02490naa a2200253 a 450000100080000000500110000800800410001910000170006024500830007726000090016052018390016965000090200865000130201765000140203065300100204465300120205465300180206665300140208470000260209870000170212470000180214170000210215977300560218017925682017-03-10       2003    bl ---       0--  u    #d1 aANDRIOLO, A.  aActivity period of marsh deer (Blastocerus dichotomus) monitored by telemetry.  c2003  aThe marsh deer (Blastocerus dichotomus) is considered as vulnerable species by IUCN. Its habitat is systematically thre atened by the building of hydroelectric dams, which results in an artificial and permanent extensive flooded area. Ethological information about marsh deer in the wild is scarce, because it's cryptic behaviour in the marsh habitat. The aim of this study was to use the telemetry system to study the activity period of marsh deer. A female and a mal e were monitored in the Peixe River marsh are a (Parana River Basin), and another pair at the reintroduction are a of Estação Ecológica de Jataí, SP. Animals were captured and instrumented with radio collars with movement sensor, which permits the identification of the collar/animal movement. The animals were monitored continuously during 72 hours. Each animal was monitored for 30 minutes per hour and the duration of the activity signals were recorded. We calculated an activity index per minute and the day was divided in 2 periods (Diurnal 6:00h to 18:00h and Nocturnal - 18:00h to 6:00h). We performed the Anova with F test to compare individuals and period of the day. No significant difference was observed among the individuals (F3 92+1.912; p=0.133). But comparing the diurnal and nocturnal periods of the day we found i significant difference (F'94=6.125; p=0.015), where the calculated activity index for the nocturnal period was higher (mean=0.35: t0.21) than the diurnal (0.25). This result suggest that marsh der has an important part ofits activity during the night. Ir is often to observe animals lay down on the marsh area during the hottest period of the day. This species is not considered as nocturnal specie,  but the preference for nocturnal period of activity could be related with the body temperature control. Financial support: CESP.  adeer  aPantanal  atelemetry  aCervo  aEtology  aMonitoramento  aMonitored1 aCOSTA, M. J. R. P. da1 aPIOVEZAN, U.1 aTORRES, H. A.1 aDUARTE, J. M. B.  tRevista de Etologiagv. 5, supl., p. 141-142, 2003.