Saturday, March 31, 2012

A Memo From the Resident Coyote.....

Above: a taxidermied Coyote (Canis latrans). 

I've posted photos of Coyote scat in the past (see here, and here), but as far as I'm concerned.....if you're interested in learning to ID animals by their tracks, scat or other sign....the more examples you see, the better.

Plus, I need to justify this bizarre tendency I have to photograph every pile of poop that I find while on a hike!!

Anyhoo....while out and about today, we came across another perfect message along the trail.  Coyotes will often take the path of least resistance through a given area, and so they have a tendency to run hiking trails.  They also have a habit of leaving information for others along these trails.  Just a memo.......in case another critter comes by that really should read it.  Some of the most important cues that Canines leave are markings with urine and/or feces (although they will also use scratchings and combinations of these three to mark territories). 

Trail intersections are particularly attractive spots, as they can leave a sign for any other critter coming or going along multiple trails.  Today we found a great example of this in some fairly fresh Coyote scat. This scat was impossible to miss, as it had been deposited right in the middle of a wide trail, slightly off-set from a major trail intersection.

Above: the trail intersection where we found the Coyote scat (see the scat in the bottom center of the photo).

This was a large pile of scat, but we can be fairly certain it was no domestic dog as they are not allowed on-site. On closer inspection, hairs were visible....and the general consistency would suggest alot of animal flesh was consumed (there's also no evidence of vegetation).   



Rezendes (1999), states that scat which is "dark, smooth, and wet-looking" with only bits of hair is an indication that the animal has been eating organs from a recent kill.  I'm not certain how we can tell that scat with these general characteristics are indicative of organ meat vs. other muscles...but the point is, the critter is eating meat.  The coyote scat I had come across last week (that was already pretty old) consisted mostly of hair and tiny bone fragments, which is typical of coyote scat in the winter (Rezendes 1999).  I'm assuming the winter scat appears this way because 'yotes have to rely more on scavenging carcasses to find food in the winter.

Coyotes are most territorial during the breeding season (January and February 'round here), and one would assume their rate of marking should increase during this time.  Work on Coyotes in Yellowstone has shown that alpha members of the group increase their rate of scent marking with urine during the breeding season, while subordinates marked at constant rates throughout the year (Gese and Ruff 1997).  Interestingly, rates of defecation didn't vary based on time of year social status.  Also, scent marking with urine occurred more frequently along the boundaries of a territory vs. the interior...but rates of defecation did not.  So, based on this work we can conclude that, although scat is important in communication, it is possibly less so than urination.

Literature Cited:

Gese, E.M., and R.L. Ruff. 1997. Scent-marking by Coyotes, Canis latrans: the influence of social and ecological factors. Animal Behavior 54:1155-1166.

Rezendes, P. 1999. Tracking and the Art of Seeing. Harper Collins Publishing.  New York.

Further Reading on Coyote Scent Marking:

Barrette, C., and F. Messier. 1980. Scent-marking in free-ranging Coyotes, Canis latrans. Animal Behavior 28: 814-819.
 
Bowen, W.D., and I. Cowen. 1980. Scent marking in Coyotes. Canadian Journal of Zoology 58: 473-480

Thursday, March 29, 2012

Phenology: Mourning Dove Copulation Log

It's a copulation "log" in two ways: (1) that it is my logging of a copulation event between two Mourning Doves (Zenaida macroura), and the fact that (2) the copulation literally took place on.....a log!

So, the event begins down at the old make-out spot with a single male, checking out the scene.........

His patience pays off....

Then, the showing off begins....

 ....and continues.....

Then, the preening of eachother begins....

The girl also decides to show off a bit....

This is followed by alittle more co-preening......

....and more.....

The picture says it all, I should think!

....next the cuddling.....

But eventually, that inevitable awkwardness sets in....

They apparently try to ignore eachother with alittle self-preening. Perhaps hoping the other will get the hint and leave.  They both work pretty hard at putting out the "take a hike" vibe, but it doesn't seem to work.

....but neither is willing to give it up.....

For a moment, it appears they might confront the elephant in the room....but the male gets the wrong idea.

...and so it's back to pretending the other isn't there.....

Finally, they put a bit of space between themselves.....

...and the male starts to plan his exit strategy....

They both must have left, because that was the last picture of either!

Notes on Mourning Dove reproduction.  In our neck of the woods it is common for this species to reproduce from April through September, so this is a tad early compared to a "normal" year.  The reproductive behavior outlined above is typical, although there is often much head-bobbing, etc. that doesn't really come out in still photos.  Although my commentary above gives the impression that they don't want to be around eachother after copulation, the Mourning Dove is actually a seasonally monogamous species (they remain in the same pair during a single nesting season).  So, these two will probably be together for much of the rest of the season, and there is even some evidence that this species will re-pair with the same individuals in subsequent years.  The co-preening behavior and the self-preening behavior outlined above is typical of this species during pair-bond formation and copulation.  Nests are often a loosely aggregated bundle of materials (pine needles, etc.) that are placed in dense foliage.  Females usually lay one to two eggs at a time.

For more information see:

Otis, David L., John H. Schulz, David Miller, R. E. Mirarchi and T. S. Baskett. 2008. Mourning Dove (Zenaida macroura), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/117doi:10.2173/bna.117

Tuesday, March 27, 2012

Of Newts, Turtles and Timber Wolves...


....alright....I suppose there is debate about whether or not the Timber Wolf (Canis lupus lycaon) is a valid subspecies....and regardless, the US Fish & Wildlife Service has deemed that we can only have the Gray Wolf (Canis lupus) in our part of the U.S.......but "Timber Wolf" fit into the title so well!


Anyways, with the nice weather (unseasonably warm...in the 80s in March, which here doesn't happen until May) hiking is a viable daytime activity.

So, the kid and I went to a nearby state forest for a little hike.  She's sort of a paradox, this daughter of mine.  A nearly perfect mix of myself and her mother, as evidenced by the outfit she selected for a day of getting dirty (which she has no problem doing...nor picking up anything that she finds interesting, including a nugget of Canada Goose turd, which she threw into the water, before I could stop her...).

So...the chosen get-up included a shirt with colorful print, the skirt from her Snow White dress-up outfit, a pair of leggings with whales on it, and her La Crosse brand rubber boots.  This was drawn together with a plush purse, in which she carried countless treasures...including an orange (which I had not seen her grab) that she proudly produced later after exclaiming she was hungry.

One of the first things we found along the trail was a pond with a boardwalk that allowed us to walk out over the water.
The Spring Peepers (Pseudacris crucifer) were screaming around the pond peripheries....which possessed a nice buffer of flooded woodlands.  These were the first Peepers I've heard this spring, although I've recieved reports of them calling for the past several weeks by colleagues (which is very early, by the way). 

There were also Painted Turtles (Chrysemys picta) to burn in this little pothole scoured out by the glaciers.  It seemed that every available space above the water line, be it log, stick or clump of mud, had a turtle basking on top of it.  Some were even close enough to snap a picture of with a camera that has little zooming ability.

The best part, however, was peering down into the clear wetland water.  It teemed with activity, and we were obliged to get down and take a closer look.

 Water striders and other aquatic invertebrates were plentiful.  I even watched a leech swimming sinuously through the substrate.  But what drew our attention most were the amphibians.  It seemed that every square foot of real-estate was occuppied by large a tadpole.  Based on the fact that they were already sizeable this early in the spring, it's a no-brainer to assume they were a member of the Family Ranidae, and almost certainly Green Frogs (Rana=Lithobates clamitans).  Green frogs lay their eggs late in the summer and the tadpoles remain as tadpoles through winter, only to metamorphose in the following summer.  With the exception of the Bullfrog (Rana=Lithobates catesbeiana), all other frogs in our region have tadpoles that hatch and develop into froglets during the same season.  It's possible these were Bullfrog tadpoles, but they just didn't seem big enough to me.

Anyways, the tadpoles were neat...but they dont' really move much.  They basically sat in one place, soaking up some of the rays penetrating through the water's surface.  Much more interesting to watch were the Eastern Newts (Notophthalmus viridiscens).  These little guys were fairly numerous as well, we could see them pushing through the leaf litter at the bottom of the pond, and occassionally swimming up to the surface.  As I've mentioned before, the newt is a most amazing amphibian.  It has several possible "phases" in which it can exist: an aquatic adult, a terrestrial adult, an aquatic juvenile and a terrestrial juvenile.  Basically, these phases are adopted depending on environmental conditions.  If the newt grows up in a wetland that doesn't dry out, they will go from an aquatic juvenile to an aquatic adult.  But, should the water levels receed, they are capable of transforming into a terrestrial adult, or a terrestrial juvenile.  The terrestrial juvenile is beautiful, and is often referred to as a Red Eft.

The individuals my daughter and I saw were adults, and clearly in the aquatic phase.

All of this information: the basking turtles, the tadpoles that need to over-winter, and the newts in their aquatic phase tells us something important (albeit not unusual) about this wetland: it rarely goes dry....or is not ephemeral.  If it went dry by the end of the summer, there would be nowhere for the turtles and tadpoles to overwinter....and the adult newts would have transformed from their aquatic phase to their terrestrial phase.
__________________________________________________________________________
We passed the State Park's headquarters during our adventure.  They had a neat little museum, which we made use of, seeing that the kid loves to look at stuffed dead things (the reason she likes museums so much, I suppose).

A number of cool dioramas, including this rather comical scene of a pair of River Otters cleaning up the leavings of an ice fisherman (as a Mink watches from the cattails).

There was also a nice mount of a Gray Wolf (Canis lupus), which made for a perfect photo-op.

We walked on, and continued to follow the trail until we found a scenic overlook.  A decent-enough spot to stop for some juice and crackers.

...and of course...the rocky path provided many opportunities to lob some geologic protectiles down the hillside.

I guess it's hard to turn down an opportunity to throw a good rock.....

Friday, March 23, 2012

Advanced Ecology Lab Week 9: The Tod and The Bandit


This would be one of my favorite personal camera trap pictures ever, if it weren't so washed out.  But...the Cuddeback at close range can't do much better than this....

This week was basically a repeat of last week.  The goal being to increase the chances of catching critters in the wire cage traps, while allowing the students a chance to further test their skills at setting traps again.... and perform maintenance on other long-term data collection projects.



So, once again the traps went out for two back-to-back days.  This time, we sweetened the bait by mixing dog food, sardines, and drippings from St. Patty's Day Corned Beef and Cabbage.....pulling out all the stops.



The feral cats stayed away, which I was happy for...and we actually caught some wildlife, although not a ton.

Still, one Raccoon is better than nothing!


Now....a Raccoon in a trap can go either way.  Sometimes you'd think a Looney Toon-style Tazmanian Devil was in the trap. 

Other times, they are as docile as a kitten.
Photo by J. Scherer

This individual was actually fast asleep when we walked up to the trap in the morning, his belly full of dog food and sardines.  I joked with my students that, becuase he was a 'coon living in a suburban/rural mosaic landscape, he probably gets trapped and relocated once a month, so knows the drill.

Regardless, approaching with caution is always important (those deft little paws can reach through some pretty tight places).  With the threat of rabies (a serious issue with Raccoons), kevlar gloves are warranted.
Photo by J. Scherer

But, if everything goes as planned, the bandit is gone before you have a chance to think about what might happen.....
Photo by J. Scherer


Also, plenty of stuff on the camera traps.  A smattering of examples includes....
'Possum...


Blue Jay (Cyanocitta cristata)

Walkin' Bird (Meleagris gallopavo)

Stinker (Mephitis mephitis)

Deer....

One of the minions of El Diablo....


We also had one of our most productive canine weeks on the camera traps.

First, The Tod was all over the site (including the picture at the top)....unfortunately, none of these pictures are all that great.  The video clip is sort of cool though.......




Finally, we got some close up shots of a 'yote on-site.  This camera is the one the students mounted on the tree near the location of the rabbit burrow that had been dug up by a canine of some kind (see here).  This 'yote is attracted to the spot....but the red LED's must give him a start.  As I've posted before, they are incredibly wary of the red LEDs, for some reason.



Then, he puts his nose to work from a slightly safer distance....


The canine pics are often blurry.  They are just too skittish to hold still for very long!