Kestrel Raids Nest Box

While walking the field trail I heard a commotion of Tree Swallows just beyond the next small hill.  Babies were yelling and adults were excitedly giving their distress call.  I assumed a predator was at work and hurried ahead with the expectation of finding a Black Rat Snake making a meal of baby birds.  Instead, I saw this American Kestrel perched atop the bird box.

The parent birds were in the air doing their best to encourage the kestrel to move on.

All they could manage was to make the Kestrel duck as they came over its head.

Then the Kestrel dropped down to the front of the box and made a determined effort to reach the young birds inside.

There was a great amount of flapping and shifting of position as the Kestrel worked to get its head and neck through the nest box entrance.  I expected a baby Tree Swallow to be pulled free at any instant.

The Kestrel was not rewarded for its effort.  This model bird box has an extra piece added to the front that extends the depth of the entrance hole.  The intent of this design is to make it more difficult for predators to reach in and down to the nest.  Apparently it is doing its job.

But the Kestrel just couldn’t resist giving it another try.

This must have given the young birds quite a scare.  The Kestrel has its full neck thrust into the box and its head is surely hanging just above the babies.

That had to be one frustrated bird.  No amount of trying was going to result in a meal being taken from this box.

Finally, the Kestrel turned its back and gave up.  I watched it make five separate attempts to reach the nestlings and it had obviously made some attempts before I arrived on the scene.  After resting for a moment, it flew off across the field and disappeared.  A minute later, the parents were back with food for the youngsters and life went on as before.

Memorial Day Nest Box Check

Memorial Day usually coincides with the end of the first nesting attempts in the bird boxes. That makes it an opportune time to make the rounds and see how things are going.

Bluebirds are the first to nest in the boxes each year and are usually finished with their first brood by now. I try to clean the boxes before another pair of birds moves in and builds a new nest on top of the old.

It’s always a dusty mess beneath the nest. There’s an art to avoiding the blowing dust created by sweeping out the box.

Ants have moved in and have quite a cache of larvae and pupae stored in the old nest material. The presence of ants could cause potential nesters to avoid this nest box. The ants could also be trouble for any developing nestlings.

I leave the box clean and ready for the next occupants. I didn’t find any active Bluebird nests. I see a lot of Bluebirds sitting on the utility wires or the fence, along with what appear to be their latest batch of young.

All of the active nests were those of Tree Swallows. The range of activity stretched from a newly constructed nest to a batch of older youngsters. There were two nests with four eggs in each.

There were also two nests with older nestlings. It looks like Blue Jay Barrens will once again make a significant contribution to the Tree Swallow population. Competition for nest space is already intense. Some of these birds are going to have to move off and find new territory.

As is usual, I found myself between hungry birds and their parents. Insects are out in abundance, so I expect these little guys will be filled to capacity.

Bird House Tenants

All of the bird boxes are occupied for round one of the Bluebird/Tree Swallow nesting season. After checking all of the boxes, I found that instead of only one pair of nesting Bluebirds as I mentioned yesterday, there were actually two boxes that contained Bluebird nests. I my error came about by assuming that seeing a pair of Tree Swallows sitting atop the box meant that they were the owners. I don’t know what the Bluebirds were up to that they would let Tree Swallows have such easy access to their nest site.

There was really a lot of material used to create this nest. It’s possible that the base was started by another pair of birds and the Bluebirds stole the box and built their own nest on top. I’ll dissect the nest when I clean out the box to see if this was the case.

Four eggs so far. I would expect one more before brooding begins. It looks like the boxes are doing a good job of staying dry, despite the downpours that seem to occur every couple of days.

No eggs yet in the Tree Swallow nest, but it’s already looking dirty. I think the birds found some of the feathers that were cleaned out of the box last year and used them again. I don’t think I’ve ever seen that happen before. I know that Tree Swallows can really mess up a nest, but they should at least start with clean building materials.

Tree Swallows Claim Nest Box

The Tree Swallows have been busy choosing nest boxes for the start of the nesting season. Bluebirds have reaped the rewards of spending the winter in Southern Ohio and already have nests in three boxes. Tree Swallows are actively negotiating control of the remaining boxes. It may appear that these two have inherited a rundown shack, but this box has fledged more young birds than any other on the property.

One Tree Swallow, which I will designate He, looks into the box while the mate, known as She, watches other Tree Swallows circle overhead. I can’t be absolutely sure about those labels, but first year females normally don’t display the full blue coloring and show more brown on the head and back.

While He is inside, another potential tenant does a fly-by.

She isn’t happy with the intrusion and tells He to get out here now.

He obligingly reappears to find everything quiet. There are way more Tree Swallows than I have boxes for, so I’m hastily putting a couple more together. Tree Swallow chatter is so loud that it’s hard to hear anything else in the field right now.

Bluebird Boxes

I’ve noticed the Bluebirds beginning to pair off and stake out their preferred nesting box, so I went out yesterday evening to check for nesting material. This is the oldest active box I have. It may look a little bit shabby, but last year it successfully fledged two nests of Bluebirds and one of Tree Swallows. No sign that nest building has begun for this year.

This ant hill sprang up four years ago, just a couple of months after I put up this box. I haven’t seen any ants attempt to climb up to the nest. The black plastic tubing may be a deterrent. I buried the bottom of the tubing to discourage anything from climbing up through the inside of the pipe.

This box was made by the local FFA class. Several Bluebirds have roosted here through the winter. They’ve made a bit of a mess around the entrance hole.

They’ve also made a mess inside. Bluebirds exist primarily on fruit through the winter, so their droppings are usually full of seeds. I cleaned a bunch of poop and seeds out of this box about two weeks ago, so all of this has accumulated since then. Insects should soon make up the bulk of the Bluebird diet.

The seeds I cleaned out before represented a wide variety of fruits. This batch is entirely from Eastern Red Cedar. Cedar fruits are generally plentiful through the year, unless one of the giant Starling flocks moves in and decides to stay for a while. Starlings love to gorge on the fruit and scatter the seeds all over the prairies.

Checking Nest Boxes

I went around Saturday and checked some of the nest boxes scattered around the prairie. This box was built by the local FFA chapter about two years ago. Several families of Bluebirds and Tree Swallows have fledged from here.

The 2009 nesting cycle for this box was Bluebirds-Tree Swallows-Tree Swallows and then this base that was never completed. I clean the old nest material out after each fledging to help cut down on parasites.

The amount of dust accumulating beneath this material makes me think that birds have or are currently roosting in this box. I usually clean the boxes out in mid November and put a couple of inches of dry, soft grass in the box for the birds that will roost there through the winter. On those zero degree winter nights, it makes my feet feel warmer to think that the birds have a little bit of insulation beneath them.

Looks like a male House Wren built one of his stick nests on top of a Chickadee nest. This box is close to the field edge and never contains Bluebirds or Tree Swallows.

Some of the boxes become hidden in the tall Indian Grass. This box was constructed by the ODNR Division of Wildlife about sixteen years ago. About 400 of these boxes were given to landowners in Adams County as part of the Division’s Bluebird Program. I received 10 of the boxes and in return, provided several years worth of nesting records to the Program Coordinator.

Here’s another nest base that was never finished. Bluebirds fledged from this box in the spring. After that, the Bluebirds and Tree Swallows competed for the box the rest of the nesting season. One week Bluebirds would seem to have possession and then the next week, Tree Swallows would be in control. Maybe that’s why there’s such a thick layer of grass in this box. Each time a new pair would take over, they would add a little bit more nest material to the ever growing pile. There were other available nest boxes near by, so I don’t know why the battle was so intense for this particular box.

A wasp began a nest in this box. It never managed to produce a brood. Usually, wasps don’t move into these boxes until the nesting birds have left.