Videos

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  • This video shows an American Dipper searching for aquatic insects and fish underwater.
  • Notice in the fairly shallow water how it uses both its legs and wings to propel itself.
  • In the deeper water it uses its wings and basically "flies" underwater.
  • In one of sequences it chases a juvenile coho salmon which it doesn't catch.
  • However I have seen them capture the coho young as the last photo shows.
  • The leg bands on the dipper are part of a study by Mary Willson and Katherine Hocker.
  • They spent many years learning about them and published a book about them. The book American Dipper--Singers in the Mountain Streams can be ordered at http://www.takugraphics.com/other-publications2/books/19006014

Songbird Flies Underwater from Bob Armstrong on Vimeo.

  • On the Mendenhall Wetlands in Juneau many Long-tailed Voles live close to the upper edge of the intertidal zone.
  • When we get the occasional really high tides over 18-19 feet the voles often get trapped by the incoming tide and are forced to swim.
  • They seem to be fairly good at swimming but this makes them vulnerable to predation by Bald Eagles and Short-eared Owls.
  • The excellent photo by Zachary Hanna at the end of this video shows a Short-eared Owl with one of the voles.
  • You can learn more about these owls and their long-tailed vole prey at The Perfect Predator, Owl, by Bob Armstrong and Marge Hermans
  • And looking at pages 87 and 90.
  • Also look at the essay by Mary Willson on Short-eared Owls and Voles

Swimming Vole from Bob Armstrong on Vimeo.

  • The following interpretation of this raven behavior was kindly provided by John Marzluff.
  • The one calling was giving begs. We call it groveling for its life.
  • The deep calls from the background and then attributed to the bird coming in with ears up and pants down are territorial calls indicating that "I will kick your butt if you don't get out of here."
  • The beggar attacked first (a last resort out of fear) and then got out of dodge as the territorial bird exercised its will.
  • The beggar may have been an older kid of the adult that was aggressive, or not. You can tell the beggar is immature because of its pink mouth.
  • The very anxious begging (haa, haa, haa, haa calls) are a signal that usually stifles adult aggression and allows the young bird to stay in the area, but not in this case.
  • This is a common scene around food sources that the beggar desperately wants, but the adult territory owner isn't keen on sharing.

Raven Behavior 2 from Bob Armstrong on Vimeo.

  • This video shows the general sequence of coho salmon preparing to spawn.
  • The captions indicate the various changes in behavior.
  • Of interest is dispite hours and hours of taking underwater videos of coho salmon I never once captured the actual spawning act nor did I ever observe it by watching from above.
  • Among salmon the female coho seem to behave somewhat different.
  • She may dig several probable nest sites over a fairly large area.
  • She may then allow males to approach her and begin selecting specific places to deposite her eggs.
  • It seems to be fairly common for the process to get interupted by bears.
  • Since coho spawn later than other salmon bears may especially seek them out in order to build up their fat prior to hibernation.

 

Coho Salmon Arrive for Spawning from Bob Armstrong on Vimeo.

  • This video shows a male Dolly Varden courting a female Dolly Varden in front of a GoPro camera.
  • Part of their courtship involves vibrating themselves next to the female.
  • The rest of the video shows the various creatures that feed on Dolly Varden.
  • These images include American Dipper, Bonaparte's Gull, Great Blue Heron, Common Merganser, and Belted Kingfisher.
  • Humans, of course, also fish for them--the first image is of Peter Winslow, a biologist with the Alaska Department of Fish and Game.
  • Peter and his co-worker later disappeared while studiing Dolly Varden in Alaska's Arctic Ocean.
  • No trace of Peter, his co-worker, or their boat was ever found. 
  • The next image is of Bob Armstrong taken while Peter Winslow and I were studiing Dolly Varden on the Wulik River.
  • The last image shows a painting of Miss Dolly Varden a character in a play. The fish Dolly Varden was named because it resembled the pink spotting on Miss Dolly Varden's dress. That is why Dolly Varden is always capitalized.
  • It is fun to play the song "Hello Dolly" by Louis Armstrong along with the video.
  • These caddisflies seem to accumulate every year within some small rivulets leaving from beaver ponds near Mendenhall Lake in Juneau, Alaska.
  • The small streams have a sandy bottom and the caddisflies cannot seem to grip the substrate in the current.
  • So they tend to accumulate in the deeper water areas.
  • Why they are there and where they come from is a project we are working on.
  • Do they normally live in Mendenhall Lake (a glacial lake) and get caught in this area as the lake level lowers in the fall.
  • Or do they normally live in the beaver pond and move past the dams and cannot return.
  • They belong to the family called Northern Case Makers.
  • An entomologist at UAA in Anchorage has identified them as belonging to the genus Lenarchus
  • Hopefully we will eventually be able to put together the full story about why they are in this area.

A Caddisflies Dilemma from Bob Armstrong on Vimeo.

  • This shows some of the reactions of an American Dipper to a GoPro camera.
  • One time it captured a salmon fry and brought it in front of the GoPro and ate it.
  • Then it sang in front of the GoPro. They have a beautiful song and even sing year round so I was glad to have it recorded.
  • At first I thought it was either ignoring the camera or performing in front of it.
  • But then it pecked the camera a couple of times and used it as a launching platform when feeding underwater.
  • The sequence is fun to watch and to speculate.

Dippers Love GoPros or do they? from Bob Armstrong on Vimeo.

  • This video shows Northwestern Crows feeding their young at a nest in Juneau, Alaska.
  • Of interest is after being fed one of the youngsters raises its rear end and the parent takes or eats its poop.
  • What are some of the advantages of this type of behavior?
  • The young don't defecate in the nest or beside the nest.
  • This may help avoid contamination.
  • It might be less obvious for predators whereas the nest site with a bunch of whitish poop may be visible from some distance away.
  • I have read that the parents may receive some nourishment by eating their youngsters poop.

Crow Feeding and Tending Young from Bob Armstrong on Vimeo.

  • This video shows an American Dipper searching for aquatic insects and fish underwater.
  • Notice in the fairly shallow water how it uses both its legs and wings to propel itself.
  • In the deeper water it uses its wings and basically "flies" underwater.
  • In one of sequences it chases a juvenile coho salmon which it doesn't catch.
  • In this video the dipper is mostly looking for aquatic insects.
  • Why does it search in amongst the woody debris that has accumulated in the stream?
  • A lot of this searching occurs when the salmon are actively spawning in the stream.
  • Aquatic insects that live amongst the gravel and stones are usually displaced by the salmons digging motions.
  • They typically drift downstream and often accumulate in amongst the woody debris where salmon don't usually spawn.
  • Also there are some aquatic insects that prefer woody debris.
  • This video shows a few sequences of an American Dipper diving at their normal speed.
  • Watch as it occasionally turns over pieces of wood in the stream.
  • Why does it do this?

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