Thanks for all your hard work on tracking this info Chuck!! Maybe one of these days I'll actually find one when I go looking for it.
On Jan 7, 2018 11:15 AM, "Chuck & Jaye Otte" <otte2...> wrote:
Mark and Bob were talking about Snowy Owls, which seems to be a very popular topic now days.
I decided to get a hot cup of coffee and pulled up the Birds of North America (BNA) online account for Snowy Owl. I last read this in early 2012 during that big irruption and was pleased to see that it had been recently updated with new findings from the 2011-12 irruption and was surprised to see the Robbins & Otte article that was in the KOS Bulletin referenced. It's nice to know that researchers do read the KOS Bulletin.
One of the things that the BNA account pointed out was that there is a lot we don't know about Snowy Owl behavior. The BNA account did indicate that a vast majority (probably 80% or better) of the birds that move far south in irruption years are hatch year birds, i.e. they are less than one year old. But it also pointed out that every irruption is different.
It also talked about how much variation there is in plumage of Snowy Owls. Reserachers can't agree on how old Snowy Owls are when they achieve "definitive basic plumage". It is felt that it may take females 4 - 5 years to reach this and males may take 8 to 10 years to get there. Again, so much work is needed on wild birds. Most of the molt occurs in late summer so when birds reach Kansas in early to mid winter they should still be in fairly fresh plumage. Males of the same age are always much whiter than females of the same age. In looking at some of the photos this year I'm not so sure that some of the photos of Kansas birds that were clearly males that I thought might be second year birds aren't in fact hatch year birds. There are so many subtleties that need to be examined in photos of these birds and unfortunatley the preferred photographers pose - frontal - is likely the worst for age/sex determination.
Bob, and others, mentioned and speculated on movements of the wintering Snowies. Again, there are generalizations made by researchers that need more observations and research, and there seem to be as many exceptions as observations. It is generally felt that females are more likely to set up breeding territories and defend them against other Snowies than are males. Males were often felt to be somewhere for a few days, less than a week, and then move on. Of course, my caveat to that is that we are usually viewing from roadsides that occur once every mile. Even though Snowy Owls are one of our biggest owls, if they are in the middle of a section, a half mile away, it doesn't take much of a change in topography to hide them. Additionally, many of the birds that get as far south as Kansas, likely do not survive. If a Snowy Owl dies in the middle of a tall grass praire, or even in the middle of fields with crop stubble on it, the carcass is likely never to be found. In 2011-12 Mark and I often felt that if observations were more than 2 miles apart they are likely different birds. This seems to match up pretty well with researchers who noted maximum size for winter feeding territories was around two square kilometers, depending of course on food availability.
Snowy Owls are inherently nomadic - that is one thing that all researchers agree on. Which makes it difficult to track them and even to obtain good population estimates. Overall survival rates from fledglings to second year birds is hard to obtain because they may not return to their natal range the second year. I think that some of Bob's musings are on target. I think many of the birds that make it to Kansas are never seen or reported. Many farmers/ranchers may see them and while they know it's not common to see, unless they know a birder, may never report them. Likely some of the birds are reported more than once as they move around. But with as many photos as we are now obtaining, we can sometimes know definitively that there are different birds in a locality. But bottom line, we just don't know.
During and after the 2011-12 irruption, Mark Robbins and I caught a fair amount of flak from people who didn't want to believe that many of these birds died and never returned north. I think our paper showed that a great number of the birds that were salvaged were in very poor physical condition. This year quite a few people again were questioning our statements because of releases from Project SNOWstorm saying that most of the birds were in fine condition. Project SNOWstorm has done some great work and greatly added to the knowledge about Snowy Owls. BUT, it is important to keep in mind that most of their work and data are about owls that reach the very northern Continental US, a location where they are basically expected annually. I have no doubt that the information is accurate for those birds. But once the birds have moved as far south as Kansas, I think their physical condition has deteriorated significantly. If you haven't read the paper that was published in the KOS Bulletin I would encourage you to do so. It can be accessed at: http://www.ksbirds.org/kos/bulletin/Vol64No4.pdf
Last week I read a blog by a birder on the east coast who referred to Snowy Owls as the Holy Grail bird for bird watchers. I don't know if I agree with that but I do understand the attraction to them especially if you've never seen one before. I do think some people pursue them excessively once they do find them trying to get a better view or a better photo. In fact they've had to restrict access this winter at some locations along the Atlantic Coastal area due to unethical behavior that resulted in basic harassment of the owls. I hope none of that is occurring in Kansas.
After the irruption of 2011-12 I didn't expect to see anything like that for a long time. This year's irruption is not to that level, yet (but hey, there's a lot of winter left), but it is certainly noteworthy. Somebody recently asked me why so many of the sightings were near roads and I had to stop and see if they were serious. When I saw that they were I just responded, well that's where the people are! Past irruptions lasted until very late March early April. There's a lot of winter left so keep your eyes open as you're traveling down the roadways!
I am maintaining a website with a map that shows what counties Snowy Owls have been seen this year. It is at: http://ksbirds.org/KS_SNOW_2017_18.htm If you have a first hand sighting of a Snowy Owl in a county not shaded green, or you don't think has been reported, please send me the date and location (and photo if you happened to have gotten one) as I am once again trying to maintain a database with sightings.
Enjoy the birds! Chuck
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