Saturday, April 30, 2011

Isopods


Do you love looking for crustaceans but hate getting wet and salty in the ocean? Well have I got the organism for you. Pill bugs (also known as rolly-pollies) and their cousins the sow bugs and wood lice are all actually crustaceans and not insects in the family collectively known as isopods (pod or stem foot). Pill bugs are unique for their armadillo-like ability to roll up into a ball when startled (pictured above).

Crustaceans are an incredibly diverse subfamily of the arthropod family (animals with exoskeletons) that differ from others like insects and spiders in their highly modified legs. Most insects and spiders have very similar leg structure to one another but crustaceans often have modified legs that end in claws, paddle-like structures for swimming, or even extra pairs of antennae for smelling and other sensory functions.

Besides the ubiquitous pill bugs and wood lice the isopod family contains some pretty weird creatures. The deep-sea dwelling Bathynomus giganteus can grow to sizes of nearly 2.5 feet and is one of the main denizens of whale falls (whale carcasses that have fallen to the bottom of the ocean). Several parasitic isopods have evolved to a particularly bizarre niche: they replace the tongue of a fish. By sucking the blood from the tongue until it atrophies and becomes useless they will take its place. Most of these isopods then feed off of either blood or mucus produced by the fish. But hey, at least the fish are usually able to use the isopod just as they used their real tongue!

There are a few other families of terrestrial crustaceans. The others are all true crabs or hermit crabs including the coconut crab which is the largest hermit crab (and largest terrestrial arthropod) and the only one (to my knowledge) that does not protect itself with a gastropod shell or some other kind of housing.

Friday, April 22, 2011

Behind the Scenes

Hey, ever wonder what goes on behind the scenes at the Mycelial Network (besides me sitting at the computer and reading about branchiopods)? Well you're not going to read about it here. But you can read about it here.

My friend Carole Ann, who I met working at the Providence Children's Museum, writes a blog as well. It's generally about crafting and quilting and such...not really the same content as the Network. But this month she's been blogging about blogging. So she's featuring various blogs that she likes and she's honored me by choosing my blog to be one featured! So check out the feature and the rest of her blog for that matter. Thanks Carole Ann!


Her project has also inspired me to start posting blogs that I like from time to time. So look forward to some natural history blogs you should be reading besides the Network.

Wednesday, April 20, 2011

Natural History Reading: The Secret Life of Lobsters

Right now I'm reading The Secret Life of Lobsters by Trevor Corson. As a science educator, especially one who works at an aquarium, it's more or less required reading. I have had a number of colleagues recommend it to me. Sadly, I've been disappointed. I'm slogging through it, something that normally does not happen with me and science/natural history reading. As you may be able to tell from my blog, I generally love this kind of reading. I think the issue is that there are a ton of characters. The book tells the story of the Maine lobstering community from more or less the beginning up to present day. This includes the fishermen's perspective as well as the scientists' perspective. However it's told in a jumpy flash-forward, flash-back way that makes it hard for me to keep track of who's who, especially since I will go for several days without reading a page.

The one thing I really like about the book are the parts about how scientists discovered certain things about lobsters. I've learned a lot about these crazy crustaceans in the last year and it's interesting to read about the experiments that lead to our better understanding of them. If you're passionate about the Maine lobstering economy or animals that pee out of their face then this book might be for you but I wouldn't give it a strong recommendation to the general public.

Coming soon: see my blog featured on a friend's blog and learn a little about isopods.

Sunday, April 10, 2011

"Seeing"

What is seeing?

Right. We do it with our eyes.

But is seeing a strictly visual thing? When describing the way other animals perceive the world we often say that they "see" with other senses. Bats might "see" their prey with sonar. Odontocetes (toothed whales) "see" with echolocation.

When talking about different animals we use this word "see" when talking about the animals primary sense, the sense with which they extract the most information from the external world. Dogs are primarily olfactory creatures. Most of the information they process is through the nose. Instead of using eyes to visually determine the difference in individuals the way we do they smell one another. Sharks are also olfactory creatures with up to seventy percent of their brains devoted to smell.

When this is process is described (extracting detailed information using a sense other than sight) it is often described as "seeing" even though "seeing" seems to be a visual word. There may be a good reason why, though. Our brains (human brains) construct images of the world by processing light waves coming into our eyes. But sharks, dogs, bats and dolphins also construct images of the world. Even though those images are not based on light waves they still, it seems from research, really do "see" the world around them. It's just that those images are constructed from detailed information in the olfactory spectrum or from echoed sounds.

Last night while watching one of the great David Attenborough nature documentaries, "The Life of Mammals" I was reminded that there is at least one member of the animal kingdom that "sees" not with its eyes, ears or nose but with its hands. And it just happens to be a New England Native. Who is it?

Procyon lotor: the Raccoon. In the same family as cats and dogs the raccoon has evolved towards a more varied diet but feeds mainly at night in freshwater ponds and streams. If you watched it hunting in the pitch blackness of a dark New England wood you might mistake the behavior for merely fumbling along, front paws splashing quietly in the water. But you'd be missing the orchestra of neuronal impulses firing in the raccoon's brain. It is by no means merely fumbling along. The "hands" of the raccoon are so sensitive that they can, like our eyes and a bat's ears, literally construct an image of what's on the riverbed so acute that the animal is capable of telling the difference between a rock and a clam in a split second.

There are actually a lot of very interesting and unique things about this New England creature and I hope to return again to it in future posts. I'll probably never get a shot of one though so if you want to see images, as always, head over to EOL.

Columba livia

It looks like this one is getting ready to build a nest

Most people consider these birds to be pests or, at best, a nuisance. I have had a more neutral attitude towards them but, like squirrels, I'm trying to appreciate them more. I think if I had never seen one before I would think they were downright beautiful, especially the males' bright, iridescent feathers in their breeding plumage.

The Pigeon, Common Pigeon, Carrier Pigeon, Rock Pigeon or Rock Dove, is native to Europe and Northern Africa but has been introduced to nearly the entire world, especially the continent of North America. In their native habitat they used the sheer faces of cliffs as nesting sites. This is one of the reasons (besides the overabundance of human leftovers) that they have taken so well to our cities. Tall buildings mimic their natural nesting places nearly perfectly.

The diet of the Pigeon is mainly seeds and since we grow a lot of it here in North America it has become mainly corn on this continent. In cities they eat pretty much anything that has a grain base to it: popcorn, bread, peanuts, even cake. The females need slightly higher protein and calcium intake for egg development so their diets may be slightly different from the males.

male and female

Source: EOL

Friday, April 8, 2011

Branta canadensis

If you live in New England you're probably familiar with this bird: the Canada goose. There are several subspecies that look fairly similar and can be found across North America. These geese were introduced to Europe as well, prior to World War II, as an ornamental addition to estates and parks. Ironically they are now considered pests by many (similarly to swans). Compounding the problem is that many populations have stopped their normal migrations and maintain residence in many areas year-round. To attempt to mitigate the potential damage to agriculture, hunting seasons on these birds have been extended in the last decade.

Yesterday I caught several shots of these birds at the pond near my house. The breeding season is in full swing and I managed to see some displaying. It's a little tough to tell but this picture shows a male and a female, the male giving what I believe is a mating call:

The geese will find a mate at roughly two years old and typically they stay monogamous throughout their lives. They lay several eggs each season but mortality is high due to predation and the first migration. However, in populations that do still migrate, the travel is far less grueling than in many bird species. Canada geese take several rests along the way and arrive at the breeding grounds in relatively good shape. Many birds store enormous amounts of energy and spend nearly all of it in flight. I'm often reminded of the ruby-throated hummingbird which flies across the entire Gulf of Mexico to reach its breeding grounds, sometimes against headwinds of up to 20 miles per hour. In comparison the Canada goose experience a leisurely hop down the continent of North America.

These birds are very long lived, having anecdotally been found to live up to 80 years in captivity. They are entirely herbivorous and forage both on land and in the water, as you can see from some of these images.

Though some do consider them pests I think they're beautiful birds. Beautiful...but they do look kind of delicious. Hrmm...

Sources:


Sunday, April 3, 2011

Spring...maybe?

Spring is at least visiting the Boston area this weekend. Yesterday I got reacquainted with two of my favorite things: my bicycle and my camera. It was still a little cold to stay out too long so I didn't get any amazing shots. But it was nice to take a walk outside.

Things were blooming


and budding.


And though I didn't get any shots of them I saw a whole bunch of flying reptiles. (y'know...birds.)

And of course, fungus!


Certainly there will be more to come now that the city is thawing out. Can't wait to get back outside with my camera.

Saturday, April 2, 2011

Mycelial Networks in the News

Well not really news but the April issue of "Garden Design" magazine has an article all about microbial networks and how they impact gardening.

It's actually a great article and if you happen to see the magazine and are interested in gardening I would highly recommend it. It talks about the science and a few newer findings by several researchers. But as I said, the article focuses on the networks' relationship with garden plants. The author describes how plants are capable of requisitioning needed nutrients, pushing out competitors, defending against insects and a lot of other things gardeners worry about by using chemical signals. The upshot? We don't really need those chemicals we put on our gardens.

It finishes up with a strong environmental message: all those chemicals are really bad for the planet, especially the oceans and watersheds. But, hey, since the plants are doing this work we don't really need them anyway. Good stuff. I plan to look a little deeper into the research described so keep an eye out for more posts about mycelial networks on the Mycelial Network.
(Sorry, I couldn't resist).