Tom Stehn's Report: Things Are Looking Up
Feb. 26, 2010
Back to Update
Meet Tom Stehn
Whooping Crane Coordinator, U.S. Fish and Wildlife Service

As you read Tom's report this week . . .
  1. What happens to crane numbers (population) at the beginning of a new decade? Why?
  2. What has changed in the Aransas habitat since September? Why is this good news for cranes?
  3. How many cranes are at Aransas NWR today? How does this compare to the record high number?

Dear Journey North Kids,

This has been a better than expected winter for the whooping cranes. On a census flight at Aransas conducted January 5th, I counted 264 whooping cranes! I am absolutely thrilled. Yes, the 264 is down 6 birds from the record high of 270 last winter, but we were expecting much fewer than the 264. We only had 247 birds in the flock in spring 2009 after 23 birds died during the winter. (See last report.)

Another Decade Dip
Every 10 years, the population drops right close to the start of a new decade. This drop is related to some unknown factor affecting the number of chicks produced on the nesting grounds. In summer 2009, chick production was down and only 20 chicks survived. This was a big dip from from the 38 chicks produced in 2008. Once the current dip ends, mathematical analysis predicts the population should turn around and show an increase for the rest of the decade. (See? There is a use for that math you are studying.)

Help From Mother Nature
We knew food for the cranes was going to be in short supply at Aransas due to the drought over the past 2 years. Since whooping cranes are so tied to marshes, they suffer when drought hurts their habitat. There are fewer blue crabs, their favorite food, for the cranes to eat. However, Mother Nature turned on the faucet and the rains began to come in September. Rains have kept coming, breaking the record-making drought of the past 2 years. Many parts of the refuge are flooded. The cranes are feeding, maybe eating snails, in these flooded areas.

How Many Cranes at Aransas Today?
On my next census flight (January 21), I could see that one adult pair had lost their chick. We could not find the dead chick and do not know why it died, but I knew something bad had happened since I saw the parent cranes without their youngster anywhere around. So that means 263 whooping cranes are currently in the Aransas flock.
Can you find a Whooping crane juvenile and adult? A sandhill crane? Enlarge

Things are Looking Up
Even though food was short this winter, the marshes were not very salty due to all the rains. The cranes could drink right from the marsh and did not have to fly every day to find fresh water to drink. Thus, with additional areas available to feed in as the rains produced flooded areas, the cranes are doing okay, and only the one has died this winter. This is such good news compared to the 23 cranes that died last winter when everything was so dry and the marshes were too salty. Things are looking up for this very endangered species.

Tom Stehn
Aransas National Wildlife Refuge
Austwell, Texas