This is Scientific Americans 60 Second Science. I'm Jason Goldman. Got a minute?

When birds face the destruction of their habitat, some species don't make it while others survive.

But what happens at the very beginning of the process,

just as the bird's habitat starts to change?

Research in Argentina's Monte Desert has provided some answers.

Protected parts of the desert have lots of plant diversity.

Trees, tall shrubs, short shrubs, grasses, and flowering plants.

With so many options, most seed-eating birds choose to focus on large grass seeds.

The birds can get all the energy and nutrients they need with minimal effort.

But when cattle show up to graze the desert's natural landscape, birds face changes in food availability.

Some birds are happy to change their diets in response, but others not so much.

And it's the ones set in their ways that are at the highest risk.

Understanding how birds react to grazing can help conservationists figure out

how to help those species most in jeopardy.

Ecologists from the Argentine Arid Zones Research Institute

compared soil samples from the desert Neakunian Biosphere Reserve

to samples from two neighboring cattle ranches.

They discovered that grass seeds, the bird's favorites, were just one quarter as likely to be

found in the ranches compared with the reserve.

Next they captured birds and flushed their digestive checks to see what they were eating.

The common deukofinch and the rufous-collared sparrow had adjusted their diets, opting to dine on their less preferred options of the

ranches, even while they still focus on large grass seeds within the reserve.

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