Sandhill Crane Counts – Week 6

Andrew Caven, Lead Biologist

Andrew Caven, Lead Biologist

Sandhill crane numbers remained high this morning. However, conditions are good for birds to start migrating north today and tomorrow. We counted 276,000 with a +/- 10.8% absolute error. There was not really an up or down bias consulting the directionality of the error (relative error  considers directionality and was much smaller than absolute error on today’s count). Today and tomorrow are good days to migrate with high winds out of the south and very warm temperatures (mid to high 70s). Therefore, Sandhill Cranes that have been in the area a while may take advantage of these conditions to start migrating north.

Incidentally, since returning from our flight this morning, I have seen a number of birds kettling up (catching thermals and spiraling up) from the fields adjacent to the river in the late morning and early afternoon. Sandhill Cranes “kettle” to get high in the air and catch transport winds to aid them in their northern migrations. These counts are only done 1x per week and we will likely see lower numbers next week as the Sandhill Cranes take advantage of the weather in the next 2 days. We lost about 134,000 birds from last week, but Sandhill Crane numbers remain relatively high (still above last year’s peak). We conducted our count this morning before migratory conditions became good and all the birds were still sitting on the river or in adjacent fields. About 22% of the birds present on the river are on various Crane Trust properties.  Enjoy the end of March and the official beginning of spring. Until next week.

Sandhill Crane Migration 2016

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