Magnificent Frigatebird

Frigatebirds soar over the oceans. They rarely flap their wings. They are the only birds with fused pectoral girdles, giving them further rigidity for soaring. They are often called “Man-o’-war Birds” due to their habit of harassing and robbing other seabirds. They, however, capture most of their prey by snatching fish or squid from the ocean surface (Diamond and Schreiber 2002). This species lacks waterproof plumage and, consequently, is rarely seen on the water. Because of their short legs, they never walk or swim.

Magnificent Frigatebirds breed throughout the Caribbean and the coasts of Central and South America.  The closest breeding location for this frigatebird, which we saw on Sanibel Island, Florida, is probably the Dry Tortugas at the end of the Florida Keys. Frigatebirds are occasionally blown far inland by hurricanes. Erika and I once witnessed several frigatebirds over Baton Rouge after a hurricane in the 1970s. These birds apparently soar in front of storms and are accidental in Alaska, Minnesota, Wisconsin and eastern Canadian provinces. 

Notice the deflated, red throat pouch and long, but closed tail feathers.

Four-spotted Pennant

Last March, upon arriving at the Bailey Tract of the Ding Darling National Wildlife Refuge, Erika and I immediately found a new dragonfly—this Four-spotted Skimmer. The male, above, was easily identified. The female, below, was more difficult, but the white stigma are good field marks. (Stigma are the spots at the leading, outer, edges of the wings. The stigma may signal identity to mates or rivals. It may also counteract wing vibrations and fractures.)

Four-spotted Skimmers are found from Arizona east along the Piedmont of the southeastern states. As in these photos, they often rest on exposed perches. They hunt for flying insects over ponds.  Paulson (2011) writes that this skimmer can occur in swarms. We found them to be common.

Sanibel Island

On 25 March, Erika and I finally arrived at our destination—Sanibel Island on Florida’s Gulf Coast. This visit, which lasted until 1 April, was our second to the island. We visited here in January 2010. We saw many fewer birds during our 2015 trip and many, many more people.

We had a good time, however, since Sanibel is renown for the diversity of shells. On our previous trip, I was not chasing dragonflies. And we were on a quest to find a Gray Kingbird—January was too early for this lifer, and the end of March, for that matter, was marginal. Using the BirdsEye phone app, we discovered a Gray Kingbird had been seen two days earlier at the Bailey Tract, an outlying parcel of the Ding Darling National Wildlife Refuge. Refuge personnel directed us to the tract.

We made at least four visits to the Bailey Tract, a large parcel of undeveloped land containing several freshwater holding ponds—perfect habitat for dragonflies, if not kingbirds. On our first visit, we encountered a refuge ranger, who told us a Gray Kingbird was seen just down the path about 30 minutes ago. Way in the distance, we took the greatly enlarged photograph below—a Gray Kingbird candidate. The bird really did not look right—the bill is not thick enough—perhaps a Northern Mockingbird. But the bird did not seem contrasty enough for a mockingbird, although the silhouette seemed correct. Despite our great efforts, we never did see anything else at Bailey to call a kingbird. As you will learn, later, in the northern Florida Keys, we did add Gray Kingbirds to our list. At Sanibel, we were content to discover new dragonflies for our list. And we did see birds, as you will see in the next bog posts.

Sandhill Crane

While I was intently photographing the Cyprus Clubtail of the last post, Erika, some distance away, was gesticulating and pointing to my left. In  a weedy field in back of some homes and near a canal, strolled a Sandhill Crane. The crane allowed me close approach before it finally flew.

Sandhill Crane systematics are complicated. Basically six races inhabit northern North America, but these populations interbreed where they overlap (especially in these days of expanding crane populations) and the races are often further divided by wildlife managers into units determined by where they breed.

The crane in this photo is a Florida Sandhill Crane, Grus canadensis pratensis. This birds reside from southeastern Georgia to central Florida. They do not migrate. They are similar to the Mississippi Sandhill Crane, which breed in southern Mississippi. Florida birds are generally paler than those from Mississippi. A third race is resident in Cuba. The three remaining races are migratory. The Lesser Sandhill Crane breeds from Siberia across Arctic Alaska and Canada; the Canadian Sandhill breeds further south, from British Columba east into Ontario; and the Great Sandhill Crane breeds from southern British Columbia east to the western Great Lakes (Gerber et al. 2014).

Cypress Clubtail

A few dragonflies flitted about the  Harns Marsh, Florida, when we visited on 25 March. Blue Dashers,  Eastern Pondhawks, and Halloween Pennants were common, and well-known to us. When I saw this clubtail at my feet, however, I knew it was a new one for me. I called it a “Green-striped Clubtail,” and excitedly emailed Scott King for his opinion. He quickly replied that he thought it was either a Cypress or a Sandhill clubtail.

I identified it as a Cypress Clubtail. First, Cypress Clubtails are found south of Lake Ochchobee, according to Paulson (2011), whereas Sandhills are found further north in Florida. The habitat of Harns Marsh is typical of the Cypress—Cypress lined, muddy lakes. The micro-anatomy shown in my photo also points to this being a Cypres Clubtail, although I have to admit I was relieved when Odonata Central vetted my identification.

Halloween Pennant

Erika and I were greeted by a dragonfly found in Minnestoa, this Halloween Pennant, when, on 25 March, we revisited Harns Marsh in search of Limpkins. We first visited the marsh in 2010, before our focus on dragonflies. This species is found from Canada through the eastern United States south into Central America. Wikipedia claims they are particularly common in Florida. This source reports that this dragonfly often perches at the tip of weed stalk. The wings wave in the breeze, leading to the name pennant, a word that describes a small flag. I think "halloween" is an odd name. All things orange do not refer to halloween. Indeed, as I have previously written, the general coloration may mimic poisonous butterflies and therefore discourage predators.

Limpkin

In the United States, Limpkins are residents of Florida, with casual or accidental records elsewhere in the Southeast. These curious birds also breed in the West Indies, southern Mexico and Central America, and much of South America. Erika and I found them on 25 March on the east side of Harns Marsh, which is east of Fort Myers. At least in Florida, Limpkins specialize in eating Apple Snails, mollusks also sought out by Snail Kites, which we also listed at the marsh. The Limpkin bill is bent and twisted, an adaptation for removing the snails from their baseball-sized prey. Not surprisingly, Florida wetland development threatens Limpkin populations.

In Wild America, an entertaining book describing one of North America’s first birding big years, Roger Tory Peterson and James Fisher write that the Limpkin gives a “shrieking, yelping, and caterwauling…” call. Alexander Sprunt wrote that, when several males counter-call, the sound is “one of the weirdest cacophonies of nature” (cited by Bryon 2002). The screech has been compared to a woman being strangled. I recognized the call when Erika and I heard it at the marsh. I think the call is actually kind of pretty—you decide what you think it sounds like.

American Green Tree Frog

Erika and I discovered this American Green Tree Frog on the underside of a marsh plant in the Corkscrew Swamp Sanctuary on 25 March. This frog is common the southeastern United States, from Delaware to Florida and west to Texas. It is Georgia’s State Amphibian.

American Green Tree Frogs prefer wetlands with floating vegetation, grasses, and cattails. They tend to be noctural. Florida males give advertisement calls between March and September. They often have multipe clutches, with the average clutch containing about 400 eggs. Eggs take about five days to hatch. These frogs show no parental behavior beyoung mating and egg laying (Wikipedia).

Red-shouldered Hawk

Overall, during our 25 March visit to the National Audubon Society’s Corkscrew Swamp Sanctuary, we saw fewer birds than on our previous visits. Perhaps the time of year was poor, and, at the time, the swamp was suffering from drought. We were, delighted, to find the south Florida race of Red-shouldered Hawks, to be common as always. Buteo lineatus eximus breeds in the southern half of Florida. It is relatively small and has a pale gray or whitish head

Red-shouldered Hawks in Minnesota and most of the eastern United States are much larger and darker. They are named Buteo lineatus lineatus. Most of the information I am relating in this post is from Dykstra et al. (2008).

Buteo lineatis alleni breeds from North Carolina, Tennesee, Arkansas, and Oklahoma south to Lousiana, Texas, and the northern half of Florida. These birds are slightly smaller and paler than Minnesota hawks, and lack dark streaks on their underparts.

Curiously, Red-shouldered Hawks also breed in California, Oregon, Baja California and Arizona. Their range is not contiguous with eastern Red-shouldered hawks. They are relatively small and have bright rufous underparts.  These hawks are named Buteo lineatus elegans.

Eurasian Collared-Dove

Seeing Eurasian Collared-Doves is no longer much of a surprise in much of North America. During my recent travels across the country, I am surprised by how widespread and common this species has become. I have previously posted accounts of this species’ spread. John Holden and I found this dove buffeted by the wind in nearby Dakota County. I thought the back-lit tail feathers to be particularly striking.

Romagosa (2012) writes that “little appears to be limiting the spread of this dove in North America.” Bird feeders and grain storage bins provide year-round food supplies. Urban landscaping gives the birds habitat. Romagosa suggests that disease could cut back high dove populations, although she admits little evidence exists for this hypothesis.