In a new report, the U.S. Fish and Wildlife Service says the size of the Whooping Crane population that winters on and around Aransas National Wildlife Refuge was stable last winter at approximately 504 wild birds. The total from the winter of 2017-2018 was 505 cranes. The estimate for 2018-2019 includes 198 adult pairs and at least 13 juveniles.
The total is based on a distance-sampling aerial survey method conducted over several days in February 2019. The survey doesn’t count every bird, so the report, written by Wade Harrell, Whooping Crane recovery coordinator at the Aransas refuge, and Matthew J. Butler of the FWS Division of Biological Services, says the total number of wintering Whoopers may be as low as 412 or as high as 660.
During the survey period, approximately 12 cranes were reported on eBird outside the Aransas refuge and nearby survey area. Most of these birds were relatively close to the refuge, but one bird was spotted with a flock of Sandhill Cranes near Tahoka, Texas, more than 500 miles northwest of Aransas.
“This marks the second year in a row that the population has topped the 500 mark,” according to a Facebook post from the refuge. “The lack of population growth last winter likely resulted from a low chick production season on the breeding grounds of northern Canada during the spring-summer of 2018.”
Here’s how the numbers compare to previous winter surveys:
Winter 2015-2016: Estimated abundance 463; range of 392-549 birds; 8 birds beyond the primary survey area.
Winter 2016-2017: Estimated abundance 489; range of 428-555 birds; 6 birds beyond the primary survey area.
Winter 2017-2018: Estimated abundance 505; range of 439-576 birds; 21 birds beyond the primary survey area.
Winter 2018-2019: Estimated abundance 504; range of 412-660 birds; 12 birds beyond the primary survey area.
In August 2019, biologists from Canada reported that 37 young Whoopers fledged this year at Wood Buffalo National Park; in 2018, only 24 cranes were known to have fledged.
You can read more about Whooping Cranes in the cover story of the September/October 2019 issue of BirdWatching.