Help: Colony Abandoned

[oifisher]

Had all cavities occupied (wooden T-14 and 4 Troyer gourds) July 4. Saw fledglings in the air and a couple on the ground the previous 2 weeks. Also saw a couple of fledglings dead at the foot of the pole.

I noticed a couple of days after the 4th that there were no birds around--morning, noon, or evening. None. Thought maybe they all had fledged really early b/c of the warm spring.

Just cleaned the box out and found many cavities w/ bodies of babies at all stages of life--from fully feathered at the entrance to babies w/o feathers in the nest. About 30 total. Cavities w/ dead babies were scattered--a couple of the gourds and T-14 cavities in all four quadrants. Some nests had 4, 3, 2, and 1 dead babies. No adults.

They appeared to be abandoned.

I noticed several times since the 4th that groups of martins would fly around the box and want to land. But, they got w/in 1 or 2' of the box, hovered, and flushed off, making the alarm sound. Frightened.

Colony is 9 yrs old. Predator guard. No hawks, crows, racoons, snakes. Location is Outer Banks, NC.

Didn't do nest checks this year b/c the pole is warped badly. Box hangs up when trying to lower and raise. (The PMCA wooden pole design did not prevent warping.) Afraid I couldn't raise it after lowering.

Normally do nest checks and sprinkle 1/4 tsp Sevin weekly once eggs are laid. Couldn't do that this year.

When cleaning out the nests, I noticed a major infestation of a small insect, about 1/8" long. Looked like a small tick, but wasn't. Didn't hop or fly. I've seen them previously when cleaning out the cavities at the end of the season, but not nearly this bad.

Any thoughts on what (apparently) caused the adults to abandon the colony before many babies fledged?

Thanks

[Louise Chambers]

Can you post a photo of the bugs? Sound a bit like swallow bugs, which can infest swallow nests badly at times. Otherwise I'd say you had snake(s) or owls, despite the predator guard.

here is an article with drawings and photos of nest parasites:

http://www.purplemartin.org/update/Parasites.html

[ToyinPA]

Bob:
I'm going to guess the bugs were lice. If bad the chicks would jump out of the nest.

As for the parents abandoning the chicks...when one chick dies the parents won't go in the nest to feed. The remaining chicks starve/dehydrate & die. Some will jump, but end up dying on the ground. You need to do nest checks every few days & take out any dead & put in a fresh nest.

Due to the heat wave this year &/or drought parents stop feeding when it gets mid 90's or above, or if they can't find food. The chicks dehydrate & die.

I would suggest you either put up a metal pole or take down your houses. You have to be able to do nest checks or you won't have a colony left.

Toy in PA

[Louise Chambers]

Toy, lice usually spend their entire life cycle on the birds, and won't be found in the nest after the birds leave - but mites and fleas and swallow bugs can be found in nests after the martins are gone.

Martins will keep feeding and tending young even with one more more dead young in the nest - this is known from nest cams and nest checks. The parents would not abandon live young due to a dead sib. They often remove smaller dead nestlings but I've found them still present and pretty decayed at times.

[ToyinPA]

Louise:

I had 3 nests with dead chicks this year & none of the parents tried to remove the dead nor would they continue to feed the remaining chicks. That is why I stated what I did. I've had this happen in the past as well...chick dies, parents abandon the nest. Not all may do this, but in my colony they have this year & in past years. Once I removed the dead chick, replace the nest, the parents came back.

Toy in PA

Toy, lice usually spend their entire life cycle on the birds, and won't be found in the nest after the birds leave - but mites and fleas and swallow bugs can be found in nests after the martins are gone.

Martins will keep feeding and tending young even with one more more dead young in the nest - this is known from nest cams and nest checks. The parents would not abandon live young due to a dead sib. They often remove smaller dead nestlings but I've found them still present and pretty decayed at times.

[Trishy]

It must be different depending on the parents. I had a dead baby in a gourd, and the parents just pulled it towards the front, and continued to feed the others.

[oifisher]

Louise--

The bugs infesting my colony do not match anything in the article you attached to your reply. BUT, they look exactly like the swallow bugs (bed bugs?) that you mentioned. See http://bugguide.net/node/view/252639.

I've attached the best picture I could take of the bugs--one bug on my hat. Already killed most of them w/ insecticide. The bugs are brown, oval shaped, and about 1/8" long, and do not jump or fly.

I'm confident the problem was not owls or snakes, or other predators.

I noticed several of these bugs as I was raising the box in the spring. Didn't think anything of it--thought it was part of nature. Surprising that these things could destroy a year's worth of fledglings for about 12 cavities. So, you think the bugs attacked the babies and ultimately dehydrated/killed them?

I'll be sure that the box and gourds are sanitized before I raise them next year. Hope I'll get some martins to return.

Thanks[/img]

[oifisher]

Louise--

The photo of the bug didn't attach to my previous post b/c it was too large. Will try again.

[Louise Chambers]

I have read about severe infestations, usually in cliff swallow colonies, causing the birds to abandon a site - if there are so many bugs the adults won't land and feed young, that would mean nestlings starve. They are not common in martin nests but have been documented.

Be careful about using insecticides, or that is, about any residue they leave behind. I'd suggest scrubbing house with soapy water and rinsing after it's all cleaned out. Swallow bugs will hide in crevices - I am not sure what is the best method for getting rid of all of them, but will look for info.

[Steve Kroenke]

Hey Bob,

I have had several severe infestations of swallow bugs in two of my purple martin colonies in the past. These bugs are VICIOUS! They will bite humans, too! They may cause martins to abandon their nests if the swallow bugs overrun the cavities.

Here is a link to a posting of mine with photos of swallow bugs clustered around the entrances to gourds:

http://purplemartin.org/forum/viewtopic.php?t=12098

I haven't had anymore problems with these bugs after the last infestation.

Steve

[Martin man RI]

Will the birds return in the spring since they failed to produce offspring?
That is a act of nature and not a predator....

Ray

[Tim Stover]

that is about the same time i lost 10 to 12 nest all ages but the heat caused it here probaly 30 to 40 birds but not one adult

[Laverne]

Will the birds return in the spring since they failed to produce offspring?
That is a act of nature and not a predator....

Ray

I don't think it matters what causes the failure. It is the failure itself that makes the birds move on in search of a "different" site to try again. I say, "I don't think" because none of the theories are set in stone. Purple Martins are unpredictable and the ones that did fledge their young will most likely be back next year.

[Barrowdog]

Thanks everyone for the info. My husband and i couldn't figure where the bites came from this year. We saw a few of these bugs for first time this year. My birds use sand from the bay shore and I am concerned this may be an origin. Will use sevin next year at the intervals recommended. Also this year late in the season squirrels chewed away the entrances of 2 super gourds. I saw the martins attacking one. Luckily the nests had fledged. My husband is getting discouraged ,but I am not ready to call it a day yet.
Sue

[Louise Chambers]

The swallow bugs come in with the martins - as do the fleas and mites. So there's nothing you can do to prevent them, but you can work to control them in the nests.

How did the squirrels get to the gourds? Up the poles, or jump across from nearby branch, wires, etc? Pole guards should stop them if placed high enough, but branches may require some pruning. They'd eat eggs and nestlings and use gourds for a nursery. Our martins mob them when they see squirrels run along our back fence.

[Barrowdog]

The swallow bugs come in with the martins - as do the fleas and mites. So there's nothing you can do to prevent them, but you can work to control them in the nests.

How did the squirrels get to the gourds? Up the poles, or jump across from nearby branch, wires, etc? Pole guards should stop them if placed high enough, but branches may require some pruning. They'd eat eggs and nestlings and use gourds for a nursery. Our martins mob them when they see squirrels run along our back fence.

. Louise , They jumped the guard (homemade). Looks like will need to invest in real thing. How high up? Up until this year had them over the water,but this year moved them into tend to them more frequently. Thanks, Sue

[David sh]

I had a similar situation in late June. We did have some mites and it was very hot. Babies started jumping and adults seemed to have stopped feeding. Everything had gone very well up until then. We did have a coopers hawk making about two fly overs a day too. Not sure why it happened but I would like to know??? Not a snake or ground predator.(have stove guards and netting on all posts). Only other note is that this happened with our late nesters (8pairs in all failed) and they were all in brown natural gourds. Many of the failed nestlings were very close to fledgling age

[Martin man RI]

Same thing happen to me. I was to blame. I did not use Sevin on these
gourds (natural) and the chicks were covered with mites. Around eight
pairs jumped. I used sevin on all the rest and they were fine the rack was
covered with mites. The rack looked fine. Other sites were ok. You do wonder what went wrong but i can tell you to end the worry. Mites. I am sure the coopers hawk did feed well too as i cannot be there all day. That will never happen again! The mite population was high and put all there numbers in the one site that had the largest number of chicks and they went on a rampage. Sad but we learn from it. Put a small dent in my numbers
but still have just over 50 pairs that produced chicks. But hate to loose even one chick. Next year going to block half the gourds and make sure everything is ok before they fill them all. There is plenty of room in other area's of the town.