We present an analysis of the galaxy population of the intermediate X-ray luminosity galaxy cluster , Abell 1691 , from SDSS and Galaxy Zoo data to elucidate the relationships between environment and galaxy stellar mass for a variety of observationally important cluster populations that include the Butcher-Oemler blue fraction , the active galactic nucleus ( AGN ) fraction and other spectroscopic classifications of galaxies . From 342 cluster members , we determine a cluster recession velocity of 21257 \pm 54 kms ^ { -1 } and velocity dispersion of 1009 ^ { +40 } _ { -36 } kms ^ { -1 } and show that although the cluster is fed by multiple filaments of galaxies it does not possess significant sub-structure in its core . We identify the AGN population of the cluster from a BPT diagram and show that there is a mild increase in the AGN fraction with radius from the cluster centre that appears mainly driven by high mass galaxies ( log ( stellar mass ) > 10.8 ) . Although the cluster blue fraction follows the same radial trend , it is caused primarily by lower mass galaxies ( log ( stellar mass ) < 10.8 ) . Significantly , the galaxies that have undergone recent star-bursts or are presently star-bursting but dust-shrouded ( spectroscopic e ( a ) class galaxies ) are also nearly exclusively driven by low mass galaxies . We therefore suggest that the Butcher-Oemler effect may be a mass-dependant effect . We also examine red and passive spiral galaxies and show that the majority are massive galaxies , much like the rest of the red and spectroscopically passive cluster population . We further demonstrate that the velocity dispersion profiles of low and high mass cluster galaxies are different . Taken together , we infer that the duty cycle of high and low mass cluster galaxies are markedly different , with a significant departure in star formation and specific star formation rates observed beyond r _ { 200 } and we discuss these findings .