Context :

Aims : We study the resolved stellar populations of dwarf galaxies in the nearby Centaurus A/M83 group of galaxies .
Our goal is to characterize their evolutionary history and to investigate eventual similarities or differences with the dwarf population in other group environments .

Methods : This work presents the analysis of five late-type ( irregular ) dwarfs found in the vicinity of the giant spiral M83 .
Using archival HST/ACS data , we perform synthetic color-magnitude diagram modeling to derive the star formation histories of these late-type dwarfs .

Results : The target objects show heterogeneous star formation histories , with average star formation rates of 0.08 to 0.70 \times 10 ^ { -2 } M _ { \odot } yr ^ { -1 } .
Some of them present prolonged , global bursts of star formation ( \sim 300 - 500 Myr ) .
The studied galaxies are all metal-poor ( [ Fe/H ] \sim - 1.4 ) .
We further investigate the spatial extent of different stellar populations , finding that the young stars show a clumpy distribution , as opposed to the smooth , broad extent of the old ones .
The actively star forming regions have sizes of \sim 100 pc and lifetimes of \gtrsim 100 Myr , thus suggesting a stochastic star formation mode for the target dwarf irregular galaxies .
The galaxies formed \sim 20 \% to 70 \% of their stars more than \sim 7 Gyr ago .

Conclusions : The studied dwarfs have average star formation rates slightly higher than their analogues in the Local Group , but comparable to those in the M81 group .
Our preliminary sample indicates that the neutral gas content of the target dwarfs does seem to be affected by the group environment : galaxies within a denser region have a much lower M _ { HI } / < SFR > than the isolated ones , meaning that they will exhaust their gas reservoir more quickly .