DATA REUSE:

The attached file(s) contain data derived from the long term field project
monitoring individual Soay sheep on St Kilda and their environment.  This is a
request to please let us know if you use them.  Several people have spent the
best part of their careers collecting the data.  If you plan to analyse the
data, there are a number of reasons why it would be very helpful if you could
contact Josephine Pemberton (j.pemberton@ed.ac.uk) before doing so:

1) Occasionally we discover and correct errors in the data.

2) The data are complex and workers who do not know the study system may
benefit from advice when interpreting it.

3) At any one time quite a few people within the existing project collaboration
are analysing data from this project. Someone else may already be conducting
the analysis you have in mind and it is desirable to prevent duplication of
effort.

4) In order to maintain funding for the project(s), every few years we have to
write proposals for original analyses to funding agencies. It is therefore very
helpful for those running the project to know what data analyses are in
progress.

5) Sheep identifiers have been recoded and should therefore not be linked
with data archived from other papers using the Soay sheep data.

If you are interested in analysing the detailed project data in any depth you
may find it helpful to have our full relational database rather than the
file(s) available here.  If so, then we have a simple process for bringing you
onto the project as a collaborator.



DATA DESCRIPTION:
"sheep sizes.Rdata" contains the following variables
t - year in which the mass was measured
ID - identifies the individual but does not correspond to other published data sets of the same population
t0 - year in which individual ID was born
mass - mass measured in kilograms
size - natural log of mass
age - age of individual ID in year t
wnao - winter north Atlantic oscillation averaged over December (in year t-1) to March (in year t)
snao - summer north Atlantic oscillation averaged over May through August (in year t)
pop - population density in year t scaled to have mean zero and unit variance across years
prevpop - pop in year t-1 (this was used in the Brooks et al. 2017 publication rather than pop)
rep - whether or the individual gave birth to a live fetus in year t
nbabies - how many fetuses were born if the individual reproduced 
lamb - whether or not the individual was born in year t-1
yearling - whether or not the individual was born in year t-2

"sheep sizes with mum.Rdata" contains the following additional variables
birth_adultmum - mother of this individual was a yearling (0) or adult (1) in the year of this individual’s birth
birth_mumlogm - log mass of mother in the year of this individual’s birth
birth_prevpop - population density the year before this individual’s birth
birth_twin - individual was born as a twin