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Index of Subjects Hi John & All, I would not doubt how they got to SW NS (birds) or why they survived (sufficiently mild climate); as you say. It is true that trees sometimes die as a result of insect feeding; Spruce Budworm being a prime example. In this case new growth is consumed and old needles eventually die. And the Woolly Adelgid in sufficient numbers may be just as damaging; by consuming sap and killing needles. In general, weak overstocked trees with relatively small crown volume will succumb to stress, such as needle loss or sap loss, before well spaced trees with larger crowns. And I wonder if the same applies to the Hemlock situation. It seems obvious to me that it would; provided thinning were done before the trees are past that critical tipping point. If some insect threatens to kill a stand of trees by tapping phloem sap and causing loss of needles then the first logical action would be to thin the stand so each tree can develop a larger crown. And I fail to understand why this was not done years ago. Threat of spreading the pest if the wood is used, e.g for firewood, is a paper tiger because it is agreed that the pest can travel by bird flight. Yt, Dave W. Kentville On 5/19/2019 1:50 PM, John Kearney wrote: > Hi David and all, > Birds probably do move the adelgid around. They could have been carried up by migratory birds from the eastern United States. However, migratory birds would also have carried them into northern Maine, southern New Brunswick and Northern Nova Scotia where there are no hemlock woolly adelgid infestations. I suspect it is a mild winter climate that allows the adelgid to gain a foothold. Have you got any insights on this from your forestry perspective? > John > > -----Original Message----- > From: naturens-owner@chebucto.ns.ca <naturens-owner@chebucto.ns.ca> On Behalf Of David Webster > Sent: Sunday, May 19, 2019 09:08 > To: naturens@chebucto.ns.ca > Subject: Re: [NatureNS] A new song needing ID > > Hi All, > > With regard to the Woolly Adelgid has anyone done the obvious and established plots to see if selective cutting, to reduce competition for water, or watering in dry weather, can increase Hemlock vigor enough to offset Adelgid effects ? > > Because Hemlock roots readily grow together (graft) and seedlings consequently gain nourishment from nearby large trees there is a tendency to develop dense Hemlock stands; vulnerable if ppt. becomes too erratic. > > Hemlock makes great firewood, readily split even if full of branches, and the bark practically falls off. If used locally there would be zero risk of spread. And can one be sure that birds do not help move these insects around ? > > Dave W, Kentville > > On 5/18/2019 10:58 PM, Donna Crossland wrote: >> Hi Nancy: >> >> I took a listen to the recording, but found myself running through a >> list in my head. I would suggest they are call notes rather than a >> "song". Distinguishing all the calls is pretty tough (at least for >> me), with the exception of some of the more distinct ones. Maybe >> someone else has a hypothesis. It was strange to continuously call >> like that. It's too early to be 'upset' and calling over issues like >> nest robbers or predators, etc. Was it coming from mid-canopy or >> upper? That helps whittle down the possibilities. >> >> It seemed thrush-like perhaps, but not the distinct calls of any of >> the species regularly encountered. >> >> By the way, I hear that you are enlisted, as well as several other >> birders from across the province, for surveying bird species in >> hemlock stands this spring (and ensuing years, hopefully). That's >> terrific. It's an excellent idea by John Kearney and the NS Bird >> Society, to suggest a monitoring program to allow comparisons between >> song bird communities in hemlock stands that are infested with Hemlock >> Woolly Adelgid (HWA) and uninfested hemlock stands in NS. There may >> be shifting population trends if or when hemlock begin to decline. >> What a worthy application of birding skills. Thanks, Nancy. (I'm >> planning to carry out some additional hemlock surveys in Kejimkujik >> for the same purposes. It will be great to compare with a more >> regional data set.) >> >> Enjoy the birding under feathery hemlocks. They were singing despite >> the gray and breezy coolness today. The Black-throated greens and >> Blue-headed Vireos really stood out. I heard some chimney swifts at >> the Eel Weir and smiled, since I knew Paul McDonald would not have >> imagined them (he mentioned hearing them earlier this week). They >> were present (but fleeting of course) with a sizeable group of barn >> and tree swallows. >> >> Happy birding. Keep testing us with your recordings! >> >> Donna Crossland >> >> formerly of E. Dalhousie >> >> >> On 2019-05-18 7:38 p.m., NancyDowd wrote: >>> This is the first time I’ve heard this song around here. Repeated >>> every 15s. Most always the 3notes version shown (once or twice a >>> 2note version). Bout lasted from the time I went outside until bird >>> went out of range 5-10min later. Loud and emphatic enough to be heard >>> over the strong winds. At times detected a burry quality to the first >>> notes. Bird was moving through trees and eventually went out of >>> range. In mainly hardwood forest on a point in lake, some cottages >>> nearby. >>> >>> Amplified only: https://macaulaylibrary.org/asset/159368101 >>> >>> Any ideas? >>> >>> Thanks again, Nancy D >>> E Dalhousie, Kings >>> >> --- >> This email has been checked for viruses by Avast antivirus software. >> https://www.avast.com/antivirus
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