December 14, 2007

Bohemian Waxwings

Filed under: birds — matt goff @ 10:37 pm

Bohemian Waxwing (Bombycilla garrulus)

Rowan and I were riding down Biorka Street and approaching the intersection with Park Street when I heard a chirring call that sounded familiar. It took me a moment to locate the birds crossing the street above and in front of me to land in the top of a spruce tree. The light and angle were poor for a good look at the birds, and I had decided not to bring my binoculars and camera (which I typically take all the time), so I was not absolutely sure they were waxwings at first. Still, the call of waxwings is pretty distinctive, so I was pretty confident. Over Rowan’s mild protestations I waited for a few minutes to see if they would fly to a nearby Mountain Ash tree where I could get a better look at them and confirm their identity. Finally they did cross the Park Street to a Mountain Ash tree with many berries still remaining on it. There was also a Raven in the tree eating berries, and they seemed a little bit wary. They did not stay long before flying again to the top of a tall alder tree. By this point Rowan was becoming more insistent, and I did not have my camera or binoculars anyway, so I decided we should probably just go home.

I thought Connor might be interested in looking for birds after school today, so I picked him up from school. After a stop by Swan Lake, we walked down Degroff and crossed over to Park Street. At the corner of Park and Biorka, I started hearing the waxwings. A few flew up from the corner Mt. Ash to join others at the top of a tall alder just down the street. Connor and I sat down at the edge of the road to see if they would come back. After a few minutes of waiting, first a couple, then a few more, and finally the whole flock of about 20 birds flew over to the Mountain Ash tree and started eating berries. They did not stay long, flying back to the same tall alder after getting spooked by a couple of cars (including one kind of noisy one) that appeared at the intersection together. Connor agreed to wait a little bit longer to see if they would return. Our patience was rewarded as they followed the same approach pattern as before, first a couple of birds, then a few more, and finally the rest of the flock returned to the Mountain Ash tree. I was able to get a pretty good look and a few pictures of a few of them on this visit before they retreated back to the same tall alder. Though I was not sure after the first sighting this morning, all the birds I saw this afternoon were Bohemian Waxwings rather than their similar (but rarely occuring locally) relatives Cedar Waxwings.

The behavior I observed today made me wonder a little bit about the foraging strategy for these birds. On occasions in the past I have seen lone Bohemian Waxwings moving fairly rapidly through an area, but not without stopping briefly. It was almost like these individuals were scouting around. Those observations made me wonder if flocks will have scouts out looking for food sources which then inform the flock if any good food sources were discovered. Today’s behavior only reminded me of those previous observations because of the way only one or two birds first flew to the tree where they were eating berries.

Bohemian Waxwing (Bombycilla garrulus)

14 December Photos: Mountain Snow and Bohemian Waxwings

Filed under: birds, photojournal — matt goff @ 10:04 pm

Spent a little time outside looking for birds with Connor. I was able to get a few pictures of Bohemian Waxwings.

December 11, 2007

Hermit Thrush Nest

Filed under: birds — matt goff @ 10:25 pm

Hermit Thrush Nest with Young

Near the end of July I posted about finding bird nests earlier in the month. A couple of days after I wrote that post, I found another nest with young. I mentioned it briefly in a posts the day I found the nest, one day when I spent time watching the nest, and finally when the nest was empty.

I never would have found the nest if I had not been alerted to its presence by the begging calls of the young. As with previous nests with young that I was able to observe, these birds were very quiet, except when a parent returned with food, but I did happen to catch the sound of their begging while I was out at the battlesite bench. Although I could hear the high pitched calls, I had difficulty accurately placing where they were coming from, especially given their short duration. I was able to get enough of a sense about where they were that I knew they were in the trees between the trail and the beach, relatively close to the bench. Although the total area where I needed to look was small, I did not want to crash through the bushes and accidentally knock the nest over or otherwise disturb it significantly in the likely event that I did not happen to see it.

After a few minutes of looking and waiting, I was able to narrow my focus a little bit more as the parents made a couple more trips. I figured I must be close when I noticed one of the parents with food acting wary about my presence. I backed off a bit and waited until the parent had fed the young birds (though I still could not see where exactly they were). After it flew off to gather more food, I moved in closer again, sat down, and waited. When a parent returned with another bill-full of food, it seemed to notice me and be a little hesitant. I waited quietly, and the finally the parent apparently decided I was not much of a threat, so it flew in to feed. This time I was able to get a look at where the nest was.

The nest was in a short spruce tree growing up through the beach-side Red Alders. The nest was about 4 or 5 feet off the ground, in relatively easy view from the upper edge of the beach. Mostly made up of moss and twigs, I could also see feathers and some hair built into the nest, undoubtedly collected from the sheddings of the many dogs that get walked through the park. The four young, practically stacked on top of each other, filled it almost to overflowing. The feathers of the nestlings seemed well developed, and during the time I was able to observe these birds over a couple of days, I saw one of them climb up on the edge of the nest and work its wings a bit. After another couple of days had passed, the nest was empty.

It was interesting trying to stay out of sight while watching the nest. It was not so much the birds I was concerned about seeing me, but the people walking through the park. The nest really was only a short distance from the trail, and when the cruise ships are in on sunny days, as was the case when I was watching, visitors are many. The only spot to watch where I could see the nest, but not be so close the parents would not feed the nestlings was right at the edge of the alders at the top of the beach. From where I was stationed, I could not quite see the battlesite bench, but anyone who took a step closer to the beach to look around was visible. When things seemed especially busy, I sometimes just sat down at the top of the beach and got interested in insects, just in case someone noticed me. I didn’t really want to advertise the location of the nest and risk disturbing it even more than I was probably already doing.

Over the time I observed, I was able to see the parents bring in food a few times. Salmonberries and invertebrates seemed to make up the bulk of the food items. Invertebrates I noticed included a centipede, caterpillars, and a crane fly or harvestman (all I could see were the long legs).

Additional photos below.
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December 10, 2007

Can Harbor Seals Smell Danger?

Filed under: marine, marinemammal — matt goff @ 12:25 pm

Harbor Seals (Phoca vitulina)

Back on the first of October, I mentioned seeing interesting Harbor Seal behavior while at Totem Park.

The photo above shows three of the 5 seals I saw in the same confined area while at the park that day. Though it is not possible to tell from the photo directly, the water they are in is no more than 10 feet deep, and probably closer to 5 or 6 feet. One of the seals is shown holding its nose pointed up out of the water and into the wind. At various times at least three of them did this, and that is what caught my attention.

After an experience in Summer 2006 where seals unexpectedly climbed up rocky islets and the later realization that it was due to Killer Whales in the area, I have tried to keep in mind that, as prey of rather effective hunters, seals must be quite wary, lest they become lunch in a possibly lingering and presumably painful fashion. So that is what came to mind as I observed behavior that very much reminded me of other terrestrial mammals testing the breeze with their nose. In the days that followed, I heard of at least two different reports that Killer Whales had been seen near town over the same time period. Though the sightings I heard about were not in Eastern Channel or closer to the park, the Killer Whales in local waters range widely, often entirely out of Sitka Sound, so it would not be surprising at all for them to be move several miles over the course of hours and days.

An important question that needs to be considered is whether seals even have a decent sense of smell. If not, then it would seem quite unlikely that they were smelling the breeze. Though hardly authoritative, a quick Google search turned up several sites that said Harbor Seals do have a very good sense of smell. This was typically mentioned in the context of a mother’s ability to smell her pup, but I can’t imagine the sense of smell would be so specialized as to only apply in this context.

Finally, there is also a question of whether or not Killer Whales give off an odor that the seals could identify on the breeze. I have never been near Killer Whales when they are breathing, so I do not for sure. It seems fairly likely that they do, however. Humpback Whales certainly do and it’s not clear to me why they would by Killer Whales would not. Perhaps someone who has had close encounters with Killer Whales can leave a comment about their breath.

While interesting, none of this really proves in any way that the seals I saw were sniffing out Killer Whales. Certainly they hang out in the shallows fairly often. I do not remember seeing them stick their noses up before, but then there are lots of things I miss. Still, the evidence seems suggestive to me, and I will certainly keep my eyes open for Killer Whales if I ever see seals acting like this again.

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