question about BGP default routing

Hi all I have a question: I see very few prefixes in a routing table and combining the prefixes does not cover addresses space, for example, {78.41.184.0/21, 91.103.239.0/24, 91.103.232.0/22, 82.138.64.0/23, 91.103.232.0/21, 77.95.71.0/24} are all prefixes I observed from a BGP speaking router, I am just asking is this router using a default routing for all the other destinations? Thanks a lot