Pollinator Study

Wednesday, September 24, 2014

River Otters Feast on Salmon at Capitol Lake

By Nancy Partlow 

Text in Red Bold is a clickable link to video.

A family of river otters has been putting on quite a show at Capitol Lake recently.  They've been catching and eating Chinook salmon in full view of the public. 


Janet’s friend Cynthia told her she’d seen a mother otter and three pups chomping on salmon near the train trestle at Marathon Park.  We decided we  had to check it out.  Unfortunately, when we got there, no otters could be seen. 

So the next day, on a hunch, I decided to peruse the area along the lake near the 5th Avenue dam.  A few years ago we had seen otters in this vicinity in late November.   Sure enough, as I walked along the lakeshore, through the shrubbery I spied two otters slither off a log and move out into the lake.  As I entered Heritage Park, out in the middle of the north basin, five heads were just discernible poking above the water.


I began to film them.  So intently was I watching three otters masticating salmon that I only slowly became aware of people nearby saying things like, “Oh, look, it’s got a salmon head!”  Turning around, I was very surprised to see a mother otter and her pup on a log in the water about 15 feet away.  The mother had a salmon head she was biting into with obvious relish.  The look on the face of the salmon was one of astonishment with perhaps a touch of, “I came so far, was so near my goal, and then this!”

 
The Chinook salmon in the lake are following the fresh-water scents of their natal streams, the Deschutes River and Percival Creek, to their long journey’s end.  But for some, the odyssey terminates just short of "home".  For years, we have watched harbor seals corral and devour salmon on the north side of the 5th Avenue dam, which forms a bottleneck and gauntlet through which the salmon must pass before entering the lake.  It never occurred to us that the waters on other side of the dam could also be a kill zone.  For one thing, we didn’t think that river otters could catch and dispatch something as large as a king salmon, which may be as big, (or bigger), than the otter itself.  But according the WA Department of Fish and Wildlife’s page on river otters, they do eat salmon, among many other prey items:

River otters are opportunists, eating a wide variety of food items, but mostly fish. River otters usually feed on 4- to 6-inch long, slowly moving fish species, such as carp, mud minnows, stickle backs, and suckers. However, otters actively seek out spawning salmon and will travel far to take advantage of a salmon run. 

River otters can smell concentrations of fish in upstream ponds that drain into small, slow moving creeks, and will follow the smell to its origin, even in urban areas.
River otters also eat freshwater mussels, crabs, crayfish, amphibians, large aquatic beetles, birds (primarily injured or molting ducks and geese), bird eggs, fish eggs, and small mammals (muskrats, mice, young beavers).

Salmon heads must be a particular delicacy, because the mother otter didn’t want to share it with her pup.  In surveying the whole scene, I surmised that perhaps the mother had killed the salmon, bit off the head, then left the kids (most of them, anyway) out in the middle of lake to eat the body while she came near shore to nosh on the best part in relative peace.

The two otters on the log seemed not at all perturbed by the small group of humans watching them from a few feet away on the bulkhead.


A couple of folks thought the otters might be nutria, which are an invasive species in the lake.  But nutrias are vegetarians.  One woman said, “What a blessing!”, about being able to watch the mother and pup so close-up. Another man related a story of how, many years ago in front of Genoa’s restaurant (now the Hearthfire), he had seen two otters mating very loudly.

According to WA DFW, “River otters digest and metabolize food so quickly that food passes through their intestines within an hour.”  This could explain why, when I returned a few hours later, the otters were still hunting and eating, with  four otters now on the half-submerged log.


I couldn’t tell whether the mother was among them, although one was again eating a fish head. Three of the otters were playing and nuzzling each other. 


When the trio swam off together, the fish eater didn’t want to follow, only reluctantly diving into the water with the salmon head in tow.  Later, as the day moved toward sunset, Janet told me she saw the whole family swimming toward the railroad trestle. 

I had heard an intriguing rumor that river otters had been seen in the fish ladders at Tumwater Falls Park, so I decided to stop by the park on my way home.  I spoke with a DWF employee there, asking if he had seen otters in the fish ladders.  He said he hadn't.   

He did say though, that in the spring when the fish tanks are full of small salmon ready to be released into the river, young otters enter the tanks and eat many of them.  They've tried to block the otters from getting in, but the clever mustelids end up climbing over the chain link fences.

As it turns out, the story about the fish ladders was partially true.  It was referring to the fish ladders at the 5th Avenue dam. Not surprisingly, otters move with ease back and forth through the open dam to access both the fresh and salt waters of the lower Budd Inlet.  That is why the otters are frequently seen at the West Bay lagoon and elsewhere along the Olympia waterfront.

Now that the rains have returned in earnest, opportunities for watching the salmon-eating otters may decrease. A slug of fresh rainwater flowing into the Deschutes River and Percival Creek systems could trigger the salmon to make a final rush to their ultimate objectives.  Such is the cycle of life.  We here at the end of the Salish Sea are indeed blessed to be part of it.


All words, photos and videos by Nancy Partlow ©

Additional video:


Other Resources:

WA Dept. of Fish and Wildlife page on river otters:

http://wdfw.wa.gov/living/river_otters.html

Sunday, September 21, 2014

Bee Imposters

     So our intrepid photographer Nancy Partlow sent us these photos and a story.  She  was out in her garden one day watching the pollinator animals,  She was looking at the fall asters when she saw this insect.  Nancy immediately got nervous and quickly put some distance between herself and the bug:  this is of course of a yellow jacket wasp, right?   Nancy and I both have had a childhood horror of these hornets, which is pretty ironic considering that now fifty years later we plant gardens which attract them.  But even today one or the other of us will call in early spring and in a voice of doom report:  “They’re baaaaaack….”   The first fat yellow jacket queen of the year can still give us the chills.  So it was very reasonable to me that Nancy would very quickly back off of this wasp.  Except…..it’s not a wasp.

     Nancy has become an acute observer of nature, and she noticed something weird about this so-called wasp.  Yellow jackets make a low ominous droning hum as they explore their territory: that sound strikes terror in the hearts of children.  But this insect had an annoying high pitched buzzing.  Nancy said it was like the difference between a B47 and an ultralight.  
     The other thing she noticed was that it was pretty nervous and twitchy.  Now yellow jackets are a top insect predator and they behave like they own the neighborhood.  If you’ve ever tried to shoo one off of your picnic food, you know how persistent and unflappable they can be.  This insect was very flighty and Nancy had a hard time getting close enough to get these pictures.  That struck Nancy as pretty strange, too.

     So the next picture she got really tells the tale:  look at those huge alien compound eyes:  no wasp has eyes like that.  Look too at the short knobs of antenna: these are very unlike the antenna of wasps.   And those thick hairy legs are much more typical of another insect.  What we have here is a FLY, pretending to be a wasp.  By putting on the coloration of a yellow jacket, other predatory insects will think twice about trying to eat it.  This is what is known as a bee mimic. 
   
  It’s a great trick. 



Janet

Resources:  
• photos by Nancy Partlow
• This fly is probably Spilomyia citima
Megan Asche has a great blog with other photos of this insect.  Check her out at: 
• Bug Guide is a great ID resource:  http://bugguide.net/node/view/15740

     

Wednesday, September 17, 2014

Bumblebee Poster

We have created a poster of Bumblebees of Thurston County, Washington.  Four of the best BBee photos of each species, two each male and female, that Nancy has taken over the past few years make up the poster.  This poster is very regionally biased and may not match bees seen in other areas. Folk in other regions are encouraged to do something similar.  It has been a mostly enjoyable effort putting the photos into a poster, and small compared to the time spent by Nancy in the field.

The poster is now a feature of our Bumblebees page, along with some other information.


Omitted are common names.  There are common names out there, but they can be confusing in a different way and we generally either adopt our own or abbreviate the scientific name, like "Vos" for Bombus vosnesenskii.  

Bumblebee i.d. is not always easy nor certain.  The only certainty is that the more one watches the more one sees.  
Here are some hints on telling gender.   
Males are different in appearance and habit in several ways.   
1) Pollen basket.  If the bumblebee has a blob of pollen on the hind leg, the bee is female.  Even if not laden with pollen, the female hind femur is wider.  The males may have pollen on his body, but it is haphazard.   
2) Flower habits.  Males spend much more time drinking nectar and less time gathering pollen -- only enough to feed themselves.  Some flowers may draw mostly male bees, because they only produce nectar, or mostly female because they mostly produce pollen.  Some flowers draw everyone.   
3) Timing.  Males show up at the end of a nest cycle, never in early spring.  First a few queens show up preparing the new nest, then the female workers, then the males and the new queens.   
4) Appearance.  Males have longer antenna and a longer body, an extra segment each.  They typically have more yellow, although it may be a little or a lot more depending on the species.   
5) Sting.  Only females can sting, (and they can sting more than once, the stinger is unbarbed).  If you are very confident, you can test gender by hand-collecting a male.  If you get stung it was not a male.

Nancy Partlow photo credit
 B. californicus (fervidus) female
Nancy Partlow photo credit
 Bombus californicus (fervidus) male

Nancy Partlow photo credit
 B. vosnesensikii male
Janet Partlow, photo credit
 B. vosnesenskii female

Now as we head into fall, field study slows hugely with most bumblebees closing camp and dying or (if new queens) headed to ground until spring.  Mid-September and we have seen a few fat new queen vos, laden with fluids and calories, and a few workers of a couple of tenacious fall species are still out there.  In the meantime, over the next few months we will sort through photos and observations and work on both this and other pages about our native pollinators.

Glen

Additional resources

Bumble Bees of North America,  Paul Williams et al, 2014

Bumblebees of the Western United States,  Jonathon Koch et al, 2012 (PDF available)

Xerces Society bumblebee i.d.  http://www.xerces.org/bumble-bee-identification/
Xerces Society, bumblebeewatch.org



Monday, September 8, 2014

The Language of Chickadees

We woke this morning to heavy rain, the first wet pounder after several weeks of hot & dry weather.  Native to the wet side of the Pacific Northwest, we find this a source of rejoicing.

Chestnut-backed Chickadee
So does the world outside of our windows.  As I sit snuggled up in a warm fleece blankie, a small flock of chickadees shows up in the big picture window.  One works its way through the rhododendron beneath the window, picking off scale insects.  Another is using its tiny beak to glean out minute insects from between the shreds of moss that coats the branches.  As I look out the window beyond the rhododendron, I see several chickadees, working almost as a team, methodically providing insect removal service to our yard.  The yard is full of chick chick chick contact calls, as they keep in touch with each other.  The wet conditions deter them not at all.

We have a long relationship with chickadees.  For many years we had a tube feeder stuffed full of their favorite black oil sunflower seeds.  We kept it going year around, and the chickadees were very aware of this.  And on some level, they seemed to recognize us as their neighbors. They seemed to know we lived in the house and that we were no big threat. They also seemed to know that the tall lanky human guy was the one to refill the feeder. Over time they trained us to take care of them.  Here is an example:

In winter, chickadees take their time getting up.  I remember many weekend mornings while we were still in bed, hearing the small local flock of chickadees moving slowly alongside the wall outside our bedroom window.  They were working through the native yew and rhododendrons, quiet sleepy chick chick noises marking their progress.  We knew that their ultimate goal was the front yard, where the tube feeder of sunflower seeds sat.  This was a reliable source of breakfast food.

Every once in a while, the tall lanky guy neglected to fill the feeder.  When the chickadees rounded the corner of the house and discovered this serious betrayal, the sleepy contact noises burst into loud, imperative CHICKa dee  CHICKa dee CHICKa dee as they registered their deep unhappiness with this state of affairs.  But through the course of many years together, we had learned their language. That call was enough to get the lanky guy out of bed, into enough clothes to venture outdoors, where he filled the feeder.  The complaints then stopped, forthwith.

I remember one spring I was laid up with a bad knee, awaiting joint replacement surgery.  I spent a lot of time sitting around that spring, waiting for the operation that would give me relief and make me mobile again.  During that spring we put up a chickadee nest box on the front of the house, near our rarely used front door.  Our invitation was promptly accepted by a pair of Chestnut-backed Chickadees, though they had to put a vigorous fight with others of their kind in order to “win” the box.

These chickadees entertained me during that long period of waiting.  I watched them ferry in beaks full of shredded moss to line their nest.  They were pretty sneaky about it:  they would fly into a nearby bush, moss hanging every which way out of their beaks.  They would lurk and look carefully around, very wary, before finally making a mad dash into the depths of the nesting box.  This went on for a few days and finally the nest was done.  From the outside, it appeared to be deserted, but looks were deceiving.  One of the pair was sitting in the box, quietly incubating a clutch of eggs.  The male often found a hidden perch high in a tree nearby.  He would sing a distinctive, mournful DEEE, Deee, dee, a series of notes in a minor, descending scale:  this is the distinct call of breeding chickadees.  As he sang (incessantly) and she sat, the eggs finally hatched and after a few days we would hear tiny peeps as the adults took turns, flying in to stuff their begging maws.

The nesting chickadees seem to get to know us and also knew the usual pattern of visitors to the yard.  For example, the postman always delivered to the wall slot just under the chickadee box.  The birds were not thrilled about his daily incursions but they accepted it with a quiet alarm call.  This call was distinctive: from inside the house I recognized it and would get up and check the mailbox.  They were always right.

They were more unhappy about cat visitors.  Our next door neighbor had a young hunting cat who regularly prowled the yard and killed birds.  The chickadees knew this cat and whenever it appeared, they would let loose a loud volley of Chick a DEE chick a DEE chick a DEE!!  When I heard that call, I knew to get up and chase off the cat.  After a couple of times, the chickadees knew I was available to provide this service and I believe they came to rely on me.  Who was training who, anyway?

While the cat was a serious threat, we had put the nesting box high up on a wall where it was out of the reach of cats, so there was no real risk.  However, the biggest threat to the young nestlings was Stellar’s Jays:  these are large birds who regularly prey on other birds’ eggs and nestlings; they of course fly and can reach into the nest box,  and the chickadee parents are very aware of this.  When the Stellar jay flocks made their circuit through the yard, the chickadees would sound their own version of screaming chickadee hysterics: CHICKA DEE DEEE DEEE CHICKA DEE DEEE DEEEE!!!!!!.  I heard that shrieking and jumped from my chair, chasing off the jays and once again earning my keep in the eyes of the chickadees.

Over that spring, I learned the different calls and was able to predict what the problem was even before I opened the door.  Sometimes I got a mixed message: one day I looked out the window saw Stellar’s Jays, but the call from the chickadees signaled a cat.  I opened out the door and watched the jays attacking the cat, who was attempting to hunt for one of their nestlings.  Jays have seriously long sharp beaks and the flocks they live in are only too happy to go after prowling cats.  As I looked out, it was clear to me that all of us: jays, chickadees and me were really enjoying the sight of the overfed cat put to scrambling, panicked flight.

After a few weeks, the hatchlings fledged and the nest box was empty once again.  But throughout the year, the chickadees continued to glean in our yard, to come to the feeder, speaking their own language and allowing us a window into their lives.  It remains one of my favorite memories as a bird watcher.

Janet Partlow
     ------------------
Resources:
•  Photos by Nancy Partlow
•  Short YouTube by Nancy Partlow:  Chickadees at a nest box  (Mason bees in foreground)
•  The Black-capped Chickadee by Susan Smith.  A wonderful book on the lives of these birds.