley]

John, I've had it happen only once this year. It was two females in a new S & K Double gourd crescent hole. Both wings on outside but body on the inside. Don't know how she managed that! Her head was pecked pretty good by the owner of the gourd but she is fine. I found her just this week in a Lone Star cavity, no head feathers, but she had healed. Glad some guy found her attractive!

Just to clarify, this is not to slam the S & K gourd. It is a great gourd and I like them very much. The martins do too. The 4 I have are all occupied. For some reason they are not attractive to the sparrows at my place.

Thanks for looking at new and better ways to help our martins.
Peggy

[John Miller]

Peggy

Are your gourds porched on the interior? I can only surmise that like my case, your martin was laying on its side, on the interior porch, with her back to the hole. One wing pops out and in the struggle, the second wing.

I'm glad you caught this in time.

I'm going to mock up a foam wing guard soon. Maybe that's the most feasible approach.

John Miller

[Peggy Riley]

The porch is just on the outside of these gourds so yes she was kind of laying on her side. I was afraid I was going to hurt her trying to get her unstuck. She flew away kind of tilted at an angle but obviously her muscles were a little strained and I am sure she was terrified. The owner of the gourd was also a little stressed out. I figure they had been that way a couple of hours.

[Emil Pampell-Tx]

John, I think you have the right reason for them getting stuck. All of my gourds have tunnel entrances, and I have never seen one get stuck in my crescents, or any other SREH.

[Guest]

John, I found two dead martins at our place early this martin season. One was in a last year dead tomato plant between our house and the martin housing. The other was dead, back to the front wall, but not blocking the door, of a Lone Star Alamo, round entrances. Nothing was hanging out the door. From the ground, I thought it was nesting material. Then while watching through binoculars I could see a few feathers wiggling in the breeze.
Right after a large arrival of martins, we had several days of cold drippy weather when martins could not feed. I think a very weak martin happened into the lair of "Jaws" and it died wasting the last of its energy trying to escape. From its positioning it looked like it was pulling against something. SREH could make it more difficult for the victim to pull away, but I think "Jaws" killed the one at my place, and it was not any fault of SREHs, although it was an aluminum house with nest boxes. I just wanted you to have this information in your quest for better entrances.

[RC Moser]

IMO this can happen in any style entry hole, but the happen more often in crescents. I have noticed that during the fight as noted one gets turned side ways and get one or both wings out. I have also noticed and had to pull a martin out of a WDC a couple of weeks ago, in this case during the battle the invader wasn't given a chance to enter completely. Once he was about half end the fight started now he couldn't back up and when he did he got stuck. Maybe he would of got free evidently, but I was observing during this encounter and decided to intervene. I got him out and when I looked in there were two already in the compartment. A male and female. evidently he also wanted the Deluxe premium T-14 compartment with the view to kill for. IMO this could happen in round 2" holes if the get both wings out with there bodies in, but I have not witness it.

My only thoughts on the tunnel design is if the invader it confronted while entering pass the point of no return and when he did try to back up the possibly of getting stuck could exist IMO. I have loss three to this crescent phenomena over the years I have had crescents. So far none have died in WDC to date.

As you can see with the overlay of most Srehs available the crescent has the least space IMO, with the Excluder being the most restrictive at the breast IMO if the picture attached.

[John Miller]

RC wrote:

"My only thoughts on the tunnel design is if the invader it confronted while entering pass the point of no return and when he did try to back up the possibly of getting stuck could exist IMO."

RC, that's partly why I just made the tunnel a one-inch arch. But tunnels do seem to be totally safe in gourds, where they empty out into the cavity. I've wondered how multiple nestlings in these tunnels, with their heads out the holes to be feed, know to back back in. Maybe its from eons of being reared in tree holes.

Really just braining storming with these wing-guard designs for now, but we just gotta make these holes safer. If we can put a man on the moon? (Well, maybe that's showing my age)

John Miller

[abernathys]

Hey John--I hope that you are successful in trying to find a solution, I lost one female who become stuck. She was in the crescent sideways both of her shoulders were on the outside entry way and the rest of her on the inside of the hole. This happened while I was at work, I was so scared that others would be in the compartment but they were not. Last year a adult male became stuck, he was sideways with one wing and one foot on the outside and the rest on the inside of the compartment, luckily I was home and got him unstuck and inside the hole was a adult male and female. Everyone was fine.

Keep us updated, because I will be first in line to try it out!



Sandy

[John Miller]

Sandy

I'm going to create a mock up of the foam wing guard that Louise Chambers suggested and will post a photo soon. I have an idea for what to use.

What is the material of your crescents? Aluminum?

John Miller

[abernathys]

Hey John--yes aluminum. Thats Great!

Thanks so much!

Sandy