Thursday, October 25, 2012

Lucky Bucky

We live in the Badger State, afterall.

Bucky Badger has been elusive, though....and I certainly didn't expect to see him at this site.  He (or she) comes through rather quickly in the video clip below.  Clearly moving with a purpose....and I have not seen a Badger (Taxidea taxus) at this site since. 

Then, several weeks later, the badger (or A badger) showed up at one of my cameras mounted on a property across a country road from the site where the video clip came from.

A fleeting shot.  But given the lightning fast trigger speed of the Reconyx, this one must have been burning through the woods for me only to catch a single blurry image of it.

Now, prior to these images, I had never seen a burrow on either of these sites that screamed "badger" to me.  And in 6 months to a year of camera trapping these properties, I never before got a photo of a badger.  So, I'm not certain if he's a resident or a transient. 

Badger Movement- I had always thought badgers didn't move around alot and stayed near their borrows.  Yet, when I started doing alittle digging....I found this wasn't true!  For example, Sargeant and Warner (1972) followed an individual with radio telemetry and determined that, in the summer, she patrolled an area of 752 ha (2.9 mi-sq.) that contained 50 den locations.  Her home range size (or area she patrolled in a given time period) changed seasonally, however, and in fall she roamed an area of 52 ha (0.2 mi-sq.), while in the winter kept it to a 2 ha (0.007 mi-sq.) area.  Another study reported a home range size of 1700 ha (6.5 mi-sq.) in the summer (Lampe 1976)!!!  This individual's home range also decreased as the seasons progressed.  Males are the ones that apparently do most of the moving, and this has to do with the breeding season.  Long (2008) summarizes past research and reports that mating is usually in late summer/early fall and that females can remain in "heat" through the end of August.  This timing would correspond with when I got this picture and video I'm going to assume this is a male on the hunt for ladies. 

I wish we had gotten a better picture!  Recently, I've found some promising burrows on-site and I've had my students shift a camera over one.  When we last checked the burrow entrance (yesterday), it did not look as if there at been any fresh activity.  Unfortunately, we are heading out of the season for Badgers here.  Harlow (1981), who monitored Badgers in outdoor enclosures, observed a 93% decrease in activity above ground from November to February (and reported stretches of time where Badgers remained below-ground for up to 70 days!).

But...I'm keeping my fingers crossed!

Literature Cited

Harlow, H.J. 1981. Torpor and other physiological adaptations of the Badger (Taxidea taxus) to cold environments. Physiological Zoology 54:267-275.

Lampe, R. 1976. Aspects of the predatory strategy of the North American Badger, Taxidea taxus. Ph.D. dissertation. University of Minnesota ant Minneapolis St. Paul. 103 pp. (NOTE: I did not obtain a copy of this dissertation, but included information summarized in other sources).

Long, C.A. 2008. Wild Mammals of Wisconsin. Publication No. 65 of the Museum of Natural History, University of Wisconsin-Stevens Point. Pensoft Publishers, Bulgaria.

Sargeant, A.B., and D.W. Warner 1972.  Movements and denning habits of a badger. Journal of Mammalogy 53:207-210

Thursday, October 18, 2012

Back to the Backyard Denizens: Carnivores in Suburbia

I really like the picture of the Gray Fox above. 

I've been wanting to post this picture for a while, but didn't have a good reason to, until now. 

I think it nicely captures the idea of "Urban Wildlife", and a good way to get back into the blog mini-series I started on urban wildlife back in early 2011 (see The Gray Ghost posted on February 20, 2011; Backyard Denizens and Cronon's "The Trouble With Wildnerness" posted on March 15, 2011, and Return of the Backyard Denizens posted on June 10, 2011; and Aerial Backyard Denizens posted on January 10, 2012). 

I'm going to follow up on this theme with information gathered over a year ago.....while we lived in suburban North Carolina.

I often put a camera out in the backyard when we lived there.  This began as an intermittent, when I remembered it, sort of thing. 

After a while it became interesting to the point where every night, with few exceptions, I'd set a camera out and pull it in the morning.  

Why did it become interesting, you ask?  

Thanks to the little critter with the big scientific name: Urocyon cinereoargenteus.

But....let me back up a bit.  As I mention in the Gray Ghost post referenced above, I first started seeing Gray Fox first-hand in our neighborhood back in Spring of 2010.  Their sightings became frequent enough that I was prompted to actually put a camera back there some time in early 2011 and started getting serious about recording my camera trapping records and visual sightings. 

My first pictures of Gray Fox in the back yard occurred in January of 2011 (see the Gray Ghost post referenced above).  Around this time, our family also saw a Gray Fox trotting along the back lot line at dusk as we played outside.  This led to a brief string of photographs, which ultimately dried up some time in February.  This short dry spell snapped a few weeks later, and March yielded two pictures: one on March 9...the other on March 21 (see above picture). 

Then the observations ground to a halt until about mid-May.

On 5/11/2011, I took the dog out with me while programming the camera for the evening's deployment.  We walked slowly, and my attention was focused on the little plastic box in my hand.  Suddenly there was a tug on the leash, and I turned around to see the dog squatting in the middle of the yard.

Dang it, Sampson!, I said....knowing I'd have to go inside and get a bag to remove the pile o' shite, lest our daughter find it interesting the next day.

But...then the wheels started turning.  How could I both (a) avoid having to go all the way inside for a bag and (b) use this steaming pile to my advantage? 

The answer was clear!  I placed the camera on one of my daughter's kiddie chairs directly overlooking the dog's evacuation.  If anything was moving about that night, perhaps they'd come to investigate.  I'd used Sampson's "leavings" in this manner at my study sites with good results.  I'd even had success placing my cameras over an area where he had emptied his bladder in the yard (see pic at the top of this post).

However, the first night (post-fecal evacuation) was eventless! 

Bummer, I thought.  

But..still...why go all the way inside and get a bag to clean up this fine pile of animal attractant? 

I'll just keep an eye on my daughter when in the yard and make sure she doesn't step on it (-I know...I know...your minds are racing wildly...coming up with a million terrible father things to put in a comment on this post).  If I'm going to be lazy...then I better also be right about being lazy.  As such...failure was not an option!

On the afternoon of 5/13/2011, I even upped the ante.  We cooked burgers on the grill.  HUGE patties of succelent grass-fed beef acquired from a local farmer.  They put it absolute delight.  As an aside, let me just say: for those of you squandering your taste buds on hamburger from a giant corporate beef producer that you've picked up from your big box grocery are missing out!  Seriously.  There is NOTHING like hamburger from a grass-fed cow that you buy at your farmer's market.

Anyways...that beautiful aroma wafted out for hundreds of yards from my grill, I'm sure.  Spreading the news that something good to eat might be here.

That night, a storm blew through the of many storms that plagued us that spring.  Seemed like we'd had one a week from the beginning of April to the end of May!  I put the camera out because I forgot we were supposed to get storms and I was excited about the new olfactory cues I had introduced into the backyard.  I didn't usually leave the backyard camera out during a lightning storm.  But when the thunder and lightning started, I shrugged and figured the camera wouldn't catch any critters. 

Perhaps it was the unintentional lures...perhaps it was the storm...who knows.  But...low and behold....I had a surprise on the camera the next morning.

Above:  The offending pile can be seen at the right in the field of view.  In the background is an Eastern Cottontail that triggered the camera before the storm hit.  Note: I don't, and never will, seriously attempt to draw carnivores into the yard with food or scent lures....but scent remains from Sampson's crap were all over out there anyways, so I figured I'd make it work to my advantage.

Above: My first backyard Coyote (Canis latrans) sniffing at my dog's home-brewed scent lure.  I'm not shocked by the fact that Coyotes were in this suburban neighborhood.  I'm more shocked that I hadn't gotten pictures of them before.  Too bad the camera lense was covered with moisture from the recent rain!

Above: The Gray Ghost (Urocyon cinereoargenteus) investigates things.  I've obviously seen these in the yard before.  What's strange is that it came by not long AFTER the coyote did.  I figured any evidence of the Coyote might scare them off.

Above: either a different, or the same, Gray Fox noses around near the camera again alittle later.


A few nights after this, Sampson and I went through our usual routine for deploying the backyard camera.  This time, the cam quickly captured activity after our departure.

Above: Sampson and I leaving....

Above:  Note the difference in time-stamps.  This little fella slinks through less than 10 minutes after my dog and I passed the camera


Unfortunately, about three days before the pictures above were taken (on May 15th) a rabid Gray Fox bit two people not less than a mile from where we live.  In one case, the fox first tangled with the person's dog while they were out on an evening walk.  When the owner tried to intervene with his foot, the fox moved on to him.  The second rabid fox incident did not involve a domestic dog.  This one occurred in the morning (8:30 am) rather than at night. 

On May 25th, someone in a neighboring county (about 25 minutes away) was attacked by a rabid Gray Fox while walking his dog.  He actually grabbed the fox by the neck after it bit him and threw it as far as he could.  The fox, however, did not give up so easily.  It apparently ran all the way back up the hill and attacked him again.  The man grabbed it once more, but this time was was able to secure it in a garbage can for animal control officers. 

Rabies was relatively common in that part of North Carolina.  For example, from January 1 to June 1, 2011 there had been four confirmed cases in our county alone.  Incidence of rabies may increase when potential carriers reach high densities, as the fox currently are in this general area.  HOWEVER, as Gehrt and Riley (2010) point out, there is not much information known on how living in urban areas alters wildlife disease dynamics for canids.

Don't take the wrong message from this post.  The risk of rabies from wild animals is low (see other posts regarding Wildlife Disease, including rabies here).  You're more likely to contract it from an unvaccinated domestic dog bite, according to many sources. 

Yet, given the number of fox we'd been seing around, I figured I'd start carrying a bit of personal protection when I took the dog out at night. 

Not that a bat would really help....especially considering I'm also dumb enough to wear shorts and sandals.  Even a small nip from a rabid animal can expose one to the virus and result in having to get the very unpleasant treatment.  Thus, to really protect yourself, you'd have to kill the rabid critter in one quick swing of the bat, before it's actually on you.  Even if we assume I'm deft enough to swing a bat so perfectly that it kills the rabid critter (a huge assumption), I almost certainly couldn't do it in one quick shot and without a scratch.  

But it at least made me feel a tad better. 

Also, as an aside, my dog wouldn't have been much help to me.  Despite his intimidating size and bark, he's not much of a brawler....but at least he's vaccinated.

Thankfully, the Gray Fox in our neighborhood didn't exhibit any signs of strange behavior.

They kept right on coming through the yard.

Above: our last Gray Fox picture on the camera trap for the month of May.

In fact, the sightings continued even without the aid of a camera trap! 

At 5 pm on May 26th, my wife called me at work and told me she had witnessed a Gray Fox crossing the road into neighbor's yard with something hanging out of its mouth (a prey item, although she couldn't tell what).  The area that our two yards made up was large...and wide open (no trees).  So the Fox was very exposed when he crossed here.  My wife asked if she should be concerned, given the recent rabies cases not far away.  I said that if the fox was out during the day and appeared to be wandering aimlessly, acting unafraid of people, or acting aggressive, then there should be concern.  If it was moving with a purpose, and away from human activity.....that was probably normal fox behavior.  Especially considering there were likely pups in the picture this time of year.  Perhaps this was the male bringing some food to the female while she nursed.  My wife then saw ANOTHER fox at about 8:30 pm that evening heading the same direction.

At 11 am on May 29th we saw the Gray running across the street and adjacent yards again.  We were all outside (including my dog), which didn't deter the little fox.  He moved with a purpose and was gone before the dog even got wind of him.  That night at about 10 pm, I took Sampson out and saw the fox's outline in the glow from a lone street lamp about 50 yds away.  He actually crossed through the area illuminated by the street lamp twice as I watched.  I say "he", because I'm still assuming it was a male who had a gal nursing pups nearby.  As such, he was on the move constantly to forage for himself and her.

Interestingly, despite the camera being in the yard every night....I didn't catch any more fox activity until the early morning of June 6th at about 2:14 am

Back then, I rarely used the video function on my cameras.  Mostly becuase it took up too much memory card space.  But, for a while, I felt like trying it with the backyard camera for a while...and got a nice clip of the gray.

The clip below was taken just off of the cement slab of my backporch (the camera is sitting on my daughter's little play picnic table).  So, this one came all the way up to the house, rather than skirting the back lot line. 

He takes sniff, wanders off in one direction and then cuts back across the yard a few seconds later.

In the early morning of June 14, 2011, the camera grabbed another video clip of a Gray Fox in our yard.  However, it wasn't a very good clip (about 1 second of fox, and 19 seconds of nothing) so I didn't post it.

June 16, 2011 (in the early morning), the camera took two pictures.  I had set the camera on a chair on the edge of the concrete slab of our back porch, facing out into the yard.

This is the second Coyote (that we know of) that passed through our yard.  He was on a mission, apparently, and the camera only recorded one blurry photo of him.

A few hours later, the little Gray Fox carefully sniffs his way through....following the same path as the 'yote.

On June 24 at about 12:51 am, a Gray Fox also meanders through the yard....but the picture isn't particularly good.

On June 27 at 10:00 am, I was out at my study sites when my phone rang.  It was my wife, and she was calling to report seeing fox pups for the first time!  She first saw an adult run across the road with four pups in-tow, as she pushed my daughter in the swing not 50 yds away.

On July 7, again at 10:00 am, I stopped home after field work to get some things together before heading out.  My daughter (not even three years old at the time) was standing by the window as I milled about next to her in the kitchen.  

Suddenly, I heard her say:

"Look Daddy!  A Fox!"  

Now, my daughter said stuff like this often (she had quite an imagination for a nearly 3 yr old).  I often heard things like "Look Daddy!  Creatures!"  or "Woody and Buzz want to talk to you!" and so on.  Because of that, I almost ignored her comment about the fox.  But couldn't help but take a look (I was impressed she remembered the word Fox at all, so I had to at least look).  

To my amazement, there was an adult Gray Fox running across the adjacent road and lawn!  On the opposite side of the road from the adult, I also saw one of the pups.  It ran part-way across the road, but turned abruptly and retreated back into the brush.  The adult sat completely exposed for a good thirty seconds looking back at the juvenile.  Eventually, a car came along and the adult casually trotted off in the opposite direction.

A half hour later, Dave had come by.  We were all going somewhere as a group (Dave, me, my daughter and wife).  Just before we left, my daughter saw the fox again with the juvenile.  She turned to Dave and said "Look a Fox, Dave!  The big fox is looking for the little one!"

Now, I can't help but brag a little about my daughter.  

Prior to that day, she'd only gotten one fleeting glimpse of a fox in the backyard...and maybe a few black and white IR pictures from my cameras.  Not only did she see the fox (which was more than 50 yds away), but she remembered it was a fox AND told me and Dave!  This on top of the fact that she was not even three years old at the time.  

What more could a father ask for?  :)


Interestingly, the pictures of them at my more "natural" study sites had ceased as of March.  They must have been tending to young some where on-site that didn't happen to be close to the cameras.

There were also no more accounts of rabies in the area to my knowledge during that spring/summer..... 

I miss those little canines.  They are much more rare up here in the midwest and I don't get the pleasure of seeing them anymore.

Further Notes on Urban Gray Fox and Coyotes:

Coyotes (I cite a variety of sources below, but have taken liberally from the outstanding review by Gehrt and Riley, 2010):

According to Bekoff and Gese (2003) Coyotes are one of the most-studied canids in North America.  Despite this, as Gehrt and Riley (2010) point out, relatively little of this work has focused on Coyotes in urban or suburban settings.  The most detailed work on this subject probably comes from Stanley Gehrt and his colleagues, who have focused on Coyotes in very urban areas in or around Chicago, Illinois.  Furthermore, Seth Riley has worked on urban Coyotes in southern California, and Jonathan Way has done considerable research in Cape Code, Massachussets.

Population Density and Survival-. Densities of Coyotes in urban/suburban landscapes have generally been found to be higher than in rural settings.  As Gehrt and Riley (2010) review, urban density estimates in a site from southern California (a site considered "urban-adjacent") were 2.4-3.0 per square kilometer.  Increased food sources (i,e, trash and domestic fruit) may be contributing factors, as "anthropogenic food items" were 14-24% of the diet of these coyotes.  In the greater Chicago area, density estimates of 2 to 6 coyotes per square kilometer were calculated.  On the other hand, Bekoff and Gese (2003) review density estimates in a variety of more natural settings and report numbers of 0.1-0.9 coyotes per square kilometer and one fall estimate of 1.5-2.3 / square kilometer.  Survivorship is generally high in urban areas...with survival estimates being comparable to un-hunted or un-trapped populations in natural settings.  Yet despite high survivorship, threats to survival of urban coyotes still exist.  For example, vehicle collisions represented 62% of all Coyote mortality in the greater Chicago area.  In southern California, over a nine year period, 27% of coyote mortalities were the result of anticoagulant rodenticide poisoning (perhaps picked up by eating dead or dying rodents that have consumed the rodenticide).  In the same study, vehicles were found to be the cause of 51% of the coyote mortalities (Riley et al. 2003).

Activity and Habitat-.  Several studies have confirmed that Coyotes in urban areas shift their activity to be mostly nocturnal (rather than crepuscular or diurnal).  This is largely believed to be because it allows urban Coyotes the opportunity to avoid humans during the day, while also making it possible to move around when the volume of traffic is lower.  This would explain the fact that the pictures I have collected of them both in my yard and at my study sites are all in the evening or very early morning.  Furthermore, studies that have occurred in a variety of geographic locations have found that the habitats selected by urban coyotes usually involve a small natural island or natural buffer, which is used as the core of the home range (Riley et al. 2003, Gehrt et al. 2009).  Their territories then include forays into the adjacent fragmented urban landscape from this central natural location.

Urban Diet and Threats to Pets or People-. Urban Coyotes have slightly different diets than their counterparts living in more rural landscapes.  In the Chicago area, for example, an important dietary stable were the eggs and hatchlings of Canada Geese (Branta canadensis).  These have become very abundant around a variety of water sources, including man-made stormwater retention ponds, making them an easy food source.  Coyotes are also an important predator of urban white-tailed deer fawns.  As Gehrt and Riley point out, this may be a useful means by which urban deer are managed, given the fact that hunting may not be allowed within city limits.  Domestic cats that allowed to roam freely and feral cats also fall victim to Coyotes, a phenomenon that increases in frequency in residential areas.  This has been correlated with higher songbird densities by Crooks and Soule (1999).  Urban coyotes may also attack domestic dogs.  According to Gehrt and Riley, most attacks are on smaller breeds (e.g., Jack Russel Terriers, Shih Tzus), but a group of coyotes may attack larger domestic dogs, as well (Gehrt and Riley 2010).  Attacks appear to peak during the mating season (December-February) and in April when pups are born. 

Attacks on humans are known to occur.  White and Gehrt (2009) reviewed 142 coyote attacks on humans and place them in the following categories.
  • Predatory (37%), primarily involving children
  • investigative (22%), including a a minor bite, or nip, usually directed towards adults
  • pet-related (6%)
  • defensive (4%), usually directed towards adults
  • due to rabies (7%), usually directed towards adults
Attacks on people possibily involve some level of habituation, but this is poorly understood in urban coyotes (Gehrt and Riley 2010).  Coyotes are known to actively avoid humans most of the time, and the context surrounding habituation of urban coyoes has not been rigorously investigated.  Yet, habituation (much like attacks on humans) are not common.  For example, of 150 coyotes followed with radio telemetry in the Chicago area, only five adopted problematic behaviors (Gehrt and Riley, 2010). This included taking frequent advantage of food sources in residential yards, such as birds at bird feeders.  Yet, as Gehrt and Riley point out, seeing Coyotes near residential homes eating trash, fruit, pets, or being active during the day should not be automatically considered a sequeway to attacking humans.  Instead this is equally indicative of the behavior exhibited by a "flexible" generalist predator.  Instead, concern should be raised when certain types of aggression are shown, such as failing to run from humans, or growling and barking in the presence of humans.

Gray Foxes:

Surprisingly little research has been conducted on urban/suburban Gray Fox.  According to Riley and White (2010), the most detailed studies come from California (Riley 2001, Riley 2006 and Riley et al. 2004), and New Mexico (Harrison 1997, but also see Kapfer and Kirk 2012).  Farias et al. (2005) also radio tracked Gray Fox near Los Angeles, but the tracked animals did not use urban or suburban areas.  Riley and White (2010) indicate that Gray Fox cannot stand landscapes inhabited by humans as well as other carnivores.  In fact, Harrison (1997) suggested that they would only withstand a housing density of 1 house/3.1 acres (or 50-125 residence per km-squared).  Geographical Information System (GIS) analysis of our neighborhood in NC revealed a much greater density of buildings (237-347 buildings/km squared) then Harrison suggested Gray Fox would tolerate (Kapfer & Kirk 2012).  However, we also have some pretty sizeable woodland buffers in our area, which may explain why our Gray Fox withstand heavier development than in Harrison's (1997) study (Kapfer & Kirk 2012).

Use of Urban Areas and Periods of Activity -.  The work in California found that most of the radio-tracked Gray fox (which were associated with a national park north of San Francisco) used urban areas only sparingly.  This use included forays into developed areas during the evening.  Harrison's work in New Mexico found that, although Gray Fox avoided urban areas during the day, they actually selected for them at night.  This seems similar to what I've seen this species doing in NC, with the exception of the time period when the males were bringing food for nursing females.   In California, vehicles are a known source of mortality for urban Gray Fox...and I'd seen at least three dead on the roads near our home from 2010 to 2011. 

Diet and Threats-. Interestingly, food associated with people was not a major portion of fox diets in the previously mentioned studies.  We don't leave dog food outside, and there's really no other food for them to get into around our house, aside from maybe the trash....but I'd never noticed any problems there.  I had found a dried up roadkilled squirrel husk in the backyard the morning after witnessing two Gray Fox run along the lot line one evening.  The most commonly consumed food in the diet of urban Gray Fox are small rodents (Riley and White 2010).  Attacks on pets and people are apparently rare.  Probably the biggest threat in this regard is possible attacks by rabid individuals.


I'm glad that I finally came back to this topic of urban wildlife (even though it was after we had moved from our suburban home).  A few of my "ongoing" post topics have been in need of revisitation for some time.  I have other Backyard Denizens from NC that I will report on in the future.

Literature Cited:

Bekoff, M. and E.M. Gese. 2003. Coyote (Canis latrans). In G.A. Feldhammer, B.C. Thompson, and J.A. Chapman. (eds.). Wild Mammals of North America: biology, managment and conservation.  2nd Edition. Johns Hopkins University Press.

Farias, V, T.K. Fuller, R.K. Wayne, and R.M. Sauvajot. 2005. Survival and cause-specific mortality of grey foxes (Urocyon cinereoargenteus) in Southern California. Journal of Zoology 266:249-254.

Gehrt, S.D., C. Anchor, and L.A. White. 2009. Home range and landscape use of coyotes in a major metropolitan landscape: coexistence or conflict?  Journal of Mammalogy 90:1045-1057.

Gehrt, S.D, and S.P.D Riley. 2010.  Coyotes (Canis latrans). In S.D. Gehrt, S.P.D. Riley and B.L. Cypher (eds.). Urban Carnivores: ecology, conflict and conservation.   Johns Hopkins Press.

Harrison, R.L. 1997. A comparison of gray fox ecology between residential and undeveloped rural landscapes. Journal of Wildlife Management 61:112-122.

Kapfer, J.M., and R.W. Kirk. 2012. Observations of gray foxes (Urocyon cinereoargenteus) in a suburban landscape in the Piedmont of North Carolina. Southeastern Naturalist 11:507-516.

Riley, S.P.D. 2001. Spatial and resource overlap of bobcats and gray foxes in urban and rural zones of a national park.  In A. Woolf, and C.K. Nielsen (eds.).  Proceedings of a Symposium on the Ecology and Management of Bobcats. Illinois Department of Natural Resources, Champaign.  (NOTE: I could not find a copy of this report and cited the interpretation of it given by Riley and White, 2010).

Riley, S.P.D. 2006. Spatial ecology of bobcats and gray foxes in urban and rural zones of a national park. Journal of Wildlife Management 70:1425-1435.

Riley, S.P.D., R.M. Sauvajot, T.K. Fuller, E.C. York, D.A. Kamradt, C. Bromley, and R.K. Wayne. 2003. Effects of urbanization and habitat fragmentation on bobcats and coyotes in Southern California. Conservation Biology 17:566-576.

Riley, S.P.D., J. Foley, and B. Chomel. 2004. Exposure to feline and canine pathogens in bobcats and gray foxes in urban and rural zones of a national park in California. Journal of Wildlife Diseases 40:11-22.

Riley, S.P.D., and P.A. White. 2010.  Gray Fox (Urocyon cinereoargenteus) in Urban Areas.  In S.D. Gehrt, S.P.D. Riley and B.L. Cypher (eds.). Urban Carnivores: ecology, conflict and conservation.   Johns Hopkins Press.

Saturday, October 13, 2012

A weasel on the stink poles....

Mustelids are my personal "Holy Grail" when it comes to camera trapping.

For years I have went the extra mile for pictures of otters, mink, fishers and weasels.

Usually, my efforts go un-rewarded (they are a difficult group to camera trap 'round these parts!)....and although I've had some success with otters and mink, the others have eluded me.

Occassionally, gets lucky.

I *believe* this is a Long-tailed Weasel (Mustela frenata).  Unfortunately, the animal is pretty far away, but there are a few lines of evidence that would suggest M. frenata to me.  This species is slightly larger than the other weasels found in our area: the Short-tailed Weasel (M. erminea) and the Least Weasel (M. nivalis).  They can reach lengths of 18 inches and, based on the distance this one is from the camera (which would be about 15 ft), the size would indicate it's a Long-tailed.  Furthermore, according to Long (2008), the tail has a very distinct black tip, which is fairly obvious from these clips.  Now....the Short-tailed Weasel also has a black-tipped tail, but it is generally not found this far south.  Furthermore...and also according to Long (2008)......if the tail length is 1/3 or greater of the body length, it's a Long-tailed.  From what I can tell in this video clip, the tail length conforms with what I'd expect for M. frenata

Yet...there is one more wrinkle in all of this. 

This part of the state is also the unnatural home of a Mustelid introduced from Europe: The Stone Marten (Martes foina).  It was believed to have been introduced by a fur breeder in the '40s, and although apparently established, is not common.  For example, reports have trickled through that a few have been captured annually for roughly the last 15 years (Long 2008).  The Stone Marten's dorsal and ventral surfaces (or back and belly) are concolor (or...of one color), although, the limbs and tail fur is apparently slightly darker than the dorsal fur.  All three weasel species native to the area are bicolored (of two colors): with a brown back and a cream or buff belly.  Stone Martens do have a striking white patch on the throat, but no black-tipped tail.

It's hard to see for certain in this video, but I don't believe there is an obvious white patch on the throat of this animal...and it also doesn't appear that the belly/back are the same color.   Then...of course....there's the fact that the individual in these clips has a black tail.

Anyways.....I'm leaning towards Mustela frenata.

People are not kidding when they refer to weasels as bundles of energy.  Look at that thing go!

They have to be that quick if they want to catch some of their preferred prey items (which are also very quick) and avoid being eaten themselves.  Weasels prey upon many types of small animals, ranging from insects and snakes to small mammals.  Yet, rodents are often a favored dish.  In fact, they so frequently dine upon mice, that this behavior is even reflected in their genus name (Mustela), which translates to "one who carries off mice" (Cold 1998).  Long-tailed weasels are excellent examples of dietary generalists, and apparently readily switch to alternate prey when normal prey densities are to low.  According to a review by Sheffield and Thomas (1997) these generalist behaviors have resulted in their relatively stable populations.

Another cool thing about weasels and their relatives is that they don't shy away from bigger fare.  They are well-known to take down an animal as large as a cottontail.  Check out this footage of a "Stoat" from BBC's oustanding series LIFE, which includes a stunning series of one killing a rabbit (warning: this footage may be too intense for some viewers, but it is amazing!). 

Note: "Stoats" are apparently the common name used for Mustela erminea throughout the rest of the world, although in North America we refer to it as the Short-tailed Weasel (King and Powell 2007). question: weasels are very neat little critters.

I have never actually seen a Long-tailed Weasel before.  I've encountered Least Weasels several times in the past.  Well........I'm assuming they were Least Weasels given the fact that Leasts are found in the southern part of the state and like grassy or marshy habitats/forest edges where I encountered these (Long 2008). 

The weasels that I encountered were captured.....basically by accident.  They were all captured in funnel traps that I had along drift fences to catch snakes (this would have been back in 2006-2007).  We had been running these surveys for an entire summer and had been catching many small rodents in the funnel traps, in addition to snakes.  Then...suddenly....for a breif period (maybe a week or two), I caught four Least Weasels spread across two sites.

Two were completely alive and kicking (in fact, they basically ran circles loop-de-loop style inside of my minnow traps when I picked them up).  They were gone in the grass the second I opened the trap.

One, unfortunately, was dead upon my arrival (died from exposure), which I felt terrible about. 

The last individual appeared dead (at first) when I picked the trap up.  However, closer inspection revealed that he was still alive, but appeared groggy and suffering from stress/exposure/dehydration.  I didn't know exactly what to do...and of course I had no special gloves or anything with to deal with a critter like this.

But...against sound judgement.....I took it back to my car (in the trap).  I found a pair of extra socks in my car and placed the weasel inside one of my socks so that his head was poking out.  Then I poured a bit of water into the bottle cap from one of my water bottles and barely touched his chin with the water.  Immediately, the weasel started lapping the water up.  I continued to fill the little cap as long as the weasel would drink....and quit when he sort of coughed/sneezed a bit from the water. 

I tried to come up with some sort of a plan for this little guy.  He was still groggy (eyes closed), breathing seemed regular.....but he was listless.  I called a nearby vet clinic, but they said that they didn't deal with injured wildlife.  They told me to contact the Humane Society in the area....which I did only to find out they were closed.

So, there I was....with a sleepy-looking weasel in one of my socks on the front seat of my car.

Not knowing what else to do, I waited.  Eventually, the animal seemed to start perking up.  He opened his eyes, became semi-alert and looked like he might want to move.

At this point, I took the critter (in the sock) back out to the field location near the drift fence.  I found a nice protected spot under a dense growth of dogwood and placed the weasel there (in my sock).  I watched for a minute...but decided I didn't want to stress the animal out any I walked away.

Several hours later, I came back to find my sock laying there....uninhabited.

I hope that means the little weasel went safely on about his way.

Literature Cited:

King, C.M., and R.A. Powell. 2007. The Natural History of Weasels and Stoats: ecology, behavior, and management. Oxford University Press.

Long, C.A. 2008. Wild Mammals of Wisconsin. Publication No. 65 of the Museum of Natural History, University of Wisconsin-Stevens Point. Pensoft Publishers, Bulgaria.

Sheffield, S.R. and H.H. Thomas. 1997. Mustela frenata.  Mammalian Species no. 570.  Published by the American Society of Mammalogists.

Tuesday, October 9, 2012

Some New Brutes for 2012

I'm not one to go nuts over "big bucks"....however, there are some brutes hanging around the property.

Could be one of the same individuals from last year (see here and here).

Seeing that the "rut" is soon to be upon us....I can't resist posting some clips of these guys.

This one is at a completley different site....almost in the next county.  But he's still a brute.  His antlers are not quite as impressive as the top fella, but check out the neck on this one!  Thick as a mature oak branch!

The clips below were grabbed at a location very near where the video clips at the top of this post came from.  Either it's the same individual (hard to tell from the clips), or another large bruiser in the area.

I've also captured some interesting behavior associated with this last individual. 

But I'll save that for a subsequent post!

Wednesday, October 3, 2012

A Lucky Shot in the Dark!

I was fortunate enough recently to be able to get away to northern Wisconsin for some fishing with high school buddies.  The set-up available to us was spectacular: huge house on the lake with a fishing boat and pontoon boat.  Also, unlimited dry firewood...a healthy supply of food and drink....and a fair amount of untouched northern forests to play in (when not fishing, of course).

I can't help but bring my cameras when I go on these kinds of trips.  In fact, I did it on a different fishing trip with high school buddies at a completely different location this January.

I'm realistic when I put cameras out in these situations.  I know the likelihood of actually catching things is pretty low.  I typically have one or two nights to work with (assuming we reach the site on Friday with enough daylight).  I also don't know the location particularly well, so may not have enough time to find the best place for a camera and have to stay close to our base camp (where I know I'm not tresspassing).

But I'm willing to risk disappointment, because there's always a chance that I'll get some Bob-tailed Cats (Lynx rufus), Fisher Cats (Martes pennanti), or....fingers crossed...Wolves (Canis lupus).

This time, I brought four cameras along.  Two of the cameras went in a boggy, sphagnum and fern carpeted forest across the street from our "cabin".  One was placed on the grass "driveway" used to back the fishing boats into the lake from the roadside.  The fourth camera was placed along the bank of the lake not far from our fishing dock. 

The latter two cameras were very close to the house.  Just down a short (but steep) slope from the fire pit behind the house. 

The first night, we sat up pretty late at the fire (1:30 am, to be exact) and I figured the nearby cameras were going to be complete busts.

The first few critters did little to quell my disappointment.

Feral Cat (grrrr...)

Eastern Cottontail (Sylvilagus floridanus)

......and a Mouse (Peromyscus sp.)

So, imagine my surprise when I saw this:

About 20 yards from where we had been making lots of noise just a few hours before!

Only my third camera trapped Bobcat (Lynx rufus)!  Needless to say, I was thrilled as I had actually gotten pictures of a species on my "wish-list" for the weekend!

Bobcat densities are generally reported to be on the rise in most of the continental United States, including Wisconsin (see further discussion of this here, and in Roberts and Crimmins, 2010).  Thus, I'm not surprised that Bobcats are in the area.  However, although their densities are on the rise, this is usually a loner species, that naturally exists in relatively low densities in parts of its range (Anderson and Lovallo, 2003).  This is particularly true of the Midwest, where densities as low as 4-6 individuals/km-squared have been reported (Berg, 1979).


The undisturbed plot of boggy woodland across the street from the cabin didn't yield Bobcats, unfortunately.

Numerous game trails.....if only I had more time to trap and more cameras to hang!  I decided to help the process along with a few little remnants left-over after cleaning the fish we caught.

The first taker is actually this Blue Jay (Cyanocitta cristata).  Neat to see them shredding and swallowing bits of fish flesh.

And the next visitors are what one could refer to as "the usual suspects" (but look at the size of that second one!).

At another nearby camera, baited with more fish, the Bandits again quickly zero-in on the free meal.

What's interesting about this clip is that it really shows how important the combination of scent and tactile sensation (i.e. "touch") is to a Raccoon!  Watch how he runs his fore paws over that fish, really trying to get a sense of it.

We have to remember that, out in the remote north woods, there's very little light....and the IR filter is giving us the false-impression that the area is lit-up like a Christmas Tree. 

Not so!  It's blacker than pitch out there at night (by our standards), and although Raccoons have better low-light vision than us....being able to smell and feel a potential food item is important.


Finally, I'll leave you with a first for me (I think).  It's hard to tell from these pictures and video clips....but I'm fairly certain that the cameras are picking up a Shrew.  I don't know what species, but given the size....I'm going to guess the Short-tailed Shrew (Blarina brevicauda), although there are Sorex in this part of the state too.

The critter I'm referring to is in the circled location on the picture below.

See a blown up version of this circled area here....

Now, take a look at it moving around in this video clip....which may help....

Interestingly, I tried to place another camera over a bit of fish remnants along the lakeshore.  Hoping for a mink, but didn't get any.  However, I *think* I got a video clip of a shrew chewing on the carcass.  He's close to the camera (so alittle washed out and out of focus). 

His backside is facing us, which also makes it difficult to ID him.  But, from this vantage we can see there's not an obvious long tail.  This would also suggest the Short-tailed Shrew. 

Short-tailed shrews are formidable little predators.  They eat, not only many invertebrates, but will also take small vertebrates (including smaller shrews, rodents, amphibians, and small snakes; Kurta, 2005).  I could find limited information that this species eats carrion, however.  They are known to hoard food, so they apparently have no aversion to eating dead stuff.  Jackson (1961) also reports recieving a letter from an individual whose property was apparently "overrun" with Short-tailed Shrews.  He recounts throwing the carcass of a freshly killed Western Fox Snake (Elaphe vulpina = Pantherophis vulpinus) onto a refuse pile that was "shortly devoured", aside from the skin.  

BTW....for those interested....the snake was dispatched for eating a fledgling Rose-breasted Grosbeak.  The nerve of that snake!

Literature Cited

Anderson, E.M., and M.J. Lovallo. 2003.  Bobcat and Lynx (Lynx rufus and Lynx canadensis). Pages 758-786. In: Wild Mammals of North America: biology, management and conservation (second edition). G.A. Feldhammer et al. (editors). Johns Hopkins University Press, Baltimore.

Berg, W.E. 1979. Ecology of bobcats in northern Minnesota.  Pages 55-61 In P.C. Escherich and L. Blum (eds.). Proceedings of the 1979. bobcat research conference (Science and Technology Series 6). National Wildlife Federation, Washington, DC.

Jackson, H.H.T. 1961. Mammals of Wisconsin. University of Wisconsin Press, Madison.

Kurta, A., 2005. Mammals of the Great Lakes Region (revised edition). University of Michigan Press, Ann Arbor.

Roberts, N.M. and S.M. Crimmins. 2010. Bobcat population status and management in North America: evidence of large-scale population increase. Journal of Fish and Wildlife Management 1:169-174.