Ornithologi

A studio for bird study

Tag: conservation

Rough-legged Hawk Nestlings

by Bryce W. Robinson

Rough-legged Hawk Nestlings

I was surprised the first time I saw the proximity of nesting Rough-legged Hawk and Gyrfalcon. It was my first summer in Alaska. I was along the Dalton Highway peering through a scope at an incubating white Gyrfalcon. Only 100 meters down the cliffside was an incubating Rough-legged Hawk. Now that I’ve gained an in depth experience with cliff nesting birds of the Arctic, I see why these birds tolerate one another. There simply aren’t enough locations to be choosy.

These eyes were watching me as I pulled out one of my Gyrfalcon nest cameras the other day. This is on the extreme end of Gyrfalcon – Rough-legged Hawk nest proximity. These nests are only about 10 meters apart, and given that these young Roughies are about to fledge, they will both be successful. Almost every cliff I’ve worked in this summer has had a nesting Rough-legged Hawk pair. Some cliffs have had two, along with nesting Raven and Cackling Goose (yes, they nest in cliff nests often). Real estate is limited, so all suitable sites are usually occupied given enough food in the area.

Rough-legged Hawks are a favorite. I gained a familiarity with them during past winters in Utah, and it was always a dream of mine to see them on their breeding grounds. Each time I’m around a nest, I remember my current place and business in life, something that is not to be taken for granted. I’m living a personal dream, and I’m happy.

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Gyrfalcon Nest Observation

by Bryce W. Robinson

Somewhere between 45-50 days after hatching, young Gyrfalcons take a leap from their nest and fly for the first time. The clip above shows an angsty female preparing herself for that first jump. Her two siblings, both male, had already left the nest. This fact added to her anxiety as they called from outside of the nest.

Last year I put some effort into seeing a Gyrfalcon’s first flight, but was never in the right place at the right time. This year, I’m making another attempt. The clip above – as seen from a tent through our Zeiss Diascope – is as close as I’ve come to seeing a first flight. I spent hours with my field partner Ellen in a tent outside of the eyrie waiting for the bird to make the leap. The clip shows the closest she came. After this intense flapping bout, she sat down and went to sleep. We had to leave before the bird left the nest, but the time spent watching her was worthwhile.

B_Fieldnotes

First hand study is invaluable. We live in an interesting world where technology gives us so much, so fast, so often. We are able to learn at such a high pace, and research is no exception. For instance, I’m gaining insight into multiple nests using motion-sensor cameras. This provides me an in-depth exposure to Gyrfalcon nests at a higher rate than ever before . This is all due to the camera technology. But I’m missing out on a slow pace digestion of first hand observation. I’m missing out on the whole picture. To get the full perspective, and truly see what it is like in the nest, I need to watch them myself.

B_observation

While I watched, I took notes on behaviors. I also did a bit of field sketching. Field sketches force you to focus, and digest very small details that can heighten your understanding of your subject, but also enhance your observation skills. Besides all that, it is an enjoyable way to pass the time while the nestlings sleep.

Ellen_observation

Ellen and I took turns watching the nest. We were able to see two prey deliveries during our time watching. A male fledgling returned after one of the prey deliveries, hoping to get part of the meal. The female, however, would not oblige. I most enjoyed watching their behaviors. The birds interacted with one another in an endearing manner. They would pick at each other, as if preening. I wasn’t quite sure if this was curiosity, playful, or truly preening. They would also watch flies buzz around the nest, as if they were about to pounce. You could see the predator engineered mind in the way they followed the flies. They were figuring out what they needed to do to survive.

Male (R) and female (L) Gyrfalcon fledglings. Digiscoped with a Zeiss Diascope 65 T* FL

Male (L) and female (R) Gyrfalcon fledglings. Digiscoped with a Zeiss Diascope 65 T* FL

Although we missed the first flight of the female, we’ll have a few more opportunities to try with other nests. This means more hours behind the scope to watch, and more hours to learn.

To find out more about The Peregrine Fund’s Gyrfalcon Program, visit The Tundra Conservation Network and www.peregrinefund.org

Banding Nestling Gyrfalcons in Western Alaska

by Bryce W. Robinson

Gyrfalcon Nestlings

Photo 1. Gyrfalcon nestlings just after seeing their very first human being. One nestling is attempting to hide, while the other looks boldly into the eyes of the onlooking researcher.

The best part of working on a project focused on nesting Gyrfalcons is interacting with the nestlings. I can’t help but spend a moment or two to admire them each time I get one in my hands. They are young, yet full of personality and intelligence. I lose the ability to articulate the experience of dropping into a nest, and being the first human these nestlings have ever seen. Their response is remarkable, as they recognize me as an intruder and prepare to fight. There is, however, a certain degree of curiosity in their eyes. What impresses me most is their confidence, seen in their posture and stare.

Female Gyrfalcon Nestling

Photo 2. A tenacious young female Gyrfalcon, age 25 days. She is full of fight and intelligence. This attitude will serve her well after she leaves the nest and needs to learn to hunt and kill to survive.

We schedule our second round of nest entries when the nestlings are 25 days old. At this point their legs have fully developed, so we can outfit them with aluminum USGS leg bands. These bands give them a unique identification number, so that if the bird is caught or found researchers can tell where the bird came from, and where it went.

Banding Gyrfalcon Nestlings

Photo 3. Crimping the “lock-on” band. Most Gyrfalcons take band size 7B. We put bands on the right leg, and crimp a metal fold-over to ensure this piece of leg jewelry stays with the bird for its entire life.

As the nestlings grow, they begin to realize the tools that evolution has provided them to hunt, kill, and defend themselves. When we enter the nests to band, the nestlings have developed into fighters. They bite, rip, and use their talons to lash at intruding researchers. Because of this newly developed tenacity, working with them takes its toll.

Part of the Work

Photo 4. A hand weathered by tenacious Gyrfalcon nestlings. This is part of the work. The young are held in a way that they are unable to bite the hands of the researcher, but they are intelligent and talented. Often, they figure a way to make us pay for the important data we collect.

It’s great to see youngsters that have so much fight. This aggressiveness will translate into behaviors necessary for their survival. Although the most aggressive young are not the most enjoyable to handle, it means the birds have what it takes to be a large falcon in the Arctic.

weight

Photo 5. Weighing a young Gyrfalcon. We weigh the nestlings to help calculate a general age, if unknown. Weight also helps us determine the health of the nestling.

Apart from banding, we have a number of other tasks to complete while handling the young. We take DNA samples, weights, wing and tail measurements to estimate age, and check for parasites. After each nestling receives its treatment, we switch out batteries and memory card in the nest camera. We will not come back to the nest until the young have left, so it’s important to make sure the camera continues taking data until the end.

So far, we’ve been to three of our twelve nests. Our hands have a lot more abuse ahead of them, but we are excited to continue nonetheless. More pictures and stories to come.

Thanks to Ellen Whittle for the photos of the work

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

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)

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 ScienceFriends 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