Nest Survival: Nesting season confusion

[eaburnet]

Hello everyone,

I am a student working on a project to determine the daily nest survival rate of three different species of birds using program MARK, and I have a question that I haven't been able to find an answer to in the manual, in published papers, this forum, or by my two advisers. My question has to do with the definition of the nesting season...

The manual for MARK says that the nesting season starts on the date that you begin recording data for nest survival. This would be when the first nest is found, correct? This is day one, and then the last day of data collection is the last day of the nesting season. This makes sense, because the "i" value is the day of the nesting season that the nest was found. That way, the "i" value will always be within the nesting season. This is confusing because I have heard that the nesting season begins when the first egg is laid... but then what would the "i" value be when the nest was found before this nesting season began?

Any advice or help will be greatly appreciated!

Lizzy

[Jochen]

Lizzy,
hope I got the point: I gather from your question that you found nests before eggs were laid. Usually the period of interest in a nest survival study does not start before a nest contains eggs, depending on the species of interest it may only start with the onset of incubation of the (almost) complete clutch. The fate of empty nests may be meaningless in many species.
Hope this helps
Jochen