artwork | | Page 5

February 8, 2015

Thoughts on the Past, Present, and Future of the Snowy Plover in North America

by Bryce W. Robinson

Snowy Plover – Charadrius nivosus. 11 x 14 ” prismacolor on bristol. Image copyright Bryce W. Robinson 2015

I’m becoming increasingly fascinated with how our changing world may impact the distribution of a given species, either shifting or fragmenting breeding ranges. I have a particular affinity for the family Charadridae , and I’ve found myself paying closer attention to one species in particular, the Snowy Plover – Charadrius nivosus. The Snowy plover occupies a widespread but disjunct breeding range in its western North American population(Figure 1). This range is likely a result of the bird’s need for specific (in turn limited) habitat for breeding.

Figure 1. Range of Snowy Plover – Charadrius nivosus in North and Central America. Image taken from Birds of North America Online (see referenced information)

The Snowy Plover is a species that has faced many challenges with the ever increasing human presence. Throughout the bird’s North American breeding range (Figure 1), human impacts have caused a multitude of threats to its ability to reproduce. These threats include but are not limited to environmental contaminants, an increase in nest predators such as Raccoon, Common Raven, Coyote, and Red Fox, all of which have experienced a human-subsidized boost in population numbers in recent decades, and recreation on beaches causing both disturbance and nest destruction. A great discussion of all factors impacting Snowy Plover populations can be found on the Birds of North America species account under the Conservation and Management section.

Multiple organizations are working with state and federal wildlife authorities to augment the negative impacts humanity and its residuals are having on Snowy Plover populations. These organizations include Point Blue Conservation Science, Friends of the Dunes, the National Audubon Society, and many others. The effort is impressive and has seen some success. Still, there is a looming threat on the horizon, the impacts of human induced climatic changes.

What the threats of climate change mean for the Snowy Plover in western North America and across the rest of its range in S. America are still to be determined, but I’d like to emphasize the need to determine and augment these threats as they are occurring. I’ve become aware of a population level analysis that is meant to track the distributional patterns of a given species throughout its yearly cycle (Ruegg et al. 2014). The idea is to identify population structures during the major life events of a species through genetic analysis of individuals at each location; breeding, migration, and non-breeding. Understanding where individuals spend each part of the year holds the power of identifying where negative impacts are occurring that are driving population declines. This is the big idea behind the banding effort, but this technique provides larger sample size and more power for determining population structures. It’s a huge step in the right direction.

My point is, wouldn’t this be a great tool for assessing changes in populations of the Snowy Plover over its disjunct range as the impacts of climate change become more visible and severe? The answer is yes, and we ought to begin the effort…

Referenced Information:

Page, Gary W., Lynne E. Stenzel, G. W. Page, J. S. Warriner, J. C. Warriner and P. W. Paton. 2009. Snowy Plover (Charadrius nivosus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/154

Accessed 7 February 2015

Ruegg, K. C., E. C. Anderson, K. L. Paxton, V. Apkenas, S. Lao, R. B. Siegel, D. F. Desante, F. Moore, T. B. Smith. 2014. Mapping migration in a songbird using high-resolution genetic markers. Molecular Ecology 23:5726-5739

November 2, 2014

Red-tailed Hawk in Pen and Ink

by Bryce W. Robinson

After second-year Red-tailed Hawk – Buteo jamaicensis. 11 x 17″ Pen and Ink on bristol.

I view illustrating birds as an exercise of my ability to create an accurate rendition of my subject. I’ve recently began recognizing a need to incorporate study into this exercise, and as I stated in a previous post, I plan to do so by first illustrating and then reading a scientific article that pertains to my subject. But, I’d like to add another component to my illustrations. I want to make an image that communicates useful information.

I was asked to illustrate a Red-tailed Hawk in black and white, so I took the request and made it an opportunity for me to try a concept I’ve been thinking about. I want to create images that I can teach from, or that simply communicate information for those looking to learn something about each bird. For the Red-tailed Hawk, I wanted to create an image of a bird that could be aged, as if it were a real bird being scrutinized by a biologist.

The above bird is my first attempt at illustrating staffelmauser, or staggered molt. Through illustrating this as it is seen on actual hawks, I made an attempt at communicating the necessary information for age determination.

Here is the breakdown of the birds age:

This hawk is an adult, as dictated first by shape. The wings are broader, giving the tail a shorter appearance as well. The presence of a thick subterminal band on both the tail and wing also indicate that this bird is older than a juvenile. In age determination terms, it is at least “after hatch year”. But, we can take it further. The next step would be to search for molt limits in the flight feathers, that is the presence of retained feathers. Retained juvenile secondaries would be shorter than adult feathers, and lack a thick subterminal band. If this is found, then the bird is in its second year. I illustrated the bird with two generations of adult feathers in its secondaries, and two waves of molt in its primaries ( the staffelmauser, or step-wise molt). The older feathers are paler, as they would be in an actual Red-tailed Hawk. Because of these two generations of adult feathers in the secondaries, we know that this bird is an “after second year”.

Tail banding in Red-tailed Hawks is variable. Many “western” birds, subspecies calurus have multiple banded tails in their definitive plumage. So, this is a useless trait for age determination. To read more, and for a more clear and detailed explanation by the expert, check out a recent article written by Jerry Liguori on Hawkwatch International’s blog.

After all I produced the image I was hoping for, but it isn’t as correct as I’d like it to be. That is the exercise. Each time I finish an illustration, I take a few days to let it sit and be, then return and look for areas that I need to improve. This time I requested some additional critique from a knowledgable (understatement) friend. I now have a list of things to pay attention to the next time I illustrate this bird. I like where I’m at, but I see the need to keep going.

October 8, 2014

Burrowing Owl Illustration

by Bryce W. Robinson

Burrowing Owl - Athen cunicularia. 11 x 17" prismacolor on bristol

Burrowing Owl – Athene cunicularia. 11 x 17″ prismacolor on bristol

When I first began illustrating birds seriously almost three years ago, I spent the majority of my time on owls. For whatever reason, I was fascinated in the way their faces translated onto both canvas and paper. I remember when I realized the power that the eyes have for communicating the spirit of life within a creature. The exercise of illustrating owls taught me the importance of light and detail in the eyes of birds, especially raptors.

In the past I was focused on illustrating the face and busts of birds of prey. I stayed away from illustrating the full body of birds due in part to my fascination with the face, but also because I felt that I couldn’t create a proper and natural bird. Now I’ve started a campaign with myself to overcome my weaknesses and illustrate birds as a whole, either perched or in flight. While the exercise is to properly portray a bird in whole, I’ve made it a priority to take the lessons I learned from illustrating a birds face and invoke the same sense of life and attitude in the full-bodied bird.

Creating images of living creatures has more to it than I’ve ever thought. I see incredible paintings of Gyrfalcons in flight pursuing prey, or a Great Blue Heron stalking something in shallow water, and I can’t help but marvel at the mastery the artist holds over both their medium and their subject. I hope to reach even a fraction of the ability of some artists, but at the same time I’ve realized that perhaps the process is more enlightening and more worthwhile than the product. In the end, I’ll understand birds to a greater degree simply because I have put energy and focus into their details, and attempted to communicate their life and spirit through my own creative ability.

14 Comments

September 4, 2014

Molting Gyrfalcon in Flight

by Bryce W. Robinson

While in Alaska this past summer conducting research on nesting Gyrfalcons – Falco rusticolus, I made many notes and observations concerning the stage of molt for each adult bird that I encountered. I’d like to share a few things that I noticed. I’m still a young student of ornithology, so none of this is new information, just a few interesting things that I noted and count as important information to retain.

First, I was interested to note the difference in stages of molt between male and female Gyrfalcons during the incubation period. The bird I have illustrated above portrays the stage at which most females molt had reached in early to mid May. Males on the other hand had either not initiated molt yet, or had just started. Needless to say, the general trend was that females were farther ahead of males and in some cases were even more advanced than what I have drawn.

Another interesting thing I noted was that this difference in molt stage by sex changed. Once the female began provisioning for nestlings, the females molt slowed as the males caught up.

I set out to illustrate a Gyrfalcon in flight to show some of my observations on molting Gyrfalcons, however creating the digital image of the illustration did not transfer some of the aspects I had hoped it would. One thing I noted concerning the body molt was that the rump was the first to be replaced. All birds in early summer had nice contrasting rumps consisting of fresh feathers. The mantle and scapulars as well as the upper wing coverts had yet to be replaced.

The Gyrfalcons in May were growing in feathers at their initiation points. In Falcons, this is P4 or 5, S4 and 5, the inner tertials, and in the tail the central deck feathers T1. This beginning stage is important for understanding the difference between hawks and falcons, and is another reason I wanted to illustrate a molting falcon

I love studying molt, and in the largest of the falcons it interests me to a great degree. Molt is costly, energetically. When you consider a large species that lives in a harsh climate such as the Arctic, it is remarkable that they complete an entire molt a year, save perhaps a few underwing coverts. Other large avian predators of the region like the Rough-legged Hawk and Golden Eagle do not do this, a fact that makes my respect for the Gyrfalcon grow evermore.

I enjoyed the exercise of drawing this falcon in flight, and adding the aspect of molt to tell a story. I plan to make this a goal of my illustration, to combine creative imagery with context that communicates ideas and facts about the chosen subject. Of course my ability to do so is still a work in progress itself, but as with learning, the process is ultimately satisfying and something I look forward to for the remainder of my life.

4 Comments

Tag: artwork

by Bryce W. Robinson

by Bryce W. Robinson

by Bryce W. Robinson

by Bryce W. Robinson