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Tuesday, February 28, 2012

Suet as camera trap bait

We were in the Dollar Store last week and I saw suet cakes for sale. On an impulse, I bought two -- one was a berry blend and the other nuts. I figured the price was right (FYI: I subsequently learned that the same suet cakes are 97 cents at Walmart -- six cent fail!) and it would make for interesting results. On Sunday I crumbled up half of the berry suet and put the pieces in front of the camera I have set in the back scrubby area. Today I checked and rebaited. All the suet was gone. I did not get many photos bit a nice diversity.

Species 1: Striped skunk (compare to the skunks in this post. Is it a new or known skunk?)
Striped skunk
(Seneca Falls, NY 2/12)

Species 2: Blue Jay. There are three in this photo. I obtained five photos of Blue Jays; one contained a Red-bellied Woodpecker as well.
Blue Jays
(Seneca Falls, NY 2/12)
Species 4 (remember the Red-bellied not shown): Opossum
Opossum foraging
(Seneca Falls, NY 2/12)
Species 5: Red fox
Red fox
(Seneca Falls, NY 2/12)
Species 6: Gray Squirrel. I expected more squirrel photos
Gray squirrel
(Seneca Falls, NY 2/12)
A fun two days of results. I found it unusual that each mammal species appeared only once -- and each individual stayed only long enough to be photographed once. Only the Blue Jays stayed long enough for multiple photos.

I rebaited so I should have more results in a few days....

Sunday, February 26, 2012

Orlando, Florida coyotes

Eastern coyote
(Orlando, FL 2/12)
Photo: Jack Van Niel
Mom and Dad spend the winter in Florida and Dad brought a Cuddeback Capture with him this year. After a week of nothing, he captured a few nice coyote images. Coyotes are relative newcomers to Florida, with some sources citing an arrival date of the 1970s to 1980s. They have now essentially stretched across the entire state. I wasn't able to find any information that definitively said that these Florida 'yotes are smaller than their NY relatives, but I would expect that to be the case. Compare this photo of a Florida coyote to the Upstate New York coyote photo posted below. Some of the difference in wiehgt may be apparent -- those Florida canines have a thinner coat. But some of it sure seems to be meat.

Eastern coyote
(Seneca Falls, NY 2/12)
Eastern coyote
(Orlando, FL 2/12)
Photo: Jack Van Niel

Saturday, February 25, 2012

Black bear den in Addison, NY

Black bear hair on barbed wire fence
(Addison, NY 2/12)
In my previous post I wrote about our first black bear for the 2012 season. Students from FLCC and I joined NYS DEC personnel and a Cornell graduate student to change a radio collar on a 380 pound make black bear. When the processing was over, we closed the bear back inside the culvert trap to allow the immobilizing chemicals to wear off completely. While the bear was waking, we took the opportunity to examine his den. There was a well-worn trail to the den as this bear had been repeatedly visiting bird feeders. Although the home owners were thrilled to have the bear in their yard, rewarding a bear with food is never a good idea. There were literally 20 bird feeders in this particular backyard and the home owners were not trying to attract bears. However, once the bear started showing up, they made no attempt to stop putting out feed. The law is clear in NY: It is illegal to intentionally or unintentionally feed bears. This is for the bear's safety as well as the people. It is difficult to tell people that the best way to show their love for an animal is to not see it anymore, but in this case, that was the best advice.

Black bear den
(Addison, NY 2/12)
As we got closer to the bear's den, the undergrowth got thicker and pricklier. We were surrounded by rose. This bear had selected an excellent location in order to maintain his privacy. You can see the entrance to the den to the left of the person in this photo. This is an excavated den. Not all dens are. Some are in brush piles or even in hollow trees. Many people think all bears den in caves but I have yet to see that in person. Regardless, this bear had done some digging to make this den his own. Perhaps this had started as the den of another animal, say a fox or coyote. We may never know (nor was there any evidence for or against this theory that I could see). The den itself made an immediate left turn from the entrance making it hard to photograph (well, that and the giant piles of scat that I had to work around). I ended up just reaching in and taking a blind photo. Much of the den was without a roof. I wondered if the den was like that from the beginning or if it had slowly collapsed from repeated entry and egress.

Inside a black bear den
(Addison, NY 2/12)
Look at the back of the den and see the area where the soil is darker. That is approximately the area that was roofed. The rest is all skylight :)

On the right side of the photo, you can see where the bear had bitten through a large root in order to clear the way. This particular den had little or no vegetation or "nest" material brought in. Other dens we have been to show large amounts of sticks, etc. that have been purposely collected.

We had some clues that this den was here. First, the area was well matted from repeated use. Second, there were large and relatively fresh piles of bear scat around. All the scats contained sunflower seed shells.

Large black bear scat
(Addison, NY 2/12)
Here is a particularly large scat. I wasn't even sure this was a single episode at first. I did not place anything down for scale, but you should be able to make out some sunflower husks and other items in the photo to give it some scale. Normally, bears are not feeding in February and therefore are not producing scat. But it has been so mild here and this bear had found a very reliable source of food.

Bear scratches on ash tree
(Addison, NY 2/12)
Our final visual marker indicating the presence of bear was a marked tree. This ash tree (green ash maybe?) was well scratched in three distinct places. One at about eye level, a second mark about 10 feet up and a third heavy scratch about 15 feet off the ground. I found no evidence of biting, just scratches.

We found no other evidence of markings on any other tree. Why this tree? Why ONLY this tree? Why mark so high? Why mark at all? Why no biting? This semester, the class is exploring the relationship of bears and biting of trees and utility poles. Perhaps we will have some ideas to report as the weeks progress...

Inspecting the height of bear scratches
(Addison, NY 2/12)

Thursday, February 23, 2012

2012 black bear season begins!

Black bear in culvert trap
(Addison, NY 2/12)
I spent the day with three of my students from FLCC in Addison, NY while the NYS DEC and a Cornell graduate student changed the radio collar on a black bear. This marked our first bear visit of the season (for previous posts on bear den visits click here). The bear in question has been leaving his den and visiting some bird feeders. So wildlife staff members from the DEC placed a culvert trap out yesterday and within hours, the bear was captured (It isn't always that easy). At the left is a photo of our guest of honor today. He is a big male, five years old and weighed in at 380 pounds. As you can see he already has ear tags. i mentioned he is part of a Cornell study to bear movements. He had a radio collar as well, but managed to pull it off while in the trap. You can see it between his front legs. I took a few photos through a small opening in the trap and he became a little agitated. He showed that by vocalizing and popping his jaws. I got the hint and stopped taking photos.

Agitated black bear in culvert trap
(Addison, NY 2/12)
The bear was immobilized using a jab stick. Imagine a syringe on the end of a pole. Here Matt from Cornell on the left delivers the drugs while Jeb from NYS DEC distracts the bear with a stick.
Culvert trap
(Addison, NY 2/12)
While we waited for the drug to take effect, we looked around in the mud for tracks.
Black bear tracks, rear (l) and front (r)
(Addison, NY 2/12)
It took less than five minutes for the drugs to take effect. We marked the data sheet "Head down" at 11:36 am.

Everything just went so well with this bear. That doesn't always happen. But today they estimated the weight exactly and the bear responded as he was supposed to. Once the bear was out of the trap and laid on his left side, his eyes were covered to protect them from the bright sun and any dirt or other debris. When the bear is immobilized, it cannot blink.
Next came a general health inspection. TPR = temperature, pulse and respiration. Below, the guys inspect their tattoo work from this summer. Usually, the tattoo number matches the ear tags.

The bear was fitted with a new collar. This is a pretty high tech collar. It takes GPS locations and can be reprogrammed with a cell phone.

Tomorrow, a look at his den!

Wednesday, February 22, 2012

One year of blogging

(Seneca Falls, NY 2/12)
I had planned to post a much longer and more fitting entry to mark one year of blogging but the day just got away from me. It is hard to believe I started this all a year ago! With almost 11,000 hits I feel as if the effort has not been wasted. Stay tuned for some interesting stories in the next week,

I returned from a trip to Texas last night and took advantage of the unseasonably warm weather today to walk out back with Laura and check the cameras. My anniversary gift from the camera trap was the photo below. Any photo of a weasel is a treat for me. This is only my second. Not sure if this is a long-tailed or short-tailed but I am leaning toward short. Opinions welcome of course. Thanks again to all of my readers. JVN

Sunday, February 19, 2012

Texas Bobcat!

Quick post as I do not have much time!

Bobcat track
(Austin, TX 2/12)
 I am near Austin, Texas this week for a workshop and brought along a Cuddeback Capture. I arrived at the lodging Friday at 4:30 pm and was out on their hiking trail by 4:45 looking for a likely location. I found some OLD bobcat tracks in the mud and hoped to get lucky. It rained for the first 30 hours I was here and I got no photos the first night. But it cleared up last night and I literally ran out to check the camera before breakfast. i found fresh bobcat tracks on the hiking trail and I just "knew" I caught an image of my first bobcat. I opened the camera and it indicated two photos. I had to get all the way back to my room and fire up the laptop to confirm what I already knew. I couldn't have asked for a better portrait for my first bobcat!

I have two more nights of trapping. :) I showed the photo to one of the staff members and she asked me to please not show any of the guests so they wouldn't be afraid... sigh.....

Bobcat on the prowl
(Austin, Tx 2/12)

Friday, February 17, 2012

Otter latrines and zebra dung middens

River otter scat
(Muller Field Station, Richmond NY 2/12)
Today's post ain't pretty, but IMO it is interesting. The last time I was at our Muller Field Station, we visited an active river otter latrine. This is exactly what it sounds like: a place where river otters repeatedly defecate. They are sometimes called toilet sites or just toilets. I always make sure I tell my students that otters do not exclusively defecate at toilet sites, but they do so often and for a purpose. Think of the amount of information that can be conveyed in scat. Certainly one animal could tell what another individual was eating, but the vast majority of information is chemical (largely scent). And don't think of the scat itself as the main source of info, but rather the other products that are left behind probably tell the story better. Cells from the intestines mixed into the scat, hair left behind either through the process of ingestion or through the animal rubbing and rolling, scent from glands on the animals body (often anal glands that purposely deposit scent with the scat), etc. etc. What a waste to think of scat as just, well, waste!. At left is a photo of some river otter scat. There is a large quantity of undigested fish scales mixed in with a few aquatic inset parts. We resisted the temptation to pull it apart as our guests from Jamestown Community College were there to collect such items for later DNA extraction. This particular scat was part of a very active latrine site. The next photo shows the whole latrine. Notice the muck that has been pulled up from the channel. At least river otter and beaver do that and it is often hard for me to be 100% certain which species is responsivble. Even at this latrine site, I would not be suprised to find that a beaver had done this.
River otter latrine site
(Muller Field Station, Richmond NY, 2/12)
River otter latrines are particularly interesting for several reasons. As seen above, the scats often contain lots of interesting stuff that provide information regarding the diet of the animals. Second, the latrines make great places for camera traps and last, otters often leave behind another substance besides scat: jelly. In 2009, I volunteered for a week on a river otter research project in British Columbia. Our main task was to find fresh jelly (called otter or anal jelly in the literature) and collect it for analysis. The jely is actually produced by the otters so it is 100% otter DNA as opposed to the scat itself that has the DNA of the animal(s) that were consumed to help confuse the issue. As a general rule, otter jelly is preferred for DNA analysis for that reason. Here is one particularly interesting photo of fresh otter jelly from British Columbia:
River otter scat and jelly
(Victoria, BC 7/09)
Have a look at that string of jelly. I have always imagined that the otter was standing in one spot and gave a mighty squeeze rather than the otter moving as it emitted the jelly. Regardless, that is what fresh jelly looks like (although it can come in slightly different colors as well as in clumps rather than strings -- we even found depostis that looked as if the scat and jelly were combined that were dubbed jelly-scats).

On our family vacation to Africa this summer, we witnessed a different species of mammal deposting scat in piles. The very first Grevy's zebra we saw showed us an interesting behavior. He walked right up to a large pile of scat, sniffed and then added his own to the accumulation. This is a common behavior among zebra males as a way of marking their territories. The books (and our guide William) say that these are created along the boundaries of two males' territories. They are called "dung middens" rather than latrines...
JVN:"Hey! A Grevy's!"
DVN: "Is eating that poop?"
DVN:"DAD! Stop taking pictures. This is gross."
In truth, not everyone was as excited to see this behavior as I was...

Sunday, February 12, 2012

Wolf and coyote scratchings

I captured several nice coyote photos this week. That got me thinking about some of the photos I took in Yellowstone last week and I decided to wrote a post about scratching. But first, a few camera trap photos from our place.

Eastern Coyote
(Seneca Falls, NY 2/12)
A few tips to tell coyotes from wolves. First, look at the dainty snout. Wolves have thicker snouts. Coyotes are built to kill prey smaller than themselves while wolves are built to kill prey bigger than themselves (not that they always follow that rule..). Secondly, look at how long the tail is compared to the length of the legs. Wolves are more long legged and the tail appears far shorter.

Eastern Coyote
(Seneca Falls, NY 2/12)
Another good way to distinguish wolves from coyote is foot size. Wolves simply have enormous paws. But we should save foot size for another post.

I was in Yellowstone for two days last week and was able to see numerous coyotes. I was in Lamar Valley when a pair walked across the road in front of my car.
Western Coyote
Yellowstone National Park, 1/12)
As the coyotes moved away, the lead coyote appeared to urinate on the trail and then scratched over it.

Coyote scratching
(Yellowstone National Park, 1/12)
When the trailing coyote crossed the path of the first he(?) stopped to investigate.
Pair of coyotes
(Yellowstone National Park, 1/12)
And he appeared to mark over the spot:
Coyote overmarking
(Yellowstone National Park, 1/12)

Wolves exhibit the same behavior. This summer, I took a tracking class in Idaho. On our last day, we had the opportunity to follow a paor of fresh wolf tracks for quite some distance. The wolves passed in front of a camera trap, so we knew we were about five hours behind them. We came upon a spot where one or both of the wolves scratched the trail. Have a look:
Gray Wolf scratch
(Idaho, 7/11)
Here is a closer view:

Gray Wolf scratch (and track)
(Idaho, 7/11)
A little farther up the trail, we found a fresh urine

Gray Wolf urine
(Idaho, 7/11)
Note the wolf tracks in the photo. I particularly like the one in the bottom right.  

A surfeit of skunks

Striped skunk
(Seneca Falls, NY 2/12)
The "collective noun" for skunks (in other words, the name for a group of skunks) is a surfeit. Technically, I am using this word incorrectly as all of my camera trap photos are of single individuals and not a multitude of them. HOWEVER, I have never had so many total skunk photos in such a short time, nor have I ever photographed so many INDIVIDUAL skunks. I am curious about several things. First, why so many skunk photos? It has been an unusually warm winter here, so it is no surprise that the resident skunks have been active. In cold weather, skunks will hunker down and go into a state of torpor. But why am I getting more skunk photos than I do in the summer? And why so many different individuals? Perhaps that is a reflection of the lack of food that winter brings, even a winter of mild temperatures and little snow.
Another possibility for increased activity could be the onset of mating. It is typical in many mammal species for males to wander farther afield in search of receptive females. I personally believe it is too early for mating. I also don't believe skunks are "fooled" by an unseasonable winter into mating "early". Day-length is probably more of a trigger than temperature to set many biological actions in motion (migration, breeding, antler growth, etc.) as it is far more reliable. Imagine setting your "clock" forward and breeding early because of some unexpected warm weather only to have typical weather return a few weeks later and lose all of the young for the year.
Striped skunk
(Seneca Falls, NY 2/12)
Perhaps there is no reason other than chance. :) But I don't think that is the case. I obtained my first daytime photo of a skunk this week. Although I will never know why that skunk was out and about so late, it adds more weight to the theory that the skunks are more active than usual right now. So let's have a look at the photos and see how many skunks have been prowling around in front of my cameras.
I currently have two Cuddeback Captures out. Both are set on mowed trails. One is directly in the back yard on the pond dike. The other is at the back of the property almost a half mile away. I have had the cameras out in these locations for over four weeks. I checked them on February 5th and then again on the 11th. The camera in the back of the property produced no skunk photos in January or through February 5th, but two photos of two different skunks between the 5th and the 11th. The camera trap in the backyard produced five photos in late January and early February and then another six photos between February 5th and 11th. I am unsure exactly how many individual skunks were photographed. That makes a total of 13 skunk photos but amazing 11 of them came from one camera in a short period of time.
Let's examine the data. First, here are the two photos from the back of the property. The time and date stamps are correct.

SK01: Feb 6 - 01:35
Skunk 01
Back camera

SK02: Feb 6 - 08:32

Skunk 02
Back camera

Clearly, these are two different skunks. To review, these are the only two photos I obtained from the back camera. Now for the camera in our yard. Please note that the date is correct but I have the AM/PM reversed... In order:
SK03: Jan 25 - 19:27

Skunk 03
Backyard camera

Clearly Skunk 03 is a different individual. I have two photos (the other is jan 27 at 0620) of this skunk and both are just tails.

SK 04: Jan 28 - 02:35
Skunk 04
Backyard camera

I have another image of Skunk 04 on Feb 4 02:13.
SK05: Feb 05 - 0405

Skunk 05
Backyard camera

This is another distinct individual. His body markings look a little like Skunk 01 but the tail is clearly different.
SK06: Feb 6 - 02:36

Skunk 06
Backyard camera

Skunk 07 Feb 7 - 19:52

Skunk 07
Backyard camera

Skunk 08: Feb 8 - 22:46

Skunk 08
Backyard camera

SK09: Feb 11 - 19:50

Skunk 09
Backyard camera

I believe skunk 08 is a unique individual as well. I welcome additional opinions, but when I compare I see too many differences for this to be one of the other skunks. NOTE: I am working under the assumption that skunks are symmetrical. Some of the skunks have their right side photographed while others have their left side photographed. I conducted a quick internet search and was unable to find any information as to whether my assumption is warranted or not.
SK10: Feb 11 - 23:37

Skunk 10
Backyard camera

Amazing! Ten individual skunks in such a short period of time. We have few species that are easily identifiable as individuals in New York (antlered deer come to mind). But I wonder what can be done with high quality images and some attention to detail?