This is scientific Americans 60 second science. I'm Jason Goldman. Got a minute?

Once upon a time on the big island of Hawaii, it would not have been unusual to hear.

That's the call of the Hawaiian crow.

It's a critically endangered species, now extinct in the wild after decades of habitat loss, persecution by farmers, and invasive diseases.

In the mid-1990s, wildlife biologists rounded up the few surviving crows

and put them into a captive breeding program.

Today Hawaiians can once again hear the calls of more than 100 Hawaiian crows, or

a la la as they are called there, but only in aviaries.

Researchers once focused their efforts primarily on breeding and husbandry, but now they need to know more.

And now that, you know, they're doing so well and it's at the point where, you know, that they could be in the wild again that now we can look at you know their

vocalizations and their behaviors and things like that.

University of Hawaii bioacoustics researcher and Tanamoto.

Those other aspects, culture, if you will, are critical for a species as socially complex as the

Al-A-L-A-L-A.

Tanamoto and her team made recordings of captive-Barr-Barr-A-L-L-L-A- recordings made in the early 1990s by Fish and Wildlife Service biologists of the last few wild pairs.

The wild have more like almost double the number of alarm calls than the Avery Allah do and they also have these

really cool territorial broadcast calls that they do in the wild that weren't found in captivity.

The absence of the territorial call in captivity makes good sense because captive birds have different

territory demands than wild ones.

It also makes sense that they would have fewer alarm calls because captive birds don't experience

the threat of predation.

The study was published in the journal Animal Behavior.

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