Tuesday, February 28, 2012

Busy, Busy Beavers (and Frog)

I've posted before, about Minthorn Springs Wetland in Milwaukie.  It's a great little wetland habitat, surprisingly close to commercial, light industrial, and residential development along the Milwaukie Expressway (HWY 224, connecting I-205 and HWY 99E).

My office is on the edge of this wetland, so I drive by frequently.   On one recent trip, I looked in to the woods around the wetland as I was driving by, and noticed the bright, exposed wood of fresh beaver chews on several large trees.  One was pretty far along, and I was hoping to get back there with a camera before the tree came down.  Turns out I was too slow.  But I think the one felled tree with the three or four soon-to-be-felled trees actually made for a more interesting picture.


That's the Milwaukie Marketplace shopping center in the background.  Doesn't seem to bother the beavers.  In fact, it looks like they're trying to clear a better view!

I'm always amazed by the size of the wood chips made by the beavers.  They look like something from a commercial chipper.
A Beaver's "To-Do" List

The Wetlands Conservancy manages this area along with the City of Milwaukie.  Someone has protected some of the larger trees with wire fencing, but others have been left to their own defenses. It won't be too long before the trees pictured here give way.

Beaver Teeth Marks in Detail
A beaver's gotta do what a beaver's gotta do!

A beaver's teeth have a high iron content, making them very strong - and orange.  And they never stop growing either, so they don't get worn down.  Pretty handy if you like to chew on wood.

I recently saw a beautifully-filmed documentary about beavers, called Beavers - The Biggest Dam Movie You Ever Saw.  That film had me thinking that beavers were diurnal, because it has lots of great footage of beavers doing their thing in broad daylight.  One website I read said that beavers can be seen during the day (especially early or late), but it said they are mostly nocturnal.  Maybe the beavers in that film just felt safe because their pond was so pristine and remote.  (Or maybe they were paid actors - I don't know.)  Actually, the remote habitat might be precisely the reason those beavers were day-workers.  According to the Oregon Zoo, "beavers are active during the day... but become nocturnal with human encroachment."  I'm guessing the beavers at Minthorn Springs are nocturnal.

Beavers are one of the largest rodents - weighing up to 65 pounds - and they can be found in many places around the Portland Metro area, across Oregon, the Northwest, and beyond.  Beavers, in fact, can be found across most of North America and throughout a large part of Eurasia as well.  Where have you seen them?  Any surprising places around Portland?  (Remember - nutria can do a pretty good beaver impression if you don't get a look at the tail.)

Can you spot the native amphibian in this image?
OK, enough about beavers.

Somewhere in the picture above is a small, native amphibian.  Hint: It jumped out of my way as I was leaving the wetland.

Did you find it?

There it is!  It's Pseudacris regilla, a Pacific Tree Frog! (Or Pacific Chorus Frog.)

Here's a closer (if a bit blurry) look at the little jumper (it's in the upper right portion of the first photo).  I believe it's a Pacific Tree Frog, also known as the Pacific Chorus Frog.  Apparently the species is not technically a tree frog, so Pacific Chorus Frog may be a more accurate name, but it seems like there is some disagreement out there about exactly what to call these native frogs. 

Pseudacris belongs to the genus Hyla.  And according to Wikipedia, because of some geographic-turned-genetic separation, "...the genus Hyla has been split into three separate genera: Aris, Limnaoedus, and Pseudacris. This is where the current confusion has taken place. Although the Pacific Tree Frog has carried the scientific name of Hyla regilla for many years, the most current consensus among scientists is that they should actually be Pseudacris regilla. This is still not agreed upon completely, and in the future we will see what becomes of these names."

When I saw this frog, I wasn't sure what kind it was.  But I had heard about the Pacific Chorus Frog, and thought that might be it.  Looking through pictures of Chorus Frogs online, I couldn't find one with the exact same markings.  Then I learned that, not only can these frogs change color from brown to green, they can actually change between distinctive markings and solid colors.  (Although the dark stripe from the nose, through the eye, and back to the shoulder - which is just visible on the frog's right side in my photo - is a more permanent field mark along with the presence of rounded toepads.)  From what I've read, these color changes are not fast like a chameleon, but slower changes in response to changes in their environment, or to seasonal color changes in their surroundings.  

I wanted to get a closer, clearer picture of this frog, but he jumped down into one of the many sinkholes that dot the dry ground in this wetland.

Minthorn Springs may be small in size, but it never fails to present something interesting.

Read my older post about Minthorn Springs, which includes maps and more info, here.

Thursday, February 23, 2012

Nature Word of the Week: Cere

This week's Nature Word - cere - was pulled from the avian morphology category.

The cere on this Peregrine Falcon is yellow.
Cere is defined in two ways by thefreedictionary.com  (see link for pronunciation):
  • To wrap in or as if in cerecloth (cerecloth being  a type of waxed cloth used for wrapping a corpse)
  •  A fleshy or waxlike membrane at the base of the upper beak in certain birds, such as parrots, through which the nostrils open.
So the cere is as plain as the nose on a bird's beak.  Or at least on "certain birds" which have ceres, such as raptors, owls, skuas, parrots, turkeys and curassows.

The cere can be feathered, but is more commonly bare, and it is often brightly colored.  According to Wikipedia, the cere in raptors "is a sexual signal which indicates the "quality" of a bird".  (Makes you want to look a little more closely at the Raptor Cam, doesn't it?)  Also, the cere can be a good field mark, helpful in distinguishing between the sexes of some species.

The cere should not be confused with the operculum, which is more of a cover for the nares (or nostrils) of some birds.

Thursday, February 9, 2012

Portland's Native Plants Spring to Life

Remember all that sun we had recently?  Wasn't that amazing?  I wonder if we'll feel that kind of warmth on our shoulders again before, I don't know... June?  I sure hope so, because I've got a bad case of Spring Fever!

This past weekend, I tried to soak up as many of those precious rays as I could.  So while millions were watching Superbowl XLVI, I was out puttering around the yard, doing whatever I could find to keep me outside a little longer.  I did some weeding, a little pruning, and some removal of last year's dead growth.  I was somewhat surprised to see just how much some of my native plants had also noticed the warmth.

This is my Indian Plum, or Osoberry (Oemleria cerasiformis).  It's a large native shrub, and one of our earliest bloomers.  An important early nectar source for all those Mason Bees and other native pollinators.

The female plants produce small purple berries that look like tiny plums, but to get the berries, you'll need both a male and a female plant.  I only have one of these right now, and I believe it's a male.  I'm going to be adding two more Indian Plum starts to a reclaimed parking strip this spring, so I'm hoping to end up with fruit for the local birds.

These racemes produce small white flowers that some say smell unpleasant.  I personally think they smell kind of nice and woodsy.

I think it's interesting that the racemes turn so drastically downward after emerging.  Seeing one full of flowers you might think it was the weight that pulled it down, but that's not the case.  They turn downwards almost immediately.  Maybe to make room for the lance shaped leaves to emerge upwards?  Maybe for pollinator access?  I don't know, but there must be a reason.

Because I do think the flowers smell fine, I brought a couple of stems inside and placed them in water, after trimming them away from the house.  Three days later and I have instant Spring!

My Indian Plum has been in the ground for about 3 years, and it's about 10 feet tall right now.  I just trim it gently, after flowering, to keep it away from the house and path.  I've read that you can trim these down to the ground to reclaim an overgrown specimen.

This is a bud just opening on one of my Red-flowering Currants.  One of the showiest blooms in my yard full of native species.

OK - these last two plants are not native species.  Two of the very few non-native plants in my yard.

Sprouting up through the mulch, these Stella D'Oro daylilies look like little green fingers pointing toward the sun in the southern sky.

This last one is a Persian Ironwood tree, Parrotia Persica "Vanessa".  (Also called Vanessa Persian Witchhazel.)

  I chose the Persian Ironwood from Friends of Trees because - although it's not native - established trees, are drought, cold, and insect resistant.  They also have beautiful fall color and these lovely little blood-red flowers.  The flowers remind me of clover flowers in shape and size.

 I wanted to include this photo not only because the tree is blooming, but because the picture shows that amazing blue sky we were enjoying.

Those are the major signs of spring in my yard, what native plants are blooming in your neck of the woods?

I'm looking forward to spring, and to my parking strip planting project.  Hopefully we do get some more of that sun and brilliant blue sky before June, but I shouldn't complain about the clouds and rain.  Without them, Portland and western Oregon wouldn't be so beautiful and green, would they?

Sunday, February 5, 2012

Columbia Gorge-ous Winter Afternoon

I took a quick trip out to the Columbia Gorge on the last weekend in January, to see the falls in their full winter glory (must be all that pluviosity - lots of rain the week before), and to celebrate my mom's birthday.  She chose the destination, and I thought it sounded great.

Multnomah Falls

It was a cold but beautiful, sunny afternoon.  (The north-facing Oregon side of the Gorge doesn't allow much of the winter sun to hit the ground, but still...)

Here's a quick post to share a few pictures.

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Multnomah Falls
There was a lot of water coming over the cliff at Multnomah Falls!  There was even a "bonus fall"off to the right a little bit.

Multnomah Falls
As we drove along the Historic Columbia River Highway to visit some of the other falls, we saw several sort of impromptu falls - streaming down in places that are normally dry.

Most rock surfaces were alive and green because everywhere you looked there was moss...


and more moss!

I love this last moss here.  It's tiny leaves almost look like one of Oregon's native succulents.

 The next fall we stopped at was Wahkeena Falls.  The name Wahkeena comes from a Native American phrase meaning "most beautiful", and I tend to agree.  The way this fall comes from both sides at the top, then twists and tumbles its way down into the gorge is incredibly beautiful.

Wahkeena Falls
 Next up was Latourell Falls.  This is another straight drop, more similar to Multnomah Falls, but it's even more free-hanging than Multnomah.  The water absolutely thunders as it hits the rocks at the bottom, unimpeded by the cliff face. 

Latourell Falls
View East from Crown Point

We came to Crown Point and Vista House as the light was turning orange.

A final look back at Vista House overlooking the Columbia Gorge, taken from the Women's Forum viewpoint.

An excellent day enjoying some of the beautiful scenery very close to Portland.

Happy Birthday, Mom!

Thursday, February 2, 2012

Graham Oaks Nature Park (Part 2): Restoring Oak Woodlands in Wilsonville

In Part 1 of this post, I was taking you along on my first exploration of Graham Oaks Nature Park.

Let's pick up where we left off - on the Legacy Creek Trail as it emerges from the conifer forest, to join the Coyote Way Trail.

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Click image to enlarge

What's that sitting atop that young Ponderosa Pine?  This is as close as I could get with a 300mm lens, and without leaving the trail which would be frowned upon here in the Nature Park, but I believe it's an American Kestrel.  I love these pint-sized predators.

One section of the Coyote Way Trail skirts the mature oak woodlands, where I spotted some of the largest oak galls I've ever seen.

After crossing the northern end of the park, and before turning back to the south on the main Tonquin Trail, I took a short side trip to a small bridge over a marshy area, where I was hearing the sounds of Red-winged blackbirds.  Before I got there, they all flew up to the near-by trees, and I realized it was actually a variety of birds that had been enjoying the shrubby growth along the wetland.  In the shot below, I believe you can see three European Starlings, one male Red-winged Blackbird and a pair of Purple Finches (or House Finches or...? My ID skills and my camera lens are both somewhat lacking in this instance.)

Back to the Tonquin Trail and a little farther south, there's another short side-trail that leads to this artful bird blind overlooking the restored wetland area.

There's an educational flip book...

...and even a key that identifies the birds represented on the screen.  How great is that?

Mallards enjoying the wetland

While I was watching, a flock of Red-winged Blackbirds took flight, circled around, and landed back along the wetland shrubs and grasses.

Turn up the volume on this video clip and listen for the Red-winged Blackbirds.

As the sun was getting low on this gorgeous January day, I came to another side-trail that lead to the Elder Oak.  What a magnificent old tree.  Hopefully this tree will be around for another 150 years and more, to witness the return of this oak savanna and woodland.

I noticed the bright color of this shrub's twigs from a distance along the wetland, but then ran across a section of it right along the Tonquin Trail.

I've done a lot of searching on the intertubes in an attempt to identify the plant.  It reminded me a little bit of Red-osier Dogwood, a plant that I have in my native landscaping, but the twigs are golden-green instead of red.  I thought maybe it was Golden Twig Dogwood, but I think I've ruled that one out.  The closest thing I can find is Lemmon's Willow (Salix lemmonii), but I'm not sure.  One article I read said that Lemmon's Willow grows on the eastern slope of the Cascades.  Anyone have a more definitive ID?  Update: 2/5/12 - I sent an e-mail to someone at Metro's Native Plant Center, and she said that Lemmon's Willow is not used in the Willamette Valley.  The plant would be Piper’s, Scouler’s or Sitka willow.  I had a hard time finding images of any of these plants online, with twigs as golden-green as the ones I saw.  (The twigs on most of these plants turn brown or gray as they age.)  I did find one page that described the twigs of the Sitka Willow as "yellow-green when young", so I think that might be the one.  If I had a spot wet enough to support these, I think they would look great along side some Red-osier Dogwoods.  They could both be trimmed down each year to maintain the color. (End update.)

Getting close to the end of my walk, I happened to see what looked like the traces of a bad dog just off the path (actually I should say bad dog owner - pick-up bags are provided at the park).  I averted my eyes and walked on, but then my brain did a double take and I had to walk back to take a closer look.  Upon closer inspection, the next option that entered my mind was coyote droppings, due to the presence of what appeared to be gray - possibly rodent - fur and tiny bones.  

The closer I looked, the more it seemed like the fur really made up the bulk of this... "object", so then I though it must be an owl pellet that was somewhat deteriorated by the recent rains.

Doing a little research, I learned that owls are not the only birds that regurgitate the indigestible bits of their meals in pellet form.  According to Wikipedia, hawks, eagles and "many other species produce pellets, including grebes, herons, cormorants, gulls, terns, kingfishers, crows, jays, dippers, shrikes, swallows, and most shorebirds."  So judging from the location and the presence of bones, I'm guessing this pellet is from an owl or hawk of some kind.

With the sun setting, it looks like my time is up for now.

Graham Oaks Nature Park is already a great place to visit, and future generations will have a truly wonderful piece of restored habitat to enjoy, thanks to Portland area voters and all the work that Metro has put in to this project.
If you want to learn more about the park and how Metro  supplies all the native plants for their restoration projects, I recommend the four short videos on this Metro page.

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