BLACKJACK PENINSULA – A family of whooping cranes stepped forward on their stilt-like legs while probing the ground for wolfberries and blue crabs.
They were absorbed in this task. They have to be as their appetites match their size. But then another crane intruded on their patch of marsh.
This would just not do.
One crane, presumably the patriarch, stiffened his neck, raised one of his legs and went airborne to chase the intruding crane away.
Liz Smith, John Pistone and Anna Turkett watched this territorial dispute unfold in a flat-bottomed boat a few hundred feet away. The three of them make up the International Crane Foundation’s Texas office. They will be spending at least the next three months documenting the endangered species’ behavior on Blackjack Peninsula and St. Charles Bay near Lamar.
They are using a method established by Felipe Chavez-Ramirez, an ecologist and conservationist, in the ’90s. They write down what each member of a whooping crane family is doing every 15 seconds for 20-minute intervals.
They have trained Texas Master Naturalists and members of EarthWatch to do this for years, but this is the first year they are focusing on families.
And they think they will learn a lot.
First, the data is expected to show why juvenile cranes stay with their parents for a year.
Some other migrating birds leave their young before they are fledged. Red knot juveniles, for example, know instinctively how to migrate from their nesting grounds in the Arctic.
“It’s very unusual for an animal pair to invest so much time in their young, a whole year of their time, and so why is that? And are they doing that in the other reintroduced populations?” said Smith, who has a doctorate in wildlife and fisheries science and is the International Crane Foundation’s senior whooping crane scientist.
There are three reintroduced populations of whooping cranes: the eastern migratory flock, which has 101 cranes, the Louisiana nonmigratory flock, which has 66; and the Florida nonmigratory flock, which has 14, according to the International Crane Foundation.
Second, documenting the cranes’ behavior should show the quality of their habitat.
Data collected by Chavez-Ramirez in the ’90s and by others more recently shows the cranes spend about 65 percent of their time on Blackjack Peninsula foraging.
Smith said the cranes’ behavior on Blackjack Peninsula would serve as a baseline because Blackjack Peninsula is considered ideal habitat. It has an abundance of food and is somewhat isolated.
She said they will compare the percentage of foraging the cranes do there to the percentage of foraging they do in other areas along the Texas coast.
These cranes are part of the Aransas-Wood Buffalo migratory flock. Once below 20, the flock is now estimated to be more than 500, so families will either have to live closer together or spread out. Right now, two families can live on one square mile of habitat in a good year.
Smith said if the data shows they spend more time moving than foraging in the areas they’ve spread to, that could be because they aren’t finding food. And if they spend more time alert, that could be because predators or humans are disturbing them. All of this information will be useful in restoring the iconic species.
“And they are like an umbrella species,” said Anna Turkett, the outreach coordinator for the International Crane Foundation’s Texas office. “Protecting them protects so many others.”