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.

Sunset

I love walking on the beach near sunset, especially when the weather isn’t too warm.  The sand feels delightfully soft and cool, the clouds stretch across the sky in gorgeous pastel shades, and waves provide a relaxing soundtrack as they steadily lap the shoreline.

The seashore birds’ calls—some raucous, some guttural, and some piping—punctuate the sounds of the water and wind.  Black-bellied Plovers may look fairly drab in their winter plumage, but their plaintive, whistling notes are anything but dull.  These close relatives of the familiar, pasture-loving Killdeer remain on the Gulf Coast through the winter, but migrate north in the spring.  It amuses me that this bird doesn’t have a black belly at all during this time of year.

Black-bellied Plover at the shoreline

Like most egrets and herons, the Snowy Egret has a very unmelodious—even grating—call.  But few people would deny its elegance as it gracefully strides through the tide pools, hunting for small fish and invertebrates.  Although the water is a bit too cold for me, the Snowy Egret appears to pay it no mind.  Black legs ending in bright yellow feet are one of its identifying features.

Snowy Egret striding

While the egret moves off, the small, browinish Dunlin comes forward to prod the mud near the edge of the pool with its pointed beak.  The Dunlin is a common winter visitor and migrant on the Gulf Coast, and, on most beaches, only the grayish but equally small Sanderling outnumbers it.  These species may mingle with each other, but the Dunlin tends to feed in somewhat deeper water, as the slightly greater length of its bill would suggest.

Snowy Egret and Dunlin foraging

As I look up and slightly to the right, I see several more species of shorebirds, including Marbled Godwit, Willet, and Semipalmated Plover.  The larger individuals, such as the godwits and the willets, forage in the deeper water, while the smaller plovers and dunlins stay in the shallower sections.  The names godwit and willet may seem strange, but they were intended as transcriptions of the birds’ calls.  I hear neither of these species calling at the time, but the persistent chirps and whistles of the others more than make up for that.

Shorebirds foraging in the tide pools

The sun starts to drop below the horizon, signaling that it’s time for me to leave.  I will miss the sights, sounds, and sensations of the beach, and I hope that I can re-experience them soon.

The Red-shouldered Hawk

It wouldn’t seem quite like winter without the hawks and falcons hunting along fencerows, darting through the woods, or soaring on the breezes. I have been seeing a number of raptor species over the last few months, including the swift and agile Cooper’s Hawks, the slower but more powerful Red-tailed Hawks, and the wary and fidgety American Kestrels.  Another common species, large and vocal, but sometimes overlooked, is the Red-shouldered Hawk.

Unlike Red-tailed Hawks, Red-shouldered Hawks tend to prefer low-lying, heavily wooded environments. They are commonly found year-round in many hardwood and mixed forests throughout southeastern North America, and, in the fall and winter, this southeastern population is boosted by migrants from the northeastern United States and southeastern Canada. The difference in habitat between Red-shouldered and Red-tailed Hawks means that their dietary preferences are a bit different, as well; like Red-tails, Red-shouldereds eat lots of small mammals, but, because they inhabit denser, swampier woods, they’re also likely to catch frogs, snakes, and lizards. However, even though they’re primarily forest hawks rather than field hawks, they will often hunt from powerlines and prominent snags at the borders of woodlands and fields. Presumably, this makes it easier for them to find and catch their prey, given that they lack the maneuverability of species such as the Cooper’s and Sharp-shinned Hawks.

Appearance-wise, Red-shouldered Hawks are a little smaller and slimmer than Red-tailed Hawks, and, of course, they lack the brick-red tails that adult Red-tails have. They DO have reddish-brown “shoulders,” but this usually isn’t the most obvious field mark. The barred, reddish-brown breasts, black-and-white banded tails, and black-and-white wings on the adult hawks are far more noticeable features in the field. As you can see in the first of the two photos below, there are also vertical breast streaks on top of the chestnut-colored horizontal barring. Juvenile Red-shouldered Hawks look fairly similar to the adults, but have drabber, browner feathers and lack reddish barring on their breasts. In flight, both adults and juveniles show “wing windows,” which are essentially just pale crescents near the wingtips. This is a great field mark to look for if a hawk is soaring overhead. 

The rusty breast feathers on this adult hawk are a useful field mark.

Juveniles have browner plumage and streaks on their breasts.

Crescent-shaped wing markings are visible on this soaring adult hawk.

At this time of year, the immature hawks have been independent from their parents for several months, so they’re essentially competing with adult hawks for food and territory. If they survive the winter and later become breeding adults, then they will likely build their nests in large trees in the woods and lay two to five eggs per brood, with only one brood per season. Apparently, little is known about Red-shouldered Hawk nesting habits, so if you happen to spot a breeding pair next year, there is a chance that your observations could be of significant scientific value! In the meantime, enjoy watching Red-shouldered Hawks and other raptors this winter. 

Source:

Dykstra, C. R., J. L. Hays, and S. T. Crocoll (2020). Red-shouldered Hawk (Buteo lineatus), version 1.0. In Birds of the World (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.reshaw.01

 

Blast from the Past: Gulf Coast Edition

I recently came across this piece of mine from nearly two decades ago.  Interesting how the coast has changed since then!

It has been something of a tradition among my mom, sisters and me to spend a few days each year on vacation on the Alabama gulf coast.  Due to the severe hurricane damages it sustained over the past couple of years, however, we chose not to attempt this custom again for a while.  This year, though, we received feedback from some relatives of ours (who had actually camped in Gulf Shores State Park a few months after Katrina and the flooding that it brought with it) on the actual condition of the area, and because the news seemed pretty good, we decided last month to get a hotel room and spend some time enjoying --- if nothing else --- the gorgeous beaches.  I naturally also wanted to see to what extent the region’s ecosystems had been altered by the storms.  Fortunately, although there were places that still seemed barren and deserted, stripped somewhat of their distinctive character, the experience in general was very pleasant and indicative of nature’s resilience.

One of the first differences we noticed as we made our way around the Gulf Shores/Orange Beach area was the greatly reduced number of buildings and tourist attractions near the beach (in a way, not really a bad thing).  The absence of familiar landmarks was oddly unsettling, though; you’re so accustomed to seeing them as a tourist that you hardly notice them, and when they’re gone, you know that the landscape seems bereft of something, but exactly what it is you can’t tell immediately.  It takes a while for the feeling to sink in.  One thing we did easily notice, however, was that the sand dunes were practically gone --- they were in the process of being built up again, a job that nature will have to finish.  Park Service experts had heroically planted back the sea oats and other plants along many sections of shoreline, in an effort to accelerate the recovery.  In our frequent excursions to the beaches, I didn’t notice a major difference in the numbers of birds inhabiting the area.  Ruddy Turnstones and cryptically-colored Sanderlings skittered around at the edges of the waves, with the larger Willet occasionally showing up to utilize the deeper waters.  There were Least Terns by the dozens, diving in midair and slicing through the water to come back up with silvery fish in their beaks.  Actually, the fish were far from the only live creatures we saw in the waves --- this is where conditions seemed a little different from the other times we spent on the coast; coquinas (the little rainbow-hued clamlike mollusks) were everywhere, but there were also augers (sharp cone-shaped mollusks) and olives that were alive and burrowing into the wet sand.  My sister Deanna even discovered a hermit crab in a shell she picked up from the waves, thinking it was empty.  We all saw other sorts of crabs as we waded in the shallows, but thankfully no jellyfish.  I’m not sure whether these animals were evident simply because we were more observant this time, but I don’t remember seeing this many live seashore creatures during any of our other coastal trips, and I suspect that they may have had more opportunity (i.e., fewer human developments) to re-colonize.

Sanderlings

As far as seashore birds go, the gatherings of Brown Pelicans and Laughing Gulls, with small groups of Black Skimmers, Royal Terns, and the occasional Osprey didn’t appear diminished.  The shore may have taken a hard hit, but the swaths of coastal scrub farther inland were damaged more severely.  Most of the trees fared pretty well, I guess, with some inevitable wind and salt damage to the weaker ones such as the pines (the ancient Live Oaks were fine), but the change that made the whole area look like a dead zone was the understory of shrubs, a gray, water-damaged, skeleton-like mass stretching as far as we could see.  It might have just been our heightened discernment of changes here, but the numbers of forest birds seemed down.  On the other hand, a few woodpeckers were busy at work on some of the damaged wood, so the devastation clearly wasn’t detrimental to everyone.  A change that was upsetting to us was the state park, bereft of shade with the absence of most of the trees, and the areas between campsites open and bare of shrubbery.  We’ve spent several vacations in this park, and one of the things we most enjoyed about it was the pleasant shade and privacy afforded by the thick vegetation it once had, but in the long run these changes are probably not really a big deal.

We decided on our second day in at the coast to go on a chartered sailboat ride, something we’d never done before but figured would be enjoyable.  After making our reservations, we traveled to the boat dock, met our captain, and finally set off with a good-sized group of other like-minded people in the comfortable sailboat.  The weather was great, and the boat went smoothly with the motion of the waves out on the bay.  Pelicans soared in and landed on the water, gulls flew past on the breezes, and at several times during the expedition, pods of dolphins surfaced, some of the animals making brief leaps over the waves.  As I stood looking over the rail of the boat, watching the calmly rolling bay waters and listening to the calls of gulls in the distance, I thought that this was a most fitting way to stop and reflect on the recent changes on the gulf coast --- in the midst of this ecosystem that seems the most changeable of all, but in some ways is the most stable, as it constantly refreshes and renews itself.  In the same way, the natural environments of the gulf coast can and will refresh themselves in their own way and time, if we just allow them the opportunity.

Coastal Woodlands

Beaches, bays, and marshes come to mind most readily when I think about coastal environments.  But the Gulf Coast also boasts a variety of wooded landscapes that provide crucial habitat for many animals and serve as buffers against storms.  In the photo below, a Great Egret fishes along a wooded coastal creek in late December.  One consequence of the moist, warm regional climate is that many woodlands tend to stay green and blooming well into the fall and winter.

Great Egret (Ardea alba)

I love the diversity of these coastal forests.  The canopy trees may be hardwoods like black gum, water oak, or live oak; pine species; or a mixture of both.  Several of these trees, like the water oak, can be found across much of the southeastern U.S., while others, such as the southern live oak, are highly representative of coastal ecosystems.

Slash pine (Pinus elliottii) is a common, fire-resistant tree in coastal woodlands.  Note also its broad patches of bark.

Water oaks (Quercus nigra) typically have smaller leaves, but these saplings were growing in to the understory, and therefore needed more leaf surface area to capture sunlight.

This is a typically enormous live oak (Quercus virginiana).  These trees grow rapidly in the first few decades of life.

The understory trees and shrubs of coastal woods are particularly interesting, since they tend to bear obvious adaptations to the ever-changing environment.  For example, there are a number of species that are evergreen and have waxy leaves: features that help to prevent desiccation and protect against the fires that were once natural, expected occurrences on the coast.  In more recent decades, prescribed burning has aided in forest recovery.

Swamp bay and wax myrtle are two of these common evergreen coastal trees (or shrubs, depending on their growth pattern).  Both species produce provide cover for animals during the winter, and their flowers and fruits can attract many birds and other wildlife.  The wax myrtle’s leaves are smoother and have wavier margins than those of the swamp bay.

Swamp bay (Persea palustris)

Wax myrtle (Morella cerifera)

A little farther inland, mountain laurel is often a surprisingly common understory plant.  It usually grows in montane forests in the northerly portions of its range, but it may be found in low-lying areas in the coastal region.  Like the swamp bay and the wax myrtle, it has thick, waxy, evergreen leaves.  While birds and insects may enjoy feeding from its flowers, it is highly toxic to most other animals.

Mountain laurel (Kalmia latifolia)

Of course, not all understory plants of the Gulf Coast have a typical tree-like growth form.  The dramatically spiky, waving fronds of the saw palmetto give panache to the forest floor.  Like other palm species, saw palmettos stay green all year.  Their berries provide food for a multitude of wildlife species.

Saw palmetto (Serenoa repens)

 

What of the non-shrub understory plants of these coastal woods?  Well, switch cane is one of the most noticeable.  This is especially true during the winter, when many of the herbaceous—or non-woody—plants have died back, and only the toughest of them, the graminoids—a group that includes grasses and sedges—are left to provide groundcover.  Canes and bamboos actually belong to the grass family, which isn’t surprising when you consider their shape and growth habits.  Being a native bamboo, switch cane commonly grows in low-lying, swampy habitats.  In other words, don’t necessarily expect to find it in urban areas!  Of course, if it does happen to be growing there, leave it be.  Native plants deserve a chance to thrive.  

Switch cane (Arundinaria tecta)

As always, there are countless other plant species that you may find in these coastal woods.  The colder seasons along the coast don’t always look the way that you might expect, and there is generally a lot of greenery in the woods.  As the season eventually shifts into early spring, however, watch for changes—particularly the proliferation of herbaceous plants along the ground and the blossoming of some of the trees and shrubs in the other forest layers.  It’s always nice to have an excuse to duck into a comparatively cool, shady woodland after a long walk at the beach on a sunny day!