Aeroecology is an emerging interdisciplinary science focused on the study of airborne organisms with the aim of deepening understanding about the ecological functions of the aerosphere and the bio-organisms that move through it. In addition to having important applications to the understanding of animal migration and foraging movements, global pest and disease control, biodiversity and conservation issues, and monitoring of the effects of climate change, aeroecology has also been critical in ensuring the safety of military and civilian aircraft from bird strikes. Although the capability of radar to observe bioscatter has been known for nearly 70 years, radar aeroecology has now entered an exciting new phase, with the prospect of continent-wide monitoring of flying animals by means of networks of operational weather radars. In this work, the technological challenges of using radar for the detection, characterization, and monitoring of birds, bats, and insects is discussed in detail. Current efforts to further develop radar signal processing algorithms for aeroecology is discussed in light of a multi-national European research initiative, ENRAM.