A Chipping Sparrow collecting nesting material. (Photo: Connie Morgenstern)
The Private Lives of Bird Moms: a peak into the nesting habits of 5 common backyard birds
Here’s a look at some familiar bird moms and a few nesting behavior traits that may surprise you. The following birds are common backyard visitors and likely very familiar, but do you know some of the following more intimate details about their lives?
#1. American Crow
Crow mom has clearly figured out how to delegate to get things done and make sure that the rest of the family doesn’t just sit idly by and leave her to do all the work! Crows mate for life and carry out the tasks related to nest building and caring for their offspring with help from their older offspring from previous broods. Once the female has laid a clutch she will sit on the nest to incubate the 6-9 eggs, sitting on the nest all night and for the majority of the day. Fortunately, unlike a human mom who might be inclined to order out for pizza at this point, Crow mom has her older offspring out searching for food to bring back to feed her. In the meantime Crow dad is sitting somewhere nearby looking out for predators who might want to usurp the nest. If for some reason the pair doesn’t have this community support, the male will spend more time away looking for food. For the short time the female is off the nest, she will stretch, preen and defecate then rush back to resume her duties at home.
Once the eggs begin to hatch both the dad and older offspring pitch in with housekeeping duties such as carrying away the egg shells and helping to feed the nestlings. When the nestlings have reached the point where they are able to regulate their own body temperatures, Crow mom will start to join in the food gathering duties. Once leaving the nest, the fledgling’s flight skills aren’t quite fully developed and so the parents continue to feed them for several weeks, then help them learn to find food on their own.
#2. American Goldfinch
The American Goldfinch nests later than other songbirds. It waits until summer when the milkweed and thistle plants that it uses for nest building and food are available.
Paired couples choose the nest site together but the female builds the nest which may take up to 6 days. Nest are so tightly woven they can even hold water! The nest is securely lashed to a branch using spider webs. Goldfinch mom lines the interior of the nest with the soft downy fibers she obtains from thistle, dandelion or cattails seeds. Both parents feed the young by regurgitating semi-digested seeds. American Goldfinches will only rarely feed their young insects.
#3. Chipping Sparrow
Females arrive on the breeding territory a week or two after the males and pair formations begins soon afterwards, as does selecting an appropriate nest site. Reminiscent of a human couple looking for a place to build their dream house, the female Chipping Sparrow will try out a few locations first. She will squat in place to size up a location, maybe even pick up a bit of vegetation lying about to mimic nest building in the given space and then repeat the behavior in several different spots before deciding on the most suitable one.
Female chipping sparrows have been observed returning to the same nesting sites from year to year. While they won’t reuse a nest, they are known to dismantle old ones and recycle the materials. Preferred construction materials include fine plant fibers such as rootlets and dried grasses. In addition, they also use a higher proportion of animal fur to line their nests than do other birds and are even known to pluck hair from live animals! As a matter of fact, the Chipping Sparrow’s love of horse hair as a nesting material earned it the nickname “hair bird” back in the days when horses and farms were more plentiful.
During the egg-laying stage the female returns once a day to lay an egg and may abandon the nest if disturbed. During incubation the male will feed the female. For the first few days after the chicks have hatched, the parents will feed them seeds. This is unusual as most songbirds feed their chicks a high protein insect diet from the beginning.
#4. Mourning Dove
Although the soft cooing vocalizations of the Mourning Dove are a familiar sound to many of us and may help to make this bird an endearing presence, Mourning Doves can seem a bit quirky. Unlike the American Goldfinch, they certainly won’t win any nest building awards; nest construction can be so flimsy that eggs may even fall through the bottom! The female constructs the nest with materials brought to her by the male who sits on her back while she lays them in place. This has been described by one author as seeming as if he is looking over her shoulder!
However, on the more remarkable side of things, Mourning Doves are one of the few birds that have the ability to suck; this is useful during the first few days of a nestling’s life when it drinks “crop milk” from either parent’s bill. While many species have crops that are used for food storage, Mourning Dove crops are somewhat unique. The enlarged chambers in the esophagus of both sexes produce this “milk” which has a cottage cheese like consistency. Packed full of protein, fat, antioxidants and immune enhancing properties, it is fed to the nestling for the first few days of life at which point seeds are added to the nutrient mix. Incidentally, the only other species that share this ability are pigeons, flamingos and some penguins.
#5. White-breasted Nuthatch
White-breasted Nuthatches mate for life and remain on their territory throughout the year. Yet despite their long term association, the male carries out the courtship behavior of feeding the female during the nest building and egg laying stage every year anyway. This is a typical behavior among birds and It is believed one purpose of such displays is to help stimulate the female’s ovulation.
Nuthatches nest in naturally occurring cavities but are also perfectly happy to use old woodpecker holes. While the White-breasted Nuthatch doesn’t actually do any of its own cavity excavation, it will occasionally do a bit of DIY remodeling and enlarge a hole entrance. In terms of interior nest construction, the female is the handy one of the pair. While the male helps haul home materials, the female will construct a cup shaped nest of rootlets, bark flakes and grasses inside the cavity to prepare for their one brood of the season. The floor of the cavity is lined with bark, hair, fur, feathers, lumps of earth or rootlets. Although only the female broods, both parents feed the young and share the housekeeping duties of removing fecal sacks from the nest.
Sources and Resources:
Erickson, Laura, and Marie Read. Into the Nest: Intimate Views of the Courting, Parenting, and Family Lives of Familiar Birds. North Adams, MA: Storey, 2015.