[Babase] missing tdates in cycles

Jeanne Altmann babase@www.eco.princeton.edu
Wed, 07 Jul 2004 11:22:05 -0400


Dear Babasers,
This note is a followup on Steph's message of 5 May04 and is meant as a 
start to a discussion in today's conference call.

Daphne and I have looked at the periods of most persistent 
gaps--1989-1990.  It is true that I only coded D dates and major 
reproductive events, i.e. births, T dates when they represented Puberty or 
Resumption of cycles after a pregnancy.  This was done because it was a 
period in which gaps were often about 5-7 days--Alto's Group was fissioning 
and had moved west, we didn't have radio collars, Hook's Group was often 
still east, etc (probably not 'etc'; those listed things were bad 
enough.  Because D dates were always considered the key marker of a cycle 
(easiest to estimate from missing dates, most important for determining 
pregnancy onset, fertile periods, etc), and my earlier data/analyses were 
set up with a D-D focus, I always scored D dates but did not, I now recall, 
record M's and T's when this could not be done within a useful level of 
precision.  For M dates, I stopped entirely by the late 1980s, perhaps 
earlier--once we were doing more than one group, M records could not be 
counted on.  I had forgotten, however, that this also applied to T's for 
some years.  What I don't know at this point is to what extent this 
accounts for almost all of the missing T's, but I expect that most are of 
this sort.

So what to do:
1.  Find these all, make up t dates with a high degree of 
uncertainty.   This would not be a priority now, and I am not convinced 
it's a good idea to do in any case.

2.  Repstats should record cycling
--whenever the state is not pregnant or lactating and the female has 
reached maturity, ie has had her first T
another way of thinking of this is:
--from a T until the D that starts a pregnancy, Cycling should be the state 
in Repstats.

Karl?  sorry that this is the case, but glad we've identified the issue and 
the cause of most,

jeanne