I believe your post contains 2 aspects. The first is about differences
in detectability (g(x)) for species or groups of species. You can
easily accommodate those differences using species or species size
(large,medium,small) as a factor variable using the MCDS or MRDS
analysis engines in DISTANCE. The second aspect is in regards to
design. This is a more difficult question. It is rarely possible to
have a single design that is optimal for several species. To get the
best precision for a particular species, you want to stratify the survey
and put the most effort in the strata with highest abundance. Trying to
do this with several species is difficult because the areas of highest
densities usually differ for the species. Thus, I'm afraid you will
have to stay with a single survey design although you may be able to add
lines to improve precision for species of particular interest. Also,
spatial modelling may help improve precision.
Urbain BELEMSOBGO wrote:
> Dear all,
> I am conducting multispecies density estimation using distance sampling techniques with one sampling design i.e. 50 inequal lines transects in an area of 910 km². Because of high costs of these annual estimates, the same sampling design is used for 1) larges mammals species like Hippotragus equinus, Alcelaphus buselaphus, Kobus ellipsiprymnus defassa, 2) medium mammals, Kobus kob, Phacochoerus africanus, Tragelaphus scriptus and little mammals like savanas duikers and oribi.
> I suspect influence of g(x) of individual species , the detection fonction by others species when analysing data. How can I solve this problem without making an design for each species.
> Any help/suggestions you can offer will be greatly appreciated.
> Urbain BELEMSOBGO
> Director Wildlife and hunting
> 06 BP 9307 Ouagadougou
> 226 50 35 69 23
> Burkina Faso
> (MS; Univ Claude Bernard, Lyon I France)
> Sur Windows Live Ideas, découvrez en exclusivité de nouveaux services en ligne... si nouveaux qu'ils ne sont pas encore sortis officiellement sur le marché !
> distance-sampling list home page:
> To unsubscribe, go to the home page and click "Join or leave the list",
> or email [log in to unmask] with the following message body:
> leave distance-sampling
> Before posting to the list, read the list guidelines at
> Any questions, email the list owner at
> [log in to unmask]
distance-sampling list home page:
To unsubscribe, go to the home page and click "Join or leave the list",
or email [log in to unmask] with the following message body:
Before posting to the list, read the list guidelines at
Any questions, email the list owner at
[log in to unmask]