Zero confidence intervals

Hello Everybody,
I have examined cat numbers after i made several surveys and used the POPAN module in MARK.
Some of the areas (=groups in the model) had very low kitten numbers, like 2-5 kittens per area, and for these areas, the output that i got gave me zero confidence intervals.
Is that legit?
If not, how can it be fixed?
Thanks,
Hilit
I have examined cat numbers after i made several surveys and used the POPAN module in MARK.
Some of the areas (=groups in the model) had very low kitten numbers, like 2-5 kittens per area, and for these areas, the output that i got gave me zero confidence intervals.
Is that legit?
If not, how can it be fixed?
Thanks,
Hilit