November 5, 1998: Whooping Cranes Now Arriving in Texas--Finally!

Today's Report Includes:

• Better Late Than Never!
• Counting Cranes from Above
• High Tide Habitat

Whooping Crane Migration Route

"It always amazes me how variable the timing of the migration is, with all birds having their own inner clocks and itineraries", said Whooping Crane Coordinator Tom Stehn on October 22, 1998 as he awaited the cranes' return to Aransas NWR in Austwell Texas.

The first returning cranes were spotted at Aransas on October 28, 1998, which is the latest first sighting date in 35 years! What factors do you think might influence the date when cranes return? See if you can gain any information on this question as you read Tom's comments below about his recent aerial crane surveys at Aransas.

Counting Cranes from Above
During his first aerial survey on October 22, no whooping cranes were spotted, but Tom estimated they would be late this year: "The first arrival at Aransas is going to be at least one week later than the average of October 16. Last year, the first whooper arrived on October 21....There have been reports of whooping cranes as far south as Salt Plains NWR in Oklahoma. Thus, the population is currently strung out between Saskatchewan and Oklahoma. The peak population last winter was 152 + 30 =182. With 24 chicks sighted in Wood Buffalo N.P. in Canada in mid-August, 190+ cranes are expected to arrive at Aransas this fall."

Whooping Crane Coordinator Tom Stehn

On his next aerial survey on October 29, Tom reported that "7 were located, believed to be one adult pair (nest 11/98) and 5 subadults. The whoopers may have arrived earlier in the week when northeast winds (Oct. 22-25) were present. The first whooping cranes (2) were sighted October 28 by USFWS Biologist Jim Bredy, nearly 2 weeks later than average. The October 28th first sighting date is the third latest since records began in the 1950's, and the latest in the last 35 years. In the fall of 1951, with only 31 total birds in the flock, the first cranes were documented present November 3. No aerial counts were done in October that fall, but no cranes were seen on a ground count on October 27. The first arrival in 1963 occurred October 29."

Tom's third aerial survey on November 5 revealed 16 adult whooping cranes and 0 young. Tom remarked that "an estimated 9 cranes have arrived since the last flight on October 29. The migration is more than a week behind schedule. Sightings indicate the whoopers are spread out between North Dakota and Texas, with a group of 13 documented in North Dakota on November 3rd, and 3 whoopers spending their second week on the Platte River in Nebraska. Snow is forecast for this weekend in the crane migration corridor so the cranes are expected to move rapidly across the States within the next two weeks."

The main food source of the whoopers

High Tide Habitat
During his October 22 aerial survey, Tom noted that the refuge had received more than 15 inches of rain since mid-August. Take a look at Tom's description below of the conditions he saw in the refuge from the plane. Will this have a positive or negative effect on the cranes?

"The flight was notable from the high tides present. The flooding Guadalupe River (9 feet over Highway 35 north of the refuge) is pouring huge amounts of freshwater into the bays and raising water levels. Bay salinities were measured at zero on October 21.

Checking the tide

Many of the whooping crane marshes were flooded. Water levels were the highest I have observed on a whooping crane flight in the past 15 years. All of the marsh vegetation on Matagorda Island and Welder Flats was completely underwater. To look for whoopers, only one transect was required on Matagorda along the upland edge of the marsh where egrets had congregated to forage. This demonstrated why a large amount of debris accumulates on this upland border. Even the road down the center of Matagorda was flooded north of Panther Point. The road into the Cliburn cabin at Welder was also impassable.

Four barges were parked at the Welder Flats mooring, possibly due to flooding of the Colorado River further along the channel.

The freshwater should be beneficial to the whooping cranes since it benefits reproduction of blue crabs, the main food source for the whoopers. Late summer rains from two tropical storms also helped the refuge marshes with much needed moisture. The refuge has received more than 15 inches of rain since mid-August."

The Next Whooping Crane Update Will be Posted When Journey North Begins in February 1999.