Intruders or Guests?

[JohnT]

I was out of town for work for 10 days, and when I did my first nest check after I got back I found a nest I've never seen. It nearly fills the gourd like a sparrow nest, but the material is a little coarser with an open pocket lined with finer materials and feathers.

Sorry the eggs are blurry. I wasn't wearing my glasses, and it was dark before I had a chance to look at the picture on my phone.

I've spent quite a bit of time looking at egg pictures of cavity nesting birds with no luck. And I've not seen anything other than martins on the rack, though the particular gourd faces away from the house and I can't see the rack as I approach it.

[John Miller]

Pretty sure it's a house sparrow that found a coarse source of nesting material...but watch closely and confidently ID the squatters before you pull the nest and set a trap. Lower or tap the pole if needed to flush the female off the nest, but if it's house sparrows, the male should be sitting on the house a lot.

If you are not good at trapping, you may be better off just taking eggs as pulling the nest alone will set off male house sparrow revenge now that the nest has progressed this far. But again, ID first.

John M

[JohnT]

I'm pretty sure it's not a house sparrow. Though it's hard to quantify, the nest is much more well-built and neat than any house sparrow nest I've seen. Looking through the entrance, I thought it might have been one, but as soon as I opened the lid everything looked different. The cavity itself is carefully lined with what may be a rusty brown down and cattle hair.

I have 7 bluebird houses on our place and two racks of gourds for the martins in farm country, but I've never come across eggs or a nest that look anything like this.

But then again, no egg I've found looks even close to these, so it may be a house sparrow that is OCD about its nest. I may have to trap a bird to identify it. If I do, I'll wait until the weekend so I can check the trap frequently. I'll probably be setting a trap on another gourd on the rack at lunch time, so I'll try to get a better picture.

[John Miller]

If the eggs are smaller than house sparrow, I'd suspect wren...,maybe Bewick's wren. but don't pull and trap until you observe the adults and ID. Native species are protected, and it just ain't right. whew. I'm retiring.

John Miller

[Louise Chambers]

Those look like House Sparrow eggs to me, too. Here is a link to photos: http://www.purplemartin.org/update/NestID.pdf Wren eggs are usually tan-brownish, but can't be positive as to color in the photo.

Once you get a look at adult birds, you'll know for sure and can take steps to deal with the issue. And wonder about something - in the photo, at front right, those look like martin feathers in the nest - wonder if something got a martin and the feathers were used in the nest. Classic house sparrow nest is big ball of grass and trash and stuff, with tunnel entrance. They often, maybe always, use some feathers in their nests, whereas wrens use mostly twigs, sometimes some fur and moss, depending on species.

[BrendaVR]

Those eggs look awfully dark to me. Maybe its just the way the photo was taken and is shadows. Hard to know ID from this.

Maybe consider other species too: Flycatcher http://www.sialis.org/nestsgcfl.htm (lots of others to brows through there on sialis)

[Louise Chambers]

Flycatcher is good suggestion, Brenda - and they like furry nest linings, too. John T, is the nest a complete dome with tunnel, or open at the top, like a bowl. Flycatchers are shy, too - could be. I thought HOSP at first but this is still a mystery nest!

[Matt F.]

I'm with Brenda - looks like a Flycatcher nest and eggs.

[JohnT]

Flycatcher is good suggestion, Brenda - and they like furry nest linings, too. John T, is the nest a complete dome with tunnel, or open at the top, like a bowl. Flycatchers are shy, too - could be. I thought HOSP at first but this is still a mystery nest!

Open at the top. I didn't disturb anything to take the picture other than removing the cap. The nest doesn't quite fill the gourd, and the bowl is almost like I put my fist down in and formed the nest around it. A bit smaller at the top.

[John & Linda - KY]

Isn't it flycatchers that usually use a snake skin in their nest? -- John

[Louise Chambers]

Okay then - I wrongly assumed it was house sparrow nest with tunnel. So now consensus is leaning towards flycatchers, but, now that I think about timing - they are migrating through Texas and southern states now. Would they have eggs already in southern Indiana. Could this be a titmouse or chickadee nest? Those would be my next birds of choice - still a mystery nest! Nuthatch? http://sialis.org/nests.htm

John, we'll enjoy following this along with you.

[JohnT]

Those eggs look awfully dark to me. Maybe its just the way the photo was taken and is shadows. Hard to know ID from this.

Maybe consider other species too: Flycatcher http://www.sialis.org/nestsgcfl.htm (lots of others to brows through there on sialis)

Yes, they are very dark. That was the first thing I noticed about them. Nothing I've ever seen, including killdeer eggs, is as dark as these.

[JohnT]

Okay then - I wrongly assumed it was house sparrow nest with tunnel. So now consensus is leaning towards flycatchers, but, now that I think about timing - they are migrating through Texas and southern states now. Would they have eggs already in southern Indiana. Could this be a titmouse or chickadee nest? Those would be my next birds of choice - still a mystery nest! Nuthatch? http://sialis.org/nests.htm

John, we'll enjoy following this along with you.

I regularly see all three birds around the farm. I've had black-capped chickadees raise a brood in a bluebird house before, but I don't remember the timing.

It about has to be a cavity nester to fill up so much space, but I've spent hours on the web and not seen anything close to these eggs. I know some birds are outliers with regard to egg coloring, so I'm hoping to spot an adult.

[Matt@atx]

Its a little blurry but Aren't those eggs a dark black and white swirl marble like color? How odd.

[KathyF]

Very cool....if those eggs are really that dark, I'm agreeing on the fly catcher ID. Ohhhhh, a mystery!
Can't wait to find out!

[MamaBruff]

I googled images of GCF eggs, and they do look a lot like JohnT's mystery eggs, I think. Wasn't it last year when Bulldog had a Mystery nest in a gourd that turned out to be GCF? How fun! I too love a good mystery.

[Matt@atx]

Having taken a couple more looks at the photo, they appear like dark grey(not white) and black marble-like swirl pattern color eggs.
If that's not some weird really uncommon sparrow or Starling nest, that should be a keeper to hang with those Martins if it will do so peacefully.
Very neat find. Thank you for the photo share.

[JohnT]

Had a cow go into labor last night and a dog apparently got in a fight with something along with a garden that needed protection from frost, so I didn't get to spend as much time watching as I'd have liked. By the time we got the calf pulled, dog to the vet and garden covered, I was worn out.

I spotted a tufted titmouse in a tree nearby this morning, so that is the leading contender right now.

Though I was using an LED light when I looked, the speckles on the eggs tend toward purple or burgundy. There was an additional egg last night that was much lighter and more toward tan speckles. All are a bit more heavily speckled towards the large end, and that tends to point that way as well. Took a dozen pictures and couldn't get anything to show up without disturbing the nest, so I gave up.

I did some reading at lunch today which indicated that titmice like to use hair in the nest as well.

The only concern I have is that my reading says they are not as tolerant of nest inspections as bluebirds. I don't want to scare her off the nest, but I also don't want to ignore my martins. It looks like she will have her babies hatched and fledged well before the martin eggs hatch, so maybe I can work around her schedule!

Once the eggs hatch, I'll try to snap a picture of a parent on the porch of the gourd to document. I have a blind and a long enough lens to get the job done.

When I put up martin houses and bluebird boxes, I hoped to get martins and bluebirds. I never expected bonus birds in the form of tree swallows, chickadees and tufted titmice. Kind of cool!

[Louise Chambers]

John, we have titmice in bluebird boxes, and they tolerate weekly nestchecks okay - let us know.

[DebA]

This has been a fun read. It started to remind me of what color was that dress? Blue? Black?
Deb