All birds reproduce by laying eggs.
Some, like many precocial birds, lay about a dozen eggs in their nests.
Many have multiple nests each breeding season, but they have smaller clutches.
Robins, of which most are familiar, are altricial birds, laying about four eggs.
They then incubate them, feed and care for the young in the nest, help them after they fledge, and maybe a week or two later, begin the process again.
Some bird nests are intricately constructed taking a week or two in the process. Some, like a mourning dove, hastily gather a few thin twigs and fibers and in two or three days complete the nest building. The doves have multiple nests each summer with usually only two eggs per nesting.
But what you may find quite intriguing, is that a robin nest in Pennsylvania is constructed almost identically to a robin nest in Missouri. Adding to that, each species usually finds a similar type of tree, shrub, or structure in which to place the nest.
Here in the Times News area, I have seen/found nine bald eagle nests, seven were in or near the top of large white pines and the other two near the top of large red oak trees. Both tree types have large limbs near their tops to support nests that they use every year. In fact, the nest gets larger and heavier as they add branches year after year.
Bluebirds, fortunately, and unfortunately, build their nests in cavities.
The fortunate part is that the cavity will help exclude some predators.
But unfortunately, the European starlings and house sparrows also nest in cavities, and being more aggressive, started claiming the available cavities.
It might be better for the bluebirds to nest differently, but as I mentioned earlier, each species evolved with a nest site preference and nest building style.
I’ll conclude by reminding you that no young birds get to see the parents build the nest they were born in, yet, innately, they construct the same type of nest with nearly all the same type of nesting materials. If you find birds nesting, avoid making many trips there to observe the process. Your regular trips to “check in” on them could lead predators, like feral cats, to an easy meal.
Test Your Outdoor Knowledge: There are _____ species of bluebirds found in the U.S. A. 3, B. 4, C. 5, D. 6
Last Week’s Trivia Answer: I asked you to arrange the following birds from largest to smallest wingspans: bald eagle, 80 inches; turkey vulture, 70 inches; black vulture, 59 inches; red-tailed hawk, 52 inches; raven, 46 inches; and crow, 40 inches.
Five soon to fledge barn swallows, line up for the “chow line” along the nest rim. Swallows can make about 800 trips carrying mud pellets to complete the nest. Nests are usually placed on rafters or spikes in barns or open bay garages or farm outbuildings. BARRY REED PHOTOS
Eastern phoebes build their nests on a protected ledge or most likely today under a lightly used bridge or even under a porch roof or at a cabin that is used less frequently. Note the amount of moss used in its construction.
Baltimore orioles build their nests on a fork of thin branches in a deciduous tree It is often on some of the highest and thinnest to discourage raiding squirrels from robbing the eggs.
In contrast, great blue herons make no effort to conceal their nests, and in fact, nest in rookeries sometimes containing dozens.
Screech owls nest in cavities. A no longer used pileated woodpecker nest hole is perfect. However, with more humans erecting the proper size nest boxes, they will readily accept made boxes. They'll not normally add nesting materials, but nest on the woodpecker chips or man's wood chip introduction.
Rough-winged swallows once used cavities in stream banks or rock ledges to nest. However today, they look for drainage pipe openings in retaining walls. They even nest in the drainage holes at the cantilever area of Lehigh River Gap along Route 248.
Red-tailed hawks nest in sturdy forks of large deciduous trees (most often large oak trees) usually more than 60 feet from the ground. Note: these nests, the next year, are often claimed by great horned owls who don't construct their own.
Robin nests are all constructed with the same mud and grass composition. However, their nest sites vary more than other birds. The first nest of the summer is often in a dense conifer. Their second nest, often in a tree fork when deciduous trees are fully leafed out, are then a common option. However, they may nest atop a porch light, on top of a rafter in a farm out building, or even atop an elbow of a downspout under a roof eave.
Cliff swallows are tireless builders. They need to wait for enough rain to create the mud needed to construct their nests. When people were not such a great influence, they nested out of the rain under cliff ledges. However today, it is now more likely they'll nest in small colonies under bridges or under barn roofs. More than 1,200 mud pellets are needed to complete a nest, sometimes taking nearly two weeks to finish.
Ospreys normally nest close to water sources where they catch their food. They can use the forks of a tall tree, but may nest on a channel marker buoy in the middle of a bay, atop a cell tower, or now with efforts to increase their populations, atop man-made nest platforms. BARRY REED/SPECIAL TO THE TIMES NEWS
Only by sheer luck was I able to find a ruffed grouse nest. She chose a leafy spot on the south (sunny) side of a large tree trunk. Often, some leaves lay atop the nest when she vacates it for a short period of time. Old hunter tales claim that she places leaves on her back so when she leaves they'll drop onto the nest. More likely though her hasty exit with such speed scatters a few leaves there.
Bald eagle nests are placed high in large trees. White pines and oaks are favorite choices. Bald eagle nests used year after year, can eventually weigh hundreds of pounds or more and could be 5 or 6 feet deep.