What would cause this?

[Keith]

While in the process of taking down and getting ready to clean the 30 gourds that were used this year, I noticed two of the gourds had a layer of PM feathers spread all over the nest. Nothing but feathers. could find no skeleton or other body parts. These gourds were on two separate racks. I have predator guards, netting, and streh entrances. The nests were still in good shape. Hope someone can help and have been a landlord for several years but never witnessed this.
Keith

[~Ray~Gingerich]

Maybe a screech owl entered the nest.

[TerryG]

Tree swallows make nests with feaathers, I had one gourd this year the same way, the TS fledged 4 young. Hope this might help.

[Keith]

Hello Ray, I did think of a screech owl as I have heard them around here but just not sure they could enter a clinger entrance.

Terry, I have never seen a tree swallow here and besides these feathers were only Martin feathers spread and pasted all over the gourd bottom and not in a nest bowl at all.

I really do appreciate the responses.
Keith

[Louise Chambers]

Screech owls can get into a round, standard martin entry but their skulls are probably too big for them to enter a SREH.

Did you take a photo of the feathers in the gourds? That might help. Could you tell if the feathers were from nestlings or adults? Did birds fledge from those two gourds?

[John Miller]

Might be a long shot, but I found a dead mouse on top of my housing one year, and wonder if a mouse might have gotten in and chewed up the boney parts. Check for mouse droppings inside maybe.

Inspector Lewis.

[Keith]

Louise, I can't be for sure that any fledged from these two gourds, but feeding of young was noticed when the young were about grown. Many of the pairs were fledging about the same time and I saw birds on and around these gourds but noticed no unusual behavior. Many of the feathers were flight feathers, either wing or tail or both. There were enough feathers to be more than one bird.
As I think about this problem, I have a question concerning bats. Most summer evenings we noticed 2 to 4 bats feeding in the yard and even around the Martin housing. Is there any possible chance that they would enter a gourd cavity and feed on the young?
Keith

[Louise Chambers]

Flight feathers, lots of them, suggest dead birds - adult or nestling. I don't know why there would not be skeletons, too, though. Birds can die in the nest from disease but usually bodies stay intact, so it's hard to say what went on.

As to bats, they eat flying insects just like the martins do, so no way they could or would harm martins.

Do you have fire ants in your area? They will climb poles and consume nestlings.

[M.Stephens]

Fire ants..... that's what I thought when I first read this thread a few days ago, but when there's no bones left behind I kind of ruled that out.

[Keith]

Thanks Louise and M. Stephens,
In the past when a dead PM was found in the cavity they were usually intact and confined to that one area. I'm just not sure Ants would leave only feathers scattered over entire area of the gourd floor, and I gather that was your concern too. These two gourds were on separate racks and all other gourds successfully fledged. I did not lower these racks the last two weeks of the season but will certainly watch closer next year. I do always watch for unusual behavior in and around the colony however. May never know what happened. At least it was only two pair. Two pair too many.
Keith