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.


  1. Great post Trailblazer. I didn't realize you also had rabies in your neck of the woods. Its a nasty disease and we're also fortunate that its pretty rare around here.

    1. Thanks, Jeremy!

      Yeah, rabies in the state of North Carolina was a big issue. Skunks, Fox and Raccoons all carried it, and the latter two were very abundant.

      It's also a big deal where I currently live, but not as bad as down there.....thankfully!

  2. Wow. I had to read this 2 times to get it all in. Really, really interesting post. I love the grays, for whatever reason I feel like they are less common than reds here in Upstate NY, yet in the same day I found a road kill and had 3 pics on my camera (granted the locations were 3 hours apart). It was just strange to have both in one day. Kudos to your little one, perhaps you have a budding biologist in the household! Do you journal everyday? I'm impressed, I should be doing it too.

    1. Hi Alyssa.

      Thanks for reading and glad you enjoyed the post.

      This post had been sitting in various forms as a draft for over a year. I started it after getting the photo at the top of the post, but realized I should hold off until I could tell a more complete story.

      The topic of urban wildlife is an important one, as many wildlife species are forced to live in urban/suburban landscapes. Unfortunately research on the topic of urban wildlife (although steadily increasing) doesn't seem to be quite the hot-bed of activity that I had thought it would be (who wants to study coyotes in a city, when you can study them in Yellowstone?!).

      If you're interested in more, Gehrt and Riley's book Urban Carnivores is a great source.

      We don't have any Grays where I live now (but lots of Reds). I miss seeing them very much. Cool that you get both of them! During my two years living in North Carolina, I saw loads of Gray Fox....but only ONE Red Fox.

      Re: keeping a journal. I always have a field notebook close at hand and/or try to jot down observations (of phenology, for example) in a word document so I have a record. Currently, I don't record field observations as frequently as I should. Primarily due to a hectic life and associated forgetfullness. In graduate school, however, I was much more dilligent.

      It's a good habit to be in, however! I've always felt as if I was better at learning the ecology/natural history of various organisms if I kept my own records. It's great to look things up in a book, but I seem to remember it better if I observe it and write it down!

      This fox project, however, was alittle different. As soon as I realized these Grays were around the yard alot (and the first few times weren't just a fluke), I started keeping more dilligent notes on how often I was seeing them.