April 17th, 2007
nature study
I shot these photos on the weekend before the latest blanket of snow once more covered the fields and woods. Temperatures are turning mild once more, so perhaps this will be the last delay before the spring season gets underway.
Last week, when I gave my talk about nature photography, I began by distinguishing between photography used for creating beautiful images, and that which is used for nature study. There’s some overlap between the two purposes, but I see them as being a little different. In the one case, the photograph is used to create a beautiful composition, while in the other case, it’s used to record data, tell a story, or allow us to examine an object more closely or in a way that isn’t easily possible with the naked eye. Today’s photos are an example of the kind of shots that I find useful for learning about an object found along the trail when I’m out walking. Incidentally, they’re also the type of photos that I most enjoy looking at.
The top photo is of a nest that we found fastened to the branches of a small Beech tree (click on all images for larger views). From its size, shape and construction, I would guess its identity as being the nest of some species of Vireo. Here are examples of nests of a few species of Vireo from the Canadian Wildlife Federation’s Project Wildspaces website: Yellow-throated Vireo here and here; Red-eyed Vireo here; and Warbling Vireo here. Their nests are neat little basket-like structures made of grasses, fine strips of soft bark and other soft vegetation carefully constructed upon the framework of Y-shaped branches.
This second photo is of something I’ve been finding a lot of over the past couple of weeks now that the snow has melted away in the meadows — egg cases (ootheca) of Praying Mantis insects. I’ve found several on the walking paths through the fields and brought a couple back to the house on Friday. I’ll keep them in a container outside the front door and begin watching them closely a little later on this spring. With any luck, I’ll get to see them hatching out. I find it interesting that these egg cases seem to be so rarely damaged, especially as they are actually quite large and conspicuous. However, I did a bit of searching around on the net and did find a page on raising mantids that states:
Females lay eggs in an egg case called an ootheca; a liquid secreted from the ovipositor is mixed with air to make a froth that solidifies into a case as hard as a walnut shell around the eggs. The eggs cases are deposited in fall and the eggs overwinter in the hardened foam, which provides insulation and protection from ants. The foam also contains a bird and mouse repellent that gives it a pungent smell, but that does not protect the eggs from parasitic wasps which can use long thin ovipositors to lay eggs in the eggs.
So, perhaps that explains why so many appear undamaged. Of course, the reference to the parasitic wasps probably explains why the world isn’t overrun with mantids!
The next photo is of a piece of comb found on the ground on Saturday. I’m not sure just where it came from as it was in the middle of the trail. I sometimes find these lying on the footpaths around the farm and attribute their appearance to skunks or other mammals, or perhaps birds, that find a comb and tear it apart to get at larvae within.
The last of the photos is of a rock found beside the trail on Saturday. It had interesting round lichen patches, so I stopped to take a closer look and shoot a few photos. The photo below is a closer shot of one of the patches (you might want click on that image to see the larger view). From what I can tell, these are some kind of Lecidea lichens – also known as Disk or Tile lichen — perhaps Lecidea tessellata or Lecidella stigmatea. I’ll have to spend a bit of time reading the descriptions and studying the identification key to have a better idea.
Anyhow, those are a few of the photos I shot over the weekend — there were a couple of dozen more like them. They’re a reference of what I saw while out and about, and give me plenty to puzzle or ponder over in the days that follow.
Tags: Red-eyed Vireo, Warbling Vireo, Yellow-throated Vireo, Praying Mantis, Mantis religiosa, ootheca, Lecidea lichen, Lecidea tesesellata, Lecidella stigmatea