Finding newly hatched birds on ground - every day!

[David Jenkins]

We have had a successful colony supporting 12 pairs for many years. Have had occasional jumpers in the heat of the Texas summer, but never this:

Every day since birds have started hatching, we (or I should say, our dog) have found 1 or 2 dead, naked babies on the ground fairly near the housing. In one case, the neighbor found one in their yard. They appear to be just a few days old.

We have no HOSPs in this new subdivision (time out to knock on wood), and SREHs have successfully kept starlings from getting into the gourds. Further, we see no starlings, nor have we ever seen any other predators threatening the colony. (We do have a bald eagle that occasionally fishes our lake, and a hawk in the area now and then, but these gourds are such that I don't believe that a hawk could reach in and grab a baby.)

We have heard no untoward noises from the colony, and although we have water snakes and rat snakes around, I don't believe they have got into the gourds, or we would have heard the martins raising hell. Anyway, the snakes wouldn't throw the babies overboard - they would eat them.

Any theories as to what might be going on? Could we have a rogue PM causing this damage?

Thanks.

[Tengai]

Do you have house wrens? They are notorious for displacing eggs and newly hatched chicks of competitors

[Matt F.]

Could we have a rogue PM causing this damage?

Hi David.
Sorry about your babies.
I think you may have very well identified the perpetrator, when you asked about a "rogue PM".
If it were a starling, or house sparrow, I would think they would drop them right off the porch - certainly not carry them off, like the one your neighbor found.
House sparrows also usually inflict some sort of trauma to the babies, which it sounds like you did not see.
What your describing sounds a lot like the observations and reports from some landlords here on the forum over the years, that have had to deal with "rogue" SY male Martins.
Are your housing compartments all taken?
If so, that again would point to an SY male Martin.
Some folks would even put up temporary, extra housing, to try to keep overly aggressive SY males from wreaking havoc on the already nesting ASY Martins.

[flyin-lowe]

Do you have any or many new SY's arriving? As above, they could very well be your problem.

[David Jenkins]

Matt:

AAMOF, I think this problem started manifesting itself when the SYs started showing up - or maybe a few weeks later. And yes, all our gourds are full. One of the SYs may, indeed, be our perp.

We have neighbors a few blocks away that have had completely empty new rigs for a couple of years. This year, they managed to get some SY pairs. I wonder if the SY pressure was unnaturally high this year in this area.

As a side note: Pulling a new baby up and out of a horizontal Troyer gourd, and then flying with it, would be no mean feat Purely from a observational standpoint, would like to have seen him do it.