Sunday, April 29, 2012

Vulpes vulpes

I've been marveling lately on an illustration I saw recently of an extinct species of crocodile lunging out of the water, reaching to grab a Tyrannosaurus Rex.  The event itself, that it occurred on the planet we now inhabit, is a marvel in itself but what I've really been marveling at is the sheer amount of energy involved in that event and how systems involving that much energy all begin their story in the form of single cells (both evolutionary and developmentally speaking).   From just two little cells comes a massive, 30 or 40 foot crocodile death-rolling a T. Rex.  Just so cool.

The day I took the photos below I witnessed what may have been the most wild biological energy I've seen.  The event was too far away from me so I don't have any photographs but here's what I saw: at first we noticed a group of gannets plunge diving.  You can see the group of birds circling around, looking a bit like gulls and then one will just drop out of the air and slash into the surface.  One after another was diving over and over.  That's already a lot of energy but you have to imagine the enormous school of fish that was hidden below the surface as well.

After a few minutes we walked a little further and noticed a second and third large group of gannets plunge diving.  Now I had the thought..."there's an awful lot of fish under there.  I wonder if there are whales nearby."  Sure enough, we waited and began to saw fin slapping, a behavior humpbacks and some other whales will do to signal good fishing spots to their kin.  You see the huge pectoral fin (humpbacks, even though not the largest whales, have the longest pectoral fins) rise up from the surface and then come crashing down, making a noise loud enough to hear from shore.

After watching all this energy, all these cells consume one another for a while we then noticed that there were more cells around.  I did get photographs of these and so they're the title of the post.  Here is Vulpes vulpes, the red fox:

By being quiet we were able to watch these two cubs rough and tumble play for a good 10-20 minutes.  It was really quite cool and a fairly unique experience for me. I've seen foxes in the wild before but never out in total daylight playing like this.

So V. vulpes here is the world's most widely distributed wild carnivore.  And though they mainly feed on small rodents like mice and voles they will eat just about anything they can get: other mammals, small birds, inverts like beetles and worms, decaying fruit and bits from compost piles are all on the menu.  I've even seen foxes "fishing" (for what I'm not entirely sure).

Unlike wolves foxes do not form packs but do live in smaller social groups usually consisting of a mated pair and a few of their daughters who will help to raise subsequent pups.  Like all canids and most mammals they mark their territory with urine.

V. vulpes's territory is limited by C. lupis (the grey wolf) and C. latrans (the coyote) however reduction of the former's range has increased the range of v. vulpes.  The red fox is also capable of inhabiting nearly any temperate terrestrial biome from coastal scrub/dunes (as pictured above) to alpine ridges.

V. vulpes also includes a vast number of subspecies/subpopulations that vary in coloration.  If you see a fox in the United States that is NOT the typical reddish orange of the animals depicted above it is still, in all likelihood a red fox.  Though this exchange did not involve as much energy as a T. Rex or a whale I was still glad I had the opportunity to photograph these beautiful animals and looked forward to sharing them here.  I have a few more that I may just post to the web album.  Enjoy!

One note:  I have been failing to include references for the last few posts on L. littorea and Uca genus crabs. Those along with this post have nearly entirely been based on information from  As always this is my go-to reference.  The post on L. littorea also came from my knowledge as a marine educator....yeah, I talk about snails a lot.

Natural History Reading: Four Fish

So as I mentioned recently in my post about dolphin strandings I am finally beginning to see myself as not just a science educator but also a marine educator.  I've worked for a public aquarium for a little over two years now but until very recently I still strictly referred to myself as a "science educator."  The distinction is that my background is in neuroscience and my teeth cutting experience in the field of informal ed. happened a children's museum where I mostly designed experiences related to they physical sciences and my main interests related to animals are still evolution, classification and  the more nerdy, "sciency" topics rather than what I would consider "marine" topics.  However working at a public aquarium for two years can influence your thoughts and perspective and teaching and even though I still hold the belief that the most important way we as educators encourage stewardship, especially with young children, is by scaffolding appreciation and excitement about nature, I am coming to include the "marine" part of my work more and more into my self identity.

So why is this important?  Why the preamble?  Because the book I'm reading right now, Four Fish by Paul Greenberg, I think does a great job of showing how much fascinating natural history there is behind a modern marine stewardship problem like over-fishing.  The book is ostensibly about our (our meaning humanity) relationship with four fish, (hence the title) salmon, bass, cod and tuna.  It tells the historical story of their fisheries and why these four fish have become modern staples.  It deals with the idea of fishing being the last "wild" resource that humans consume and where we seem to be going and where, perhaps, we ought to be going (baramundi farming, spoiler alert!).

But the most interesting part of the book, for me, is the natural history (I know, huge surprise).  Greenberg writes eloquently on how the natural histories and life histories of these particular animals forged our relationships with them and are often counter to how we attempt to continue our modern relationships.  He also relates this concept to fishes he believes are indeed more suited to our continued consumption.

Overall this book is a great read and one of the reasons I'm enjoying it so thoroughly is that I see his writing as a bit of professional development, helping me remember that because I'm a marine educator I don't need to stop being a science educator.  His ability to present current policy and environmental issues through their natural history is quite inspiring and completely enjoyable.  If you eat fish, keep aquaria, love fishing or have any strong emotional ties with fish (read: if you are from New England) I highly recommend this book.

Saturday, April 28, 2012

Littorina littorea

This is an animal that I spend a lot of time with.  The common periwinkle or little winkle (they have big winkles in Europe) is an introduced species that has become ubiquitous in nearly every Northeast US coastal habitat.  Even though this snail is not native I tend to use the terms "introduced" or "non-native" rather than "invasive" when describing this species.  Terminology related to human introduction can be controversial and I find it varies widely between environmental educators and conservationists.  The reason I choose to describe the periwinkle L. littorea as non-native and not invasive is that it is now a part of the ecology.  It's done whatever damage it's going to do and is now a major presence in the New England inter-tidal. The idea of controlling it or removing it is a joke.  Just go to any inter-tidal in New England, but especially a rocky inter-tidal, a  place like Brant Rock in Marshfield, and you will quickly come to see why I know the l. littorea is here to stay.  This idea of shrugging our shoulders and sort of giving in to invasives is, as I say, a controversial one.  I don't want to dwell on the nuances of the conversation here but if you're interested I recommend the book Out of Eden by Alan Burdick.

That being said, some scientists have put forth the idea that it was the very introduction of L. littorea probably in the mid 19th century that transformed much of the New England coast from marsh flats to rocky inter-tidal.  Perwinkles are voracious grazers and preferentially consume the algae and detritus that hold marsh substrate together.  All snails use a structure called a radula to scrape their food from surfaces (check out this video from youtube) and as these snails became more and more numerous they began scraping the rocks clean.

So besides the unfortunate status of this animal as a once invader I LOVE this snail.  They are one of the world's best observation animals because they are hardy, small, easy to transport and if left unmolested will begin moving around a tank pretty quickly.  They do have the slightly unfortunate requirement of salt water but unlike other inter-tidal inverts they are fairly indifferent to temperature changes.  If you live near the coast in the northeast I highly recommend trying these out with students.

Friday, April 27, 2012


There are over 100 species in the genus Uca, commonly known as fiddler crabs.  I believe, from distribution information, that this is probably uca pugnax, but I'm not certain.  I can't quite seem to find a perfect match to ID this little guy.

Many are familiar with this semi-terrestrial crab as it inhabits sandy beaches and marsh flats of the northeast United States.  These crabs are a great example of what we call "sexual dimorphism."  This is where the male and female of the species look different, sometimes drastically so.  (Cardinals, and many other yardbirds, are another clear example of this).  Di = 2 and morph = form so dimorphism = 2 forms.  You sometimes see reference to polymorphism as well (poly = many) when species have more than two morphs.

In this case the dimporphism is the male's much larger claw.  This is a mate recognition/mate choice feature.  The male crab will wave his large claw, visually and often auditorily signalling to females and other males.  They will also use the large claws in combat with one another.  These little crabs live in pretty close quarters, making small burrows in mud or sand so presumably their lives are consumed by waving and fighting.

Oh, and feeding!  Something I did not know is that their common name comes from their appearance specifically during feeding.  They will use their smaller claw to pick up detritus and move it to their mouths so in the males it appears that they are bowing (with their small claw) a fiddle (their large claw).  I guess I always just assumed it was just an analogy between the large claw and a fiddle.

The day I took this photograph we found a great number of fiddler crabs under the wrack in a marsh flat so the next time you're at the coast poke around a bit and see if you can find these common arthropods.

Saturday, April 14, 2012

Dolphin Strandings

Because I am not just a science educator but also a marine educator I get asked about the recent dolphin strandings a lot. In fact I get asked about whale beachings/dolphin strandings a lot in general. This late winter/early spring they have been in the news a lot so I've talked to more people recently. The question is either "are you helping out?" or "why is this happening?" The former seems to be a kind of vague assertion that there must be something we can do, which really there isn't. The main thing humans do after these large stranding events is perform necropsies. Which relates to that second question. The answer there is we still have no idea. We have some pretty good guesses and there are really smart people working on it but no one knows why whales beach and dolphins strand 100% of the time.

A few things to keep in mind if you're ever asked: this is a normal, seasonal event. Pretty much every year we see this happen. It's happening in larger numbers this year but a lot of our science points to that being, overall, a good thing. We think it's just that there's more dolphins. More dolphins, more strandings. It's received extra coverage this year purely due to numbers.

Second, the dolphins are not sick or going insane or involved in any kind of kool-aide dolphin cults. Here's what we think might be happening: groups of dolphins are foraging in tidal flats, often flats that they have not explored very well. These areas can be very close to sea level and at low tide you can often walk three or four miles further to the sea than you can at high tide. If a group of dolphins is foraging here and suddenly the tide shifts currents can be incredibly strong and the tide can empty quickly, leaving groups of dolphins stranded. Yes, they are very intelligent but they make mistakes.

On my trip to Cape Cod I actually saw evidence of these strandings. I took a few photographs and uploaded them to the web album. I didn't want to insert them in the post because...looking at images of dead dolphins can be upsetting for some people.

At first I was surprised that they had just been left in the marsh. One of these animals was just right next to a trailhead. After thinking about it a bit I thought, well this is part of the ecology, there's a huge amount of energy here. When I talked to one of my colleagues about it, though, she seemed to indicate that really it had nothing to do with that and it's simply that IFAW is overwhelmed. They would ordinarily take them all and do necropsies on as many as possible. Because we're seeing such a large number this year some of them have been left behind.

I think the emotions these animals bring out of people are good in a way. We should care about animals. But I also think there are other animals that could benefit from human intervention more. People believe that dolphins are inherently good somehow or friendly or have some kind of connection with people. It's just not the case. They're large, carnivorous marine mammals. They are very intelligent and have been known to help people but I believe we should try to take a step back and interact with them in the same way we interact with any wild animal.

Friday, April 13, 2012

Storytelling Redux

This came across my email last week. Interesting in light of my post on the same topic:

The Horseshoe Crab Diaries Part Six: In Which Paul Shows a Nice Photograph and Explains Molting

Go to the web album for the full effect

So several things. We went to Cape Cod this last weekend and found evidence of everyone's favorite chelicerate: limulus polyphemus! I thought this photograph was actually one of my best in a while. Even after owning my camera for about six years I'm still learning things about it. I was playing with the various white-balance mechanisms and found that you can have the camera measure the light and tweak the white-balance. Seems really obvious but I just never bumped into the option before. That provided me with a couple of fairly nice shots and this one which I think is well above average.

So I hear this a lot: "I went to Cape Cod/the beach/the marsh/Duxbury/etc. etc. and I saw a dead horseshoe crab/my brother picked up a dead horseshoe crab/it was crawling with dead ones etc. etc." But 99 times out of 100 it's not a dead animal. It's usually what is called a molt. Limulus, like all members of the phylum arthropoda, must remove its exoskeleton periodically. It can be a slow, difficult process because every last inch of its body is covered with the chitinous armor including eyes and its little legs. This is why the molts are often mistaken for dead animals: it looks just like a complete limulus.

Not a dead limulus!

The reason why is that tough armor, great for keeping them safe from predators, is rigid and cannot grow. Instead of growing gradually like most vertebrates they grow in spurts. When they're ready to get a little bigger first they stop taking in water, dehydrating and shrinking the soft parts of their body within the exoskeleton. They then start a crack right along the front ridge of their "helmet" and slowly wriggle their way out of the old armor. The outside of their body is soft at this point but ready to become hard and chitinous again. The arthropod will then grow, usually a full 30% of their current body size, and then the outer layer of their body begins to harden again. The whole process can take a few weeks so arthropods that grow in this way are especially vulnerable to predation during this time. Limulus, lobsters, crabs all seek extra shelter and typically focus entirely on staying safe rather than feeding or any other behaviors during this time.

Many people have eaten soft-shell crab or lobster. These are not different species but crabs and lobsters that have been trapped just after molting. By designing a trap to look like a comfy, safe cave fishers are able to trick the arthropods into crawling right inside. Instead of safety they walk right into the waiting clutches of hungry terrestrial vertebrates.

The next time you're walking around on the mud flats keep an eye out for these signs of limulus.


Just a few things possibly of note to any Mycelial Network readers out there in TV land. First, I totally missed the second birthday of the Network. Yay! You're two now, Mycelial Network! What wonders will you unleash on your adoring public in your third year of life?? No one knows!!

And I've recently gotten myself full-time employed like a real person. This means I'll be a little busier (though it's not like I've been writing up a storm anyhow) but I'm going to continue to try to make a point of posting on my weekends especially during spring and summer when I'm out in nature the most and I'm taking the most photographs. Speaking of being out and nature and taking photographs, stay tuned for a couple of posts today and tomorrow.

Wednesday, April 4, 2012

90 Trillion Cells

"So if you were to take all the bacteria in your body and just made them into one lump it would be about three pounds."

"Think of it as another organ, I mean, your brain's about three pounds..."

-Carl Zimmer on Radiolab