[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