The morning of the 21st of March we estimated 471,000 +/- 118,000 Sandhill Cranes and 9 Whooping Cranes in the Central Platte River Valley. This is a slight increase from last week. Despite normal trends for this time of year, increases were actually seen in the east rather than the west. However, the chances of cranes in the west already leaving the CPRV are slim since a large portion of these cranes likely arrived around a week ago. More likely is that large groups left the river early to forage in fields outside of our survey area as we saw groups of cranes upwards of 7 miles away from the river on our flight back to the airport after the survey. Cranes often try to stay as close as they can to their roosting ground when going out to forage. This helps them save energy by not needing to fly as far. However, the fields and prairies closest to the river can deplete earlier in the migration causing later arrivals to search farther for ample food. This past week we heard a report that there were still Greater Sandhill Cranes in their wintering grounds in the South which is later than normal. So, both lesser and greaters will continue to arrive in the Platte Valley this week but cranes that have been here for 3-4 weeks already will likely head north when weather permits. Considering this week and the last were very similar in numbers, we are most likely experiencing a low and slow peak where the highest numbers for the year extend over many weeks. The main changes between weeks will be the distribution throughout the river valley. Next week is the start of our west to east flights which will capture more cranes on the river in the western segments.
Till next week,