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Hi Ron;
=A0
Scott's comments/concerns have been expressed to me before in regards to th=
e BBS data we gather.=A0 Cindy Staicer, from whom I took an Ornithology cou=
rse at Dalhousie, believed that the birds singing on a BBS route in June we=
re unpaired birds and therefore could not be used to give an indication of =
how many birds were breeding on that route.=A0 It certainly made sense - bu=
t raised a lot of questions in my mind, such as: if a lot of birds are sing=
ing on territory, does that mean they were attracted there because it was g=
ood breeding habitat?=A0 other birds of the same species are nesting fairly=
close by?=A0 the singing birds found an abandoned nest site and were hopin=
g to use it?=A0 There's no sure=A0way to answer these questions but it woul=
d seem that a lot of birds singing in one area would be an indication of a =
fair amount of breeding success even if it weren't those particular individ=
uals who were doing the breeding.
=A0
Since all these surveys are meant to show indications rather than exact res=
ults (there's no way to say exactly how many birds are present when you onl=
y spend a proscribed number of minutes at each stop) then perhaps BSC (and =
Cornell and Audubon) is way ahead of us on this?
=A0
Cheers;
Suzanne
=A0
=A0
=A0
=A0
--- On Wed, 4/17/13, Ronald Arsenault <rongarsenault@gmail.com> wrote:
From: Ronald Arsenault <rongarsenault@gmail.com>
Subject: Re: [NatureNS] Lapland/Laconia Owl Monitoring Route
To: naturens@chebucto.ns.ca
Received: Wednesday, April 17, 2013, 9:10 AM
Hello Patricia,
Very interesting question and one to which I do not know the answer. =A0I s=
hould also point out that the sentence which prompted your question was my =
interpretation of what Scott had said, so I will attempt to clarify. =A0Ple=
ase note that this is based on a=A0conversation=A0which happened three to f=
our years ago.
As I recall, Scott found during his monitoring that owls were less vocal wh=
en tending nests with eggs or young than was the case during years when the=
y did not nest or the nesting was not successful. His concern was that the =
results of the owl survey were being (or would be) interpreted as "more cal=
ls =3D more birds", which his monitoring showed was not the case.
At the time, his intent was to discuss his findings with Bird Studies Canad=
a to make them aware of his concern. I do not know what eventually happened=
. =A0Perhaps the "silent listening" was implemented as a result?
I do not recall Scott going into detail re owl behaviours that would explai=
n this. =A0I would suggest though, that there are a number of factors which=
are likely to affect the calling rate, including the response rate to play=
back, of owls. However, I would not expect complete suppression except for =
cases of severe starvation. =A0Some factors which likely affect the calling=
rate of owls (with or without stimulation by playback) are: =A0timing - ho=
w far into the nesting season are the owls when the survey is done; whether=
or not the bird is paired - single birds would be more motivated to call; =
prey density - more time needed to catch enough prey =3D less time for call=
ing; distance from nest - the closer the playback to the nest, the likelier=
the response; density of the owl population could even play a role; perhap=
s even the age of the birds could also be a factor - well established pair =
vs first time nesters?. These are just some of the factors which come to
mind, and of course, these are not necessarily independent of each other. =
=A0Perhaps others (Randy?) can add to or correct the above.
Hope this helps,
Ron
On Tue, Apr 16, 2013 at 10:56 PM, P.L. Chalmers <plchalmers@ns.sympatico.ca=
> wrote:
Hi Ron,
=A0=A0=A0=A0=A0=A0=A0=A0This is an interesting observation.=A0 But it leave=
s me with a question.=A0 Are "owls which have settled down with nesting dut=
ies" less likely to call AT ALL, or just less likely to respond to a record=
ing?=A0 The ":silent listening" portion of the survey, which is the first p=
art, preceding the broadcast of recorded calls, is considered the most sign=
ificant part of the survey, I believe. {In some parts of the country the of=
ficial survey protocol doesn't use broadcast calls at all.)=A0=A0 So are ow=
ls which are freely calling, i.e. when unprovoked, more likely to be unsucc=
essful breeders than those who remain silent?
=A0=A0=A0=A0=A0=A0=A0=A0 Suzanne Borkowski and I usually detect many of the=
owls we find during those first two minutes of the survey; if they react t=
o the broadcast calls later, it gives us more time to confirm distance and =
direction etc.=A0=20
=A0=A0=A0=A0=A0=A0=A0=A0Cheers,
=A0=A0=A0=A0=A0=A0=A0=A0Patricia L. Chalmers
=A0=A0=A0=A0=A0=A0=A0=A0Halifax
=A0=A0=A0=A0=A0=A0=A0=A0
At 02:16 PM 16/04/2013, you wrote:
Hello Randy,
This may in fact be good news.=A0 Scott Makepeace, NB Dept. Nat. Resources =
biologist who monitors owls, told me that his work has revealed that the re=
sponse rate of owls is actually inversely related to their nesting success,=
especially with Barred Owls, if I remember correctly.=A0 In other words, o=
wls which have settled down with nesting duties are much less likely to res=
pond to a taped call than are owls who are either looking for a mate or who=
se nesting attempt has failed.
Hope this cheers you up!
Ron
On Tue, Apr 16, 2013 at 11:30 AM, Randy Lauff <randy.lauff@gmail.com> wrote:
Krista and I did the Fairmont (Ant. Coi.) route last night. Frogs were bare=
ly an issue as it was about -3 oC the whole time. Three or four years ago, =
I got a dozen (?) or so Barreds, GHOW and S'whets. Last year, skunked. This=
year, under similarly ideal conditions as last year...skunked. Very perple=
xing.
Randy
_________________________________
RF Lauff
Way in the boonies of
Antigonish County, NS.
On 16 April 2013 01:13, James Hirtle <jrhbirder@hotmail.com> wrote:
An interesting evening for running this route with owls on 8 out of 10 stop=
s.=A0=A0 We missed out on owls interestingly on two of the stops that we us=
ually get them.=A0 One of these stops now has a trailer at the location, so=
that could be the reason.=A0 The other stop we always have wood frogs and =
spring peepers so loud that it is unbelievable,=A0 but by that point the te=
mperature had dropped to around freezing.=A0 Wood frogs and spring peepers =
were at the first five stops and I suspect we would have heard them on all =
stops had the temperature not dropped.=A0 As the temperature dropped the ow=
ls seemed to become less vocal.=A0 I don't know if any studies have been do=
ne in respects to this observation or not.=A0 In all we had 10 barred owls.=
=A0 Most of the owls all except for the first stop where there were three, =
two of which were seen, were all more distant than is the norm on this rout=
e.=A0=20
=A0
James R. Hirtle
Bridgewater
--=20
Ronald G. Arsenault