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Hi Nick & All, Jan 24, 2016
Once again I think your overall approach is sound. One should always =
attempt to stand back and identify the major forces before fussing about =
possible minor forces.
And if the context is species decline then it will be strange indeed =
if the three major forces at play are not habitat quantity, habitat =
quality and habitat continuity. Abundant food in July is worthless if =
May, June, August and September are filled with want.
Predation usually has the effect, on average, of removing the less =
agile, the less healthy and less the capable and thereby gives the =
remaining population better access to food, shelter etc and a better =
shot at survival. For a stable population, temporary growth must be =
balanced by attrition. So predation can have an effect on population =
only in extremely unusual circumstances [ e.g. flightless birds who =
evolved in the absence of flightless predators, such as rats.].=20
Swifts, so I understand, land only after they have entered a nesting =
or communal roost. And I also understand their decline has been =
dramatic. How much of their decline is due to flying cats or other =
super-cats who somehow nab them just before or just after landing ?
Yt, DW, Kentville
----- Original Message -----=20
From: Nicholas Hill=20
To: naturens@chebucto.ns.ca=20
Sent: Sunday, January 24, 2016 1:37 PM
Subject: Re: [NatureNS] Vancouver has new "bird strategy"
yes Darrell, they have an impact. My point is that this factor is =
overblown and is not put in context of the many other factors that are =
truly reducing bird populations in the temperate region:
climate change
land use (e.g. short rotation forestry)
pesticides
oil?
Cats, cars, windturbines, reflective glass would be minor in =
comparison and I'd suggest we first focus on the major causes of decline =
and then look at tempering the minor threats which we are not going to =
fully eliminate as they are part of our life style:
1. Cat--keep cat in at night, fix feral cats and get them places
2. Car--slow down..I killed a swallow last year when in what I thought =
was a hurry
3. Windturbines--research placement of windmills out of flight =
pathways
4, Glass--hard to know how to reduce bird impacts on existing windows, =
this national geographic article discusses some ways
=
http://news.nationalgeographic.com/news/2014/11/141113-bird-safe-glass-wi=
ndow-collision-animals-science/
We won't get anywhere legislating that cats be not allowed out but =
increasing attention on barn populations and making people responsible =
(or finding funding for) for fixing barn cats on their property, then =
suggesting that owners keep their cats in at dusk and night, will have =
impacts. Currently, this negative focus on cats creates the impression =
that a biodiversity crisis is the fault of cats not their humans who may =
also drive cars profligately and eat crops grown using neonicotinoids.
Nick
On Sun, Jan 24, 2016 at 11:43 AM, <darrell@abolitphotos.ca> wrote:
I disagree Nick, any animal can become a pest and cats and their =
irresponsible owners are exactly that. Myself, living in the countryside =
where cats are brought to barns and dropped off and many owners letting =
them roam free, I have seen many birds killed. Seen one cat jump up on a =
cloths line to kill a saw-whet owl. An impressive predator but way too =
many (all) at loose in the daytime and night. Dog owners are not allowed =
to let their animals/predators roam free and neither should cat owners. =
No pet should be allowed to roam free to kill at will, period.
=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
On Sun, 24 Jan 2016 11:24:43 -0400, Don MacNeill =
<donmacneill@bellaliant.net> wrote:
I agree Nick.
Don
Don MacNeill donmacneill@bellaliant.net=20
On 24/01/2016 10:37 AM, Nicholas Hill wrote:
Grayson and Calver (2004, Regulation of cat ownership to protect =
urban wildlife: a justification based on the precautionary approach. =
Royal Zoological Society NSW 169-178) found previously that Cat Density =
was not a predictor of passerine numbers but that distance to bushland =
and the density of urban housing were (both negative factors). In the =
study cited above (regulation of cat ownership etc), they conclude that =
"cat welfare is the key issue in a precautionary approach for protection =
which respects interests of cat owners". Cat welfare means keeping the =
beasts in at night and desexing them so that we do not have a feral cat =
problem. In the country here, people let cats breed in outbuildings and =
this leads to a desperate situation for these cats and for wildlife. =20
Other authors warned that conclusions drawn in Britain over the =
impact of cats (million birds and small mammals killed) were drawn from =
data on one single village study in Felmersham. This author (BM =
Fitzgerald, 1990. is cat control needed to protect wildlife? =
Environmental Conservation 17: 168-169) questioned the extrapolation =
which we should in a rural area like NS where birdlife is spread widely =
over woodland and clearings
We have 3 desexed rescue cats that are in at night and well fed. =
There is a local impact on mouse, vole and shrew (no birds seen taken =
yet) but the population of these animals is greatly increased by the =
landuse round the house..as was observed in Felmersham (rodents and =
house sparrows there).=20
Surely all of the following factors need to be considered before =
we relegate the cat to the indoors:
woodland edges..plant more trees
brush piles..dont be tidy, a pile of woody debris is a refuge =
for small birds and voles
sustainable agriculture..minimize use of pesticide sprays (see =
the " Declines in