Wednesday, August 20, 2008

The King of the Butterflies, and an experiment with the digital camera's manual settings

The Monarch's name is well deserved, but it's getting some competition from the Giant Swallowtails gradually moving northward into this area. This scent glands on the hind wings identify this individual as a male.

Larvae of the Monarch (Danaus plexippus) absorb toxins from their food plant, the milkweed. The toxins are present in the adult insect and most predators find this butterfly unpalatable and learn to leave it alone.

The Viceroy, which makes a perfectly good snack for a bird, has capitalized on the Monarch's toxicity by imitating the latter species' bold warning colors. Viceroys are smaller than a Monarch, have a band on the hind wing and lack the white spots on the body. A bird familiar with Monarchs will focus on the orange coloration rather than notice the minor differences – and probably look for dinner elsewhere.

The common Cabbage White (Pieris rapae) is a species introduced from Europe. The butterfly in the photo below is a female, males have only one black spot on the forewing.

This picture was taken in partial shade; the amount of white in the scene overwhelms the camera to the point where the image is blurred if taken on "Auto" in full sunlight.

Today I had the good fortune to cross paths at close range with a Twelve-Spotted Skimmer (Libellula pulchella). These skimmers are strong and fast fliers and tend to rest on the rushes out in the lake, so until today I haven't had any luck getting a good picture. This following photo of a mature male, taken from several feet away, is as close as I have been able to approach one of these elusive insects without a pair of hip waders. Males have a whitish bloom on the wings and their abdomens also whiten with age.

The female in the next three pictures was content to sun herself and didn't seem to mind being approached closely (although this required no small amount of patience on my part). To date I have been relying on the camera's auto and macro settings ... every now and again, for whatever reason, the camera won't focus on the subject. This was one of those times ...

As of a couple of weeks ago I had no clue as to what the ISO film speed numbers or focal length meant, nor how to set these variables on the camera. Having spent some time reading and taking practice shots, now seemed a good chance to put the theory into practice ... so: my first shots with the film speed and focus set manually.