Wintering Whooping Crane Update, April 7, 2017


Wintering Whooping Crane Update
Wade Harrell, – U.S. Whooping Crane Recovery Coordinator

Whooping crane spring migration is in full swing. It has been another tremendous winter season here at Aransas NWR, but the whooping cranes are ready to get back up to Wood Buffalo National Park for another breeding season.

Whooping Crane Update

Whooping crane family flying over Aransas NWR. Photo by Chuck Hardin

As of yesterday, of 7 birds that have active satellite transmitters, 5 have departed Aransas NWR. Quivira NWR (Kansas) and surrounding areas seem to be a hotspot for stopovers this spring, with a group of 14 whooping cranes reported last week and a group of 8 reported this week as well as sightings of smaller groups. There have also been a number of whooping cranes reported in the Platte River in Nebraska and a number that have already made it to the Dakotas. Here in Texas, 2 marked whoopers were spotted on Ft. Hood Army Base this past week. The number of whooping cranes at Aransas will quickly dwindle over the next couple weeks. Spring migration is typically shorter in duration than fall migration, usually only taking about 30 days.

As soon as results from the Annual Whooping Crane Winter Abundance Survey are complete, we will post a summary on the Aransas NWR website.

Whooping Cranes on the Refuge

Whooping crane update

Whooping Cranes over Aransas NWR at sunset. Photo by Kevin Sims

Cranes have recently been seen from the observation tower on the Refuge, but it’s difficult to say how much longer they will remain. But there are many other interesting wildlife species to view at the Refuge now, including many spring migrating songbirds, so don’t hesitate to come out and enjoy other spring wildlife watching opportunities.

Texas Whooper Watch

Please report any whooping cranes you observe in migration in Texas to Texas Whooper Watch. We’ve had a number of people making use of the new Texas Whooper Watch I-Naturalist phone app as well, which is encouraging. The old saying “a photo is worth a thousand words” applies to reporting whooping cranes as well. Just be careful not to disturb or get too close the birds!

Habitat Management on the Refuge

Refuge staff burned 4 Units this winter, totaling 4,871 acres. This year’s winter season was challenging given that our cold weather windows with consistent north winds were limited and the latter part of the winter brought significant rains.

Precipitation/Salinity

The Refuge received 6.16” of rain from January-March 2017. Freshwater levels and food resources remained high throughout most of this winter season.  Salinity levels in San Antonio Bay stayed in the low teens (ppt) most of the winter, but recent rains in the middle portion of the Guadalupe river watershed have dropped salinities significantly this last week. Let’s hope we stay in a wet cycle for a bit longer.

***** FOTWW’s mission is to help preserve and protect the Aransas/Wood Buffalo
population of wild whooping cranes and their habitat. *****

Friends of the Wild Whoopers is a nonprofit 501(c)3 organization.

Are whooping cranes destined for extinction?

Are whooping cranes destined for extinction? Climate change imperils recruitment and population growth

Matther J. Butler, Kristine L. Metzger, Grant M. Harris
First published:

Summary

Are whooping cranes destined for extinction?

Whooping Cranes on their wintering grounds at Aransas NWR. Photo courtesy of Kevin Sims

Identifying climatic drivers of an animal population’s vital rates and locating where they operate steers conservation efforts to optimize species recovery. The population growth of endangered whooping cranes (Grus americana) hinges on juvenile recruitment. Therefore, we identify climatic drivers (solar activity [sunspots] and weather) of whooping crane recruitment throughout the species’ life cycle (breeding, migration, wintering).

Method and Model

Our method uses a repeated cross-validated absolute shrinkage and selection operator approach to identify drivers of recruitment. We model effects of climate change on those drivers to predict whooping crane population growth given alternative scenarios of climate change and solar activity. Years with fewer sunspots indicated greater recruitment. Increased precipitation during autumn migration signified less recruitment. On the breeding grounds, fewer days below freezing during winter and more precipitation during breeding suggested less recruitment. We predicted whooping crane recruitment and population growth may fall below long-term averages during all solar cycles when atmospheric CO2 concentration increases, as expected, to 500 ppm by 2050. Species recovery during a typical solar cycle with 500 ppm may require eight times longer than conditions without climate change and the chance of population decline increases to 31%.

Future climate change threat

Are whooping cranes destined for extinction?

Whooping cranes on nesting grounds at Wood Buffalo National Park. Photo by John D. McKinnon / ©Parks Canada / Wood Buffalo National Park

Although this whooping crane population is growing and may appear secure, long-term threats imposed by climate change and increased solar activity may jeopardize its persistence. Weather on the breeding grounds likely affects recruitment through hydrological processes and predation risk, whereas precipitation during autumn migration may influence juvenile mortality. Mitigating threats or abating climate change should occur within ≈30 years or this wild population of whooping cranes may begin declining.

To read full research article, click here.

 

***** FOTWW’s mission is to help preserve and protect the Aransas/Wood Buffalo
population of wild whooping cranes and their habitat. *****

Friends of the Wild Whoopers is a nonprofit 501(c)3 organization.