Accessing bar graphs
Click on the location name to view to view the HTML version of the bar graph (right click to open in new window).

PDF version (raw bar graphs only).
Click on  the PDF icon adjacent to the location name to view the Adobe PDF version (free Adobe reader required). The PDF should open in a new browser window in "fill width of screen mode". Depending on your display, this may look just fine or it may be over magnified. Play around with the scaling as you see fit. Printing tip: be sure to set scaling as "none" in the printer dialog box. The bar graph should then fit nicely on the page with room to 3 hole punch the left margin. Please let me know if you have any problems - thanks.

General Information
The bar graphs are based on personal data gathered on a regular basis as I go about my work. Data collection is most definitely not scientific due to the many variables involved. Some major factors that affect results are time of visit and length of stay, type of visit (target versus casual birding) and route covered. Another significant factor is season -- I visit mountain locations more in spring and summer than I do in fall and winter, whereas the opposite is true of lowland locations. Nevertheless, for most locations included here, I have a considerable amount of data so you can certainly use it as a fairly reliable indication of what to expect in any given month. 

I consider 400 visits spread over at least 10 years to be the minimum requirement for truly meaningful data. For some locations, I have published data based on too few visits and this should be borne in mind when interpreting the information.

For those interested in such matters, I record my sightings using the AviSys program from Perceptive Systems. However, the bar graphs are produced using home grown software written in Visual Basic.

The monthly columns are divided into 4 equal sections each representing roughly one week. Days of the month are allocated to each “week” as follows: Week #1 = 1 - 7, Week #2 = 8 - 15, Week #3 = 16 - 23, and Week #4 = 24 - 31. The thickness of the “bar” is calculated as the ratio of the number sightings to the number of visits, and thus represents your chances of seeing a bird expressed as a percentage. The legend is as follows:

It is important to understand that the bar graph data reflects the statistical chances of seeing a particular species rather than its actual abundance. Some factors to bear in mind when comparing your results against this data are: a) species may be localized to specific habitat zones within the measurement area; b) species that are seen rarely or infrequently within the measurement area may be quite common in nearby areas; c) for many species, finding a bird depends on your ability to detect its presence by hearing it. Therefore, if you are not an ear birder, you will almost certainly find that the graphs show a higher probability than your results.

Raw Bar Graphs
The graphs are created automatically by performing calculations directly on my database. With only one small exception, the data is presented without modification. That is, data is not smoothed by interpolation except where single sightings occur adjacent to a week with multiple sightings. In this case, the sighting is calculated as a percentage instead of being shown as a single dot.

The number of visits for each month is shown at the head of the monthly columns. Species are listed in Clements’ checklist order which may be unfamiliar to many. The three numbers following the species name show total sightings, number of months in which sightings have occurred, and the number of (calendar) years in which sightings have occurred. This data can be loosely interpreted as follows: the “number of years” data indicates how regular a species is, “number of months“ indicates length of residence, and “total sightings” is an overall indicator of abundance when compared to the total number of visits (birding days). Species count numbers at the bottom of each monthly column are the cumulative species seen in each month.

At the risk of stating the obvious, you'll note that locations with a high number of visits (e.g. Sierra Vista EOP) produce the smoothest (and most reliable) data. I'm constantly working to fill holes caused by insufficient visits, but there are only 7 days in a week and lots of places to go! A week missed means another year before the next opportunity arises.

Standardized Bar Graphs
These are edited versions of the raw bar graphs with missing data filled in by interpolation for the vast majority of species. Exceptions are those species with just a single sighting or even a few scattered sightings. If I considered the data insufficient to extrapolate what might happen given more time, I have left the raw sighting data intact. Species counts at the bottom of the monthly columns represent the number of potential species for each month.