Sunday, July 28, 2013

Bernheim Arboretum

Bernheim Forest is one of our favorite places. Sometimes, it seems as if Dick lives there, since he volunteers so many hours, but then, who am I to talk!  I haven't been there this summer, and joined Dick at a session led by two of the arborists yesterday. We usually spend our time in the forest, enjoying the native plants and trees, but it is also an Arboretum, where non-native plants are cultivated. In fact, the arborist stressed his enjoyment of the wide variety of trees to be found there, a point of view I don't often hear.

In the winter, we find balls of Mistletoe growing in tree branches, but large thick balls of growth in a tree is called "Witches' Broom," since witches were said to hide their brooms of dense twigs high in a tree during Mideval times. We found them easily visible in both pine and ginko trees. A number of stresses, both biological and environmental, can lead to the formation of brooms. Organisms such as fungi, phytoplasmas (bacterial-like organisms), mites, aphids, and mistletoe plants can cause abnormal growth when they attack a host tree. Environmental stresses that injure the growing points of branches can also trigger the formation of brooms. Some brooms appear to be caused by genetic mutations in the buds of the branches. Unlike brooms caused by living organisms, there is usually just one broom per tree when the cause is a genetic mutation. By either climbing up or shooting samples out of a tree, the broom can be grafted to a normal root, then cultivated, resulting in extremely thick growth that looks like a bush rather than a tree.

Walking over to a particular sweet gum tree, he pulled three leaves from the same branch. One was the normal green, while the other two had developed a variegated coloration. These natural mutations are highly desired by arborists, since they can be cultivated to create new varieties of plants. If the mutation breeds true, Bernheim can then give it a name and sell the new variety. The problem is that after a while, the color variegation can revert to the natural green.

We explored the dwarf evergreen section of the arboretum, finding trees that started as dwarf have outgrown that status now. This little blue spruce has the expected blue needles, but only on the bottom side...

...while bending the branch down for a view of the top reveals the same needles to be green on the top!

Staff shortages can result in surprises sometimes.  When a young plant is waiting to be placed in the ground, they are stashed in pots behind the green houses. Recently, one of the interns discovered a little "Franklinia" tree, which is extinct in the wild and no one knew they had it. Our friend Wren was really excited to learn about it. Franklinia is a monotypic genus in the tea plant family. The sole species in this genus is a flowering tree, Franklinia alatamaha, commonly called the Franklin tree, and native to the Altamaha River valley in Georgia in the southeastern United States. It has been extinct in the wild since the early 19th century, but survives as a cultivated ornamental tree.

As much as I enjoyed seeing a different side of Bernheim, I was determined to track down the Bobwhites we heard while eating lunch. It didn't take much of a walk to find two fast running little birds along the roadside. Restoration of the prairies habitat has made a good home for this reintroduced species. It is such a thrill to hear them whistling "Bob-white!"

Thursday, July 18, 2013

Mississippi Kites in Kentucky

A few years ago, Raptor Rehab of Ky took in a Mississippi Kite, found in far western Kentucky, which had been impressed on humans and couldn't be released. He was the sweetest bird, who was happy to eat meal worms from your hand, and sang every time you walked in his cage. These Kites normally migrate to Argentina every winter, to have a good ongoing supply of insects to catch and eat on the wing. Although we did our best to keep him warm over the winter, he developed respiratory problems and didn't survive. We still miss little Miki.

In the last few days, emails and messages are going around about a pair of Kites actually nesting in a nearby Louisville neighborhood. I normally would expect to find them closer to a nice open field where it's easy to find and catch large flying insects, but the local residents say they have been here for a couple years now.

For someone unfamiliar with this raptor, and I'd never heard of them till Miki came to RROKI, you might think this was a Mourning Dove or maybe a Pigeon. They have long dark wings and a long tail - all the better for catching grasshoppers and cicadas! But look at the eyes, which are surrounded by dark feathers making them look really big. The sharp hooked beak also says this is a raptor.

Kites have many features expected in a falcon - the long wings and tail, and dark around the eyes - an example of form following function. When you are chasing speedy flying insects you have to be fast and maneuverable. Their usual habitat is in the plains area, where they are known to nest in colonies. The young birds come back to the same area after their first migration, and help feed and tend the new nestlings. After their second migration, they will get these beautiful feathers and red eyes, indicating they are sexually mature. I must admit, this was the easiest life bird I've ever found!