@parados,
To answer your questions as simply as possible, I have been a bird watcher in the past, and so I understand the difficulty and likely inaccuracies of a number of people that are doing the identifications and counting. It is not an exact science, the identifications are subjective and not determined by an instrument that has been calibrated to do the measurements in a consistent manner. As I have attempted to explain to you already, a scientific measurement done by an instrument is pretty straightforward and exact, while bird identification and counting would be highly influenced by who is doing it, which simple common sense would tell you that it varies. And even if the same people were doing it in all locations, it would still be highly influenced by other factors, including local weather (not climate), time of day, time of the month, and all kinds of factors. I pointed out one other factor that you ignored, which was West Nile Virus, which has wiped out almost entire populations of certain birds in some areas, one that I am aware of is the Magpie.
To summarize, the bird species and numbers, and migratory patterns, are interesting and possibly could add to the debate, but are hardly very deserving of representing solid evidence of something like global warming.
As a matter of note, I grew up on a farm, and as a boy in grade school, I became interested in nature and science, because of a good friend of mine that stimulated my interest in those things. That largely explains why I ended up majoring in geology and pursuing the career that I did. To make a long story short, as a kid, I was very familiar with the wildlife and other natural phenomena around the area, as was my brother and others. We trapped, hunted, and so forth, and as I explained, I became an avid amateur birdwatcher and accumulated long bird lists. I can report to you that the wildlife and bird populations varied by year, as far back as I can remember, which is the early 50's. One year, there was an infestation of field rats, literally hundreds of them in the fields nearby. Everything in nature is cyclical.
I can also attest to the fact that the armadillo has migrated northward from Texas, now into Kansas I understand, as part of its natural range or habitat. Whether this has to do with climate, I do not know. I also know that the number of armadillos has seemed to decrease greatly in the last 3 or 4 years in that area of Oklahoma. There are also many more deer in that area, an animal that we rarely saw as a kid. Also, wild turkey have recently exploded in population, although they have always been around as long as I can remember. The numbers of trees, and types, have also proliferated in the area, primarily due to human influence, but the numbers of cedars in particular have exploded just by nature itself doing the seeding and growth. There are now programs available for farmers to remove the cedars that have taken over entire farms or pastures, so that it can become more productive again.
The point of all of this is that climate is only one factor of many factors, and a bunch of birdwatchers going out and counting bird species, yes it is interesting, but count me as a skeptic in terms of proving anything. It could be considered along with other more reliable forms of data. I go back to the simple fact that weather stations must have reliable siting standards and the temperature data being gathered must be reliable. That is the foundation of any decent scientific research, it is sound and reliable data. So far, I don't think we have even established that, and therefore to liken this science to being in its infancy stage, we have not yet learned to crawl, let alone walk or run. The science has a long way to go to establish any degree of credibility, especially given the politicians that have invaded the science to the point of committing fraud to further their particular political cause.
