CRANE MIGRATION IN NORTHERN NEW MEXICO

Greater sandhill cranes (Grus canadensis tabida) and foster-reared whooping cranes (G. americana) were monitored on a 345 km migration between their traditional stopover in southcentral Colorado and their winter grounds in central New Mexico during 4 autumns (1984-87) and 1 spring (1985). Autumn sandhill crane counts totaled 17,363 in 1984, 9,317 in 1985, 29,053 in 1986, and 26,552 in 1987. Peak flights of over 7,000 cranes in 1 day were recorded in both 1986 and 1987. More than 50% of the cranes were counted on just 4 days in 1984, 1986 and 1987. At least 27% of the sandhill cranes counted stopped overnight in 1984, 58% stopped in 1986, and 46% in 1987. Most completed 225 to 280 km of the journey and roosted on rivers and mesas north of Albuquerque. Stopover rates were affected by wind speed/ direction and solar radiation, but were most highly correlated with frontal movements. During the 1985 spring migration 25,890 cranes were counted. Aided by southerly winds, over 95% apparently completed the northward journey in 1 day.