Blue Birds: Not Just Bluebirds

 Henry David Thoreau wrote that the bluebird “carries the sky on his back.”  Although this poetic description referred to the Eastern Bluebird, the meaning could just as easily be applied to two other commonly seen, predominately blue birds that are found throughout the southeast.  The trio of common “blue birds” in Mississippi includes the Indigo Bunting (Passerina cyanea), the Blue Grosbeak (Guiraca caerulea), and, of course, the familiar Eastern Bluebird (Sialia sialis). 

If any of these three birds has a claim to the distinction of carrying the sky in its plumage, it’s the Indigo Bunting—the male of this species can seem to change hues as quickly as the spring sky can fade from clear blue to a duller gray over the course of an afternoon.  Although any blue coloration present in feathers is the result of light reflecting off of the structure of the barbules, the Indigo Bunting’s appearance is especially changeable.  The reason for this is that the feathers are iridescent, catching different amounts of sunlight to appear any shade from blue-black to bright turquoise.  In contrast to the male, the female Indigo Bunting is a much subtler brown, with hints of blue in the wings; this more subdued coloration helps camouflage her at the nest, which is generally placed in a small tree or shrub.  In fact, thickets, woodland edges, and overgrown fields are the favorite environments of this sparrow-sized member of the cardinal family, and, like cardinals, it will come to backyard bird feeders for sunflower seeds and white millet.  Its relatively thick, stout bill aids it in cracking hard seeds, but, like many birds, it also feeds on insects.  During the spring and summer, the excited, up-and-down warbling song of the male bunting cues observers in on its presence—helpful, considering how difficult it can be to catch a glimpse of the vibrant blue bird when it is hidden in vegetation.

Singing male Indigo Bunting in the sunlight.

Male Indigo Bunting on an overcast day.

Female Indigo Bunting

The Indigo Bunting’s larger cousin, the Blue Grosbeak, lacks the eye-catching iridescence of the bunting, but it is also a stunning bird.  The plumage of the male grosbeak is a deep, royal blue with brown bars on the wings and a black “mask.”  For the same reason as the female Indigo Bunting, the female grosbeak is more cryptically colored: brownish gray, with a touch of gray-blue on the wings.  “Grosbeaks” are aptly named—their dark-colored, conical beaks are very stout and large, and point to their relationship with the well-known Northern Cardinal, which also has a large bill.  They can be found in the same habitats as the Indigo Bunting, but usually in much smaller numbers.  However, in spring and summer, it is not uncommon to see these striking birds helping themselves to feeder offerings, bringing delight to observers who realize that their backyard visitors are not simply oversized Indigo Buntings.  Once learned, the song of the Blue Grosbeak is quite different from that of the Indigo Bunting; it is a series of throaty, rolling warbles that befit this larger, less hyperactive bird.  Blue Grosbeaks may be less jumpy than their smaller cousins, but anyone who has seen the males battling for territory in the springtime, chasing each other through the underbrush, knows that they are far from lethargic!

Male Blue Grosbeak

Female Blue Grosbeak carrying nesting material!

Nearly everyone has heard of or seen the bluebird, known to some as the “bird of happiness.”   Unlike the other two “blue birds,” though, the Eastern Bluebird—washed with vibrant blue on the back—has a rust-colored breast fading into a white belly.  Female bluebirds have a similar pattern, but with more subdued coloring.  The contrasting palette of colors makes this species difficult to confuse with anything else, and the song—a short, lilting warble—is a familiar sound in rural areas.  Open woodlots, abandoned fields, and pastures all provide habitat for Eastern Bluebirds, which nest in rotting posts, snags, and the bluebird nest boxes constructed especially for them.  Bluebirds’ diet consists mostly of insects and berries that they find in their natural habitat, although they will also occasionally come to backyard feeders for suet, mealworms, and fruit.  Unlike the Indigo Bunting and Blue Grosbeak, the Eastern Bluebird is a member of the thrush family, which includes such familiar birds as the American Robin and Wood Thrush.  Because bluebirds—like robins—lack spots on their breasts, they do not greatly resemble thrushes at first glance; however, their slim, slightly curved bills, upright posture when perching, and tendency to flutter their wings all point to this relationship.  Interestingly, bluebird young look far more like their thrush relatives.  They have streaked and speckled brown plumage, with blue only in the wings and tail. 

Male Eastern Bluebird

As for seasonal occurrence, the Eastern Bluebird can be found year-round in the state, and the Blue Grosbeak and Indigo Bunting are present during the breeding season.  In a way, we are fortunate that these three “blue birds” are common and widespread across the southeast.  About thirty years ago, Eastern Bluebird populations were declining due to loss of nesting cavities and competition with invasive European Starlings and House Sparrows.  Concern over the bluebird’s plight led many people to construct nest boxes for them, which helped increase the population to a healthy level today.  The Blue Grosbeak is also doing fairly well—it has even expanded its range northward in recent years.  The Indigo Bunting is declining across many areas of its breeding range due to habitat changes, but it seems to be maintaining relatively healthy populations regardless of this fact.  Because it does not use heavily forested habitats, the bunting has fared better than many songbirds, but both it and the grosbeak are at risk from destruction of habitat on their wintering grounds in Central and South America.  Hopefully, measures taken to prevent habitat destruction in both North and South America will ensure that these three species of “blue birds” continue to thrive, bringing welcome touches of sky to the earthly environments that they inhabit.

Greater Roadrunners

I lived in Arkansas for several years, and one bird from that region that I sometimes find myself missing is the roadrunner.  Luckily, where I am now, I can still watch some of its close relatives, the Yellow-billed Cuckoos.  The following is a brief species account of the Greater Roadrunner.

The Greater Roadrunner (Geococcyx californianus) is a large, ground-dwelling cuckoo (Order Cuculiformes) that occurs in North America, typically in deserts, shrubby habitats, and chaparral.  As a member of the Cuculiformes, the roadrunner has zygodactyl feet (i.e., two toes pointing forward, and two pointing backward), and, like many others of that group, it also has a proportionally long tail.  Its plumage is brown and streaked, and it has a crest and bluish skin around the eyes. 

Greater Roadrunners begin breeding in early spring.  Egg-laying occurs mainly during April and May, although some eggs have been found during mid-March.  Two broods may be produced per season.  Courtship includes the male singing a song composed of low, cooing notes, and drooping the wings and tail during a courtship dance.  The nest is usually placed about 3-15 feet from the ground in a low tree, thicket, or cactus clump, although nests are occasionally also built on the ground.  The nest, which is a foundation of sticks with leaves, grasses, feathers, roots, and other materials as lining, is about one foot in diameter and 6-8 inches high.  The clutch size is usually 3-6 eggs, which are ovate or elliptical, about 39.2 by 30.1 millimeters in size, and are white with a chalky, yellowish film.  Eggs are laid at long intervals, and both sexes begin incubating as soon as the first few eggs are deposited.  The incubation period lasts approximately 18 days, and the newly-hatched chicks are altricial with black skin and scattered white, hair-like plumes.  The young are cared for in the nest for about 2-3 ½ weeks, and adults may continue to provide care for young for over a month after fledging occurs. 

Roadrunners consume a variety of foods, including lizards, snakes, spiders, scorpions, insects, rodents, ground birds and their eggs and young, fruit, and seeds.  The diet is approximately 90 percent animal matter.  Roadrunners range from the southwestern United States south to central Mexico.  More specifically, the range is north to north-central California, southern Kansas, and Colorado; east to Kansas, central Oklahoma, Texas, Pueblo, and Tamaulipas; west to Jalisco and Baja California; and east to southwestern Missouri, Arkansas, and Louisiana.  They are nonmigratory, year-round residents in these areas. 

Greater Roadrunner

Sutton, G. M.  1940.  Roadrunner.  In A. C. Bent (Ed.), Life Histories of North American Cuckoos, Goatsuckers, Hummingbirds, and Their Allies: Orders Psittaciformes, Cuculiformes, Trogoniformes, Coraciiformes, Caprimulgiformes, and Micropodiiformes (pp. 36-50).  Washington: United States Government Printing Office.

Northern Cardinal Life Stages

Previously, I discussed the nesting process of Northern Cardinals.  But what happens to the young cardinals after they leave the nest?

At first, not much: Fledglings continue to be fed by their parents for at least a month as they learn how to function as adults.  They’re not that different from human teenagers, when you think about it.

In my long time as a birder, I have had many opportunities to witness “teenager” cardinals as they hang out with their parents.  One year, some of the cardinal parents brought their young to the backyard feeding station, allowing me to see them up close and to study their plumage patterns and behavior.

Juvenile cardinals have dark bills, unlike their parents, which have red or orange-red bills.  The color change is generally complete by winter.  In the photo below, you can see a little bit of orange beginning to come through on the base and margins of the juvenile cardinal’s beak.  Female and male cardinals look very similar in the juvenile stage, but males can have a hint of red on their flanks.  It can be hard to tell, though, and the photo doesn’t provide a lot of strong clues in either direction. 

Juvenile cardinal

This next photo shows a different bird—an immature male.  This cardinal probably came from an earlier brood than the last bird, and its molt into adult plumage has progressed much farther.  Look at the red blotches on the head, back, and flanks. 

Immature male cardinal

The first of the two photos below shows the young male bird from another angle, where you can see all of the red feathers that are coming in on the breast.  The bill has also turned almost completely red.  A bird that looks like this has probably been fending for himself for a while, but he won't be ready to compete with scrappy, aggressive, adult males, like the one in the second photo, until the next year.

Immature male cardinal -- not quite there yet

Adult male cardinal

Although both adult female and juvenile cardinals have reddish tails and flight feathers, adult female cardinals have red crests, as you can see in the first of the two photos below.  In about a year, female cardinals are ready to compete for territories and start nests.  Yes, they compete in much the same way that males do; research has shown that, on breeding territories, female cardinals chase away other females, and male cardinals chase other males.  Females also sing, if somewhat less frequently than males.  Juvenile cardinals might sing softer, unstructured versions of adult songs, as they are still learning.  They will consistently give whistled begging calls whenever they want food from their parents, though!  If you find some juvenile cardinals in the wild, watch for their wing-fluttering behavior and listen for those piping calls.

Adult female cardinal -- note the orange beak

Juvenile cardinals with gray beaks

As cardinals—both the adults and the juveniles/immatures—molt from one plumage to the next, sometimes they wind up looking a bit weird.  One of the most common “oddities” is when a cardinal loses most or all of the feathers on its head.  These cardinals can look as though they have a horrible disease, but, in most cases, they are perfectly normal and will have new feathers in due time.  The cardinal in the foreground of the next photo is an adult female with a bald, gray head. 

Once, there was a distinctive female cardinal that I routinely watched over a period of many days.  There was a clump of feathers sticking up on her back.  (This bird is actually the female cardinal in the fifth photograph of the post.)  Try as I might, I never could tell whether this was an injury or simply a scraggly patch from a recent molt.  The cardinal seemed to have no difficulty in foraging, flying, and generally moving around, so I didn’t worry about it, but it was certainly interesting to observe.

Ruffled feathers?

As you can probably tell, the wide variety of plumages that Northern Cardinals display during this season of the year makes it fairly easy—at least, for a brief window of time—to determine their age and to track some of them as individuals.  By next spring, some of this year’s juveniles will hold breeding territories of their own, and the cycle will continue.

Source:

Halkin, S. L. and S. U. Linville (2020). Northern Cardinal (Cardinalis cardinalis), version 1.0. In Birds of the World (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.norcar.01

Nesting Northern Cardinals

 

Female Northern Cardinal in Arkansas, November 5, 2013.

Male -- also November 5, 2013, in Arkansas.

If you live in eastern or central North America and spend any time outside, chances are good that you’re familiar with the Northern Cardinal.  Cardinals are so common, in fact, that I confess I tend not to pay them much attention—especially if there are more unusual birds nearby.  But nearly a decade ago, a pair of these birds nested in the thorny elaeagnus shrub near my home, right outside the living room window.  Naturally, I had to pay attention to that!

The cardinals began nesting in the thorny elaeagnus shrub right around the time that the White-eyed Vireos that I wrote about previously were nearly fledged.  I first noticed the female cardinal carrying twigs in her bill to the nest site, which was a few feet higher in the shrub than the vireos’ nest had been.  This was typical behavior.  Female cardinals construct the nests and incubate the eggs, while males bring food to the females during incubation and assist in feeding the young after they hatch.  

As you can see, cardinals build their nests on top of limbs, unlike vireos, which suspend theirs from forks in the branches.  Whenever the female cardinal added new material to the nest, she bent it with her bill and pushed it into a cup shape with her feet.  The outside layers were constructed from twigs, bark, and leaves, while finer materials, such as grasses and pine needles, formed the lining.

June 19, 2016 -- Cardinal building the nest!

Checking early-stage nests too frequently can lead to the parent birds abandoning the site, so I was cautious about getting photos at that point.  By June 28, there were two eggs in the nest, but, since I had been avoiding the nest, I assumed that they had probably been there for two or three days.  Cardinals lay anywhere from one to five eggs, with two to three being more typical.

According to Birds of North America Online, incubation takes 11-13 days.  The eggs were definitely hatched on or before July 7, when I photographed the slightly downy nestlings for the first time.

By July 11, the young birds were much larger and more heavily feathered.  You can see how their bills are starting to turn dark, a characteristic of juvenile cardinals.  Their beak color doesn’t change to red or red-orange until late in the fall.

July 11, 2016

On July 14, the nestlings were nearly ready to fledge.  Although it’s difficult to determine exactly how heavily feathered the average dinosaur might have been, this is what I tend to imagine juvenile dinos looking like.  (On the anatomical level, though, modern birds and the dinosaurs from which they evolved differ very little—so I’d guess that quite a lot of dinosaurs may have had full plumage.)

July 14, 2016

I think that these cardinals fledged on July 15 or 16.  Fledging usually occurs after about nine or ten days, so this estimate seems reasonable.  You can just barely make out one of the nestlings in the center of the photo below.  That photo was from July 15, and the one of the empty nest was taken the next day.  This might have been the second brood of the year from these nonmigratory birds, but I can’t say for certain.

July 15, 2016 -- at least one young cardinal still on the nest

July 16, 2016

Spring Migrants: Solitary and Spotted Sandpipers

The mention of sandpipers often brings stress to inexperienced birders.  After all, sandpipers are those dull, brownish little creatures that skitter over mud and all look alike.  In other words, it can be hard to appreciate them.  But actually, on closer study, sandpipers are unusual and highly fascinating birds.  And, no, they don’t all look alike!  I will focus on two very distinctive, common sandpipers that can be seen in migration now: the Solitary Sandpiper and the Spotted Sandpiper.

Solitary and Spotted Sandpipers

Although they are not closely related, the Solitary Sandpiper (Tringa solitaria) and the Spotted Sandpiper (Actitis macularius) are often seen together feeding in the same ponds and lakes, frequently those with woods or at least low-lying vegetation nearby.  Both can be found migrating in Mississippi from about March to June in the spring, and late July to late October in the fall.  The Spotted Sandpiper is an occasional winter resident in the state, as well, but is more common along the coast than inland.

Both sandpipers forage and migrate singly or in small groups, and both exhibit tail-bobbing behavior.  With the Spotted, the entire body is teetered; the bird is in constant, jittery motion: scampering along the water’s edge, picking up small insects, mollusks, crustaceans, and even tiny fish.  The Solitary Sandpiper has slower, more deliberate movements, and when it pauses, it often bobs its head and tail.  It has longer legs and a longer bill than the Spotted, which enables it to feed in slightly deeper water, where I assume the menu would include bigger fish and frogs!  As an additional feeding adaptation, it often shakes its foot above the water to draw small fish and insects to the surface.

If you come unexpectedly upon either of these sandpipers, they will probably fly up immediately, uttering high-pitched peet-WEET calls (the Solitary’s call is the higher pitched of the two).  Fortunately, their flight styles are very different and distinctive.  The Solitary Sandpiper has graceful, swallow-like wingbeats and displays long, pointed wings and white edges on its tail.  Spotted Sandpipers fly close to the water and give fluttery, shallow beats of their shorter, more-rounded wings, each of which shows a thin, white stripe.

Once the sandpipers land on the bank and begin feeding again, their colors and patterning are apparent.  The Solitary Sandpiper is slightly larger than the Spotted, with a longer neck and body, and it has a wide, white eye-ring that gives it an alert look.  Its head, neck, and breast are finely streaked with brown, its belly is white, and its back is dark brown and shiny, with a dusting of tiny white spots.  The thin, dark bill and dark, greenish-gray legs complete the picture.  The Spotted Sandpiper is relatively small and stocky, with orange legs and bill, brown upperparts, a white eyebrow and slight eye-ring, and in the breeding season a boldly spotted breast and belly.  At least before the birds molt in the fall and replace the spotted front with plain white, you can sometimes tell the sexes apart.  Females have larger spots that extend farther onto the belly than males.

But why would the female bird be more distinctively marked?  The answer lies in the Spotted Sandpiper’s breeding biology.  Along with phalaropes, it is unusual in that the females are polyandrous, mating with more than one male—sometimes up to five!  Each time after mating, the female lays a clutch of up to four brownish eggs, which the male is solely responsible for incubating.  However, the female does help with constructing the nest—a shallow scrape in the ground, lined with grass.  After the eggs hatch, the male alone raises the chicks, which are born precocial like all sandpipers.

While the Solitary Sandpiper is monogamous and doesn’t exhibit such unusual breeding behavior as the Spotted, it is unique among North American shorebirds in that it nests in trees.  A female Solitary Sandpiper will add a little extra nesting material to the abandoned nest of a songbird, such as a Rusty Blackbird, American Robin, or Cedar Waxwing, incubate her four well-camouflaged, brownish eggs, and care for the young with her mate.  Tree-nesting is so unusual among shorebirds (the Green Sandpiper of Eurasia is the only other species known to do it regularly) that, for decades, no one was sure where the Solitary Sandpiper nested until 1903, when the secret was finally discovered.

Spotted Sandpipers are one of the most widespread shorebirds, commonly found over much of North America, although they aren’t known to breed in Mississippi and some other southern states.  Solitary Sandpipers are more restricted in range, occurring in the breeding season mainly in Canada and Alaska.

The numbers of both of these sandpipers appear to be fairly stable, and that’s good news.  With care and protection, generations years into the future will be able to observe the fascinating behaviors of these and other birds that have been living here for eons.  A world without the little brown sandpipers that enliven our fields, woods, and wetlands would be bleak.

Nesting Strategies

April is about to begin, which means that, here in the southeastern U.S., most of the year-round resident species—including phoebes, cardinals, Carolina Wrens, and bluebirds—have probably started nesting.  Several of these common, resident birds spend a lot of time around human habitation, so if you live in this region of the country, you may have noticed lots of interesting behaviors over the last month or so.  

In the spring and summer, Carolina Wrens will often build their small, domed nests in garages, outdoor furniture, or potted plants.  Here's a photo of a nest from several years ago.  As you can see, the wren parents used grasses, oak blossoms, mosses, leaves, and string in the outer layer.

Carolina Wren eggs

Finer grasses and various bits of fuzz—feathers and possibly fur—lined the nest, and, as the photo shows, the female wren laid five eggs.  This is normal for Carolina Wrens, which lay anywhere from three to seven.  The female wren incubated the eggs for several days.

Incubating

Wren nests are a familiar sight for me, and, apart from peeking into the nests every now and then during the roughly month-long process from incubation to fledging, I never really do anything that could disturb them.  For one thing, it’s generally illegal to disturb or damage the eggs and young of wild birds, and for another, I figure that interfering with nature is usually unwarranted.  The main exception I will make is for species that are endangered, or just generally imperiled.  Carolina Wrens, though?  Thankfully, they seem to be doing just fine.

The empty nest

The species is doing just fine, that is.  Unfortunately, these particular individuals had their nest raided by some sort of predator before the eggs could hatch.  Maybe a snake?  Several nonvenomous species, including gray ratsnakes, black racers, and speckled kingsnakes, are common in the Southeast.  I do not endorse killing snakes, by the way; they have a right to be here, and the benefits that they provide (e.g., rodent control) far outweigh any damage that they occasionally do to the birds that people love to watch.  Below is a picture of a large gray ratsnake that had taken up residence in the garage a couple of years before.  A raccoon is another possibility; although you may not often see them, they are extremely common in wooded areas, and their opportunistic feeding habits make them remarkably persistent.

Gray ratsnake

It was bad luck for the Carolina Wrens, but there's usually a chance for a second brood, at least.  

On a lighter note, even though the wrens failed, the Eastern Phoebes that year successfully raised at least three young over the garage entrance.  Phoebes typically don’t build low to the ground, so unless you bring out a ladder, you’re probably going to have a hard time looking into their nests.  Until they hatch and the young birds are large enough to stick their heads over the edge, I usually have no idea how many eggs there are.  The brood sizes of phoebes can vary fairly widely—from two to six.  Like Carolina Wrens, phoebes easily acclimate to human activity; as long as you leave them alone, they will nest year after year in the same spot on a ledge, over a porch, or under an eave or a bridge.  

The phoebes' nest

The phoebe nestlings in the garage nest grew rapidly, and eventually the concrete below became coated with bird droppings—yuck.  I expected the birds to fledge a day or two before they finally did; they had been looking very large and mature, but they weren’t finished developing yet.  On the day that they did wind up leaving, I was standing at one side of the garage entrance and peering at them through my binoculars.  My presence apparently agitated them, because they all blasted out of the nest at once and flew strongly to the row of hardwood trees lining the driveway.  Clearly, they were ready!  For many other bird species, however, the season was just getting started.

Phoebe nestlings

Shorebirds Quiz

Ready for a challenge?  The shorebirds in the following quiz are commonly found across much of the Gulf Coast.  See how many of them you can identify.

1.  Although some features of this resting bird are hidden, the relevant field marks are still visible.

2.  This tiny shorebird has a larger relative that is abundant across much of North America.

3.  After the first two, this next shorebird should be a relatively easy ID!

4.  A black-and-white shorebird flying low...

1. This individual is chunky with drab, brownish upperparts, a white belly, grayish legs, and a semi-long bill that droops at the tip: all features of the Dunlin.  This species spends the winter on the coast before migrating to Alaska and northern Canada for the breeding season.

2.  Piping Plovers are related to the Killdeer, an abundant and widespread plover species.  Unlike Killdeer, though, Piping Plovers have incomplete breast-bands.  They also have orange legs, unlike the slightly larger Snowy Plover, which has grayish legs.  Like the Dunlin (but unlike the Snowy Plover), Piping Plovers do not remain on the Gulf Coast to breed.

3.  The moderately short, slightly decurved bill; short, yellow legs; and warm-brown upperparts help to distinguish the Least Sandpiper from other shorebirds.  Its small size is a useful field mark, as well.  Like the Piping Plover and the Dunlin, the Least Sandpiper migrates north in the spring.

4. The American Oystercatcher is a large shorebird with bold black-and-white-and-brown plumage.  Its almost clownish-looking red bill makes it unlikely to be confused with any other species!  Oystercatchers are year-round residents of the Gulf Coast, and they do indeed eat oysters.