Eared Grebes (Podiceps nigricollis) marked with small radio-transmitters in 1995 and 1996 at a breeding site in south-central British Columbia, Canada, were subsequently detected in fall at Mono Lake (California) and Great Salt Lake (Utah). At least 50% of all marked birds were detected on Mono Lake, and data collected in mid-October suggested that this proportion was consistent across years. These observations largely confirm a fall migration pattern that had been previously based on leg-band returns. Radio-tracking also confirmed that some movement occurred between Mono Lake and Salton Sea. In terms of the number of marked birds detected, the internal antenna-type transmitter produced superior results over other (attachment) protocols but their short range (<2 km) means that they will be effective only at sites where the birds are both abundant and concentrated such as Mono Lake, Great Salt Lake, and Salton Sea.