Cranes and Crabs

Whooping Crane at Aransas National
Wildlife Refuge, Texas

The Whooping Crane (Grus americana) is a comeback species. These cranes once ranged across North America. They were contemporaries of the great ice age animals like Giant Sloths, Mammoths and Dire Wolves. Whooping Crane fossils have been unearthed from California to Idaho to Florida. European settlers found these large birds numerous and delicious. Market hunting as well as habitat loss drove the Whooping Crane to near extinction. In the 1940s the Whooping Crane population in the wild was twenty-one birds. Now it exceeds 800.

Two adult Whooping Cranes in a marsh at Aransas

The last natural population of Whooping Cranes breeds in Northern Canada then migrates to Texas to winter in coastal marshes. Conservationists have established a new migratory population that breeds in Wisconsin and winters in Central Florida. Two new non-migratory Whooping Crane populations have also been established in Florida and Louisiana.

In November, Diane and I saw Whooping Cranes on their wintering grounds in the Aransas National Wildlife Refuge near Rockport, Texas. The day started by boarding Captain Tommy Moore’s boat the Skimmer. Upon leaving the boat harbor we entered Aransas Bay. The bay is brackish and shielded from the Gulf of Mexico by low barrier islands. Salt water from the Gulf enters the bay through Aransas Pass and Cedar Bayou.  The gulf water and mixes with freshwater that flows into the bay from the Aransas and Mission Rivers. Captain Tommy piloted the Skimmer past natural gas wells and oyster bars covered with pelicans. We soon reached a large marsh and Whooping Cranes were scattered about, feeding in small pools. Whooping Cranes are large birds, standing 5 feet tall and weighing up to 16 pounds. Adult cranes are white with black wingtips, a red crown and a dark, dagger-like beak.

Whooping Crane with freshly caught Blue Crab

Another crane another crab

In the Texas marshes, the cranes eat whatever they can catch, including frogs, fish, and mollusks. But, their favorite food seems to be Blue Crabs (Callinectes sapidis). The cranes stalk through shallow ponds in the marsh, probing with their beaks and stabbing their crab dinner. They then throw the crab up on the bank and eat it in pieces.

Someone asked me once what the rarest bird I had ever seen was. I did not have an answer because I do not think about birds in those terms. Now I have an answer. Whooping Cranes, those relics of the ice age, numbering in their hundreds, living on the edge of extinction and on the edge of the continent, are the rarest birds I have seen.

Florida Interlude

Our visits to Florida always turn up interesting revelations in natural history. A brief stay in late December presented Diane and me with three small wonders.

Puss caterpillar (Megalopyge opercularis).  Its long hair gives it a
cat-like appearance. 

While hiking at the Wakodahatcheee Wetlands in Delray Beach, Florida we saw a longhaired caterpillar crawling along a handrail of the boardwalk. It was a Puss Caterpillar (Megalopyge opercularis) the larval form of Southern Flannel Moth. Puss Caterpillars got their name because they look like miniature versions of long-furred cats. The name for the genus, Megalopyge, translated big rump, comes from the long hairs of the caterpillar combining to form a tail. This caterpillar is quite dangerous because those long hairs conceal stinging spines. If you make contact with these spines, they release a venom that immediately raises red welts on the skin then cause severe pain, nausea, fever, rapid heart rate or even convulsions. These fascinating and dangerous caterpillars metamorphose into a very hairy moth that we did not get to see. The Southern Flannel Moth ranges throughout the Southeastern US and west into Texas.

Psychotria nervosa (what a marvelous name) or Wild Coffee, is a plant native to Florida, Central America, the West Indies and South America. We found Wild Coffee growing in abundance in the coastal hammock at Lantana Beach Nature Preserve. Wild Coffee bears shiny green leaves and produces white flowers. These flowers develop into red fruits, each of which contains two hemispherical seeds that resemble the “beans” of its relative, true coffee (Coffea arabica). Birds eat the bright fruits and disperse the seeds in their droppings. The small seeds of Wild Coffee is not a good substitute for regular coffee because the seeds do not contain caffeine and drinks brewed from them taste bad and cause headaches.

Wild Coffee (Psychotria nervosa) plant with fruits.

Wild Coffee fruit cut in half showing its two seeds.

Wild coffee seeds.  They look very much like
regular coffee beans but much smaller.

In the late afternoon of a short winter day, we found a spectacular butterfly, the Ruddy Daggerwing (Marpesia petreus). Ruddy Daggerwings are found from Brazil, through Central America, the West Indies and into south Florida. A few even make it to south Texas and Arizona. When we first saw this butterfly flying fast and low in a park in Palm Beach County, we thought it was a Monarch or Julia. As we approached, it was clearly something different. The Ruddy Daggerwing is bright orange with dark brown lines of the upper side of the wings. Each hindwing has a long tail, the dagger in its name. The underside of the wings are brown and resemble dead leaves. Ruddy Daggerwings lay their eggs on the fig (Ficus) trees that are abundant in South Florida.

Ruddy Daggerwing feeding on the nectar of Spanish Needles (Bidens pilosa) 

People from around the country and around the world go to Florida in winter. Florida is warm, green and bright when many places are cold, brown and dim. However, beyond the weather and landscaped housing developments, Florida offers a peek at the tropics, a whiff of rain forests from the south.