next message in archive
next message in thread
previous message in archive
previous message in thread
Index of Subjects
<div>The project has tagged snowy owls from Minnesota to Massachusetts w --089e0149c506c9c60c04f458150c Content-Type: text/plain; charset=ISO-8859-1 hi folks, The question of the relationship between plumage colour and survivability in the South (and North) is interesting... Although sometimes they are difficult to see in snow-covered environments, behaviourally, they are not that cryptic...using mounds, telephone poles, roof tops. A recent paper (IBIS, 2011, which, disclaimer, I haven't read) suggests that darker plumage is almost always absent from the most conspicuous areas of the body (face, throat, breast - although, those could be hidden quite easily with posture adjustments), perhaps suggesting a role of plumage colour in sexual signalling too... To build on Andy's ideas, eBird also now allows users to search for checklists containing images or videos and there is a wealth of Snowy data up there...any patterns in the plumage of birds by latitude, snow cover, date? (there are issues of differences in detectability of these owls related to plumage patterns and snow cover too that would have to be faced...) cheers, James. On Tue, Mar 11, 2014 at 1:39 PM, Andrew Horn <aghorn@dal.ca> wrote: > Hi all, > > We'll know a bit more about these winter irruptions thanks to Project > Snowstorm, whose website is full of useful info and very cool maps of the > movements of several individual owls: http://www.projectsnowstorm.org > > The project has tagged snowy owls from Minnesota to Massachusetts with > transmitters that track their winter movements. It's a crowdfunded project > (thus the site's many pleas for funds) that was started to take advantage > of this winter's big irruption, since so little is known about where > wintering snowy owls go and why. > > Cheers, > Andy > > > On Mar 11, 2014, at 1:02 PM, James W. Wolford <jimwolford@eastlink.ca> > wrote: > > My experience from Alberta in the 1960s & '70s was much like Lance just > discussed re Montreal area, that snowy owls came south every year, but the > numbers vary greatly from year to year. And, as Lance says, it is assumed > that those overwintered owls that survive and are capable of heading back > toward the north do so. Their northward destinations would be unknown > perhaps for the immatures, but definite for those that had previously > nested at least once. > > I disagree with Jamie Simpson that because the southward irruptors have > no definite destination, other than some place with food, that they would > have no instinct or desire to head back to the north after winter. > > I do recall one example of a snowy owl that stayed in Nova Scotia for > the summer. It was very surprising one year in The Brothers Islands off > the Pubnico communities, and caused a lot of problems for the roseate terns > that were trying to raise young there. Consult Ted d'Eon/D'Eon? on when > that happened, in the 1970s? or early 1980s? > > Cheers from Jim in Wolfville. > > Begin forwarded message: > > *From: *"Laviolette, Lance (EXP)" <lance.laviolette@lmco.com> > *Date: *March 11, 2014 12:04:15 PM ADT > *To: *"naturens@chebucto.ns.ca" <naturens@chebucto.ns.ca> > *Subject: **Re: [NatureNS] Surviving Snowy Owls - What Next?* > *Reply-To: *naturens@chebucto.ns.ca > > Hi Jamie, > > My take on this is that while this may be a food/territory driven > phenomena it is not simply a case of Snowy Owls, mostly young, being driven > south to never return. From my experience in the Montreal Region, many owls > make the trip south each year and have done so for a number of years. This > has been confirmed through individuals with unique physical characteristics > that could be used to identify them. They stay for the winter months and > then head back north. At least I believe they head back north. They > certainly leave southern Quebec. > > Whether some of these birds remain through the summer or not is another > matter. There are a number of bird families that irrupt south. Along these > lines, every year Ron Pittaway publishes the winter finch forecast which > predicts which finch species will irrupt south in the coming winter. In > most cases the birds that irrupt south and survive head back north. However > there are a number of cases where northern species have bred in the south. > In Nova Scotia I would bet that a lot/most of the mainland Evening > Grosbeaks that are still breeding are a result of a huge irruption that > took place throughout eastern Canada in the 1970s (I think that's the time > frame). > > So I'd say that irruptions serve both an immediate survival role, > sending excess population to other areas in search of food, and a mechanism > that may result in an expansion of the species' range. Some of Nova > Scotia's Snowy Owls may stay through the summer and perhaps survive. Some > may leave and return again next year. > > All the best, > > Lance > > *Lance Laviolette* > Glen Robertson, Ontario > > > *From:* naturens-owner@chebucto.ns.ca [ > mailto:naturens-owner@chebucto.ns.ca <naturens-owner@chebucto.ns.ca>] *On > Behalf Of *Shouty McShoutsalot > *Sent:* Tuesday, March 11, 2014 8:43 AM > *To:* naturens > *Subject:* EXTERNAL: Re: [NatureNS] Surviving Snowy Owls - What Next? > > My understanding is that irruption and migration are two very different > behaviors, and that irruption is a diaspora - the animal leaves because it > is forced to, with no predefined destination as exists in a migration, and > thus no instinct to return to it's point of origin. > > > On 10 March 2014 14:24, Paul Ruggles <cpruggles@eastlink.ca> wrote: > Jamie, > I have been videoing two snowys for over a month at Lawrencetown beach. > They seem to have moved away in the past 2 weeks. I thought they might have > begun their migration back to the tundra? Have any of you seen any lately? > Paul. > > > On 2014-03-10, at 11:30 AM, Shouty McShoutsalot wrote: > > > My understanding is that there are surviving overwintered Snowy Owls in > NS from the irruption of Dec 2013; that these birds are not migratory in > the normal sense; that an irruption is not a predictable, repeatable > migratory event; and that, having survived a winter that I believe was > fatal to a higher than normal percentage of our resident bird predators, > the surviving Snowys have proven adaptive and survival skills in NS. > > > > So I'm wondering what becomes of these birds. Will they become > residents like our other Owl species, perhaps establishing territory and > reproducing? Will they return from whence they came e