By Chester McConnell, Whooping Crane Conservation Association
A few whooping cranes arrived on the Aransas National Wildlife Refuge on October 24 according to refuge employees. No official count has been made at this time but whoopers have been observed in several locations. One pair and a sub adult have been recorded.
The whoopers are doing what many of their species have done for millions of years, moving from their nesting grounds to their winter habitats. A record number of approximately 300 whooping cranes have departed their Wood Buffalo nesting grounds and are scattered along their migratory path headed towards their wintering habitats at Aransas National Wildlife Refuge on the Texas coast. The Whooping Crane Conservation Association has received reports off whooper sightings from 17 cooperators telling of birds from Saskatchewan, Canada to Aransas, Texas. A few whoopers have not yet departed from Wood Bufalo.
Robert Russell, bird biologist with the U.S. Fish and Wildlife Service in St. Paul, MN recently reported that he Aransas-Wood Buffalo National Park (Canada) population of whooping cranes rebounded from 263 in the spring of 2010 to 279 in the spring of 2011. With approximately 37 chicks fledged from a record 75 nests in August 2011, the flock size may reach record levels of around 300 this fall.
While there have been many studies of whooping crane travels, wildlife biologists still do not know all they need to about migration routes. With more wind farms and other developments occurring in the migration paths, more precise information is needed. Twelve whooping crane juveniles were captured in Wood Buffalo National Park in August 2011 for attachment of radio-tracking devices, bringing the total number of radioed birds to 23. The radio signals are used to track movement of the birds. According to personnel of the Aransas National Wildlife Refuge none of the 22 radio-tagged birds in the flock had arrived there as of Friday October 28.
Habitat conditions at Aransas National Wildlife Refuge are fair. Park Ranger David True said recent rainfall of about 2 inches has replenished drinking water sources for the whoopers for the present. Other refuge personnel confirmed that about 20 ponds created by windmill pumps are available for the birds to drink. The whooping crane flock will also will benefit from prescribed burns across almost 10,000 acres of the refuge this year. Natural foods found on the burned areas supplement the primary blue crab diet found in the saline marsh areas. The prescribed burn acres make it easier for the cranes to find prey, and they feed on creatures that perish in the fires. While the current habitat conditions are improved, “More rainfall would be useful” according to Ranger True. Rainfall is essential to restore fresh water inflows to Aransas Refuge and create proper conditions for blue crabs and other aquatic animals used as food by whooping cranes
Now that the wild, migratory whooping crane population has rebound from a low of 15 birds in 1941 to 279 in the spring of 2011 the whooper population situation is much improved. With approximately 37 chicks fledged from a record 75 nests in August 2011, the flock size will hopefully reach record levels of around 300 this fall.
Whooping cranes were on the brink of extinction during the first half of the past century (1900 to 1960). Then with a major public relations effort by the Whooping Crane Conservation Association, the U.S. Fish and Wildlife Service received reinforcements to initiate a successful management program. While the whooper population is on the rebound, current threats to the flock are also increasing. In Texas threats to whooper habitat include land development, reduced freshwater inflows, the spread of black mangrove along coastal areas, the long-term decline of blue crab populations, sea level rise, land subsidence, and wind farm and power line construction in the migration corridor. While the Canadian nesting grounds at Wood Buffalo National Park in the Northwest Territories Canada are relatively safe, the migratory whooping cranes must have both their summer and winter habitats which are about 2,400 miles apart.
The Whooping Crane Conservation Association has initiated a habitat protection program to improve the winter habitats in the vicinity of Aransas National Wildlife Refuge on the Texas coast. James Lewis, Association Treasurer reported in “Grus Americana” (May 2011 issue) that the Whooping Crane Conservation Association approved expenditures of $$286,750 to acquire three tracts of private land currently used by whooping cranes. The three sites are located within the lands designated as Critical Habitat wintering areas along the Texas coast. These lands are considered essential to the conservation and recovery of whooping cranes.
According to Lewis, “Association Trustees believe it is important to do everything possible to protect these sites from residential and commercial development and to preserve them for future use by whooping cranes.” Lewis wrote that, “A majority of the funds committed for these acquisitions came from bequest to Whooping Crane Conservation Association from two women. Laurae A. Brinkerhoff of Green River, Wyoming and Elizabeth F. “Betty” Overton of Pueblo, Colorado. The Association accepts donations for whooping crane habitat acquisition on their web page at: www.whoopingcrane.com .
For many years, only one small flock of whooping cranes teetered between survival and extinction. That population now uses nesting habitats in Wood Buffalo National Park, Canada and winter habitat at Aransas National Wildlife Refuge on the Texas coast. Massive drainage of wetlands during the 1800s to the 1960s and hunting by early settlers escalated the decline of whooper populations. Ambitious recovery efforts were needed to save the species.
Projects to protect the one remaining wild flock and to create new populations were put in motion and began the whooping cranes’ long journey to recovery. There are currently three other experimental whooping crane flocks in addition to the wild Aransas-Wood Buffalo naturally migrating group. There are 105 whoopers in the Wisconsin to Florida ultra-light aircraft-led flock, 20 non-migratory birds in Florida and 5 non-migratory in Louisiana.
Another 157 cranes are in captivity, making for a total population of 566 birds. The whoopers in captivity are used for research and to supply young birds for the experimental populations.