This is the most important time of the year for our backyard birds. This is what it was all about, the hard work of surviving the winter or chancing mile after mile on migration to get here. Songbirds barely have time to settle onto a branch, put back some of the weight lost in winter's cold or on long flights, choose a summer territory, and then it's time to dive into nesting season.
They fill the spring with song, but it's not meant to entertain us. Song is how they stake out a claim and work to catch the attention of a mate. Next, birds scour the area for building materials, using grasses, sticks, mud, feathers or moss to build the kind of nest particular to their species.
Many of us put up birdhouses for birds to nest in, but may not realize that only about 10% of birds are "inside" nesters, making use of tree holes or birdhouses. (If there aren't enough spaces to go around for the "insiders," they simply won't be able to raise a family that year.) Most birds build in the outdoors, creating a nest on a branch or on the ground.
If things go right, when the time is right, a male and female will mate, then she settles down to egg laying. Most females produce one egg a day and don't begin to incubate them, using body warmth to develop the embryos, until the last egg is laid.
Once tiny birds tumble out of their eggs, and fill the nest, generally after about two weeks of incubation, the really hard work begins, as parent birds hustle to find enough food (almost invariably insects) to stuff down their begging youngsters' throats. On average, a bird nest will contain four young, so adult birds need to bring in hundreds of caterpillars, beetles, flying insects, sometimes even tiny frogs or toads, each and every day to meet their insatiable demands.
Parent birds begin to look a bit tattered, as they go without daytime rests and sacrifice bathing and grooming to keep up with the intense feeding schedule. Think of the American robin, a species that raises two batches of youngsters each summer: While the female starts the second nest, the father bird takes care of their fledglings, now scattered around the yard, loudly demanding feedings. He must fly from youngster to youngster to keep them fed, a much tougher job than caring for confined nestlings.
It's a similar story for most of our backyard birds, although only a few — notably cardinals, robins, house wrens, ruby-throated hummingbirds and house sparrows — raise more than one batch of youngsters during breeding season.
Surprisingly, even though their nests are well-built, designed to survive bouncy young birds, many parental landings and summer storms, birds almost never re-use their nests. Once the youngsters leave, the nest is abandoned.
"Many birds build a new nest each year, and some even build new nests for each of their two or three broods in a single season," says Laura Erickson in her wonderful book, "Into the Nest: Intimate Views of the Courting, Parenting, and Family Lives of Familiar Birds."
Most wild animals are secretive creatures, scurrying into and out of view as they go about their private lives (and yes, gray squirrels are a major exception).
But birds are different, many of them living their lives right under our noses.
I'm continually in awe of birds, by how much unceasing effort their lives demand, how they overcome so many challenges, how they learn new ways to survive — and how easy they make it all look. I hope you feel the same.
St. Paul resident Val Cunningham, who volunteers with the St. Paul Audubon Society and writes about nature for local, regional and national newspapers and magazines, can be reached at valwrites@comcast.net.
Nesting season bios
Black-capped chickadee
Nests inside a hole in tree or stump or in nest box.
Materials: moss, animal fur.
6 to 8 white eggs with reddish spots.
Eggs incubated for 12-13 days.
Chicks fledge after about 16 days.
Parents continue care for 2-4 weeks after chicks leave the nest.
1 brood per season.
American robin
Builds a cup nest in shrub, tree, roof gutter, under eaves
Materials: mud, grasses
4 blue eggs
Eggs incubated for 12-14 days.
Chicks fledge after 14-16 days.
Parental care continues for several weeks after chicks leave the nest.
2 to 3 broods per season.
Blue jay
Builds cup nest in coniferous or deciduous tree.
Materials: twigs, soft bark.
4-5 pale blue or brown eggs with spots.
Eggs incubated for 17-18 days.
Chicks fledge after 16-19 days.
Parental care continues for 1-2 months.
1 brood per season.
Northern cardinal
Builds cup nest in dense shrub, small tree or vine thicket.
Materials: twigs, vines.
3-4 grayish eggs with spots or splotches.
Eggs incubated for 11-13 days.
Chicks fledge after 9-10 days.
Parental care continues for 2-3 weeks.
2 broods per season.
House wren
Nests inside tree hole, nest box, hole in walls, mailbox, etc..
Materials: sticks, plant fiber.
6-7 white eggs with red speckles.
Eggs incubated for 12-15 days.
Chicks fledge after 15-17 days.
Parental care continues for 2 weeks.
2 broods per season.
American goldfinch
Builds cup nest in fork of small tree or shrub.
Materials: grasses, plant down.
5 bluish white eggs.
Eggs incubated for 12-14 days.
Chicks fledge after 15-17 days.
Parental care continues for 3 weeks.
1 brood per season.
Live, on camera
Visit the Cornell Lab of Ornithology's Bird Cam website, allaboutbirds.org/cams, to watch parent birds raise their young. Parental stars include red-tailed hawks, American kestrels, barred owls, even condors.
Check out the state Department of Natural Resources' eagle cam for real-time views of young eagles learning to fly: dnr.state.mn.us/features/webcams/eaglecam
How to help
• Collect cat or dog fur and place tufts on trees or shrubs for nest lining.
• Maintain a birdbath with clean water daily, providing thirsty parents with a drink.
• Crush sterilized eggshells (toast in oven for 30 minutes at 250 degrees), then sprinkle over birdseed for calcium-starved female birds.
• Place sprinkler near a patch of dirt to help robins make mud bases for nests.
• Keep feeders filled and consider offering high-energy foods like suet and mealworms for hungry nest builders.
• Keep cats indoors, especially at this time, when unwary youngsters are trying their wings.
• Avoid placing dryer lint outside for nests, as it holds moisture after a rain.
Top prize
Smallest nest: ruby-throated hummingbird (about the size of walnut half).
Largest nest: bald eagle (4-5 feet wide, 2-4 feet deep, grows year by year).
Uses the most sticks: house wren (hundreds or thousands).
Softest nest: black-capped chickadee (moss and fur).
Most artistic: tree swallow (artfully arranged feathers).
Most intricate: Baltimore oriole (woven strands of grass).
Least effort: killdeer (a scrape on the ground).
Val Cunningham
