Male Martin kills baby Tree Swallow and injures two others

[Bill Pec]

First, a little background information. The Purple Martins at my site prefer to nest in gourds and all twelve gourds are occupied. Even though there are still unoccupied nest cavities in my Trendsetter-12 the martins still fight over the gourds. Because of this it is not uncommon to see newly arriving male martins investigating the Tree Swallow's gourd hanging just fifty feet from my purple martin housing. In the past all investigating martins have been soundly thrashed, chaced off, or driven to the ground by the very protective TS pair so I did not think the martins were a serious threat to the Tree Swallows. I was prepared for the normal gamete of predators and equipped the TS's gourd with a starling resistant entrance, and their pole with snake netting and an electrified pole guard. I don't have House Sparrows in the area so I wasn't concerned about them. What I was not prepared for was a very persistent rogue ASY martin. For about a week now I have observed this adult male martin sitting on a branch of a small tree that is near the TS's gourd, often singing. I did think this was odd but he was always chaced away by the TSs if he ventured too close so no alarm bells went off for me. Two days ago I did a nest check on my martins and the TS family. I found six healthy baby TSs in the pin feather stage of development. This morning I noticed that the male ASY martin was hanging onto the front of the TS's gourd and peeking inside. The pair of TSs were present and sitting on their perch a few feet above their gourd. I new that this was a bad sign because the TSs were acting like birds who have resigned themselves to the fact that they may have lost their nest and had stopped putting up a fight. Now my alarm bells did go off I chaced the martin away and headed toward my work bench to get the needed equipment to install a smaller entrance that wouldn't admit the martin. Not knowing if the martin had entered the gourd in my absents I disconnected the electric guard and made the pole sway just enough to allow the gourd to gently hit against the pole. Thinking if the PM was in the gourd he would fly out. No martin emerged so I lowered the gourd. I was not prepared for the sight that greeted me. There in the gourd was the male PM sitting tight and refusing to leave. I finally reached in and physically removed him. I then checked the TS chicks and found one dead and two bloodied. The two injured babies didn't look too bad so I replaced them. Obviously, the martin had been in the gourd before I discovered him. After installing the restrictive entrance and putting the gourd up the parent TS's resumed feeding their babies. I'll check tomorrow to see if the two injured babies survived.
Lesson learned.

Bill

[RC Moser]

not TS expert, but usually aren't ts housing is placed low to the ground and smaller entry hole? I would think slowly turning the away from the PM housing would be good Idea. In my area PMs don't bother blue bird housing placed low on trees. PMs beaks are not designed to peck holes. but I suspose if they pecked long enough it could kill or injury them.

Another problem I see in blue bird design boxes (or single gourds for TS) are the entry hole is too close to the nest. I made blue bird boxes deeper, but they just put more nest material in fill it up and the female blue bird and nest is within reach at the entry hole. I've lost alot of blue birds to bluejays, owls, small hawks, reaching in and pulling the female out and the nestling.


I added 2" PVC pipe 45 degree elbow to one to try to prevent this, but they haven't male or others haven't renested yet. I also redesigned my blue bird boxes creating baffle or shelf overhang so anything nesting in can't reach the nest , but only have one up and they haven't renested in it either.

My nest design is box in box or two chambers. The first chamber is entry 1 1/2 slot across the bottom, next a blocker board with the entry hole at the top. then the nest chamber and emergency escape at the top rear. MY thinking is anything bothering the house the female can escape out the back in case snake happens to enter. these design are still in the testing stages. I know I got screech owls and I know they are reaching in at night and pulling out the female and any hatchlings.

[TX Rehabber]

Bill,

Please remove the TS babies and apply some type of antibiotic ointment (like Neosporin) to the wounds. If the wounds, are not life threatening, the ointment will prevent Flys from laying their eggs on the wounds and maggots hatching. This will also help to deter any infection from developing. Just try to keep it away from the eyes, nose and mouth.

[Mary Dawnsong]

Hi Bill,

Sorry to hear of the unfriendly competition at your place.

I had a martin colony long before attracting tree swallows and martins are definitely dominant here. My martin housing is all gourds and after those fill up newly arriving martins will swarm over the tree swallow gourds, trying to get in.

All my tree swallow housing is Bluebird SuperGourds with a 1 1/2" hole and martins have never entered them here. However, if they could it would not surprise me to find aggression similar to what you witnessed.

Incidentally, the low height of the tree swallow gourds does not seem to discourage the martins. We have had a number of reports on this forum of martins nesting in low-mounted gourds.

My best, Mary

[KathyF]

wow, Bill - I've never heard of that! If you hadn't found the PM actually sitting on the nest, I would have encouraged you toward blaming a starling.

I use the TRES "slots" on my tree swallow boxes. This will keep out HOSP, starlings and the nosy martin.

Just cut a slot 2 1/4" long and EXACTLY 7/8" tall into some plastic, enlarge the entrances on your tree swallow houses, and screw on the plastic plates. The swallows have no problems entering, but the round fat sparrows can't.

[Bill Pec]

TX Rehabber,
Thanks for the tip. Will apply Neosporin.

KathyF, Mary, RC Moser,
Thanks for your suggestions.
The reduced entrance I attached to the gourd is a Tree Swallow slot.

[RC Moser]

Kathy can you give the demensions of the TS nest box. I want to make some for my aunt the next time I go up to tightwade MO.

[Bill Pec]

Kathy,

I too do not recall anyone posting that a martin had harmed TS's eggs or chicks. That is why I only treated this ASY male as a nuisance and not a threat. I do recall others posting that their martins had driven TSs out of their established martin colony. Maybe they never looked into the TS's nest to see how the martins accomplished the eviction.

I did see the male martin circle the TS's gourd this morning. After I physically picking the martin out of the TS gourd and had giving him a good scolding I thought I had sufficiantly frighten him enough that he would abandoned his efforts. The thing about this gourd is that it is only ten feet from a small tree along the shoreline. My PM colony is housed nearby, out on the end of a boat dock. Strange bird.
I'll check in on the five surviving chicks a little later in the morning.

Bill

[John King]

Kathy, Is these measurments ok for BB's? I know I have saw it somewheres but can not find it now, Thanks John

[KathyF]

Hi John & RC - yes, originally these were bluebird nest boxes, but I've had a swarm of tree swallows that took them over. Since I only have one pair of bluebirds nesting in another box, I let the tree swallows have the rest and put these plates on the entrances (cut out of house siding material). It's important to cut the door hole bigger than the hole in the siding and use a thin plate to make the slot entrance as the TRES can't push themselves through the slots, unless they're made of the thinner material (ie, not the thickness of the door itself). I tried just cutting the slot directly in the door, but they couldn't get in, so I made the plates. I now have 7 pair of TRES.

Here are the dimensions - you can square off the sides & top if you want, but this is the way we did ours:

Back - 7"W x 14" L - you can make as long as you want to give yourself room to mount it to pole.

bottom - 5"W x 5"L

Top - 7"W x 8 1/4" L

Sides - 5 1/4"W x 11 1/4" L

Door - 5"W x 7 7/8" L

Here are my template pieces, except for the door - (I had to use my door template, so it's not in the photo)


Picture of the nest box from the side:

[Bill Pec]

TX Rehabber,

I checked on the five remaining Tree Swallow chicks and all appeared healthy and active. Placed some Neosporin on the small skin tears I found on the backs of two of them. Saw no signs of infection. Removed a blow fly larva from one chick. Did a complete nest replacement in case there are more blow fly larvae in the nesting materials. I'll keep checking on their health.
Thanks,

Bill

[Don~VA]

Bill,
Glad to hear those babies seem to be recovering. Its sad to hear that a martin would be that aggressive and the TS's could not run him off. I have one martin that likes to fly over to check out my TS gourd and the TS's immediately show him who really owns that air space. Hope that new entrance plate can stop him from entering. Good Luck.

[RC Moser]

thanks kathy for the infor. question was that entry originally bluebird or was it specifically for TS?

[TX Rehabber]

Bill,

I'm very happy that the little injured ones are hanging in there. Keep up the the Neosporin for about 5 days and they should be healed by then. Great Job!

Penny

[KathyF]

thanks kathy for the infor. question was that entry originally bluebird or was it specifically for TS?

It was originally a 1.5" hole, but when the tree swallows moved in, I enlarged it, then put the plate over it to make it HOSP resistant.

[Bill Pec]

Penny,

Thanks for the advice. Sure is nice having someone with your experience monitoring the Forum and helping save our feathered friends. Will continue with the Neosporin for five days.

Bill