All About Stellers

On Earth Day was The Whale Museum's annual marine naturalist gear-up, a day-long series of lectures that provides continuing education for working marine naturalists. One of the most informative talks this year was Candian biologist Peter Olesiuk talking about Steller sea lions.

(Note: While Steller sea lions are in fact stellar, their name comes from Georg Wilhelm Steller, a zoologist and explorer who is the namesake for several northwest critters including the Steller's Jay and Steller's Eider in addition to the sea lion. The misspelling of StellAr sea lion is a pet peeve of mine....)

There are two distinct populations of Steller sea lions: a western population that inhabits the Bering Sea and Aleutian Islands, and an eastern population that is found from SE Alaska/British Columbia south to California. While the western population is endangered and has experienced declines of as much as 70%, the eastern population is actually doing quite well, and has rebounded to historic levels after being hunted in the 1940s-1960s in an attempt to "control" fisheries for human purposes.

There are 14 breeding rookeries for the eastern population of Stellers, where males begin congregating in May to establish territories for when the females arrive in June. The animals will stay at the rookeries until August or later before dispersing for the winter. Males will lose up to 450 pounds while defending a breeding territory, a time in which they may stay put up to two months without leaving for food or water. In the San Juan Islands, we pretty much see only male sea lions and only in the winter; they're in this area when they've dispersed from rookeries to "beef up" over the non-breeding season. Females tend to do a lot of oceanic feeding during this time, but locally we have several "bull sites" where we see the males in the winter:

Once such bull site is Race Rocks, west of Victoria, BC. This foggy photo of males hauled out was taken last September.

Steller sea lions weren't seen often in the Salish Sea until the 1960s, when the population began to rebound from the hunting that had decemated it. Since the 1990s, their population has been booming, growing at a rate of more than 7% a year. The current population estimate is 18,250 Steller sea lions in British Columbia alone, compared to the low of 5,000 in the 1960s. Harbor seals have also been experiencing a population boom, and the high abundance of pinnipeds has likely been the reason for increased transient (marine mammal feeding) killer whale sightings in recent years.

A male Steller sea lion requires more than 60 pounds of food a day, or about ten times that of a harbor seal. Their top prey item is Pacific herring, but they also feed substantially on sandlance, salmon, dogfish, polluck, rockfish, and halibut.

Another bull site in BC is the Bell Chain Islets, pictured above in October 2007.

I first heard of Olesiuk due to some of his published work on killer whale population dynamics, although his current work focuses on sea lion population models. He shared the result of an interesting exercise he did determining, based on body mass, mortality, and productivity, how many transient killer whales ("Ts") the current population of Steller sea lions could sustainably support.

Remarkably, he found BC Stellers would only be able to support 26 Ts. If he included the whole eastern population of Stellers, this number jumped to 77 Ts, but still well below the current transient whale population of 200-250 whales. Of course, Ts feed on more than just Stellers - in fact, harbor seals and porpoises probably make up a larger proportion of their diet. To account for some of this, his final calculation included all Pacific northwest sea lions and harbor seals, which the model estimated would support about 300 Ts, closer to what we actually see. This little exercise is really interesting because it demostrates that a relatively small number of whales could have a huge impact on Steller sea lion populations, even if the population seems to be doing very well. As an undergrad, I got really into this sort of thing in my population biology class, where as an independent project I used Olesiuk's models to develop a population model for the Southern Resident killer whales.

Both Steller and California sea lions brave the harsh wave action at the Sea Lion Caves near Florence, Oregon, as shown here in January 2008. While most of the Steller breeding sites are in southeast Alaska and BC, there are a few in Oregon and northern California. Interestingly enough, there are no breeding sites in Washington.

Lime Kiln Sunset

Yesterday late in the evening it was so nice I just had to get outside. I decided to go out to Lime Kiln State Park on the west side of the island to watch the sunset. For the first time this year the breeze off the water didn't have a bite to its chilliness; it felt almost warm. I took "the long way" to the lighthouse which took me along this path through a grove of Pacific madrone trees:

I was the only one in the park - a sure sign that the tourist season hasn't hit us in full yet - but I certainly didn't mind the solitude. I found a place to settle in for a while and here was my view to the southwest:

The beautifully warm spring weather of the last few days wasn't going to stay with us for very long, as evidenced by the clouds brooding on the horizon and over Lime Kiln Lighthouse:

Still, the sun broke through the clouds enough for me to have some photographic fun, like making it shine through the light of the lighthouse:

Here was my view looking across Haro Strait towards the southern tip of Vancouver Island and the Olympic Mountains. The tranquility was only broken when a Steller sea lion popped his head up for a few noisy breaths on his travels north in the straight, but I didn't mind the interruption.

Speaking of Steller sea lions, today at The Whale Museum's marine naturalist gear-up we learned a lot about sea lions from Canadian scientist Peter Olesiuk. I'll post some cool info from today's series of lectures in my next post.

Yellow Island Wildflowers

This morning we went on a trip to Yellow Island sponsored by the San Juan Nature Institute. We took a short boat ride from Friday Harbor up San Juan Channel to the 11 acre island, which a reserve owned by The Nature Conservancy. It's open to the public from 10-4 daily, and I see the island on a lot of our summer whale-watching trips. But I had never set foot on it before, so was excited to finally get ashore to explore! Here's the island on our approach:

There's a small cabin built on the island where the docent family lives. It's got to be an awesome job! The cabin is built out of driftwood and other materials gathered on the island and was constructed in 1947 by the family that originally owned the island. The cabin isn't the structure right on the beach, but is tucked above under the madrone trees just to the left above that:

I thought it might be a little early for the wildflower peak, but according to the docent it turns out the first of three "peaks" of the spring is late and is happening now, so our timing turned out to be great. Our short hour on the island was long enough for the botanists who came with us to point out more than twenty plant and flower species. Here are some highlights:

Most of the common camas (above) weren't in bloom yet, but a few were. They're a well-known plant locally because of their history of being used by the native Coast Salish people. Yellow Island was one of a few small islands that were managed via controlled fires by the Coast Salish. Fires kept brush and trees from encroaching on the island, so they could come and harvest wild plants like camas every year. Camas bulbs were harvested and cooked, and reportedly taste something like sweet potatoes. They still do annual controlled burns to maintain the local habitat, which is home to more than 50 wildflower species in all.

The small-flowered prairie star (above) was one of two members of the saxifrage family we saw.

Harsh paintbrush was a bright red addition to the landscape. The botanist said it's parastic to the grasses around it.

Finally, here are two lily species: chocolate lily (above) and white fawn lily (below). Fawn lilies were probably the most abundant wildflowers, along with western buttercup. There were several fields of the two species, and the botanist said she had never seen so many fawn lilies in one place. Here's a close-up of one:

COASST Training

Today I attended a Coastal Observation And Seabird Survey Team (COASST) training here in Friday Harbor. COASST is a citizen science program run through the University of Washington that trains volunteers from Alaska to California to monitor beaches, especially by identifying beached sea birds. Sea birds are a numerous group of species, they are widespread, and span a variety of trophic levels, making their survival or death a great indicator of overall oceanic health.

It turns out identifying beached birds is much different than identifying live ones. For starters, the bird is often damaged or beat-up, either by predators, scavengers, weather, surf, or otherwise. You won't often find neat, clean plumages, or even a body fully intact. On the other hand, the bird will stay put for you and allow you to examine it closely, allowing you to approach identification in a completely different way.

We learned how to use the COASST field guide to beached birds, which focuses on very different elements than a traditional bird field guide. The easiest characteristic to narrow down the type of bird you're looking at is foot type - either free, lobed, or webbed - and each category has its associated subcategories that can easily guide you to the bird family you're looking at. You can further use three measurements we were taught to make - bill length, wing chord, and tarsus (ankle bone) - to figure out which species you're looking at.

We practiced our ID and measuring skills on several specimens in the classroom. I'm not normally fond of handling deceased animals but it really is amazing what you can learn about seabirds up close that you would never be able to observe in the wild. For instance, cormorant feathers are shaped so that each individual feather appears to be outlined, all members of the puffin family have a pale leading edge to their wing, and some groups of birds have amazingly shaped "outercut" primaries that look very different from typical feathers when you examine them up close.

This rhinoceros auklet clearly isn't interested in letting me measure its tarsus.

As a result of my training I've signed up to be a COASST volunteer which involves surveying a local beach once a month. Unfortunately (or fortunately, I suppose) there aren't nearly as many birds reported here in the island as they get on the outer coast (but I wanted to use my new skills!). While some outer coast survey teams encounter dozens of birds every trip, only three San Juan surveys out of 219 recorded beached birds in 2006-2007. I asked about why this is and our instructor believes there are several reasons for the decreased number of beached birds here: calmer more protected waters, so there are fewer waves to wash birds up; smaller "catcher" beaches that are likely to be the final resting places of birds that have died (there are very few long sandy beaches here); and steeper drop-offs off our beaches which also affects the likelikhood of things washing up on shore.

In any case, I'll be starting my surveys this week and will definitely report any interesting things I find - bird or otherwise!

Springtime on the Prairie

Today I went down to the south end of the island to enjoy the sunny (but still a bit chilly) weather and see how spring is progessing. You may think I've forgotten about the red-tailed hawk pairs, but I haven't! They've just been very scarce and I haven't seen much of them when I've gone looking. Today, I did run into Garth RTH1 and shot a few shots of him perched using my car as a blind. Then when we took off I got this surprising shot:

Garth is demonstrating a key component of bird flight: the wing flip. To successfully take off the ground (and it helps from a perch, too), birds must be able to raise their wings above the level of their back in what is called a wing flip. To accomplish this, substantial changes in skeletal and muscular structure were necessary, and as such the ability to execute a wing flip is an important feature in the study of the evolution of bird flight. I loved studying all this in another college class I took on avian/dinosaur evolution.

I went for a walk down at American Camp and evidence of spring was everywhere. White-crowned and savannah sparrows were singing, garter snakes were slithering through the tall grasses, and more than half a dozen wildflower species were in bloom. I also saw male northern harrier - I've seen female and juvenile harriers while watching the red-tailed hawks this winter, but this was the first male harrier I've seen all year!

I've noticed lots and lots of yellow pollen cones on the conifer trees lately, which are no doubt the cause of a lot of my recent hay fever. Actually, the cones themselves are reddish brown but are so dusted in pollen they appear yellow. There is so much pollen around that every day I find a new layer dusting the windows on my car and blowing around on the street. But I hadn't ever seen anything like open red cones on the photo above. My tree ID isn't up to snuff and I'm not sure what the reddish looking "cones" are...."blossoming" pollen cones?

Here are examples of some of the wildflowers in bloom. Above is the European daisy, and below is the early blue violet.


This one is the coastal strawberry:

Poet's Shooting Star

My favorite wildflower is in bloom on San Juan Island. I first discovered this species in my vascular plant diversity class at Reed College, and I first saw it on a field trip in the Columbia River Gorge and learned it was called Poet's Shooting Star. A member of the genus Dodecatheon, it is also known as American Cowslip, Mosquito Bills, Mad Violets, and Sailor Caps.

Happy Easter! Or Should I Say Happy Eostre?

Easter Bunny sighting? No, a brown hare at Sacremento National Wildlife Refuge.

Easter is a holiday I've never really understood. While I've always enjoyed chocolate candies and jellybeans on Easter Sunday, what do bunnies and eggs and candy have to do with the Christian celebration of the resurrection of Christ? Yesterday I decided to find out by doing a little internet research. While there's controversy surrounding the history of Easter, this seems to be the prevailing story.

Early Christians, seeking widespread acceptance of their new religion, tried to coincide many of their holidays with preexisting pagan celebrations. As a result, many pagan traditions became adopted as part of Christian holidays. The Christian timing of the rise of Christ happened to coincide with the pagan festivals of Eostur-monath, a month of the Germanic calendar which roughly coincides with April that was meant to celebrate the mother goddess Eostre, a symbol of fertility in the lush season of spring. The word eventually became Eastre, and then Easter.

Rabbits/hares and eggs are ancient symbols associated with fertility, eggs by their very nature and rabbits by their springtime abundance and ability to breed. These symbols have long been incorporated into traditions to celebrate the renewal that is the coming of spring, including being part of celebrations of Eostre. Another example is of egg decorating being part of a Persian ritual associated with the spring equinox. Easter was also about renewal to the Christians, through the resurrection of Christ, so all the symbols eventually became associated.

European folklore tells stories about egg-laying hares, a myth that probably gave rise to the Easter Bunny, another concept of Germanic origin in the 1600s (though European tradition states the Easter Bunny is a hare, not a rabbit). Hares raise their young in a hollow in the ground rather than a burrow, and plovers and lapwings lay eggs in similar looking structures in the same sort of habitat, which likely led to the belief that rabbits might lay eggs.

The early concept of the Easter Bunny was that children would make a nest hidden in their house, and if they were good then in the morning it would be filled with colored eggs, candy and treats. It's not hard to see how that tradition became the Easter egg hunt.

So the result of all this religious and secular history is a holiday that is a mishmash of symbols and traditions. At least now I know why we get to eat chocolate and decorate eggs on Easter.