Thursday, May 20, 2010

Send in the Clones

I’m a sucker for big trees. For an ecologically young environment, Florida has some big ones. Bald Cypress (Taxodium distichum) and Live Oak (Quercus virginiana) are the Redwoods of the southeast and the behemoth pictured below is one of the largest Live Oaks in Florida. Located in Lake Griffin State Park in Fruitland Park, FL, the tree stands over 83 feet tall and has a 131 foot crown spread.

The name Live Oak refers to the evergreen appearance of the tree. Each year the oak develops new leaves before shedding old growth, so it lacks the bare look of its northern deciduous cousins. This particular one was once a “Champion Tree” and considered the largest of its kind until others were discovered and displaced it. One of the reasons Live Oaks are successful is their ability to clone themselves. While the Live Oak maintains genetic diversity through cross-pollination and the subsequent dropping of a crop of acorns, they can also spread via clonal roots, also known as root suckering. Underground buds attached to the roots send a genetic copy of the primary tree to the surface and the shoot begins to grow. This can be in response to various forms of damage to the primary tree; clipping, storm damage, insect damage, etc., or it is simply a way for the primary tree to compete with other forms of vegetation growing in the understory.

Live Oaks are capable of enduring hurricanes, tolerant of salt-spray and are relatively disease free – attributes which provide the opportunity to grow for centuries. It’s difficult to tell how old this particular tree is since they won’t let me cut it down and count the annual rings, but park staff suggest it’s anywhere between 250-350 years old.

Measuring the circumference was a bit easier. I had to send in my clones to measure the distance around the base of the tree. Assuming each of my clones stands 5’9” and it took six of us to wrap around the tree, that’s a circumference of 34 feet and nearly 11 feet in diameter. Now if I can just get one of my clones to write my columns for me.

Friday, May 14, 2010

Faker - The Black-necked Stilt

I remember lying flat on my back on the soccer field, staring up at an oval formation of heads. Teammates. Coaches. Refs. And my mom who warned me “you better not be faking it.” I was twelve and apparently prone to such behavior, but in this case I wasn’t. In a spectacular attempt to score a goal, I had torn my ACL. I think about my mom when I see certain birds exhibit “distraction displays” and I always think “FAKER!”

Ground nesting birds such as Black-necked Stilts (Himantopus mexicanus) and Killdeer (Charadrius vociferous) have developed a unique method of protecting their chicks. While many birds would rush back to the nest to cover up their young, Stilts and Killdeer leave the nest when disturbed. They use themselves as bait to draw the attention of the predator and lead them away from the nest. The key to success is their flair for drama. With one wing outstretched, the bird will limp along as if injured or sick. The predator thinks they’ve stumbled upon an easy meal and as they follow the feathered thespian, they are unknowingly lured away from lunch in a nest. Some fakers will sit on the ground and pretend to incubate a fake nest as well. Once the parent feels the predator has been sufficiently duped, they drop the act and take off, leaving the bamboozled hunter hungry.

Stilts have distinctly long, red legs with a higher leg/body ratio than any other bird in North America except the Flamingo. Currently they are winding up their nesting season in south Florida. Some Stilts nest near the shore and just above the hide tide mark, while others nest on mounds in muddy marshes where they have 360 degree views. The excessive amount of winter rain we received in South Florida has left the inland mud flats underwater. You can’t lay an egg if you don’t have a place to nest.

Despite knowing the injury ruse, I can’t help but follow spectacular birds with my camera and snapped these two in flight, only later realizing they had led me away from their chicks. The parents soon returned to this chick, who someday might be a good little faker too. 

Friday, May 7, 2010

Reflections - The Little Blue Heron

I never realize how different I look today compared to 20 years ago until kids see pictures of me from way back when. “You used to have hair?” is often the brilliant observation, as if I was bald from the day I was born. Yes we change. In some cases drastically and others quite subtly but when you look in the mirror it’s still you that peers back.
I imagine Little Blue Heron (Egretta caerulea) chicks having the same conversation with their parents. “You mean you weren’t always blue?” Of course this doesn’t happen. Herons could care less about these things, but if they did recognize their reflection as a fledgling compared to an adult, the bird looking back would look entirely different.
Adult birds have attractive blue-grey plumage with purple feathers around the head. While other birds develop breeding plumage for courtship, the Little Blue Heron’s coloration serves as a built in chick magnet. So to speak.
I see them foraging alone while other wading birds such as Snowy Egrets (Egretta thula), Great Egrets (Ardea alba) and White Ibis (Eudocimus albus) feed in the shallows together. These three species of white-plumed birds benefit from feeding together. Additional eyes allow for better protection from predators on land, in the sky and in the water. While ibis probe the mud for insects and crustaceans, egrets feed on the fish and other critters stirred up by the ibis.
An adult Little Blue Heron would look completely out of place in a flock of white birds. But the observant birder might notice a white bird among the flock that looks slightly different. For the first year or two, the juvenile Little Blue Heron is decked out in nearly colorless feathers. They feed and roost among other white birds and when they have the life experience to survive on their own, they molt and develop the colorful blue and purple costume.
I spotted this Little Blue Heron hunting alone. Its eyes surveyed the surface of the water for minnows or insects, but my mind considered the idea that the heron was looking at its reflection and wondering what it will look like when it grows up.