Input data may be either 'dependent' or 'independent'. Dependent data consists of species counts by a 'primary' observer and species counts by a 'secondary' observer. These counts are collected at multiple 'stops' along a sampling route. At each stop, the primary observer records the number of birds of each species he/she hears. The secondary observer notes which birds were observed by the primary observer and records only birds which were not observed by the primary observer.
Observers switch duties (primary/secondary) at each stop (collection point).
"Independent" data consists of counts of species observed by both observers and counts of species detected by each observer which were not detected by the other observer.
To use program DOBSERV, an input file must be prepared. This file must be an ASCII 'text' file (no word-processing or spreadsheet format codes). It can easily be created from Excel (or other spreadsheet program) by exporting to a 'comma-separated-variable' file. If a word-processor is used, it could be created by saving as a 'MSDOS text' or 'ASCII text' file.
The following is a subset of a sample data file (with dependent observers):
OBS1= 6,OBS2= 1,DATE=06/30/98,ROUTE=46040 6,AMRO, 5, 0 6,GRCA, 2, 0 6,HOSP, 2, 0 6,MODO, 0, 1 6,HOFI, 2, 0 6,SOSP, 1, 0 1,NOMO, 1, 1 1,AMRO, 3, 0 1,NOCA, 1, 0The first line of the input file is ignored by program DOBSERV and could contain comments or a description of the data in the file. In the example it tells the date, route and observers.
All succeeding lines must contain 4 (for dependent data) or 5 (for independent data) items, separated by commas. The example is dependent data, so there are 4 items.
The first item is the code signifying which observer is the 'primary' observer. (This is ignored for independent data.) In the first 6 observations, observer number 6 was the 'primary' observer, and in the next 3 observations, observer number 1 was the 'primary' observer.
The second item denotes which species was observed. This should be a 4- character abbreviation (for formatting purposes). (AMRO=American Robin)
The third item is the number of birds of the species which were detected by the 'primary' observer (regardless of whether the secondary observer detected them). In the example, the first observation indicates that the primary observer detected 5 AMRO's.
For independent data, the third item would be the number of birds of the species which were detected by the first observer which were not detected by the second observer.
The fourth item is the number of birds of the species which were detected by the 'secondary' observer which were not detected by the primary observer. In the example, no additional AMRO's were detected by the secondary observer, but 1 MODO (fourth observation) was detected that was not detected by the primary observer.
For independent data, the fourth item would be the number of birds of the species which were detected by the second observer which were not detected by the first observer.
For independent data, the fifth item would be the number of birds of the species which were detected by both observers.
Once the data are entered in Excel, click 'Save as', change the file type to 'comma-separated-variable (csv)', give it a meaningful name and click 'Save'. Then close Excel.
A form will appear with an abstract describing the methods and a single button labeled '>>Step 1 - Convert data to SURVIV input'.
Click this button and a dialog window will appear asking for the name of the input file. Select the dependent sample data file, 'sample.csv' and click the 'Open' button. (A reminder of the sample filenames appears on the DOBSERV form.)
After selecting the file, a dialog box appears asking if this is an independent or dependent data file. Click 'No' for dependent data.
Next, the program displays a list of species with three buttons to the right. Scroll this list down until you see the species names 'CAGO' and 'PUMA'. (I'll explain why later.) Click on 'CAGO' in the list, then click the button labeled 'Force species into group x for all models'. Click 'PUMA', then 'Force species...'. The list will be modified to indicate these selections.
Next, click the button labeled '>>Step 2 - Run SURVIV with input file'. Another window should appear briefly, then disappear. Click '>>Step 3 - Pick Best Model'.
Summary statistics from several models will appear with 'radio buttons' to the left. The top model is selected by default. Click '>>Step 4 - Compute estimates of N'.
Another window will appear and disappear, then a window of results will appear. These results will be saved automatically in a file named: 'dobserv.out'.
Click 'File', and 'Quit' to exit the program.