Ornithologi

A studio for bird study

Tag: flycatcher

Published in Western Birds: First Record of Eastern Phoebe Breeding in Alaska

by Bryce W. Robinson

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My latest publication, and my first in the excellent regional journal Western Birds (Western Field Ornithologist’s), details the first documentation of successful breeding of Eastern Phoebe in Alaska. You can find the pdf on my Researchgate profile. It’s short and to the point, and worth a read for anyone interested in the birdlife of North America.

Last year, while working in Alaska with the US Fish and Wildlife Service’s Migratory Bird Program, I caught word of an Eastern Phoebe documented near Nome. I’m very familiar with Nome, since it is where I studied the Gyrfalcon for my master’s degree. I’ve birded the area heavily in the spring and summer months. There aren’t many Eastern Phoebe records for the state, so a bird showing up in Nome on the western coast is that much more exciting. I planned to be in Nome the following month to work with Red Knots, so I crossed my fingers that the bird would stick around long enough for me to see.

Surprisingly, a second Eastern Phoebe was documented soon after. Then came documentation of nest building, followed by nesting behavior and ultimately confirmed egg-laying and incubation. On my arrival at the start of July, I joined my friend Lucas DeCicco to see the pair on the outskirts of Nome. Since July is a time when the flow of birders ebbs in Nome, no one had checked on the nest for some time.

Sure enough, we found the birds feeding nestlings. After we had photographed and observed, Luke and I resolved to return regularly to document the success or failure of the pair.

In the end, the pair was successful. It was the first documented case of the species successfully breeding in Alaska, and on top of that in a location quite inhospitable and atypical of the species. The coast of Nome is not known for mild weather.

I told Luke that I thought it important to document this novel event in a publication, and he agreed. So we resolved to report the record, and asked for the help of those that originally found the first phoebe in June.

Thanks to Luke for his help with this seemingly simple publication. It wouldn’t be so clear, simple, and clean without him. Also, a big thanks to my co-authors who first found these birds – Aaron Bowman, Scott Hauser, John Wright. Thanks for the help with cleaning up the publication, and of course documenting the birds that led to this record.

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Sulphur-rumped Flycatcher (Myiobius sulphureipygius) Foraging in the Dark Understory of Southern Belize

by Bryce W. Robinson

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I’ve been in Central America for nearly two months, and I haven’t had the time or energy to post any stories, images, or illustrations from my experience thus far. There are of course many stories to tell.

Flycatcher (Family: Tyrannidae) diversity in Central America is very high. Getting to know this diversity has been an excellent challenge. I’ve had a lot of luck seeing most species that I might encounter in Belize, and among my favorite have been the small and endearing flycatchers of the rainforest, such as the Sulphur-rumped Flycatcher (Myiobius sulphureipygius).

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I’ve seen the bird only a few times. It sits low in the understory of the rainforest, near relatively open areas and perch hunts for insects. Its large eyes are obviously engineered to spot prey, and it tactfully watches and waits until it sees an opportunity. This can be for a minute or more.

These birds don’t seem to mind my close proximity when I’m watching and photographing, and seem only focused on its task of procuring food.

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Contrasting this seemingly patient and calculated technique with another small flycatcher, the Ruddy-tailed Flycatcher (Terenotriccus erythrurus) has been enlightening. From what I have observed, these birds are constantly making attempts at captures, and hardly sit still for more than a few seconds. It’s difficult to tell if these many attempts are all successful, because the insects it is after are much too small to observe at any distant.

Hopefully I’ll be able to capture both foraging techniques on video. There’s always another way to describe the behavior, whether it be writing, illustration, or video. I’d like to blend all three for these birds.

Tail Pumping Behavior in the Black Phoebe

by Bryce W. Robinson

Black Phoebe - Sayornis nigricans. 14 x 17" prismacolor on bristol board. Image copyright Bryce W. Robinson

Black Phoebe – Sayornis nigricans. 14 x 17″ prismacolor on bristol board. Image copyright Bryce W. Robinson

The Black Phoebe – Sayornis nigricans in it’s simple suit of black and white, catches the eye of anyone remotely keen on the goings on of the natural world. This phoebe demands attention, even in a guild of flashy desert denizens. In doing so it provides some quality behavior birding that never disappoints.  

One behavior I have noted while watching the bird forage is the methodic tail flick, not uncommon in the family Tyrannidae, but somehow unique in the Black Phoebe. I’ve wondered about the habit, but never sought to satisfy the wonder until now. The illustration above came about in preparation for the coming San Diego Bird Festival that I will be attending. In practice, I decided to couple the illustration with looking into any insights in the literature regarding the tail pumping habits of the Black Phoebe.

In little time I found a paper (Avellis 2011). The study addressed four hypotheses explaining the behavior, the Balance Hypothesis where the phoebe tail pumps to maintain balance atop unstable perches, the Foraging Enhancement Hypothesis where tail pumping increases foraging success, the Signal to Territorial Intruders Hypothesis where the tail pumping signals conspecifics of the birds fitness and establishment on a territory, and the Signal to Predators Hypothesis where the tail pumps exhibit the birds vigilance amidst predators.

The results of the study indicated the following:

Balance Hypothesis – Not supported

Foraging Enhancement Hypothesis – Not supported

Signal to Territorial Intruders Hypothesis – Not supported

Signal to Predators Hypothesis – Supported

The paper reports that the Black Phoebe increased tail pumping rates significantly when a predator was detected either visually or audibly. The suggested purpose of tail pumping then is to advertise the birds awareness to the predators presence. Tail pumping communicates the phoebe’s health, and that it in turn will be a more difficult prey to capture.

So, when asked why the Black Phoebe pumps its tail, I’ll answer that the behavior is to exhibit the birds vigilance, acting as a deterrent for predators looking for the path of least resistance for procuring food. Another day, another bit of knowledge gained.

Referenced Literature:

Avellis, G. F. 2011. Tail Pumping by the Black Phoebe. The Wilson Journal of Ornithology 123:766-771

A Day of Learning Flycatchers, Warblers, and More

by Bryce W. Robinson

Male Phainopepla- Phainopepla litens

This afternoon I took a trip to a place called Indian Canyon. I never expected to find such a place. In the midst of aridity and rock strewn mountainsides, a Palm covered drainage of flowing water empties into the Coachella Valley. With the amount of time I’ve spent in the water-less desert lately, this place was paradise. I had heard it was a great place to bird, and since the spring migration is in full swing, I expected to see some special species.

I was happy to find myself with new birds, particularly warblers and flycatchers. I must admit my knowledge in these two groups is lacking, and it has become an area of focus for my current study. Identifying Empidonax flycatchers are one of the biggest difficulties that the birder faces. There are a few species that are indistinguishable from one another. In many cases, the call alone is the only way to gain a positive identification. With this said, I found two different “empids” today that I feel fairly confident I was able to ID properly.

Pacific-slope Flycatcher- Empidonax dificilis

This Pacific-slope Flycatcher was a character. It sat on the ground, occasionally lifting to the air to swoop after and insect, returning to the ground to watch for more. It paid little mind to my intrigue. It was great to watch this bird and get to know its look and behavior.

I included the photo below to show a helpful ID tip when watching empids. The color of the lower mandible can help eliminate particular species. I was fortunate to capture this image as the bird looked my way, exposing a light colored lower mandible.

Pacific-slope Flycatcher- Empidonax dificilis

Pacific-slope Flycatcher- Empidonax dificilis

Another empid was flitting around the stream. Not assuming it was the same species, I took the time to watch and note features that might separate it from the previous bird. I never heard either empid call, so perhaps I should admit that I can not be absolutely certain in my ID. I will be bold, and say that I believe the second bird to be a Hammond’s Flycatcher.

Hammond's Flycatcher- Empidonax hammondii

Hammond’s do not breed, nor winter in the area, so this would be a migrant. That fact makes my time watching the bird ever more meaningful.

I’m beginning to find myself extremely fascinated with the warblers. They are a diverse group, and contain some of the most visually stimulating birds in North America. As a birder, they are a challenge. They hardly stay still, constantly jumping from limb to limb, deep in foliage. In old growth forests, multiple species coexist in close proximity as they occupy different zones of the canopy layer. This is a helpful fact in identifying birds as the birder sees fleeting glimpses of uncooperative warblers. In a palm dominated riparian zone, I had it easy. With relatively little understory and one canopy layer, I was able to spot multiple warblers and gain sufficient views to aid in my identifications.

The first warbler was a bird I had never seen, but knew nonetheless.

Wilson's Warbler- Wilsonia pusila

This Wilson’s Warbler was loads of fun. I watched it for a while as it travelled around, low to the ground, foraging for whatever it could find.

Another Warbler that was very present along the stream was an Audubon’s Yellow-rumped Warbler. These birds are very common, but always fun. In the desert the past week, I have been seeing a few migrating warblers. One particular difficulty I have faced is differentiating between what might be a MacGillivray’s Warbler and a Nashville’s Warbler. To the experienced birder, this might seem silly. I have no problem admitting that I am still learning some simple problems. Today, however, I finally saw a bird to solidify the knowledge to distinguish the two.

Eye-rings can be problematic. So can crown markings. After all, the Orange-crowned Warbler rarely shows the orange feathers on its crown that give it the name. The Nashville warbler is very similar to the MacGillivray’s, save some subtle differences. The broken eye-ring of the MacGillivray’s is certainly distinctive, but I daresay this is not the marking that should be focused on. The throat of the birds differ; the MacGillivray’s being gray, the Nashville’s being yellow. I was troubled at not being able to confidently ID the birds I saw this week. Today, I saw a few Nashville Warblers. I include a poor photo not for quality, but to show that in some  lucky instances, the bird looks just as the guides depict.

Nashville Warbler- Oreothlypis ruficapilla

The throat isn’t visible, but everything else looks great. Note the complete eye ring and rufous cap. I even saw this bird well enough at times to pick out the whitish vent. Today, I learned what makes the Nashville, the Nashville.

I saw a few Black-throated Gray Warblers today. They were all very friendly. I was so close to one bird that I had a hard time fitting him into the frame. I was unable to get any photos that I really like. Most are obscured by foliage, or butt shots. Too bad, but I did get a few for the reference library.

Black-throated Gray Warbler- Setophaga nigrescens

I haven’t seen many thrushes in my life, so it was great to see a Hermit Thrush wandering through the brush. I followed the bird into a thicket, where it sat still, allowing me to capture a few images.

Hermit Thrush- Catharus guttatus

The day was a great day of growth for me. I make attempts to take advantage of the opportunity to learn even a little each day. I love feeling like my knowledge is growing. I wouldn’t be happy if it were any other way.