Thanks for the discussion and the opportunity to clarify certain points.
My point about the removal of grain elevators is not mainly about a food source. These were also the site of huge breeding colonies. The structure itself featured abundant niches ideally suited for their nests. The area where the grain was dumped was a major location with nests jammed next to one another across meters of beams and other areas The large doors were typically mostly opened to rid the area of grain dust and allow access except during winter or at night. in many instances access could be gained by moving through open areas associated with the hinges. As a young person. I noted various measures/campaigns to remove the abundant nests within the elevator itself. The food was also as mentioned readily available next to breeding opportunities. I think it was the combination that was vital. It is my view that these colonies were a source of large reservoirs of populations.
The removal of elevators is I think a much more substantial number than perhaps you suggest. Lampman where I attended high school had seven elevators and many of the even smaller villages featured two to five. Extrapolate this based upon the disappearance of the many hamlets, villages and town and I think the total numbers are indeed large.
The significant reduction of farm numbers, including those with mixed farm operations, must have impacted again the opportunities for successful breeding colonies. The steep reduction overall in numbers of farms is well supported by statistics about the increasing size of farms and the loss of rural populations.. This reduction though is not distributed evenly across the Province. I will concede that in certain areas, hobby farms and horse operations have sprung up particularly near larger cities. I suspect that Saskatoon maybe such an area where this development is happening. And of course the increasing prices for cattle is an incentive for expansion of this type of operation.. However, newer barns and a different type of metal grain storage appears to have reduced opportunities for successful breeding and feeding. South of Regina there are very few farms with cattle operation, instead grain farming is the major mode. Given the features just mentioned many/most of these farms do not have an excellent niche for that species.
Whether House Sparrow populations are in general decline or not in this area can be estimated from CBC's and perhaps other data. ( I know though that when I engaged in Spring and CBC's I did not seriously count every House Sparrow. They were just too abundant.) I think from my observations that these populations are in decline both within cities and in the rural areas. Whether this is a consistent pattern or not is perhaps yet to be proven. I guess as well we would have to complete a House Sparrow census with a previous population baseline to prove or disprove population dynamic or changes.The House Sparrow is reported as declining within certain areas of Britain and Europe. I am uncertain of the dynamics of this as well.
I'm uncertain that zero tillage has impacted House Sparrows;however, it no doubt has impacted many other species. Whether this is a positive across the board is debatable. We in the Regina area have noted a decline in nesting Horned Larks which appear to have better adapted to the previous tilling regimes. Whether this population decline has a causal or correlation linkage is not clear, in my opinion. The impact of herbicides and in some instances pesticides in the food chain perhaps has some consequences. Again I would need to see the research associated with zero till.
I think the diversification of crops particularly the lentils and peas has had a major impact for several species other than House Sparrows. These crops are susceptible to spontaneous shelling if the harvest is not timely and prompt. I have noted as well that sunflower crops both harvested and not harvested provide great winter habitat for Gray Partridges, Sharp-tailed Grouse, Snow Buntings, Horned Larks and Redpolls species.I have observed that migrant waterfowl including Mallards and Snow Geese occur in great numbers in harvested lentil or pea fields. When one walks into these fields it becomes obvious that there is much wastage on the ground. This also attracts mice and voles which in turn attract raptors.
The impact of predators such as squirrels in urban environments as well as Merlins and Cooper's Hawks is perhaps another factor which I have neglected to discuss. Rather than speculate about more factors rather I'll perhaps end at this point.
----- Original Message -----
Sent: Tuesday, January 29, 2008 10:51 PM
Subject: [Saskbirds] Re: House sparrows
The house sparrow's seem to be doing as well as ever on the farm. My farm, and any other
I visit, seem over run with sparrows- as usual. I'm not so sure the grain elevators
disappearing removes much of their food source... every farm has more than enough
spilled grain around to support many hundreds. A few hundred grain elevators
disappeared, but there are still tens of thousands of farms left, with lots of spilled grain
I believe that the biggest single practice which has changed the landscape for many birds
and animals, is the advent of zero tillage, by a large percentage of grain farms... the grain
stubble is never tilled, and every field has some grain which remains on the surface year
round. I think it has resulted in a bigger food source for many birds- partridges and geese
are obvious beneficiaries. I also believe mice do very well with this extra food source- I've
noted a marked increase in fox and coyote numbers the past decade. Also, there is no
question that it has helped the deer population proliferate. In all, I think it has had a very
positive effect right up the food chain.
--- In Saskbirds@yahoogroups.com, "dwnord" <dwnord@...> wrote:
> Thank you, Bob, for your thoughts on sparrows. I guess the disappearing grain
elevators would make a differenc. Dorothy Nordquist
> [Non-text portions of this message have been removed]
[Non-text portions of this message have been removed]