Friday, February 04, 2011

Gyrfalcons, Ptarmigan, Peregrines and Sakers.

This week, thanks to The Peregrine Fund, Boise State University is hosting an international conference on Gyrfalcons and Ptarmigan in a Changing World. As a graduate student in Raptor Biology and a volunteer for the conference, I received complimentary registration to attend. My schedule allowed me to attend roughly 2/3 of the proceedings. It was an excellent event!

As I have reported on other conferences I have attended, this conference too was filled with rich information stuffed into 15-20 minute segments. There was barely enough time to think through one presentation before the next one began. Here is the briefest of summaries on many of the presentations. At the end I will summarize some of my most important insights from the conference.

The conference began with a keynote evening presentation on Polar Bears and climate change that was open to the public. It might seem like a unusual choice, but many of the climate issues facing the Polar Bear are also facing other arctic breeders such as Gyrfalcons and Ptarmigan. In some cases the linkages are more direct than just weather. Arctic cod play a role in both food chains. Arctic cod is tied to sea ice. The Ringed Seals eat the cod, and Polar Bears eat the seals. Some of the Gyrfalcon prey, such as sea birds, are also dependent upon the cod. As the ice retreats, the cod retreats, and the seals retreat. Polar Bears lose and sea birds lose. In some cases, this propagates up the food chain to Gyrfalcons. The keynote was a mixture of awesome photographs of the arctic and polar bears along with the harsh realities of climate science. The presenter finished off the discussion with his elements of hope. That hope sits with the possibility that we will cap CO2 emissions by 2020. If so, they predict polar bear populations will stabilize at a level well below today's population, but not at a critically low level. Not much to hold on to...

The sessions began on Tuesday morning with an welcome message by the Peregrine Fund, BSU Vice President of Research, and then Dr. Mark Fuller, head of the BSU Raptor Research center. Then the sessions began. First up was Mohammed Al Bowardi for a summary of Gyrfalcon's role in the history of Falconry in Arabia. Falconry has be active there for more than 2000 years. The Saker Falcon and Peregrine Falcon have traditionally been the birds of choice until Gyrfalcons became available. While the CITIES treaty does not allow for legal import/export of Gyrfalcons, there is a strong captive breeding program within the United Arab Emirates. In fact, the Abu Dhabi environmental agency was a financial sponsor of this conference. They are advancing the genetic analysis of falcon blood lines in the hope to conserve both wild and captive falcon populations. One of the great aspects of this conference is its breadth of topics from history, literature, falconry, conservation, climate science, etc.

Grainger Hunt summarized the challenges facing arctic species, highlighting some of the adaptive responses to the unpredictable conditions. While Gyrfalcons and Ptarmigan appear to be linked, the situation as it often is in nature is far more complex. Each species has its unique adaptations and responses which link them at times and not at others. As rapid change in the arctic unfolds, this system gets even more complex. This is why the top avian scientists working in the arctic were all in the room.

Tom Cade, an individual I have admired through the work of his long career, provided a detailed overview of the biological traits of the Gyrfalcon. Some of the most interesting points: 1) they evolved from the Saker Falcon, but we don't know how long ago (between 15,000 years and 2million years). 2) They can withstand harsh conditions by storing up to 300g of fat and another 300g in their crop! 3) They may even enter a state of torpor (lowered body temperature to conserve energy), which would explain the often lethargic behavior of some birds. 4) 50-90% of annual diet consists of Ptarmigan, but they also eat sea birds, waterfowl, hares, lemmings, and voles. 5) They have a very long reproductive cycles. Females must build nutrient and energy stores for laying long before most prey arrives in the arctic. At the moment they commit to a nest, there is only 3-4 hours of daylight per day.

Kathy Martin followed next with the life history of the three Ptarmigan species in the Nearctic - Willow, Rock, and White-tailed. She presented research evidence into each species different critical population variables. For example, for Willow Ptarmigan juvenile survival and fecundity drive population. For the Rock Ptarmigan its survival of juveniles and older females. For White-tailed Ptarmigan in the Yukon juvenile survival is most important, but for White-tailed in Colorado older female survival is most important.

Eugene Potapov discussed Gyrfalcon diet then Ivan Pokrovsky compared Gyrfalcon distribution in the Palearctic as compared to the Nearctic. In the Palearctic the Peregrine Falcon is the northernmost breeder while in the Nearctic its the Gyr. Gyrs are more likely to nest in trees in the Palearctic as well. Jeff Johnson presented the results of genetic analysis into different plumage colors in Gyrfalcons. They have isolated one specific gene (MC1R) that appears related to the various color morphs and also separates out the Saker Falcon. This has lead to an analysis of distinct populations. Early evidence suggests the Iceland population is unique, the Greenland population is unique, and the rest of the world is one meta-population. More samples are required for more refined analysis. Using this data in a study of nesting dates, the results show that gray males mate later in the season. There must be selection pressure for this. More study is needed.

The discussions from here shifted more toward climate change. Steve Kendall discussed climate change impacts on birds in the Arctic National Wildlife Refuge, the David Douglas highlighted some of the data sources used for climate change analysis. Rhys Green highlighted the utility of bioclimate models and talked through a case study of 450 European breeding birds. The approach he described is a similar approach to what I highlighted in a recent blog post on my thesis study area. Fascinating stuff. The more I see, the more I hope that all of these models are wrong!

In an interesting case study, George Divoky talked about his 40 years of studying the Black Guillemot. The Black Guillemot was never an arctic breeder. They do not fly over land, so were isolated from the arctic until the land bridge disappeared some 21,000 years ago. At this point they still avoided it as their breeding season requires 80 days of summer. With climate change they have been moving north. George documented their first arrival on an island in north Alaska in 1975. Since then the sea ice has continued to retreat, taking the arctic cod with it. As the Black Guillemot shifted their diet to less nutritious fish, brood reduction become more common. The change has also brought in other predators - polar bears due to low ice and Horned Puffins. In the latest breeding season of 183 nestlings - 90 were eaten by polar bears, 83 by puffins, 9 by other forces, leaving only a single fledgling from the colony. During George's career, this island went from too cold, to just right, to too warm. Amazing.

The conference continued, with discussions on Collared Lemming populations which are no longer cycling in Greenland, and then to chemical contaminant levels in arctic species which have been shown to track worldwide usage, even in the fairly isolated arctic. The only good news in this is that the Gyrfalcon has a lower exposure risk than other animals including the Peregrine Falcon. Back to climate change, Travis Boom presented his analysis of climate change's effect on Gyrfalcon distribution based on the climate model processes described above. The result is expected to be a 60% decrease Gryfalcon distribution this century. This is only the climate impact. Ptarmigan are expected decrease and shift their distribution as well. The really bad news - the shifts in fundamental niche are not the same for Gyrfalcon and Ptarmigan thus further decreasing the available niche for Gyrfalcons and putting their survivability in question. All of that research in only the first day of the conference! I had to miss day two as I attended my own classes and taught my labs.

Thursday morning the conference focused more strongly on the Paleartic with Russian scientists presenting their work on the Gyrfalcon and Ptarmigan distribution and dynamics in Siberia. The afternoon was dominated by presentations on the Saker Falcon, the closest relative to the Gyrfalcon, and the Peregrine Falcon which occupies the arctic along with the Gyrfalcon. I have pages of notes on these sessions as well, but will refrain from summarizing it all here.

Every time I listen to research on the arctic, I am amazed at how much faster climate change is occurring up there. As one researcher put it - the world has warmed by 0.6 degrees, but the arctic has warmed by 4-6 degrees. The number of freeze/thaw events per year have doubled. This is having dramatic effects on everything that lives there. Change is happening here too, it is just amplified up there. I have to respect the dedication of the researchers doing this important work. They are working in a very fascinating location, but as most field biologists realize, the glamor quickly wears off when the weather gets bad and the mosquitoes smell your blood. I am sure both can get quite extreme in the arctic. While the arctic may be far away and mostly removed from our daily existence, the chain of events occurring there are connected to everyone's world and will catch up to us at some point. The researchers are working to understand those effects to not only save the species that are threatened today, but also those that will be threatened tomorrow.

I have to thank the Peregrine Fund for putting this conference together. They led the effort to prevent the extinction of the Peregrine Falcon, have fought to save numerous other species around the world, and were instrumental in getting this world-wide discussion started regarding the fate of the Gyrfalcon. There are few organizations with their proven track record and get it done attitude. I am glad I could be a part of this conference.

1 comment:

Larry said...

Great job, Rob. Thanks so much for the summary. It made me feel nostalgic for the good old days when field biology was a bigger part of my life. I worked with Steve Kendall in Prince William Sound.