:: Home

:: Biography

:: Research Interests

:: Curriculum Vitae

::Publications

:: Courses

:: Useful Links
:: Other Interests
lake turtles

.::.:.::...::: Roldan Valverde :::...::.:.::.
         

Arribada Portal


Time turtles spend laying eggs (min)

Distance between transects (m)

Time between counts (h)

Width of transect (m)


This application has been developed specifically to provide estimates of arribada abundance. Although user friendly, this application is very powerful and is intended to facilitate computations associated with empirical data collected via the Strip Transect in Time methodology. Users are encouraged to consult the papers Gates et al 1996 and Valverde & Gates 1999, both of which can be found as PDFs in the Publications section of this web site.

Directions

To facilitate understanding in the use of the application the data must be organized as in the table below (see Valverde & Gates 1999).

1) The row in yellow is the individual transect lengths in meters. The data in the lower rows are the counts of egg-laying (UELA) turtles in each transect every hour. Copy data from your spreadsheet into large window above. WARNING! It is essential that you leave a blank row after the row with the transect lengths before pasting data onto the application.

1 1 2 2 3 3 4 4 20 35 50 50 65 75 35 10 5 5 5 1.96
                                       
0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 2 5 3 2 3 2 2 2 0 2 0 0
0 0 0 0 0 0 0 1 1 0 0 1 1 1 0 0 1 0 1 1

 

2) Then input the following data (the theoretical values given in parenthesis below are simply intended to give an idea of what is possible and to stress the units; you must use your own values):
Time turtles spend laying eggs: (13.17 minutes; this must be determined empirically)
Distance between transects: (50 meters)
Time between counts: (2 hours)
Width of transects: (2 meters)
Press “process data” button

The results should be copied and pasted into a spreadsheet for record keeping. Data may be analyzed per session or per arribada.

Notes:
a) You must respect the units.
b) After performing calculations I strongly suggest that you designate an assistant to run same calculations to double check your results.
c) Feel free to contact me (roldan.valverde at selu.edu) for technical support.
d) Disclaimer: this application is provided for free to all users in good faith as developers intended. The user is solely responsible for how data and results are used and interpreted.

Developed 2010 by Feliks Volozhanin