LOVE IS IN THE AIR AND NEST BOXES

No other season is heralded by nature's song like spring. When you hear the singing of mating calls and tuneful proclamations of territory, you know that eggs and nestlings are not far behind. As recommended in the last issue of Seasons early February was the time to clean out your nest boxes for the upcoming breeding season.

Now, your boxes should be checked for use so that nesting success can be monitored. Indeed, nest box monitoring can be a very fun and rewarding part of your Wildlife Management program. Be sure to document each time you check your nest boxes so you have a record to reference and documentation for your Central Appraisal District. Documenting use of nest boxes will also help you determine which boxes are in suitable locations or should be moved. Monitoring the use of nest boxes will help measure nesting success of breeding birds on your property -- not to mention the joy in watching your baby birds grow up!

If you aren't quite sure what you're looking at as you curiously peek into your nest boxes, below are some helpful tips for identifying several species of cavity-nesting birds common in the Texas Hill Country, and most likely happily using the nest boxes on your property.


Carolina Wren - These birds usually begin breeding between mid-March and early April and will often raise multiple broods. Clutches (eggs laid at a single time) are most often between 4 to 6 eggs, but the Carolina Wren may lay as many as 7 or 8. The small, somewhat elliptical white eggs are smooth and moderately glossy and finely speckled, spotted, or mottled with reddish-brown, purplish-brown, or paler purple or gray markings. Heavier markings are usually on the larger end of the egg, with fine, profuse speckling elsewhere. Nests are made predominately of plant materials such as grasses, weed stems, strips of bark, leaves, moss, and rootlets, and lined with fine grasses, rootlets, hair, and feathers. The nestlings are hatched naked, blind, helpless, and totally dependent on their parents. When Carolina Wren nestlings begin to develop feathers, they are scantily covered with a slate gray down. Mouths are yellow and the area around the corners of the mouth will be yellow as well. The babies usually fledge (leave the nest) between 12 to 14 days of hatching.

Should you find a nest of baby birds while checking your nest boxes, try to make your inspection quickly to minimize disturbing the babies and parents. If a baby jumps out of the nest, simply pick it up and put it back in. Most birds have a very poor sense of smell, so there is no need to worry about the parents abandoning them due to the scent of humans.

Eastern Bluebird - Bluebirds begin breeding in mid-March or early April and will usually raise 2 to 3 broods over the course of the breeding season. They form loosely built cup nests made of dry grass, weed stems, and small twigs that are lined with fine grasses, hair and feathers. Clutches are usually made up of 4 to 5 somewhat elliptical, smooth, glossy, pale blue eggs with no markings. The hatchlings are born helpless and pink-skinned with dark gray down on the head, wings, and lower back. Mouths are deep yellow and have pale yellow gape flanges (around the corners of the mouth). Babies usually leave the nest at 15 to 18 days old and are tended by the father while the mother begins to nest again. Note: If you are able to monitor your bluebirds closely, make an effort to remove the nest each time a clutch of baby birds fledges. This will encourage the female bluebird to build a new nest and utilize the nest box again.

Plateau offers services and products that can help with your songbirds. Our Spring Breeding Bird Census is conducted by qualified wildlife biologists who welcome your participation on this great nature walk on your own land. Our biologists offer their professional services to guide your management activities. We also offer feeders, nest boxes, and seed. Just let us know whenever we can help.

Carolina Chickadee - Chickadees readily use nest boxes and begin breeding as early as late February in Central Texas. Their nests have a base of moss and a cup made of plant down, feathers, hair, and plant fibers. They usually only produce a single brood each year. Typically, 6 eggs are laid, but the nest size can range from 5 to 8 eggs. The eggs are quite small (15 x 11 mm), smooth, not glossy, and white to a creamy white with a fine speckling or spotting of reddish-brown or purplish-brown markings. Quite commonly there is a higher concentration of markings on the larger end of the egg. The babies are born helpless with pale pink skin and dark gray down. Their mouths are light yellow and their gape flanges ivory. Nestlings usually fledge from the nest at 17 days after hatching.


Tufted Titmouse - Titmice begin breeding in mid-March and usually fledge their second and last brood by mid-July. These woodland birds build nests with a base of moss and dead leaves and a cup made of hair, fibers, fur, wool, cotton, and other similar materials. Titmice usually produce 5 or 6 eggs that are smooth and non-glossy to slightly glossy, white to creamy-white, and finely speckled or spotted with chestnut red, purplish-red, or brown. Sometimes the spots will be a paler purple or lilac color and are typically fairly evenly distributed over the egg. There may be some concentration of spots on the larger end. Titmouse eggs are larger than those of a Chickadee (18 x 14 mm). Titmouse babies develop most of their feathers by the time they are 10 days old and generally fledge at 15 to 18 days.

Black-crested Titmouse - Although genetically and vocally distinct from the Tufted Titmouse, the Black-crested begin their breeding season around the same time in March and wrap-up in June. Their nests are built of leaves, moss, dried grass, hair, strips of bark, and sometimes feathers, and lined with hair or similar material. These Titmice produce clutches of 4 to 7 eggs that are white and finely speckled with reddish dots. As juveniles, the Black-crested Titmouse is virtually indistinguishable from the Tufted Titmouse.


Eastern Screech-Owl - Usually monogamous, most Eastern Screech-Owl pairs remain together for life. Some males, however, mate with two different females. Breeding season for Eastern Screech-Owls is generally around mid-April, but some may breed mid-March to mid-May. These birds nest in tree cavities but also readily use nest boxes. The clutch size is from 2 to 6 white eggs. If the male has mated with two different females, the second female may evict the first female, lay her own eggs in the nest, and incubate both clutches. The hatchlings are born covered in white down, eyes closed. The fledging period is about 31 days.

Bewick's Wren - Breeding season for the Bewick (pronounced like the car, Buick) begins in February. Nests are made of sticks, leaves, moss, spider egg cases, feathers, and hair, and often lined with snake skin. The Bewick Wren typically produces 3 to 8 eggs that are white with varying amount of dark spotting frequently concentrated around the large end. Hatchlings are helpless with only wisps of down. Bills are yellow, gape yellowish with an orange tinge, and skin is pinkish. They usually fledge 14 to 17 days after hatching.

Purple Martin - The Purple Martin in North America has nested almost exclusively in nest boxes for more than 100 years. The nests made of twigs, plant stems, mud, and grass will be home to 1 to 8 eggs. Eggs are white and average 24 x 17mm. Born helpless and naked, the Purple Martin chick fledges in 28-29 days.


At the end of the summer, after your avian guests have departed for the season and flown to different skies, be sure clean out the nest boxes in preparation for winter and new guests.