Tuesday, April 7, 2015

Help Ease the Crunch on the Cavity Nesters

Last weekend I noticed a Carolina chickadee gathering nesting material and then heading towards my bluebird box. A bit later I checked the interior of the box expecting to see the tell-tale signs of a chickadee nest; a thick mossy base with a cup lined with animal hair. Instead I found the box stuffed with pine needles, the sure sign that an Eastern bluebird had gotten there first. A few days later I checked the box after dark and saw a chickadee sitting atop the pine needles. So I’m assuming the Carolina chickadees won out over the Eastern bluebirds.
This illustrates that despite the proliferation of folks who now feed and attract birds to their yards, there is still a shortage of suitable nesting sites for cavity-nesting birds in urban areas. There are primary cavity nesters, those species like the woodpeckers that make their own cavities; and the secondary cavity nesters that move in after the woodpeckers have moved on. These secondary nesters can’t excavate their own home so they are dependent on the woodpeckers and folks who erect bird boxes for their nesting sites.
If every tree that dies or develops hollow cavities was allowed to stay standing there would be more natural sites. Understandably, in urban areas the dead trees are often quickly removed.
In an residential neighborhood there are about ten native species that might use a nest box if provided. Carolina chickadees, tufted titmouse, brown-headed nuthatch, house wren, Carolina wren, great-crested flycatcher, Eastern bluebird, barred owl, and Eastern screech-owl all could potentially use an appropriate box. In more rural settings, American kestrels, barn owls, tree swallows, wood ducks, and purple martins could use appropriate housing if provided.
I encourage you to provide a nest box in your yard to help alleviate the cavity shortage. It is not too late to put one up even though nesting has started for some species. Many of them have multiple nestings in a year. Make sure to pick a species that you want to attract so you can provide the entrance hole specifications for that species.

If you enjoy watching wildlife, an active nest box will provide great opportunities to observe nest building, feeding of young, fledging of young, and post-fledging activity.  

Below are a few species that might use a bird box:

Lets start with the easiest to attract. Eastern bluebirds often will check out a box within minutes after erecting it. 
Eastern Bluebird by John Ennis

Carolina chickadees vie with Eastern bluebirds for the choicest sites. Provide a custom bluebird box and a custom chickadee box to accommodate both.
Carolina Chickadee by Phil Fowler

Tufted titmice, cousins to the Carolina chickadees, readily accept a bird box too.
Tufted Titmouse by John Ennis

Brown-headed nuthatches need some help. This southeastern specialty doesn't compete well with other species for nest sites. Providing a custom built nuthatch box will help out this declining species.

Brown-headed Nuthatch by Jeff Lewis

Tree swallows are increasing in Mecklenburg County. You will need open country and acreage for them
Tree Swallow by Jeff Lewis

Great crested flycatchers are large birds and need a larger box. But they will readily use a custom box built to their specifications. they are present in the treetops in most neighborhoods.
Great Crested Flycatcher by Phil Fowler

The prothonotary warbler uses low swamps as a habitat. they also are the only eastern warbler that utilizes bird boxes. Forget it if you aren't near some swampy lowlands, but if you back up to Four-Mile Creek Greenway, Lower McAlpine Greenway, or McMullen Creek Greenway you might get lucky.
Prothonotary Warbler by John Ennis
Songbirds are not the only bird group to use nest boxes. Eastern screech-owls readily take them but you will be lucky to get them. Woodlots made up of hardwoods might harbor a pair of screech-owls.
Eastern Screech-owl by John Ennis
Even large owls will take a box if it is large enough. This barred owl chick was in a cavity in Latta Park in Charlotte. There is an owl box there that has been used most years, but last year the owls used a natural cavity. 
Barred Owl Chick by Lee Weber