Clams

Hello beloved readers!

I apologize most heartily for my relative absence- we’re wrapping up the field season here in Exmouth, with all that entails: extra snuck-in snorkel trips, boat cleaning, taking posters and papers off of the walls, last-minute photo-ops on the water, cooking strange combinations of things from the remnants of our kitchen cabinets… It’s been a bit of a whirlwind. But still fun, of course.

As a metaphor for my lack of posting, here are a series of photos of giant clams.

P1080882

The color in the mantle (the soft part, showing from inside the two shells) comes from algae that the mollusk can cultivate within its own tissue. The algae and the clam’s own filter feeding both provide it with food/energy.

P1080914

Giant clams like these can live up to 100 years in the wild, building up layers of thickening shells as they go.

P1080941

Just so that nobody emails me with warnings that these animals should be added to my list of Things-In-Australia-That-Want-To-Kill-Me (Wikipedia: “It was known in times past as the killer clam or man-eating clam, and reputable scientific and technical manuals once claimed that the great mollusc had caused deaths; versions of the U.S. Navy Diving Manual even gave detailed instructions for releasing oneself from its grasp by severing the adductor muscles used to close its shell.”) I’m pretty sure that I’d have to be trying to climb inside of one of them for it to even give me a good pinch. Most can’t even close their shells the whole way, nor would they have any desire to hang on to a snorkeler/diver. They’re about as dangerous as rotting logs. But much prettier.

Deadly Serious

“Yeah, we have to keep an anchor chain watch,” says the beanie-wearing man, stroking his stubbly chin. “They’ll just come right up the chain and into the boat if you’re not careful.”

DSC_0343

Having listened to a number of Australians at this point, there are several aspects of Australian humor that really stand out to me. First, there is the tendency for Aussies (especially men, especially fishermen) to declare every animal brought up in conversation as “real good eating, just throw ‘er on the barbie!” This is perplexing when one is researching endemic coastal dolphins, but sort of funny when you get used to it and can react with similar straight-faced absurdity: “yes, but a bit fishy-tasting. And oversalted.” And second, there is the complete solemn commitment to untruth that is used to hoodwink tourists and visitors (see “drop bears,” for example, or the persistence with which Natalie’s brother’s friend tried to convince us that he was called “Esky” because he was born in a cooler on a dusty road in the Outback). (We’re pretty sure he wasn’t actually. Like 99% sure. Maybe 98% sure.)

We’re pretty sure, as well, that sea snakes don’t climb anchor chains and enter boats. First of all, they’re almost all highly evolved to live their entire lives at sea. All but one group (the Laticauda, a more primitive group more closely related to their common ancestral land snakes in the Elapidae family, which includes coral snakes, cobras, mambas, taipans… basically all deadly poisonous), have reduced stomach scaling, making them quite vulnerable on land. They can’t coil or strike like land snakes, but can hold their breath underwater for several hours at a time, having evolved lungs that stretch nearly the whole length of their bodies, which they use for buoyancy control and gas exchange (which they can also do through the skin and scales on their backs!). They extrude salt from their bodies through glands behind their little snakey tongues, and use their vertically-flattened tails as paddles to swim. Climbing anything seems like it would present a problem for these guys. But even more unbelievable than sea snakes being physically able to climb into a boat is the idea that they might want to.

Sea snakes live interesting little lives. They’re among the most well-adapted reptiles to live in the sea, arguably more effective than sea turtles (who must all return to land to lay eggs rather than releasing large numbers of live wiggly young into the unsuspecting waters of the tropical regions in which they live). However, they’re primarily known for two somewhat contradictory characteristics: namely, that they are among the most deadly venomous creatures alive, and among the most friendly. It feels like a bit of chicken-and-egg paradox. Are they friendly to and curious about divers and snorkelers because they know they’re deadly? Or are they deadly because they’re otherwise suicidally approachable and have to have some way to stay alive?

Either way, I asked an Australian that I met on my walk yesterday, clearly an avid fisherman and also clearly familiar with boats, what he thought of the vivid yellow reptiles we see cutting the surface of the swell over the reefs.

“Pretty good with some tomato sauce,” he said.

DSC_0290

Boats and Goats and Princess Toast

The relevance of boats to this post should be relatively obvious at this point- I’ve been trying to have my camera out while we’re on the boat a bit more, taking photos of fieldwork and the water. Here’s the newest member of Team Sousa (Natalie, from England) doing some #SCIENCE:

IMG_2565

Natalie has bought a bike in town, and as a result has been doing some in-town exploring that I have avoided in my general hunt for weird Australian flora and fauna. I think it’s been worthwhile though! A few days ago she came home full of stories about a man that she met whose family has adopted a baby goat, found on the side of the road. The man carries the little goat everywhere he goes, tucked under his arm; his daughter has named it Scarlet. We followed Natalie back to the home of the goat and definitely just happened *cough cough * to walk by in time for her to reunite with her new friend:  IMG_2665

We helped feed her, but as the man and his daughter told us, she’s getting a bit old to be drinking milk all the time and has begun to take apart plants in the backyard and clothes hanging in closets… At four or five weeks old, it may be soon time for Scarlet to become a back-yard goat, but we’ll see.

All right, so we’ve had boats and goats… now on to the princess toast. Tim had explained to us the concept of “fairy bread,” the name of which I had completely misremembered while trying to explain it to one of our Aussie friends. Fairies, princesses, what’s the difference? I’d have been happy to find out I was either back when I was a kid (get it? Baby goat jokes!). Anyways, fairy bread is an Australian kid’s party snack consisting of white bread spread with margarine and then coated in little colorful round sprinkles, like so:

IMG_2970

Hello, dessert, and hello Australia points. Now for the full Exmouth experience, we’ll just have to make a pavlova, swim with a whale shark, and see at least one poisonous land snake. Then we’ll have done it all.

The Angriest Golf Ball You Ever Did See

I went for a wander through some tide pools the other day. The flats were shallow and productive, full of algae and little fish, hermit crabs and snails:

IMG_2262

But besides the cowries and more typical-looking snails, I found this guy:

IMG_2277

He may look distinctive in this photo, but he’s only about an inch long and I nearly stepped on him- he’s all the same colors as the surrounding sand and algae. Camouflage is good most of the time, but I’d have felt really bad if his turned out to be too effective.

My feet were in the water, since there were no dry places to step- I really did have to keep an eye out. Especially when I looked into a slightly deeper pool to see a little brown cephalopod scuttling across the bottom, arms tucked underneath- I leaned in and shuffled very carefully closer, hoping for a cuttlefish or a baby reef octopus. The golf ball below blanched and then flashed blue, and I snapped this photo before backing off rather hastily:

IMG_2282

It’s enough to confirm the presence of a blue-ringed octopus, one of the most venomous marine animals in the world. That angry little golf ball that changed direction and charged at my toes contained enough potent and antidote-less venom to kill me in minutes. “Not aggressive,” it says on Wikipedia. Well, as far as I know I didn’t do anything to make it mad. Perhaps it didn’t sleep well, or perhaps it wasn’t expecting any observers of its afternoon hunting and was embarrassed at the state of its hair.

Anyways, it was really blue and quite agitated, so I decided to get out of its way. It turned and headed deeper into its little pool as I watched from a nearby rocky perch, so it may not have been aimed at me anyways… I really wasn’t terribly interested in finding out for sure.

Fun fact: every photo in this post has, as its subject, a member of the phylum Mollusca. Shelled, invertebrate, mantled- each cephalopod or gastropod (brain-foot or stomach-foot, respectively) here descends from a hypothetical limpet-like ancestor. Evolution is neat! And just because I love evolution so much, here is a bonus sea hare, about the length of my hand:

IMG_2293

Hooray! Go explore something!

-AgentRedSquirrel

In Search of Emu

The Emu Saga: Part 1

Still haven’t gotten any good face-to-face emu time, but the more time I spend wandering the bush the better my odds are, right? My recently-new Vans are getting less cherry-red and more Outback-dust red, but I find no little satisfaction in recognizing my footprints day to day out on the trails near town, especially when they’re overlaid or intermingled with ‘roo and emu tracks.

IMG_2026

Emus are tridactyl- they have three toes, wide and leathery, that press into the red dirt as they walk. I love thinking about emu feet- they have to be pretty intense to hold up that much bird, to handle the prickly grasses and sharp stones of the outback, and to be able, as claimed by the emu Wikipedia article, to tear down chain-link fences.

Those feet are so formidable, in fact, that they pose a significant threat to unwise humans who attempt to make a full-grown emu do… I guess anything that a full-grown emu doesn’t want to do (cue joke about the 500-pound gorilla, except imagine that gorilla with sharp toe claws and a very wide beak. And feathers? Okay, this is just getting confusing now). I don’t think that the emu’s feet were the deciding factor in the frankly embarrassing “Emu War,” waged between machine-gun armed Australian troops and thirsty birds in the 1930s, but hey- I’m sure with those feet, an emu could handily (haha) kick my butt.

Anyways, I’ve been trying to find myself an emu friend. Apparently they’re curious about people, and will sometimes follow a lone human on foot; thus far, no such emu magic has happened to me, but I’m working on it. I’ve encountered fresher and fresher emu poops (see http://animals.io9.com/everything-you-ever-wanted-to-know-about-emu-poo-1570013557 for… everything you ever wanted to know about emu poop) as I’ve wandered the hills near Exmouth:

IMG_2347

The stuff’s like tar filled with seeds, and over time (days?) the whole mixture dries into a black solid mess, seeds browning and eventually sprouting as the black stuff greys out and (weeks later?) blows away. There is a remarkable amount of this around all of the bushy areas near our house, considering the also remarkable lack of emus on my walks. But I live in hope!

Another thing I have lived in hope for, however, has finally come true.

“Emus on the beach!” I cried on one of my first days on the boat, out by the Bundegi boat ramp. “I want to see emus on the beach.”

So quintessentially Australian, I thought. How funny would it be, gangly-legged birds with stringy feathers draped across their humped backs, trotting across the soft sand? Combine the gentle waves and romantic dunes with nobbled knees and perpetually surprised faces: what could be better?

Beachmus. Dreams really do come true:DSC_0011

Best Looking Birds

As we chatted with the tour operator at Yardie Creek, a group of elderly travelers disembarked around us. Wives helped husbands with canes out of the low seats, and their cheery organizer/guide asked for a vote on whether or not to walk up the trail a bit (it seemed like nobody was that enthused). One khaki-clad man, seemingly alone, paused as he passed us three Team Sousa members.

“Best-looking birds I’ve seen all trip,” he grumbled in our general direction before stomping up the few steps to the dock.

My first (innocent) thought: I wonder where they’ve been, and if they’re all on a bird-watching trip?

My second thought: …gross.

Crusty old Australians aside, Yardie Creek (Yardi means “creek” in one of the many Aboriginal languages of Australia, so really all of us immigrants and tourists are referring to the briny tidal waters as the “creek creek”) did in fact host some lovely birds. Ospreys seem to be a theme around here:

IMG_2189

It feels like everywhere we go, someone points out an osprey nest to us. Doesn’t make them less awesome, though- this one has reportedly been occupied nearly continuously for 80 years at least. It may not always have contained chicks, but the past few years have been productive for local ospreys, evidenced by the juveniles and new nests we’ve seen around the area. They’re very fun to watch from the boat, as they dive for fish and flap, low and slow above the waves, with their struggling prizes.

Corellas, with their cockatoo head plumes and raucous screeches, followed us from the trees of Exmouth to the cliffs of Yardie and the Cape Range. They’re not the only things sheltering in the little caves worn into the rock faces (more on their other occupants in a later post), but they certainly make an impression. They flash white feathers over ledges and splay their wingtips to impress their companions and warn away hovering birds of prey, and peer down at the boat below with heads cocked.

IMG_2157

A kestrel of some kind, with a tiny bit of snake in her mouth, landed just shy of these two youngsters who were tucked away in an overhang. They shuffled out to peer at us as we peered at them, wide-eyed and wobbly.

IMG_2100

Among the other lovely long-legged locals, this white-faced heron gave us a good show. Best-looking birds, indeed, random old guy. Best-looking birds, indeed.

IMG_2121

Creature Feature

Basically the point of this post is that I think this photo is pretty funny, and I spent a fair bit of time combing through Gerald Allen’s Marine Fishes of Tropical Australia and South-East Asia trying to figure out what this fish was. I also got significantly closer to this one than to the stonefish that I posted about a while back,

IMG_1063

without being quite aware that it, bug eyes and pouty face and all, is listed on the University of Melbourne’s “Australian Venom Research Unit” page, with the description: “It is armed with two pairs of spines – two on its back and two on its sides. Despite its commonness, stings are infrequent and little is known about the effects of envenomation by this species, apart form (sic) the severe local pain experienced by the victim.”

IMG_1050

How reassuring. You’ve done it again, Australia, and hidden a painful surprise within a fringy funny-looking underwater friend. At least this one isn’t deadly, or at least not to humans. Halophryne diemensis (probably) translates roughly to “banded salt-toad,” and like a toad this fish, the banded frogfish springs upon its prey with unexpected speed from a cumbersome head and body, but didn’t seem at all interested in the many divers who passed right overhead.

This post is dedicated to my beloved readers Ben, Camille, and Isabella, who are welcome to choose any topic or question they’d like discussed in a post! Thank you so much to everyone who puts up with my lame jokes and biological ramblings, and especially to everyone who has donated to the Vicky-Has-Internet Fund- all of your support is thoroughly appreciated.

You Won’t See It Coming

About once a week, maybe more, I get an email from someone I know (relatives, friends), with a title something like “340 Things That Will Kill You In Australia Without You Knowing” or “54.3 Ways Australia Secretly Wants You Dead” or “How To Get a Job and Stop Being a Drain on Earth’s Resources” (wait crap that last one is unrelated). Anyways, there are apparently lots of poisonous things that want me dead on this continent, though so far they’ve been reluctant to go on the attack. Anyways, part of what freaks people out about Australia I guess is the number of things that are both poisonous and sneaky.

Enter the wobbegong- this Eucrossorhinus dasypogon is considered harmless (I’ll start you off easy) if unprovoked, but certainly startling to come upon. The Navy Pier at Exmouth (dive currently run by the Ningaloo Whale Shark and Dive Company, very fun crew, very cool dive!) hosted at least two different and fairly large wobbegongs, which was excellent- they’ve been on my list of cool fishes since I was a young Agent Red Squirrel, reading books about marine life under the covers late at night. It’s harmless to divers but looks sort of creepy- those white spots aren’t actually the eyes, though. Look closer:

IMG_1035

 

 

 

But only because you’re a human- if you were a fish, you wouldn’t want to get that close. That wide mouth creates a lot of suction, and technically that fluffy carpet there IS a shark.

More fun facts about the tasseled wobbegong- its fringe is made of skin, and in the other two species of wobbegongs doesn’t go all the way around the chin. That’s why this name (Eucrossorhinus dasypogon) translates to “well-fringed nose with shaggy beard.”

 

All right, now that you’re nice and comfy down there under the pier, keeping a close eye on where the beams and columns are relative to your head but making plenty of time to listen to the humpback whales singing in the distance and look at the schools of silvery fish drifting through the beams of light in the cloudy water, take a look just off to the north:

 IMG_1063

Stonefish, like this Synanceia horrida (see, aren’t Latin names fun?) can kill a grown man with one stab of their venomous and invisible spines. Happily, I’m no grown man and can therefore get a lot closer in… just kidding, Mom. We kept our distance and used the zoom on our cameras, but I was terribly impressed by our dive guide, Wes (who is moving to London and had a touching farewell with another lovely friend under the pier, who I’ll tell you more about later) for spotting this guy in the first place. Even pointed out, photo-enhanced and zoomed in, the fish still looks like nothing much. That was the part of the dive when I was happy that all of my various dive instructors and buddies and wise old advisors had taught me to keep my arms in close, away from stingy and bitey hidden bottom-dwellers.

I love diving- even without my favorite dive buddy, I had a happy and safe (though a bit chilly) time under the man-made and ocean-encrusted pier that we see so often from our transects. Warning to photographers, though- don’t take your favorite camera, even in a fancy and expensive housing, underwater with you unless you’re very cavalier or very insured, as my little old faithful G11 has now probably closed its little lens for the last time. But so it goes. If it could think, I hope it would have enjoyed the quality of light down there under the concrete and coral, and the sleep of electronic death. I hope it dreams of nurse sharks and giant groupers, mantis shrimp and harlequin shrimp and hundreds of nudibranchs. I hope it remembers Nepal and India, Little Cayman, Costa Rica, New Hampshire, and California. And I hope it remembers Australia fondly, less in listicles of violent and painful deaths and more in images of red dirt and teal water.

 

Goodnight from a sleepy Agent Red Squirrel- we’ll be on the boat at 7 am tomorrow, dodging the migrating humpbacks and searching for some more Sousa, as we do. From the boat, I’ll salute my new pier friends below the waves and try not to yawn too much before morning tea. 

Good Signs

The weather this week looks lovely! But that’s not really why I made this awful joke title. Road signs in Australia are really fun- I’m used to deer crossings and on a really good day in New Hampshire, a moose crossing, but for the most part road signs in my area just blend in to the background unless I’m looking for directions or speed limits. Here, though:IMG_1787

Knobble-kneed emus, kangaroos poised to leap in front of cars, blue signs indicating “tourist ways” and “coral viewing.”

I’m sure they aren’t interesting to the people who live here, but I love me a goofy animal silhouette.

IMG_1798

They’re not kidding, though- emus and kangaroos are all over the road en route to our launch sites at Tantabiddi and Bundegi boat ramps. Even better than the signs are the mirrored looks of surprise on the faces of car drivers and passengers and the animals they come across.

 

Why

So the new official species name Sousa sahulensis has supplied me with sibilant alliterative opportunities, but has also changed the nature of the research we’re doing here on the North West Cape. There has been some research done on Indo-Pacific humpback dolphins, but the humpback dolphins that live their lives around the continent of Australia (and maybe Papua New Guinea?) may have less in common with their relatives than we had previously thought.

According to Science News (shame on me for not reading the actual paper yet…), skull morphology and DNA sequencing were used to determine the separation of S. sahulensis from their northern cousins, S. chinensis. Our dolphins cannot cross Wallace’s Line, a deep ocean barrier separating Australia from the rest of the world and, incidentally, explaining in part why Australia and its waters contain so many endemic (local only) species- as the Line formed, these coastal dolphins could no longer cross between the home waters of S. chinensis and the Australian continental shelf. Those on the southern side of the barrier evolved through genetic drift and natural selection such that they are significantly different from the northern side, and have now been recognized as their own unique group. But why does that matter?

Well, first of all Tim has to change all the abbreviations we’ve been using on spreadsheets (Sc to Ss) and the title of his PhD…

DSC_0117

Okay, the real reason why it matters is that, having proven significantly different from their relatives Up Above, S. sahulensis is now virtually unknown. We can’t assume they behave the same, use space in the same way, or require the same resources or protection as S. chinensis, nor can we rely on the larger population size of both species combined to buffer any human-caused losses or stresses. As oil, gas, and mining operations descend upon Australia’s coastal waters, coral reefs begin to feel the impacts of global climate change, and fishing and ocean recreation continue to increase, we need as much knowledge as we can get about these animals. Their impact on coral reefs and surrounding ecosystems could be a key part of healthy seas around Australia, and we don’t even have a good population estimate, nor any indication of whether the population is growing, shrinking, or neither. Tim’s working hard to break open the wealth of information that the North West Cape dolphins have to offer, but they’re elusive and research requires a lot of time and patience.

Much has been written about the importance of coral reefs for economic and environmental reasons, and much has been written about wildlife in general having inherent importance to humanity. I support all those reasons, and can give you pages and pages of arguments on why it’s important to maintain diverse and stable ecosystems of all types. However, I also think simply that we humans, as a species (yes, one global and multiplying species), ought to tread lightly on the world.

Yes, it’s important to understand and preserve the world around us because without diversity we and our world will be more easily overcome by change, because reefs and mangroves and wetlands provide storm shelter and water filtration to human habitations, because icy tundras and redwood forests and tigers and whales and tiny colorful fishes inspire us and make us wonder. But that all presupposes that it’s our right to choose to destroy or save those wonderful things. We approach the world assuming that we can manipulate it at will, but we are just students of systems much larger and more complex than the ones we have created.

DSC_0346