Video multicasting from cameras mounted on micro aerial vehicles (MAVs) is desirable for applications such as search and rescue, surveillance and disaster management. Because of the mobility of the video sources and the high datarate of videos, the transmission rate should be adapted to the task at hand. Rate-adaptive video multicast streaming in 802.11 requires wireless link estimation as well as frequent feedback from multiple receivers. We propose an application layer rateadaptive video multicast streaming framework using 802.11 adhoc network that is applicable when both the sender and the receiver nodes are mobile. The receiver nodes of a multicast group are dynamically elected based on their changing link conditions to gain feedback. An Application Layer Video Multicast Gateway (ALVM-GW) adapts the transmission rate and the video encoding rate based on the received feedback. Emulation results show that the proposed approach has balanced performance in terms of goodput, delay and packet loss.