Monday, April 23, 2012

Bobcat takes deer at Westmoreland Sanctuary

We have some more interesting news regarding bobcats here on the preserve at Westmoreland Sanctuary.

On Wednesday, April 18th, I was leading a walk with two other adults on the Spruce Hill trail when we came across a big patch of disturbed ground right in the middle of the trail.  There was a lot of deer hair all around the trail which really caught our attention.

At first I thought that the hair may have been left behind by a deer grooming itself, but then we noticed the hair made a path leading off the trail.  There looked to be signs of a struggle and it looked like the deer may have been dragged.  We followed the hair, and not ten feet from the trail, under the crown of a fallen tree, was the whole body of a young white-tailed deer (approx 60-70lbs) buried under a coating of leaves and sticks.

The carcass was very well concealed under the tree and the coating of leaves piled on top.  There was no noticeable smell from the deer, and it only had attracted the attention of 2 or 3 flies.  All signs point to a fresh kill, likely from the night before or early that morning.  I couldn't tell if much of the deer had been eaten, or how exactly the deer may have been subdued because of all the leaves it was buried under.

I'm was 95% sure this was the work of a bobcat.  They and other large, solitary cats are known to be able to take down larger prey, eat what they can, and then bury the rest for later when they get hungry again. If this were a coyote kill, they would have certainly torn the deer to pieces and eaten nearly everything within a few hours.  Coyotes are social, so a family unit of coyotes would have easily made short work of this small deer.

To help us solve the mystery, I placed two of our remote cameras next to the deer that evening (April 18) in hopes of capturing images of the mystery creature when they return to their stored meal.
Cameras are on the left and right sides of the image.  Deer is under the fallen tree.
On Saturday, April 20 I returned to the deer carcass to see what had happened over the past 2+ days and see what images had been recorded.  Much to my surprise, there was absolutely nothing left of the deer except a light coating of deer hair all over the leaves where the carcass was laying.  The 2 cameras had captured a total of 104 images.  Below are some images (in chronological order) of the cat as captured by the two cameras using two different angles:
The bobcat returns to its hidden meal
Surveying the area, likely smelling our scent from earlier in the day
Reappearing from behind the carcass
2 hours later, the bobcat returns
Taking note of the camera
Investigating more scent left behind, this is where I laid my pack when setting up the camera
A little grooming
Posing for the camera

Returning back to the carcass after grooming

Coming back out from behind the carcass, likely after reconcealing its meal
Our last image of the bobcat
The last bobcat image was captured at 12:24am Thursday morning.  The carcass wasn't visited again by any animals until early Friday morning (1:44am) when the first coyote arrived.  Over the course of Friday morning, afternoon, and evening, the coyotes, turkey vultures, and a few crows dined on the carcass until there was nothing left when I arrived back on the scene to retrieve the cameras on Saturday around noon.

Based on size alone, chances are this was a male bobcat.  The size of the cat in relation to the objects around it are quite impressive if you've seen this portion of the trail for yourself.  There is also some significance in the fact that we have some documentation of a bobcat feasting on a deer that it was able to capture and kill.  Though the deer was small, the bobcat may become an important predator and ally in our efforts to return the deer population to a healthy and sustainable level for our forest ecosystem.  This was quite an extraordinary find that we were very lucky to have discovered and have an opportunity to document.

-Adam Zorn, Naturalist

Tuesday, April 17, 2012

Westchester Bobcat sightings make the news

Our catalog of bobcat sightings has made it into the morning news.  Fox 5's Good Day New York conducted an interview with Westmoreland's Director Steve Ricker about the elusive animals and why they're being seen more frequently around Westchester County.  Catch the full interview here:

And the interview was sparked by a recent bobcat sighting in White Plains, which is explained a bit in this clip.  Steve answers a few questions about coyotes in Westchester County as well.

-Adam Zorn, Naturalist

Monday, April 16, 2012

2012 Spring Amphibian Surveys

Amphibian survey results from April 13 and 15:
     Despite the dry conditions that have persisted since the beginning of the year (only 5" rain so far in 2012), we observed a fair number of amphibian species over the course of two amphibian programs.  Friday evening's hike included encounters with Spring peepers, Bullfrog and Green frog tadpoles, Pickerel frogs, Red-backed salamanders (both color phases), and Northern two-lined salamanders (larval and adult).
     The woodland pool was nearly 100% dry, so the vast majority of Wood frog and Spotted salamander eggs and tadpoles have already perished.  Marbled salamander larvae can't survive in a dried out pool either.  The good news is, Friday's participants recovered almost 3 dozen Spotted salamander egg masses that we were able to transplant into Bechtel Lake.  And while these egg masses fair better in fish-less pools, a dry pool this year means 100% mortality if none were transplanted.  In Bechtel Lake, mortality from predation is likely to be high, but a small percentage of the transplanted salamanders should survive to leave the lake as an adult by summer's end.
     Sunday afternoon's follow-up visit yielded much the same in amphibian variety as Friday evening.  New additions to our observations were American toads and Green frogs calling from the shores of Bechtel Lake.
     Additional wildlife species observed during the survey programs included a variety of snails, mayfly larvae, various dragonfly and damselfly nymphs, various diving beetles, midge larvae, side-swimmers, and finger nail clams in Bechtel Lake.  Various millipedes and centipedes, pill bugs, slugs, land snail, and earthworms were observed under fallen logs with the Red-backed salamanders.  Caddis fly and Crane fly larvae were present in the stream along side the Northern two-lined salamanders and Pickerel frogs.  Flying squirrels could be heard in the trees after dark and a number of wolf spiders were seen along the forest floor during the evening's hike.

Thank you to all who participated in the amphibian programs and helped us make these observations on Friday evening and Sunday afternoon.

-Adam Zorn, Naturalist