Freshwater Jellyfish?!

Until today I didn’t even know such things existed, but this morning one of the science teachers showed up to work with a jar of water from a local lake containing about four small, live jellies. (I love how every time I’m running out of ideas for a good blog post, the universe provides something awesome!) Getting my camera to take a good photograph of a such a tiny, almost transparent, moving subject proved impossible, so I settled for a short video clip instead.

According to this fact sheet from the USGS, they’re called Craspedacusta sowerbyi and were originally native to China but are now found pretty much throughout the world. However, adult medusae like this (which are only one stage of their complex life cycle) aren’t seen all that often, only in sporadic irruptions. (An irruption is a sudden, sometimes unpredictable increase in population.) It isn’t clear whether they cause any particular problems as an invasive species – they do eat plankton, of course, which could potentially screw with aquatic ecosystems – but they’re harmless to people.

Vilas County, the county in northern Wisconsin where I live, contains more than 1300 natural freshwater lakes, the highest density of lakes found anywhere in the world. That’s literally about one lake for every fifteen people living here. I guess it’s not surprising that with so much freshwater habitat around, we occasionally find weird and surprising things!

[Update: Check out the lengthy comment below by O’fieldstream, who provides a lot more information on these creatures.]

Elegy for the Red Bay

Dutch elm disease.  Chestnut blight.  Hemlock woolly adelgid.  Emerald ash borer.  It’s the same old story over and over again, and we all know how it goes.

Red bay, Persea borbonia, is a common tree here on the island.  It’s in the laurel family, and yes, it’s related to the bay from which we get bay leaves for cooking; its leaves have a wonderful aroma when crushed.

Most of our red bays, though, are currently sporting as many branches of brown leaves as of green.  Is it because it’s winter?

Peer up into the canopy.  Brown, brown everywhere you look.  Why?

The redbay ambrosia beetle, Xyleborus glabratus, is native to Asia.  In 2002 it was discovered in Savannah, Georgia, and it has been spreading south since.  The beetle brought with it a fungus with which it lives in symbiosis.  The beetle tunnels into a tree in the laurel family, and inside the tunnel it cultivates the fungus, which is its only source of nutrition.  The fungus consumes the tree’s xylem, and the beetle, in turn, consumes the fungus.

And our red bay trees die before our eyes.  The disease is moving south toward Florida, where it will cut the crop of another member of the laurel family, the avocado, in half.

The American elm.  The American chestnut.  The eastern hemlock.  A long list of ash species.  And now, the red bay.

Feral Horses

“Wild horses couldn’t drag me away/Wild wild horses, we’ll ride them someday…”

So sang the Rolling Stones back in 1971.  It would seem that everyone, from British rock bands to American schoolgirls, loves wild horses.  When I was in grade school I was one of those kids who loved horses from afar, reading about them and drawing pictures of them without ever learning to ride.  I devoured the Saddle Club books and the works of Marguerite Henry.  We love wild horses because we see them as symbols of freedom, of, well, wildness.  But of course they aren’t technically wild at all – they’re feral, descended from domesticated ancestors, and the issue of feral horse management is much more controversial than my starry-eyed fifth-grade self understood.

They may not be as famous as the ponies of Assateague Island or the mustangs of the Great Plains, but Cumberland Island, Georgia is also home to a herd of feral horses, the descendents of escapees from Spanish explorers onward.  Pretty they certainly are, grazing among the ruined grandeur of the old mansions or lounging on the beach.  I can’t deny that I enjoyed seeing them on a day trip to Cumberland last weekend.

And yet.  Horses are not native to the island, anymore than the feral hogs (which I doubt anyone feels particularly sentimental about!), or the deer who were introduced there for the pleasure of hunters.  Cumberland is a National Seashore, and a large part of its area is a federally-designated wilderness; its dune ecosystem is fragile and would blow away without the plants that keep it in place, plants that horses eat.  Does an invasive population of large grazing animals really belong there, just because we humans think they add to the place’s picturesque atmosphere?

No effort has been made to reduce the size of the herd since the 1970s.  For now, the horses are there to stay.

The Dreaded ECD

Know what the bird in this photo, snapped from my parents’ back windows, is?

If you’re a birder you probably do: it’s a Eurasian Collared Dove, or ECD.  For anyone not familiar with the history of this bird in North America, it was introduced in the Bahamas in the 1970s, made it to Florida by 1982, and has since been spreading steadily across the continent.  Before my parents moved to Arizona, the only place I’d actually seen these buggers was in the Florida Keys, their original point of entry into the U.S.

My parents moved to Arizona about three years ago, and moved into their current neighborhood last summer.  Mourning Doves, White-winged Doves, Inca Doves, and Rock Pigeons are all common here, but for a long time I hadn’t seen any Eurasian Collared Doves – of course, I wasn’t exactly going out of my way to find them.  Then I came for a visit last December, took a walk, and suddenly started seeing them everywhere.  The question is, were they here all along, and I somehow hadn’t noticed them until them?  Or did they move into this particular neighborhood sometime between last August (the last time I’d been here) and December?  The world may never know.

It’s worth noting that this particular neighborhood is also home to large flocks of Peach-faced Lovebirds, which started (presumably) as escapees from cages and now have established quite a population in this area.  They’re so cute it’s hard to dislike them, even though they are non-native.  You can read more about Peach-faced Lovebirds in Arizona here.

Ah well.  There are plenty of cool native birds that show up regularly in my parents’ yard too, like Gambel’s Quails, Abert’s Towhees, Curve-billed Thrashers, and Cactus Wrens.  Plus the orange trees are blooming at the moment… so every time you walk outside and inhale you smell that heady orange-blossom scent.  Yum.

Wait, Dear, You Want to Build Our Nest Where?

Green leaves!  Green leaves!  The deciduous shrubs are starting to leaf out!

Of course, this is a honeysuckle bush, which is – you guessed it – an invasive species.  So I probably shouldn’t be too happy to see it thriving, but after such a long, snowy winter, any greenery at all is welcome.

The birds are really getting down to business with their nests; a pair of Red-bellied Woodpeckers are nesting in a cavity in a tree right outside the lodge, and my favorite nest to visit is the Great-horned Owls in the dead tree down by the spring.  However, I think the Carolina Wrens win the prize for site selection.

They’ve taken up residence in the electrical box thingie* right next to the fire circle, our main outdoor meeting spot!  No, I don’t have mad crazy nest ID skills, I just know this is a Carolina Wren nest because I’ve seen the culprits flying in and out with nesting material.  I was wondering whether all the activity around them might eventually drive them away, but one of the other naturalists told me that a pair of wrens actually nests in this spot every year, so I guess they’re used to it.

Good luck, guys.  Anyway, I just finished registering online to get my Wilderness First Aid certification and take the GRE.  Yay?

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*Isn’t my knowledge of electrical engineering impressive?

Wildflower Wonders

A couple weeks ago I wrote about an unsuccessful attempt to find spring beauty sprouting in my woods… I guess I was just a little too early.  Last weekend I was away in Michigan visiting friends, and this past week I’ve been on kitchen duty rather than on the trails with students, so the past couple days have been my first real chance to get out and renew my search.  Well, wowee!  Not only are the spring beauties up now, but the trout lilies, trilliums, and Dutchman’s breeches are too, and the hepatica are already blooming – I’d forgotten all about hepatica!

I’d love hepatica even if it weren’t for the flowers, because their foliage is pretty striking, too.

Anyway, the flowers aren’t the only sign of spring; the migratory songbirds are trickling back, too, as evidenced by the phoebes I can hear singing outside as I type.  FEE-bee!  FEE-bee!

Hope everyone else’s weekend has been as gorgeous as mine!

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UPDATED TO ADD: The other flower I found in bloom today was this yellow one, which after scouring some photos online I’ve identified as lesser celandine.  Sadly, it turns out this one is an invasive species, native to Europe.