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> reproducing? Will they return from whence they came e --20cf302236d1aa3c6704f4585ea7 Content-Type: text/plain; charset=ISO-8859-1 If birds go south in the fall and return north in the spring on a regular basis aren't they migrating and not irrupting? On 11 March 2014 14:30, James Churchill <jameslchurchill@gmail.com> wrote: > 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 1