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--Apple-Mail-49-225513745 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Regarding the chimney swift, the history is a bit complex and of course the mathematics of this is/are unknown. Remember that before North Americans/Europeans built chimneys to which the swifts could adapt (which of course they did in spades), the main habitat for the swifts in North America and probably also in South America (wintering areas) was cavities in trunks and large branches of big trees that were old enough to have such fungus-or-other-related cavities. Needless to say, such habitats are long gone, and one wonders if humans and nature are capable of ever producing such again -- another question might be whether the swifts would ever evolve back to natural cavities? (Hopefully, artificial cavities/towers might eventually replace the lost habitats of old hollow trees and chimneys etc. with large enough openings for the entrance & exit of swifts. Another point to bring up is the foods of aerial insectivores like swifts, swallows, nighthawks, flycatchers, and ? and whether the likely problem with those insects might be amenable to any kind of corrective actions. We probably will never be able to show cause and effect for the declines of these birds. Another thing that has entered my mind is that agricultural chemicals are quite possibly parts of the problems, and they just might be affecting all sorts of kinds of biodiversity, other than flying insects. Cheers for now from Jim in Wolfville. Begin forwarded message: > From: Fritz McEvoy <fritzmcevoy@hotmail.com> > Date: July 11, 2013 3:18:42 PM ADT > To: NS NATURE <naturens@chebucto.ns.ca> > Subject: RE: [NatureNS] Barn Swallows and Chimney Swifts > Reply-To: naturens@chebucto.ns.ca > > Hi Rob and All, > I stand to be corrected here, but my understanding is that it > was not only the old barns that were required but that farming; > particularly the keeping of livestock; was also essential. The mud > and manure were used to build the nests and the insects the animals > attracted were a main food source. We lost our local Barn Swallows > shortly after the owners of the barns the swallows used for nests, > which are still here BTW, got rid of the last of their cows. All > the best. > Fritz McEvoy > Sunrise Valley, CB (near > Dingwall) > > > Date: Thu, 11 Jul 2013 09:25:49 -0700 > From: rrtwoods@yahoo.com > Subject: [NatureNS] Barn Swallows and Chimney Swifts > To: naturens@chebucto.ns.ca > > Not to take away from the rapid decline that these species and > others are experiencing, I have wondered did these two species > first benefit from mankind as the are both strongly associated with > man made objects. Were their numbers from the peaks 30-40 years ago > actually inflated due to man made structures being available. Prior > to the building of the large wooden barns across north america what > would have been the population of Barn Swallows. Suitable nesting > habitat would have been more limited and under much more > competition or predation. > > Todays modern barns are made of metal which are almost impossible > to attach nest to and are much more BIO secure than the wooden > barns of our forefathers. The old brick chimneys that once > abandoned, provided excellent habitat for the swifts are now > falling in disrepair or are destroyed in site clean up. Both of > these structures did not exist before the industrial age and are > becoming limited now thus maybe populations of these species are > actually returning to more normal levels. > > Owner of a wooden barn with 6 barn swallow nests > > Rob Woods > Georgefield NS > > > --Apple-Mail-49-225513745 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=US-ASCII <html><body style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; = -webkit-line-break: after-white-space; "> Regarding the chimney swift, the history is a bit complex and of course = the mathematics of this is/are unknown. Remember that before North = Americans/Europeans built chimneys to which the swifts could adapt = (which of course they did in spades), the main habitat for the swifts in = North America and probably also in South America (wintering areas) was = cavities in trunks and large branches of big trees that were old enough = to have such fungus-or-other-related cavities. Needless to say, = such habitats are long gone, and one wonders if humans and nature are = capable of ever producing such again -- another question might be = whether the swifts would ever evolve back to natural cavities? = (Hopefully, artificial cavities/towers might eventually replace = the lost habitats of old hollow trees and chimneys etc. with large = enough openings for the entrance & exit of = swifts.<div><br></div><div>Another point to bring up is the foods of = aerial insectivores like swifts, swallows, nighthawks, flycatchers, and = ? and whether the likely problem with those insects might be amenable to = any kind of corrective actions. We probably will never be able to = show cause and effect for the declines of these birds. Another = thing that has entered my mind is that agricultural chemicals are quite = possibly parts of the problems, and they just might be affecting all = sorts of kinds of biodiversity, other than flying = insects.</div><div><br></div><div>Cheers for now from Jim in = Wolfville.<br><div><br><div>Begin forwarded message:</div><br = class=3D"Apple-interchange-newline"><blockquote type=3D"cite"><div = style=3D"margin-top: 0px; margin-right: 0px; margin-bottom: 0px; = margin-left: 0px; "><font face=3D"Helvetica" size=3D"3" color=3D"#000000" = style=3D"font: 12.0px Helvetica; color: #000000"><b>From: = </b></font><font face=3D"Helvetica" size=3D"3" style=3D"font: 12.0px = Helvetica">Fritz McEvoy <<a = href=3D"mailto:fritzmcevoy@hotmail.com">fritzmcevoy@hotmail.com</a>></f= ont></div><div style=3D"margin-top: 0px; margin-right: 0px; = margin-bottom: 0px; margin-left: 0px; "><font face=3D"Helvetica" = size=3D"3" color=3D"#000000" style=3D"font: 12.0px Helvetica; color: = #000000"><b>Date: </b></font><font face=3D"Helvetica" size=3D"3" = style=3D"font: 12.0px Helvetica">July 11, 2013 3:18:42 PM = ADT</font></div><div style=3D"margin-top: 0px; margin-right: 0px; = margin-bottom: 0px; margin-left: 0px; "><font face=3D"Helvetica" = size=3D"3" color=3D"#000000" style=3D"font: 12.0px Helvetica; color: = #000000