Holiday paws

  

Nice set of River Otter (Lontra canadensis) tracks in soft sand at Point Reyes today (28 November 2025). 

Who's the culprit?

  

This is a scene we came across after finishing field work this morning (9 May 2024).  Some empty-looking whelks (Nucella ostrina) on the sand...and upon closer inspection, their opercula nearby (the operculum is the "trap-door" on the bottom of a snail's foot that seals the opening to its shell when the snail is pulled in).

It looked like the snails had been eaten by a predator, but we couldn't recall seeing this before, so we looked around a little more.

We found even more evidence that something had been eating both whelks and limpets.  Here are a few examples, including snail shells and overturned limpet shells with most of the soft parts missing, but with a thin ring of tissue, evidence that they had been eaten recently:

 

 

So...who was responsible for eating these snails and limpets?

 

We weren't sure, but we kept looking, and Eric eventually spotted a clue.  Tracks in the sand around some of the predated shells:

 

 

 

After thinking through the possibilities, we're guessing these footprints might belong to a rat (!).

 

Rat predation on intertidal invertebrates has been documented previously (Thanks to Sergio!), but we don't recall seeing it locally before.  Maybe because there was a lot of sand at this site it was easier to notice the empty shells and the tracks in the sand.

 

Here's a close-up of one track in case anyone can help us with an identification.  The track was ~1 cm across.

 

 

 

You learn something new every day!

Belly dancing?

  

I saw several of these tracks on the upper beach in Truro, MA, on 28 September 2022.  

A wonderful snake track!  

Although I looked, I didn't find the snake itself.

Point A to Point B

Last week Eric and I noticed this looping trail on the beach (below).  Immediately both of us thought of an illustration from a card we like, so we added an A and a B:

 

Here's the card:

 

This illustration has seemed relevant at various times in our lives, as the paths we find ourselves on are often unpredictable and rarely follow a straight line.  This seems to ring true right now, with the way this coronavirus has upended the world.  It's helpful to think about the big picture, though, and to visualize the entire path, right?  Although it's often hard to know exactly how we'll get there, we will get to the next point!

P.S.  Thanks to the mole crab for making the path in the sand and to PAPYRUS for the wonderful card.

 

Spring track

Do these tracks look familiar?  (The animal responsible is revealed below the photo.)

 

Northern Elephant Seal (Mirounga angustirostris) tracks, 27 March 2019

Pattern in the sand -- Part 2

Okay, remember the mystery tracks that I posted last night?  I'll reveal the animal that made them in the photo below this one:

 

We followed the tracks until we got to the end, and this is what we found:

 

A rain beetle (Pleocoma sp.)!  It makes sense, because this was 24 November 2018 and it had rained the two days prior to this.  But I'm not sure how often these beetles are seen at the beach?  (We noticed several that night.)

Here's the beetle in Eric's hands. This is a pretty large beetle, but the width of the tracks in the sand is due to the reach of the beetle's legs:

 

An even closer view showing the wonderful antennae:

 

I wrote about rain beetles back in October of 2013 (when I was at a meeting at ~6000 feet elevation).  If you'd like to learn more about these intriguing beetles, check out the post called "Triggered by rain (or snow!)".

And here are more of its beautiful tracks:

 

Happy feet

 

River Otter tracks heading towards the ocean

Photographed 10 December 2016

Loping along

 

A nice set of early morning tracks, loping along towards the water's edge.

Do you have any guesses about what type of animal made these tracks?

I'll zoom in on one set of tracks for some additional clues.  Each track was ~3-3.5 inches (7.5-9 cm) wide and ~3-4 inches (7.5-10 cm) long .

 

This is a little tricky because the entire foot didn't register on the relatively hard-packed sand.  The uppermost print is probably the best.  Note that it has 5 toes, with short claws.  And the innermost toe is set lower than the others.

Here's a different set, at a slightly different angle.  Warning: The answer will be below this picture.

 

Okay — my best guess is that these tracks were made by a River Otter (Lontra canadensis).  Although the webbing doesn't show, everything else looks good for an otter — the habitat, the size, the toe patterns, and the loping stride.

I was curious about whether the individual feet could be identified.  If you want to try this, remember that the front feet are smaller and more symmetrical, while the hind feet are larger and asymmetrical because the inner toe is slightly below the other four.

Here's the first close-up again.  Which is the right front, left front, right hind, and left hind?

 

Below is my best guess for the individual feet.  If you have a different answer, let me know!

 

Although we don't get to see River Otters very often, it's fun to see their tracks and to think about them exploring the shorelines of Bodega Bay!

Tale of a trailing tail trail

 

Another interesting track in the dunes.  Sadly, this one was harder to photograph, and I was working at the time, so I only took a few shots which didn't come out great.

I'm not sure whether there's enough here to identify the animal responsible for these tracks.  See what you think.  It looks like there's a tail trailing behind the animal, creating a gentle wave-like pattern through the middle of the track. 

 

And it appears that there are feet pushing off to either side of the tail drag.

 

 

Here's another view from a different angle.  Do you have a guess?

 

I'm wondering about lizard.  (Claudia, can you help?)  My first guess was Northern Alligator Lizard, because they're the most common lizard in the Bodega Dunes.  But I searched for pictures of alligator lizard tracks on the Internet and found a few images that don't look like this.  

Then I wondered about Western Fence Lizard, since they're uncommon to rare in the Bodega Dunes.  But I couldn't find good pictures of their tracks.  So for now I guess I'll wait to see if anyone has more experience with their track patterns and can confirm or deny that these are a possible match. 

For the record, since I haven't shown this species yet, here's the only Western Fence Lizard (Sceloporus occidentalis) that I've photographed on Bodega Head.  This picture is from 24 June 2006.

 

To truly appreciate the beauty of this lizard, I zoomed in on the scales (this also allows you to see a hint of the "blue belly"): 

 

Bounding

 

A nice set of tracks in the Bodega Dunes.  Each footprint was very small — I didn't measure at the time, but I'd estimate less than 1 cm long. 

Note that the prints occur in sets of four with gaps in between (follow them diagonally from the lower left corner to the upper right corner of the picture).  This pattern indicates that the animal was bounding across the sand, rather than walking.

Here's a closer view of two sets of tracks (below).  Although subtle, you should be able to see that in each set, two prints are slightly smaller than the other two.  Which ones are smaller — the two in front that are side-by-side, or the two in back that are one-in-front-of-the-other (a bit offset)?

 

It's the two in back that are one-in-front-of-the-other that are smaller — and these are the front feet.  When bounding, the animal planted its front feet first, and then placed its hind feet ahead of the front feet.

The individual toes are visible in the picture below (there should be five toes, but they don't always register in the sand).

 

You can probably tell that this is a small mammal.  I'm guessing it's either a mouse or a vole.  I haven't learned to tell their tracks apart yet, but based on the bounding behavior, I'm leaning towards mouse (Peromyscus sp.).  What do you think?

Five toes, prominent claws

This photo was taken in the dunes on 21 January 2012.  I'm still puzzling over these interesting tracks, so thought I would share the photo and ask for ideas about the animal's identity.  I should have measured the tracks when I took the photo, but I would guess each print was about 2-3 inches long.  [I've included some notes and a possible guess below the image.] 

 

It's probably a medium-sized mammal.  It's not a canid (fox, coyote) or a feline (bobcat, mountain lion), because they have four toes instead of five.

Opossums have five toes, but their "big toe" on the hind foot sticks out almost perpendicular to the rest.  Raccoons have five toes, but they have very long, distinctive digits that produce a hand-like pattern.

So now I'm wondering about the mustelids, or weasel family.  It's large, so not a skunk.  It isn't webbed, so not a river otter.  The claws are prominent and strongly curved inward — could it be an American Badger (Taxidea taxus)?

If you have a guess or notice different things about these tracks, let me know.  I'll post any further updates.

Crossroads

Open sand in the dunes is wonderful for revealing animal tracks.

Here two animals crossed paths — a small mammal with sets of four small circular depressions (probably a mouse) and a bird (probably California Quail).  Did the mouse pass by at night, and the quail during the day?

And here's a typical rabbit track — the two larger hind feet are in front placed side-by-side (upper left), and the two smaller front feet are in back, one in front of the other (lower right).