Sunday, January 6, 2008

An introduction to Union Bay Natural Area: Turtles

Seattle is the emerald city. Still the greenest city I have seen anywhere, with many parks and green spaces throughout. Surprisingly, wildlife abounds in the city. Crows, owls, eagles, coyotes, raccoons and many other creatures are common through out the city and its many neighborhoods.

One area of Seattle I have had the pleasure of getting to know more intimately is the Union Bay Natural Area. Despite its diminutive size (~50 acres) and the fact that it is a restored wetland on top of a landfill, it is still a wildlife gem. It even shows up in Wikipedia! There is a wealth of species that occur here, some more numerous here than anywhere else in all of Lake Washington. Turtles, for instance, are very numerous and most visible on warm spring or summer days.

As with many urban or near-urban natural areas, Union Bay is a melting pot of native and non-native vegetable and animal species. It is debatable as to whether any of the turtles living in the natural area are native. The most numerous species by far is the red-eared slider (Trachemys scripta elegans).

This tiny individual was surprisingly trusting. It allowed very close approach by inflatable raft. This is about the size they are sold at pet shops throughout the country. Notice the reddish marking directly behind the eye. The beautifully clear patterns on its shell are a sign of its youth. Many members of this species grow much darker with age, their markings become less distinct. A few are known to become darker still, becoming nearly completely melanistic such as the one below.

These turtles are hardy, can tolerate relatively cool temperatures and if it gets too cold for them, they will dig down into the mud and go into hibernation awaiting warmer days. Surprisingly though, I have seen a few of them out on winter days, when the air temperature was around 48 and it was mostly sunny.

There is one species of turtle common to Union Bay that is actually native to Washington (mainly East of the Cascades), and that is the western painted turtle (Chrysemys picta bellii). A close relative of the red-eared slider, it lacks the red marking behind the eye. It also has a gorgeously patterned red plastron (underside of shell). During one of my many visits to the natural area, I found a female painted turtle that had crawled a considerable distance inland and was busy digging a hole on the side of the gravel trail for her eggs.
Amazingly, turtles go into a trance-like state of intense concentration when they are nesting. I am uncertain what benefit of this behavior is, though it no doubt serves an important function. It also allows for incredible close approach. The photo above was taken literally standing right over the turtle, which continued digging totally undisturbed. The shot at the very beginning of this post is a close-up of the same turtle's face.

Though there are likely more species of turtles introduced into the lake, I only want to mention one more here. This one came as a complete surprise to me as I had not heard anyone describe, not even the professors at Univeristy of Washington seemed to have known about them. One day during a slow paddle through the lily-pad choked wetland channels I spotted a very unusual animal sunning on a log. It appeared to be a giant turtle, with a gleaming shell... only the shell was more like a pancake on top of a turtle-shaped animal. My trusty National Audubon Field Guide to Reptiles and Amphibians helped me to figure it out: spiny softshell turtle (Apalone spinifera). Unlike the other turtles in the area, this one had a soft, leathery shell. This first animal was extremely wary and dove when I was still many meter away. It was several weeks before another one showed itself. Eventually, with a lot of patience and prayer, I got much closer to these mystery animals.

Though the first animal I saw was very large, the first turtle of this kind that let me get close was much smaller. I later learned it was an adult male of the species. It was the female that was much, much larger. The male in this shot has a shell of about 7 inches in total length. You can clearly make out the snorkel-like nose of this species which it can poke out of the water without expose any other part of its head.

The females grow to a shell length of around 19-20 inches in length. Add to that a large head and neck and they can be over 2 feet in total length! Though I can't say I ever got any exact measurements on the giant females I got close to, my estimates were at least 18 inches in shell length for the largest one I saw and photographed (she appears below).
Seeing such large reptiles makes me think of something from the ancient times, when giant creatures ruled the earth! These great turtles are one of the top predators of the Union Bay Natural Area, along with the great blue herons, bald eagles, otters and coyotes.

It is uncertain what effect the introduced turtles have on the native ecosystem of Lake Washington. The lake has been so altered by the hands of modern human beings that it is very difficult to even imagine what the native biological system may have looked like. Invasive species are a hotly debated topic and I have learned so much about them from spending time at Union Bay. I will share more on that topic specifically sometime later.

Friday, January 4, 2008

My mate, the doorstop...

A short story to share from a trip to California...

During a short hike in the Santa Ana mountains, my wife and I spotted an odd shaped object just on the side of the dirt trail. Upon close inspection, we discovered in was the body of a dead tarantula. It had been there for some time and was but a mere husk, as you can see above.

The humorous part of it was that initially when we discovered the body, it had its legs up towards the sky. Upon flipping it over we saw that it was plugging a hole. The home of another tarantula. The abdomen of the spider's body had been punctured and it was dried out like a raisin.

It appears that at some point during this male spiders life - most likely during the breeding season - it came by the burrow of a female tarantula. Unfortunately for him, she was not in an amorous mood. Instead, he became her meal! And after that, she thought he would make a nice doorstop as well!

Catchin' frogs

Winter naturally seems to bring us into an introspective state. I have definitely been in that place lately, and so it is no surprise that it influences my writings here. My thoughts have wandered to memories... many memories of fond times getting close to wildlife. Specifically, the times since I was a boy seeking and catching small critters, like frogs and snakes.

It is difficult to express the simple pleasure of seeking out the so called creepy-crawly things. Most of the best naturalists I know or have heard of spent at least some part of their childhood doing just that.

I feel so thankful for the little creatures such as : frogs, toads, snakes, turtles, and invertebrates of all kinds. It is one thing to see a photo of them, or even see them in a cage, but there is a magic in chasing after them in the wild. Getting our hands muddy trying to grab that squirmy, wet bullfrog as it kicks and jumps to get away. Chasing after them through wetlands or slogging along the edge of a pond. Grabbing them requires swiftness, but also great care and gentleness. So many lessons to learn from just the simple act of "catchin' frogs."

Than there are those little creatures that take more practice and patience. For instance, trying to capture a turtle is very challenging. I have had very few opportunities to even try. One time while on a Wilderness Awareness School trip to eastern Washington I was presented with the chance to stalk up on some wild western painted turtles. For any of you out there who have ever tried to sneak up on a turtle, you know just how wary they are. In most places if you get within 10 or 15 meters of a turtle sunning on a log, it will dive and disappear in no time at all.

That's exactly what happened at the crystal clear lake were I stalked them. Taking a lesson from the incredibly patient great blue heron, I sat poise in one place on the turtles' favorite sunning log for a very long time. At least 30 minutes passed before the turtles swam within even a few meters of the log. They spotted any small movements from me and were quick to dive again. Many of them disappeared all together for the time I was on or around the log that day. A few ventured to come near. Eventually I learned to sit very still with my hand very near the water, and after nearly 2 hours of waiting I caught one.

It was one of the smallest and youngest turtles in the lake that I observed. Still, it demanded ever bit of my patience and pushed my skills to the limit to capture it.

What wonder and joy the little things can bring us?!

Wednesday, January 2, 2008

Why is it that most people don't generally see wildlife...

Well, one reason might be that animals general work at not being seeing for a significant portion of their daily lives.

In the case of this California tree frog, it spends most of the year sitting very still on a rock face overhanging a ephemeral stream. It tucks its legs under its body to help reduce its surface area to a minimum, therefore helps it to cut water loss. For an amphibian, that means life and death! Sitting very still and blending in with its particular nook in the rock is equally important. To the casual eye, it could easily pass as a patch of lichen in the photo above....

Mammals too need to be know how to hide, especially small mammals that others might see as tasty. Rabbits are seen by many animals as food, and they are very good at disappearing.

This one hopped into the thin cover of these dead plants as I round the bend of a trail. Spotted it only in my peripheral vision. I walked within a few feet of it and it didn't budge. Like many rabbits, this desert cottontail uses camouflage first... and running away only once it has been spotted.

The larger black-tailed jackrabbit is more likely to bolt. Though it will also seek cover if it feels it has not been spotted or feels undisturbed by the observer. See if you can spot the the jackrabbit?

So what about much larger mammals? An animal the size of an elk should be easy to spot where it lives, right? Especially if this particular animal is out in open country. So, can you see it? There is a HUGE bull elk somewhere in this photo... but where?

It chose to settle on the hillside in a spot where it was at least partially hidden, and yet could look out over the surrounding country.

And birds...?

Yep, most of them do this as well. Especially the small birds, like the plentiful LBJ's (Little Brown Jobs). See the sparrows in this shot? How many are there?

Like many small birds, these 2 golden-crowned sparrows are a combination of different shade of browns and grays. At the approach of a predator - especially of people - they are quick to fly into the cover of nearby shrubs. They have to be alert... never know where those sharp-shinned hawks might be hiding!

So what other ways do animals make themselves so hard for us to spot?