A studio for bird study

Category: Behavior Birding

A Green Heron GIF to illustrate Tail Flicking Behavior

by Bryce W. Robinson

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While photographing a vagrant juvenile Green Heron (Butorides virescens anthonyi) along the Boise River in early November, I noticed a behavior I wasn’t aware of for this species. When I would get a bit too close the heron would notice me, stop foraging, and flick it’s tail while it slowly walked away, as if it had a nervous tick.

Tail flicking is a behavior that many species exhibit. A recent study with the Black Phoebe found support for the explanation that tail flicking was a sign of vigilance to predators, a topic I’ve written about here. When the bird flicked its tail, the predator got the cue that the bird was aware of its presence and the predator had lost the advantage of surprise. This seemed to make sense in explaining the behavior of the Green Heron I stalked on the Boise River. Each time it began flicking its tail, I’d let off until it relaxed and continued to forage.

Fork-tailed Storm Petrel (Oceanodrama furcata) Foraging on Tidal Flats: Part 2

by Bryce W. Robinson

 

I captured too many images from my recent experience with Fork-tailed Storm Petrels (Oceanodrama furcata) along the Bristol Bay coast of the Alaska Peninsula. Given that our observations warrant a full report in a journal, I’ll maintain some brevity for now. However, I think it is helpful in the interim to share supplementary video and images that set the stage for the publication. The rest will come out with the article sometime in the coming year.

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Stuart Fetty walks towards a resting Fork-tailed Storm Petrel as the tide rises.

We had a few days where the birds lent themselves to close proximity photography. They were all around us, and didn’t seem to understand or comprehend the concept of a terrestrial predator. In one instance, we walked as close as a meter or so to a bird sitting on the water with no response. Whether this was an ill or a healthy bird resting, I can’t be sure. We do however have some indication that these birds were healthy, but these are details that will be discussed in publication.

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Fork-tailed Storm Petrel kiting in an onshore wind. Note the fish carcass in the foreground, an attractant for the birds to this location.

The past six months have been full of unique encounters with bird life in Alaska, and have produced a nice list of potential publications that I’ll be working on throughout the winter. I’ve taken a lot of satisfaction in working in a place where the birdlife is still relatively understudied, a place where paying attention, taking good notes, and diligent photography all support the opportunity to add to our basal knowledge of natural history of the less understood species of North America.

Fork-tailed Storm Petrel (Oceanodrama furcata) Foraging on Tidal Flats: Part 1

by Bryce W. Robinson

Video 1. Dan Ruthrauff photographs passing Fork-tailed Storm Petrel as the tide comes in. Bristol Bay coast, Alaska. September 2016.

Over my time on the Bristol Bay coast near the village of Egegik on the Alaska Peninsula, I was privy to one of the most incredible experiences I’ve ever had with birdlife. The experience is captured in video 1, which shows Dan Ruthrauff kneeling on tidal flats at low tide photographing passing Fork-tailed Storm Petrels at close range. I’d never heard of anything like this for any pelagic bird. It turned out to be a regular occurrence, but still appears quite novel so far as we understand Fork-tailed Storm Petrel foraging behaviors.

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Photo 1. Fork-tailed Storm Petrel arcing down amidst a dynamic soar in high winds. This photo was taken from the shoreline at high tide. Bristol Bay coast, Alaska. September 2016.

Typical experiences with Fork-tailed Storm Petrels are like the image above: A dynamic soaring Hydrobatid at relatively close range. It’s very exciting, but nothing like walking through tidal flats surrounded by the birds.

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Photo 2. Fork-tailed Storm Petrel at rest on the water. I was standing in ankle deep water when this photo was taken. Bristol Bay coast, Alaska. September 2016

Other more typical experiences can provide observations such as the above photo, where calm water and resting birds near a boat might provide great views. Photo 2 is a bird that I stood near in ankle deep water. This bird was taking a moment to rest from foraging and seemed non-plussed by me. I’ve never heard of anything like it.

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Photo 3. Fork-tailed Storm Petrel (Oceanodrama furcata) dabbing on water. I was lying on my belly when this photo was taken. Bristol Bay coast, Alaska. September 2016

The experiences continued for the entire two weeks I was on the Bristol Bay coast. After reading through the literature, the behavior seems undocumented and may warrant publication as a note. I’m excited to organize, avail myself of the literature, and share this experience with a crowd more knowledgeable and literate than myself. For me, experiences like these make field ornithology one of the best things about life.

Rock Sandpiper (Calidris ptilocnemis) – A GIF to illustrate the power of feathers for rendering shape

by Bryce W. Robinson

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I finally had the pleasure of seeing a “nominate” Rock Sandpiper (Calidris ptilocnemis ptilocnemis) during my time on the Bristol Bay coast of the Alaska Peninsula. This bird was hanging out with darker Rock Sandpipers (likely tschuktschorum) and Dunlin. These birds breed on Bering Sea Islands and mostly winter in Alaska’s Cook Inlet, farther north than any other shorebird (Gill et al. 2002).

While sifting through the many photos I took of this bird I found three taken almost simultaneously that illustrate the power of feathers for rendering a birds shape, and how much and quickly that can change for an individual bird.

After seeing the potential of putting the three photos together, I taught myself how to create a GIF (Graphic Interchangeable Format). I feel a GIF is an excellent way to show how only a few seconds and a relaxed posture can change the shape of a bird.

Referenced literature:

Gill, Robert E., Pavel S. Tomkovich and Brian J. McCaffery. (2002). Rock Sandpiper (Calidris ptilocnemis), The Birds of North America (P. G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America: https://birdsna.org/Species-Account/bna/species/rocsan

DOI: 10.2173/bna.686