camera traps detection probability

[alqamy]

I am conducting a camera trap survey for mammals in a desert ecosystem and planning to use PRESENCE for analysis of data. My question is : Since the camera traps are active sampling tools for 24/7 should I specify the detection probability as a constant of 1?
Thanks in advance

Husam El Alqamy, B.Sc, M.Phil.
Sr. Biodiversity GIS Analyst,
Enivronmental Information Sector
Environment Agency – Abu Dhabi

[murray.efford]

The underlying idea here is that a camera site is ‘occupied’ if it lies within the home range of at least one animal. Let’s assume your cameras are 100% effective at recording presence when an animal walks into the field of view. This may happen infrequently, even if the camera is inside a home range, so detection probability is expected to be less than 1, and should be estimated. Also, remember that the ‘occupancy’ you measure is determined by home range size, and may be a poor indicator of population differences.
Murray