Thursday, August 22, 2013

Where are they now?

Various species of wildlife obviously change their routines with the seasons and as the pressures of breeding and finding food and cover vary. And those changes become a challenge and a learning opportunity for naturalists and biologists and anyone interested in wildlife.

In checking one of my camera traps the mystery of those changing routines was brought home. Last winter, long after the end of deer season, a large 8-point buck appeared in several photos at a new camera location which has since become one of my favorite spots. He was an impressive deer and must have avoided hunters for several years.

What was probably the same deer was caught by the camera a number of times in the spring, the last being in mid-May as his new antlers were already showing their potential.

The same camera location also provided photos of a piebald deer beginning in early March as the winter's snow melted. The piebald was a young buck that had just survived his first winter and traveled with his mother and sister.

He showed up repeatedly until early June and hasn't appeared in a photo since then.

In fact, this is the most notable deer that has been caught by that camera since the piebald's last appearance.

So, the question is -- Where are the big buck and the piebald now? White-tailed deer usually have a home range of about a square mile; young bucks typically disperse from their mother's home range, while young does tend to stay at home. The young bucks often travel four to six miles from where they were born before establishing their own home range, although some go much further. So, the piebald may well have traveled far beyond the area where he spent the spring of 2013. But, that doesn't explain the non-appearance of the older buck. Several researchers have found that adult males increase the size of their home ranges from late spring until the end of the fall breeding season, so the large buck is probably just spending more time further from the camera location.

Of course, either deer may have succumbed to injury or disease, been taken by a poacher or been hit by a vehicle -- the camera trap may catch them again, or it may not. That's one of the joys of having a camera trap, each time it's checked it opens the door to a mystery.

Sunday, August 18, 2013

Dragonflies Galore

A few days ago I took my lightweight canoe up to the lake and paddled around the perimeter, about six miles. A beautiful morning it was, clear and cool -- more like northern New England in mid-August than Pennsylvania usually is at this time of year.

There was an abundance of dragonflies in the vegetation along the water's edge. The Odonata (dragonflies and damselflies) is an ancient group of predatory insects and one of those dragonflies is reported to have been the largest insect that ever lived. Dragonfly adults are fast fliers that feed on other insects, while the nymphs are aquatic ambush predators.

Many adult dragonflies are very colorful insects and their common names tend to be as colorful as the insects themselves. Among the lake's most abundant dragonfly denizens were:

 Spangled Skimmers -

Halloween Pennants -

and Widow Skimmers - 

But not even predators are immune from predation; this golden garden spider, which had spun its web in the vegetation in shallow water, had gotten itself a meal of a dragonfly of undetermined species --

Sunday, August 11, 2013

Stiltgrass - UGH!

Not far from the house is the edge of the "Big Woods", several hundred thousand contiguous acres of publicly-owned woodland. Although almost all of the Big Woods has always been forested, there is a scattering of former farmland - some has been planted with tree seedlings but most has been allowed to revert to woodland naturally.

Yesterday I walked through some of the reverting fields that haven't been farmed in almost 100 years. Trees were slow to seed into those acres where the soil was depleted of both nutrients and organic matter, so many of the trees are small in diameter and widely scattered. Because trees still don't fully occupy the site, many exotic plants have invaded the fields: the Asiatic honeysuckles, multiflora rose, autumn olive and Japanese stiltgrass are the common invaders. The most abundant and pernicious of these exotic plants is Japanese stiltgrass.

Stiltgrass is an annual plant that appears to prefer moist, fertile soils but will grow in many situations, especially sites that have been disturbed. Because it creates thick mats of stems and leaves and totally dominates the site's herbaceous layer, stiltgrass easily suppresses native plants - and the fact that white-tailed deer won't eat the stuff compounds the problem. Stiltgrass is gradually (in some areas not so gradually) spreading in the Big Woods and so threatens to reduce or eliminate desirable native plants and adversely impact wildlife as food sources are eliminated.

Any type of soil disturbance increases the likelihood of stiltgrass spreading through the forest. The miles of logging roads that have been built in the Big Woods in the last 40 years have certainly helped spread stiltgrass. The thousands of miles of access roads and pipelines that many expect to be constructed to extract natural gas from the Marcellus shale beneath northern and western Pennsylvania will probably hasten the spread of stiltgrass.

Controlling the spread of stiltgrass is difficult, but possible given enough time, effort and funds. Responsible forest managers will take steps to control or eliminate stiltgrass -- unfortunately, others will not.

Tuesday, August 6, 2013

Camera Traps

Camera traps (some folks call them trail cameras or game cameras) open a new window into the world around us. Hunters use them to scout before hunting season; wildlife managers and scientists use them to determine the species or individuals in an area; and other folks find using them a fascinating hobby.

One of the best aspects of using camera traps is the surprise gift of photos you never expected. I keep a trail camera at one spot that has proven to be a great location; it's yielded pictures of seven different bears so far this year, a bobcat at least once a week, a piebald deer, many different bucks, a mouse and an occasional coyote.

Most of my camera traps are "homebrews" combining an out-of-date digital camera with an infrared sensor and external batteries to provide extended power for the camera.

In the last few days I've changed the cards and batteries on most of my cameras. The camera closest to the house had 167 pictures. Beside the usual photos of squirrels, rabbits, opossum, raccoon and white-tailed deer, there were two photos of a gray fox in the rain. The gray fox first showed up last winter and has since been captured on camera at about two week intervals; once in late winter there were two in one picture, presumably a courting pair.

Beside the fox, the camera near the house had photos of several deer, including a fawn and three different does. The fawns hit the garden fairly hard as they try many different possible foods, browsing on plants the adults never eat.

The cameras further from the house had a greater variety of wildlife including:


a bobcat:

and several photogenic deer:

But not all photos from a camera trap are worth keeping --

Thursday, August 1, 2013

I am in love with this green earth

For as long as I can remember I've wandered the fields and forests of the northeast. My father introduced me to the forest and instilled in me a love for the natural world. The English essayist Charles Lamb (1775-1834) once said, "I am in love with this green earth." And so am I, all these many years later "In love with this green earth." Here will be the observations and opinions of an aging nature lover. 
For the last few weeks a white-tailed doe with twin fawns has been visiting the yard. They're all pretty tame and typically just stand looking at anyone who comes out the door; only leaving if a human gets too close (less than about 20-30 feet) or moves suddenly. Yesterday the doe and her fawns were under the apple tree feeding on drops. Most of the fallen apples are those that the gray squirrels have cut and then dropped. Except for the squirrels, we'd get a lot more apples for ourselves from the tree -- but the deer sure do enjoy them.