The Virginia Rail

It's spring migration right now in the bird world. Many species across many different groups of birds are moving from their southern overwintering grounds to their northern breeding grounds. One such species is the Virginia Rail.

A few days ago I found myself in my hometown of Circleville, in Pickaway County, Ohio. I decided to head to the Mary Virginia Crites Hannan Park, a local city-owned park. This park has a small marsh with some open water, and last year I had found Soras in the marsh (which you can read about at this link!). This marsh had only recently been built when the city purchased the land a few years ago, and I was curious if Soras were utilizing this marsh every year, or if last year had just been a random occurrence. As I walked up to the wood deck which overlooks the marsh, I took out my phone and played the call of a Sora to see if one would call back from the reeds. Instead of a Sora calling back, a curious Virginia Rail ran straight out of the reeds. I will admit, I was not expecting that to happen!

The Virginia Rail is secretive species of rail, a group of marsh-loving birds who are known for being shy and hard to see. The Virginia Rail is a wide-ranging species, which can essentially be found across the lower 48 states in appropriate habitat at some point during the year. Generally speaking, they overwinter along the Atlantic, Pacific, and Gulf coasts of the US, and breed throughout the west and the northern portion of the eastern US.

Can you spot the rail?

The Virginia Rail is a wetland-dependent species. They mostly inhabit freshwater marshes, but occasionally can be found in saltwater or brackish marshes, mostly during the winter months. They require emergent vegetation for shelter. The browns, tans, and grays of the Virginia Rail's plumage allow it to essentially disappear among the grasses, sedges, and cattails that grow in the shallow areas of marshes. When rails feel threatened, they will often simply freeze among the cover they are currently hiding in. When a rail freezes in a stand of dense reeds or grasses, it can be nearly impossible to see the rail unless you already had eyes on it.

The cautious Virginia Rail looks to the sky to scan for any potential aerial predators.

There are 5 species of rail that can be found in Ohio (I'm excluding the Common and Purple Gallinules and the American Coot from this number; although these 3 species are in the rail family Rallidae, they aren't what most birders think of when they think of rails). Of those 5 species, the Sora is the most common and the Yellow Rail is the rarest. The Virginia Rail is the second most common species of rail in Ohio, and one of the 3 species which regularly breed in the state (the other 2 are the Sora and King Rail). How widespread and abundant are Virginia Rails in Ohio? No one really knows. Rails are super secretive, and this makes estimating populations difficult. The vast majority of them probably go unnoticed. If you check the reports of Virginia Rails on eBird, you will notice that the vast majority of reports are centered around urban areas. Does this mean that rails love urban areas? No; urban areas simply have a higher concentration of birders. More birders in an area means more eyes to find secretive species like Virginia Rails.

The Virginia Rail is an omnivore, but they focus mostly on arthropods. Like other water-tied birds with long beaks, the Virginia Rail will probe into the mud in an attempt to find various arthropods. They also feed on arthropods that are either on the surface of the water or the ground, such as spiders and beetles. The individual pictured above was actually foraging farther from the water than I thought it would. When I took this picture, the rail was foraging about 10 feet from the water's edge. There were at least 2 Virginia Rails present in this marsh, along with at least 2 Soras, and they seemed to have established trails for them to move between foraging areas. They would feed in an area of dense grasses before darting quickly along an obvious narrow trail devoid of plants to another dense foraging area.

As I mentioned in my Sora post last year, I absolutely love rails. For one, they're adorable. But I'm also drawn to the fact they are secretive and difficult to find and see. As a birder, it's always rewarding to find a rail species of any kind in a marsh, and even more rewarding to actually lay eyes on one. I'm really hoping that the two Virginia Rails in this Pickaway County marsh decide to breed here, but they might also simply be migrating through to a more northerly location. The creation of this marsh (and the surrounding prairie they planted) by the city of Circleville has turned out to be a wonderful action. This marsh and the open water in the center has proven to be a migration stopover for many species, including Virginia Rails, Soras, Pied-Billed Grebes, Horned Grebes, Blue-Winged Teals, and many other species. The surrounding planted prairie has attracted species such as the Savannah Sparrow and the declining Henslow's Sparrow. This prairie and marsh only make up half of the Mary Virginia Crites Hannan Park, however. The other half is a well-established wet forest. This forest attracts many migrating songbirds and is a great place to bird in the spring and fall.

Do you love rails too? If so, I highly recommend following Dr. Auriel Fournier on Twitter (@RallidaeRule). She is an ornithologist conducting research on rails. If you aren't interested in rails yet, you will be once you follow her!

Thanks for reading!

A Little Blue Heron in the Salt Marsh

As I mentioned in my previous post on the Cottonmouth, I recently took a 2000 mile solo road trip during my Winter Break. I spent most of my time birding throughout coastal South Carolina, racking up a total of 90 species (including 8 lifers) from December 28, 2015 to January 2, 2016. This wasn't my first time birding in South Carolina; just a few months prior I visited with my ornithology class for a 4 day field trip (which you can read about here: Part 1, and Part 2). It's an absolutely wonderful state to go birding in!

One of the locations I visited was Pinckney Island National Wildlife Refuge in the very, very southern tip of South Carolina. It's a very interesting preserve, and most of it is open saltwater or salt marsh. I went to visit a productive freshwater pond named the Ibis Pond, but first had to walk by an extremely shallow salt marsh. And in that marsh was a small white bird.

And that small white bird was a Little Blue Heron. You might be wondering why a "Little Blue Heron" is white, and this is because it is a juvenile Little Blue Heron. This species begins life in all-white plumage and individuals transition to their deep blue plumage upon maturity.

I would like to take a moment to talk a bit about the name "heron." As you might know, there are herons and egrets; both look essentially the same, aside from species-level color differences. You might be thinking there is some kind of difference between the two groups, like there's something that makes a heron a heron, and an egret an egret. I definitely thought that until I started my research for this post. Turns out, there is no significance to the names. Although the Little Blue Heron is called a heron, that name doesn't mean much in itself; in fact, the Little Blue Heron is most closely related to the Snowy Egret. So why the two groups of names? It's basically due to linguistic and societal differences. Birds in the family Ardeidae are called the herons. The name "heron," when talking about etymology (the study of a word's origin and history), comes from certain Germanic languages including Middle English. Egret, on the other hand, is still Germanic, but is based on the Old French word "aigrette," which is pronounced "egret." Aigrette can translate to "little white heron," but also refers to long, decorative plumes that certain heron species grow during breeding season. So basically, the French term "aigrette" was borrowed by English and morphed into "egret." This term was then applied to white herons, many of which also have those decorative plumes during their breeding season. However, when you look at the evolutionary history for these long-legged waders, you see that there's no biological basis for the differences in names; the birds we call egrets and the ones we call herons are all intermixed in various genera, and they don't break down into two completely separate groups. This is one of the many reasons why common names can be deceiving!

Back to the Little Blue Heron! This is a medium-sized heron species that stands about 2 feet tall. Here in the United States, Little Blue Herons are most commonly a resident of sub-tropical swamps and marshes in the southeast. However, like their cousin the Snowy Egret, the Little Blue Heron will also very sporadically breed in the northern half of the Eastern United States. Little Blues will also sometimes irrupt northward in the late summer after breeding is finished. When it comes to Ohio, the Little Blue Heron has an interesting history. A few pairs have actually nested in Ohio, and these pairs have been confined to the wading-bird nesting colony on West Sister Island in Lake Erie. These nesting individuals show up to forage in marshes throughout Ottawa and Lucas counties, including Ottawa National Wildlife Refuge and Magee Marsh. Even then, this is a very rare species to see in Ohio. To read more about the Little Blue Heron in Ohio, check out this link: OBBA Account

Although they are rare in Ohio, the Little Blue Heron is pretty common within their core range. They are typically a bit shyer than other herons, preferring to forage along the edges of wetlands either singly or in very small groups. The Little Blue is a stand-and-wait predator, meaning it prefers to quietly stand in one location and wait for prey to come to it instead of actively hunting them out. They typically feed on fish, amphibians, and crustaceans, but will also take insects and small mammals. This individual was in extremely shallow water (about 1 or so inches deep), and fish were nowhere to be found. I watched him as he slowly and carefully stalked about, turning his head to inspect the water for life. Eventually he struck the substrate and pulled up a bristle worm, as pictured above. Bristle worms, class Polychaeta, are a diverse group of mostly-marine segmented worms, and easy pickings for many wading birds.

While researching information for this post, I came across two very interesting studies that I would like to summarize. Both studies were done by Gloria S. Caldwell, and the papers can be found at this link: Caldwell 1981, Caldwell 1986. To give some background, most herons/egrets have the same plumage coloration throughout their life. The Little Blue Heron is a bit unusual in this as it is dimorphic in regard to age. The juveniles are white, while the adults are dark blue. Is there a significance to this color dimorphism? Turns out there is, and it’s incredibly interesting. Caldwell (1986) found that herons with white plumage were attacked by hawks more often than herons with "dark" plumage. At first glance, it seems that the juvenile plumage of the Little Blue would be a hindrance to survival, but it’s actually a bit more complicated than that. Caldwell also found that flocks of herons have a significantly lower chance to be preyed upon than an individual foraging alone, and this makes sense; the more eyes you have watching for predators, the less of a chance a predator will be able to commit a successful attack. How does this flocking feature factor in? Caldwell (1981) found that Snowy Egret flocks will more readily accept juvenile Little Blues than adult Little Blues (in fact, adults were attacked by the Snowy Egrets, while juveniles were left alone). Caldwell suggests that the white plumage of the juvenile Little Blues makes the Snowy Egrets, a white bird themselves, more apt to accept the juveniles than the dark-colored adults. So, although white juvenile Little Blues are more likely to be attacked by predators than the adults, they can mitigate this negative effect by foraging in a mixed flock with Snowy Egrets. In addition to all of this, Caldwell found that juvenile Little Blues actually had a higher success rate catching fish while in a flock than when they foraged alone.

Let me take a moment to sum everything up so far. Juvenile Little Blue Herons, which are white, are better accepted into mixed foraging flocks than the dark-colored adults. By being part of a flock, the juvenile Little Blues have a better chance to avoid predation. In addition, by being part of a flock, juvenile Little Blues have better success at catching fish. Therefore, by having a lower chance of being killed by a predator, and by being better-fed as they mature, a juvenile Little Blue Heron has a much better chance of making it to adulthood and passing on its genes. Having white plumage is, therefore, very beneficial, and natural selection ensures this white juvenile stage is maintained.

Now you might be wondering why there isn’t a selective pressure for the adults to be white, instead of dark blue, as well. There are some young white subadults that attempt to mate every year, and you would think those individuals would be heavily selected for, but those subadults almost always fail to mate. This implies there’s something else now at play, but what is it? It all has to do with breeding! As I mentioned previously, white herons are preyed upon at a higher rate than dark-colored herons. This is simply because white really stands out among the greens of swamps and marshes. To see this in action, look at the photo above; the white juvenile on the left stands out like a sore thumb, while the dark adult on the right blends in relatively well. Being inconspicuous is very important when it comes to nesting; nestling birds are incredibly easy pickings for predators as they can’t fly away and escape. Many predators know this, and many will actually watch for adults bringing food back to a nest in order to locate the nest. Once a predator knows where a nest is, and if they can get to it, then it’s all over for the nestlings. Because of this, adult birds try to hide the location of nests at all costs. If you are a conspicuous, attention-grabbing white, you might as well let predators waltz right up to your nest. By transitioning to a dark coloration upon maturity, Little Blue Herons reduce the chances that predators will attack them or their nest, which not only helps ensure their survival, but the survival of their nestlings as well.

In the end, natural selection selects for white-plumaged juveniles and dark-colored adults. By having this dimorphic coloration system, the Little Blue Heron optimizes survival across its entire life cycle from nestling to breeding adult.

That's it for this post! Thanks for reading!

South Carolina, Pt. 2

Part 1 can be found here: South Carolina, Pt. 1

This is the second post, covering the second day, of my trip down to South Carolina two weeks ago. I am currently taking Ornithology (the study of birds) at Ohio University. This class is one of the required classes for my Wildlife and Conservation Biology major, and also one of my most-anticipated classes of my college career. We go on weekly field labs (You can read about each one at this link), but we also get to go on two big trips. One of these trips is to Lake Erie, which is coming up in November, while the other trip is coastal South Carolina. The point of this trip was to expose us to birds we would normally never see in Ohio.

We awoke before sunrise to get a start on the day. While everyone got dressed and ate breakfast, I had some time to sneak off to watch the sunrise on the beach and snap a photo or two. Daylight wasting, we quickly loaded the vans and left Hunting Island State Park. Our goal for the day was to head a tiny bit farther south and closer to the South Carolina-Georgia border. The first stop of the day was at Pinckney Island National Wildlife Refuge. Located near the tourist town of Hilton Head, Pinckney Island National Wildlife Refuge is a collection of islands and tiny hammocks. The main (Pinckney) and surrounding islands have a very extensive history. Archaeological sites have shown Native American activity going back all the way to 7000 BCE, with intensive use from 1000-1500 AD. Temporary settlements built by the French and Spanish dot the 1500's and 1600's. The first permanent settlement was in 1708, and this began a period of intensive change. In 1804, Charles Cotesworth Pinckney, who had been an officer in the Revolutionary War and a founding father, moved to the islands and began a cotton plantation there. The land was cleared, drained, and worked by 200-300+ slaves, leaving a natural, and humanitarian, scar on the islands. After the Civil War, the islands changed hands multiple times and experienced periods of continued agriculture and management as a game preserve. 1975 saw the land and surrounding waters become a dedicated national wildlife refuge. Nowadays, several miles of gravel pathways are used extensively by the residents of Hilton Head, tourists, and nature-watchers.

A variety of habitats can be found throughout the preserve, making for great birding. Salt marshes held birds like the White Ibis pictured above. Willets, Greater Yellowlegs, Tricolored Herons, and others made appearances too. The island also features several small freshwater ponds which held the likes of more White Ibises, Common Gallinules, Black-Crowned Night-Herons, Anhingas, Green Herons, Pied-Billed Grebes, and more. Pine forests and scruffy secondary growth held songbirds like the Boat-Tailed Grackle, various warblers, Brown-Headed Nuthatches, Fish Crows, and more.

Of course, birds weren't the only creatures out and about. One of the many eye-catching insects of the day was the Gulf Fritillary, Agraulis vanillae. We saw dozens and dozens of these incredible butterflies; I have never seen such a vibrant butterfly in person. The Gulf Fritillary has a wide range that extends from southern South America, through Central America, and into the southern portions of the United States. Although this species is found primarily in the south-central and southeastern portions of the US, the Gulf Fritillary is a species that will often "wander" northward. Ohio pretty much has a one-state buffer zone around it from this species' normal range, but these can be occasionally found in Ohio. Most recently, 2008 proved to be a very large invasion year of Gulf Fritillaries in Ohio, as Jim McCormac covered in his blog. As he points out, global warming, coupled with the fact we are seeing more and more individuals farther north, suggests that the Gulf Fritillary might possibly be a new Ohio resident in the future.

Six or so miles of walking and several hours later, we left Pinckney Island NWR and headed inland to Savannah National Wildlife Refuge. Savannah NWR lies several miles away from the Atlantic Coast, which is just enough for a whole new set of habitats and animals to come into play. The refuge straddles the Georgia/South Carolina border, with half the park being in one state and the other half being in the other. We stayed in the South Carolina section the entire time, choosing to drive the length of the 4 mile Laurel Hill Wildlife Drive, a one-way gravel road which winds through portions of the park. This road passes mostly through freshwater wetlands, but also passes through hardwood hammocks like the one pictured above. A hardwood hammock is essentially an "island" of trees which can persist in a marsh due to the ground being only a few inches higher than the surrounding marshland. Notice in the case pictured above (click to enlarge), the hammock consists primarily of Southern Live Oak, Quercus virginiana. Also notice the distinctive and characteristic Spanish Moss, Tillandsia usneoides, hanging from the Live Oaks. Spanish Moss is a species of flowering plant that is actually an epiphyte, meaning it grows harmlessly on trees and absorbs water and nutrients from the air, rain, and debris that collects around it. As a result, Spanish Moss only uses the tree for support instead of parasitizing it.

One of the main features in the freshwater marshes at Savannah NWR were dikes. Dikes are man-made levees that help control water levels and flow in marshes. Back in the 1700's, much of the land in the refuge was managed rice fields. These altered marshes remained and natural vegetation came back. Now there's a whole range of birds that make this refuge home at some point of the year. A few shorebirds were present when we went, including this Solitary Sandpiper pictured above.

Other birds present included 3 species of rails. Rails are a cryptic and elusive bunch, with most species preferring dense marsh grasses and reeds. The species Ohioans are most familiar with is the American Coot. We saw several of the coot's cousin, the Common Gallinule (pictured above). The Common Gallinule can be found in Ohio, especially along Lake Erie, but it is definitely a more uncommon species there. The Common Gallinule is much more common down along the southern coasts. The most exciting bird of the day was a Purple Gallinule that I spotted along the banks of a ditch. Like the Common Gallinule, the Purple Gallinule is also a rail, but an incredibly colorful one. This truly tropical-looking rail can be found extensively throughout the tropics, but is restricted to the southern Atlantic and Gulf Coast here in the US. In fact, Savannah NWR is even approaching its northern limits. Another species of rail we observed here was the Sora. Sadly we only heard them instead of seeing them.

Another strange southern specialty in the US is the Anhinga. Although it superficially resembles cormorants, the exact relationship between the Darters (which includes the Anhinga) and the Cormorants is uncertain. They are certainly related, but how closely is still up in the air. The Anhinga is a freshwater-loving species, and prefers the marshes and swamps of the southern US. They can often be seen drying their wings on the banks of waterways, like the one above.

Other interesting birds we observed at Savannah NWR included Cattle Egrets, Northern Harrier, Great-Horned Owl, Peregrine Falcons, and various migrating warblers.

Of course, it wouldn't be a trip down to the South without one of these guys. This is the American Alligator, Alligator mississippiensis. Savannah NWR is known for its Alligator population, and we saw over 12 individuals during our time there. A large crocodilian reptile that reaches lengths of 9-15 feet on average, the American Alligator can be found throughout freshwater marshes, lakes, and swamps in the southeastern US. The American Alligator was once very endangered, but has staged an incredible comeback in the past few decades.

Part of the class on the beach at Hunting Island. I am the one in the green hat and shirt looking through the spotting scope. Photo credit: Michelle Ward

We left Savannah NWR at sunset and made the hour and a half van ride back to Hunting Island where we camped for a final night. It was an incredible trip, and I added 19 bird lifers in the end. I personally finished with 75 species of birds over the two days in South Carolina, but I know I missed a few species that others on the trip saw or heard.

Here's my complete eBird lists for the two locations of the day for those interested:
1. Pinckney Island NWR
2. Savannah NWR

I have to admit I fell in love with the southern maritime forests and the salt marshes over the course of the trip. I am planning on going back to this region on a birding trip over Christmas Break, and if that happens then I'll have many more in depth posts on this amazing region. Thanks for reading!