Ornithologi

A studio for bird study

Tag: goshutes

The Benefits of Photography for Mapping Avian Movements

by Bryce W. Robinson

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Above is a photo of an immature light morph Swainson’s Hawk that I took on the 7th of September, 2013 at the Goshutes Raptor Migration Sight in eastern Nevada. Notice the red band on the birds left leg. I’ve cropped the image a great deal, but below I’ve enlarged the section of the image to show the band in greater detail. At this resolution, the image becomes pixelated, which is unfortunate.

SWHA MAGI contacted the BBL in hopes of tracking down someone that might recognize the band. I am so very grateful for their organization, as they quickly sent out emails asking those they have permitted for color banding SWHA. Within a day or two, I had a hit.

A man name Chris Briggs contacted me and gave his firm assurance that this bird was a bird he had banded earlier this year as a nestling. He mentioned his use of special characters such as the obvious < symbol on this birds color band. He thought that the other character on the right was either an 8 or a 9. One cannot be too certain, but he did assure me that the band was certainly his.

As the birds age was apparent from its plumage, I was really interested in where the bird originated. Chris informed me that this bird was banded as a nestling near Macdoel, California, a town near the northern border just south of Klamath Falls, OR. He sent me the photo below.

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Photo courtesy of Chris Vennum

How exciting! It is nearly certain that this bird is the same bird as the bird I photographed in Nevada. I am so thankful that the organization exists such that a photographer can capture a photo of a bird with a band, and if the band is legible, can track that very same bird to the place that it was banded, without ever trapping the bird. The invasiveness of trapping hawks is curbed with the advent of the camera! Revolutionary….

Well, my question is then why are we as raptor researchers, or ornithologists as a whole not employing this technique more often? Some may state the added detriment of more bands is not worth while, and I do not discount this contention. However, how much more detrimental will one color band be to an already banded raptor? It is a discussion worth having, because with the amount of folks armed with cameras today, we could find ourselves with a lot more re-sight records, and a better understanding of spatial ecology in particular species.

I’d like to include another recent instance for emphasis. A few months ago, my friend and obscenely talented photographer Ron Dudley photographed a young Prairie Falcon in Montana. It happened to have a color band, and he was able to track down where the bird was banded. As it happened, his bird was also from California. You can read the story in detail on his blog.

How peculiar, this bird that fledged from its nest, and for whatever reason did not disperse directly south, but in a somewhat north east direction. North east enough that it passed by the Goshutes in early September on its way south. In my own personal study, I’ve learned that this non southward directionality of post fledging dispersal is something many people tracking birds of prey are seeing. The old north to south paradigm is becoming a bit more complicated than initially thought, and young birds seen traveling south on their fall migration, aren’t necessarily birds fledged from the north.

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The Gray Ghost

by Bryce W. Robinson

Northern Harrier- Circus cyaneus. 11×18″ Prismacolor on Bristol.

Deneb Sandack has been involved with the Goshutes Raptor Migration sight in some way or another since its inception in the early 80’s. For many years she has acted as the lead bander at the sight, going above and beyond to ensure that the sight runs smoothly and achieves its goals each season.

Her passion for trapping birds is unmatched. I admire her greatly for this passion. Over the years she has trapped and processed thousands upon thousands of birds. Each year she returns to the mountain with hopes of trapping what is her personal white whale, a bird that has evaded her tremendous luring and trapping skills for years. This bird is the Gray Ghost, the adult male Northern Harrier.

The Gray Ghost, a name known among raptor enthusiasts and birders alike. Termed such because of its ghostly gray plumage, and intense yellow eyes. It hunts just above the ground, floating along in search of prey, reminiscent of a specter in search of a soul. A truly remarkable and mystifying creature, very deserving of its super natural epithet.

Because the male Harrier is the single regular migrant that has avoided capture by Deneb all of these years, I thought it prudent to honor her and her goal by illustrating the bird. This bird is for her, as my tribute to her hard work and dedication, and hope that next season at the Goshutes Raptor Migration Sight she finally pulls the Gray Ghost from the sky.

Differentiating Immature Dark Western Red-tailed Hawks from Immature Dark Harlan’s- A First-hand Experience

by Bryce W. Robinson

My time at the Goshutes Raptor Migration sight has come to a close. Never have I been witness to the magnitude and diversity that I observed in the three months that I lived on the nine thousand foot island in the sky. I came away with a large collection of spectacular photos far surpassing, in quality and content, anything I have ever gathered. Even more, I came away with a great understanding and appreciation for the phenomenon of the fall raptor migration. Field work is immersive in nature. The opportunity to learn and magnify my study in this situation is truly unmatched.

I find my interest intensely involved in the genus Buteo.  Specifically, I am enamored by the polymorphism present in this group. Of these birds, none matches the diversity and allure of the Red-tailed Hawk. The Harlan’s Hawk is quite possibly my favorite bird at the moment. I was obsessive about analyzing every Red-tailed Hawk that passed. Finally, near the end of October, I began seeing the birds of the great north. The banding station was hard at work, capturing and banding all that they could. Every morning I gave them my good luck speech about the inevitability of catching a Harlan’s on that day. Finally, they came through, trapping a dark juvenile Harlan’s Red-tailed Hawk.

Luck seemed to be on my side that day. I spent the majority of the season bothering the banders for pictures to document the diversity of the species. Earlier, hours before the Harlan’s was trapped, they caught a beautiful dark western bird. I was able to get photos of this bird. The result is my ability to show, with photos, the differences between the immature dark Harlan’s, and the immature dark Western Red-tailed Hawk.

I will first introduce and discuss the dark immature Buteo jamaicensis calurus:

Immature Dark Western Red-tailed Hawk- Buteo jamaicensis calurus

It is rare to find a solid chocolate immature Western. This bird is a nice, almost solid bird, however there is still a somewhat mottled appearance on the breast and wing linings. Dark western birds are a beautiful chocolate brown. On dark birds, the upper-tail coverts appear the same as the color of the scapulars and mantle. They do not have the contrast of the whitish upper-tail coverts that a light morph usually has. Sadly, this photo does not adequately display this feature. Of course most immatures have a heavily banded tail that is not the indicative brick red of adults, and they possess the obvious pale primaries giving the appearance of what is referred to as wing windows. The tail often reflects the color morph of the bird, as seen in this bird, having a color that matches the dark solid brown of the body. It is hard not to get too in-depth discussing color morphs of the Red-tailed Hawk. As this is not a discussion on the particulars of each morph, I will discuss the important features to contrast with those of the Harlan’s.

It is important to note that the features I discuss are not always reflected in identifying these birds. As diverse as the Red-tailed Hawk is, it often lacks or reflects certain traits that may throw ones identification into a confusing headache. As in most bird identification, it is necessary to incorporate many factors into an I.D.

For the dark immature western, first note the solid color of the upper-wing coverts, scapulars, and mantle. Also, the head of this bird lacks any mottling, or white markings. Pay particular attention to the area around the eye. As seen in the front view photo, the remiges are banded. The banding is not in heavy contrast with the general color of the wing. This factor is also present on the tail. One factor in contrast with an immature Harlan’s Hawk are the dark emarginated outer primaries. In most Harlan’s, these primaries are banded. I recently learned from Jerry Liguori that this feature is usually only reflected in immature birds. Adult Harlan’s often have solid outer primaries, much like western birds.

Here is the dark immature Harlan’s Red-tailed Hawk- Buteo jamaicensis harlani:

Immature Dark Harlan’s Red-tailed Hawk- Buteo jamaicensis harlani

Separated by the text from discussing the western, it might seem difficult to truly compare the two. Below I have included some comparison photos that can be referenced following the discussion. For now, pay attention to the factors of each bird exclusively. Getting to know the face image of a bird, rather than the nit-picky particulars of individual characteristics will better aid one in identification.

First, Notice the banding on the emarginated primaries of this bird. It is obvious on the front view of the bird, not so much on the backside. Although still a dark brown, this bird is obviously highly melanistic. Harlan’s are often severely dark, even black. This bird is not as dark as some, but it is obviously darker than the chocolate color of the western. The physiological reasons for this are extremely interesting, but for another discussion.

The most obvious feature of this bird, in conjunction with the dark coloration, is the presence of mottling across the body of the bird. This creates a bird of high contrast, which is a feature that might possibly be the reason for my addiction to the aesthetic of this Alaskan wanderer. The mottling is present on the breast, belly, and wing lining of this bird, however, this feature is not exclusive to the Harlan’s. The area to focus on in relation to mottling is the backside of the bird. Notice the heavy mottling present on the upper-wing coverts, scapulars, and mantle. This feature adds to the other factors that make the bird a Harlan’s. Also, notice the presence of white on the face and crown.

I note in the video below that the tail is heavily banded, and the presence of the contrasting white and dark in the tail is unique. These factors do not necessarily add to the identification of a Harlan’s, but it is interesting to note. The tail of the Harlan’s is quite different from the Western. The bands are thicker, and contrast more with the coloration of the rest of the tail. Take the time to see the bird in the video. I briefly discuss all the factors that make the bird a Harlan’s, but the video is really valuable to present the bird in a comprehensive way.

The following photos illustrate a visual to aid in intellectualizing the differences between the dark immature Harlan’s and Western.

Dark Western(top) and Dark Harlan’s(bottom) bottom-side

Dark Western(top) and Dark Harlan’s(bottom) topside

The experience I had this season left me with some impressions and ideas in relation to the Red-tailed Hawk. Much discussion and disagreement is present in the raptor world in relation to the status of the Harlan’s. I have some insight into the issue, provided by exposure to the number of birds I observed this fall, coupled with conversation, and personal study of the bird.

The plumage diversity present in the species Buteo jamaicensis is vast. I observed that the birds of the desert of southern California appear to have plumage differences from those that I observe in the great basin. Also, across the course of the season I documented through photography, the differences in the birds that traveled past the migration sight. I can say, through personal experience and observation, that there is so much diversity in the species that it becomes difficult to differentiate morphs, and at times, even supposed subspecies. The debate in the bird world in regards to the Harlan’s is whether or not it deserves a status as a separate species. I feel that the debate is arbitrary given the knowledge we have about these northern birds.

I even question the status of subspecies in regards to the Harlan’s. The parameters that factor into substantiating subspecies status are particular, however it is my impression that there is not enough known about the breeding ecology of the Harlan’s Hawk to definitively term it a subspecies. Perhaps the Harlan’s is a color morph, an exemplification of variation in plumage, not as geographically tied as we believe.

It ultimately comes down to my lack of knowledge and really, the lack of the collective knowledge of the raptor community. What needs to be done is a comprehensive study, documenting the movements and breeding ecology of Harlan’s Hawks. Through a well crafted scientific study, we can once and for all discover the knowledge that will lift us past what is now only a discussion in speculation.

 

Views of Migration- An Update From the Goshutes

by Bryce W. Robinson

Immature Northern Goshawk- Accipiter gentilis

Progressively, the daily totals are rising. After a month of counting, the season total has already surpassed 3000. I’ve left the mountain for a day, so I would like to take the opportunity to make a brief report of the season to date. I haven’t the energy or the time to put much into the writing of this post, so I hope poor grammar and diction can be overlooked. Pay attention to the images, as I attempt to convey some of the images of the ridge top raptor migration at the Goshutes.

Broad-winged Hawk- Buteo platypterus

 

The highlight of the season thus far has been the Broad-winged Hawks. Six have flown through, and the above photo is the first of the season. This bird is actually a first for me. I had never seen a Broad-winged before. When I noticed the bird, and knew what it was, I could hardly contain my excitement. Hooting and hollering ensued, and I celebrated for minutes following. The western migration of Buteo platypterus was a thing of rumor in the past. It was thought that the bird did not migrate through the inter-west, and did not pass by the Goshutes migration sight. Jerry Liguori was the first to discover that the bird did indeed use the flight line, and many have been counted in the years since his revolutionary discovery. I hope to see many more to come, and am holding high hopes for a dark morph bird in close proximity to the observation point.

Red-tailed Hawk- Buteo jamaicensis

I’ve been able to get some amazing photographs from passing birds, many very close and detailed. I am saving the best for a future project, so for now I would like to present some photos that show what it is really like at the sight. Mainly, while watching the migration, the observer gets distant views at birds. Identifying the birds to species, sex, or age can be extremely difficult at times. Jerry Liguori has written two books to aid the observer in this task, illustrating a vast amount of tips and tricks to gleaning positive Identifications from distant specs. These books have become invaluable in my study.

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Sharp-shinned Hawk- Accipiter striatus

Even better, Jerry has joined me many times at the sight this season. It has been great to have one of the best raptor experts, and arguably the best migration counter, on the ridge to teach me and aid me in becoming a better and more effective counter. I am in intense study of raptor migration, and I am neither overwhelmed or exhausted by this fact. It has been remarkable. My only complaint is that the season will end too soon.

Osprey- Pandion haliaetus

One of my favorite passers-by is Pandion haliaetus, the Osprey. We usually see a few a day, each bird a delight. I have heard of the bird carrying with it a fish, a next meal. I look forward to the day I witness this peculiar behavior myself. Hopefully it is soon, and I am able to get photos.

Male American Kestrel- Falco sparverius

The evenings on the ridge are dramatic, to phrase it lightly. The long light casts shadows across the mountains, highlighting hills contrasted against dark canyons. Often birds will catch light streaming through deep canyons, lighting up agains the dark hillside. The beauty is indescribable, and so often leaves me with a feeling of peace as my soul settles and I fall upon thoughts of comfort. I am in the right place, doing the best thing, feeling no anxiety, and having zero complaints. I am fulfilled, and for the first time in a long time, I have found a home.