Scientists report changes in vegetation determine how animals migrate

May 11, 2011

The predictability and scale of seasonal changes in a habitat help determine the distance migratory species move and whether the animals always travel together to the same place or independently to different locations, according to a paper published online in February in Global Ecology and Biogeography by the National Zoo's Smithsonian Conservation Biology Institute researchers and partners.

The study's findings have significant implications for around the world working to conserve endangered species that migrate.

"We knew that Mongolian gazelle in the Eastern Steppes migrate long distances, but when we put radio collars on them, we were surprised to discover that they go off individually in different directions," said Thomas Mueller, a research associate at SCBI and lead author of the study.

"Previously researchers had not paid much attention to how individual animals that migrate long distances move relative to one another," Mueller added.

The researchers compared how Mongolian gazelle migrate to the movement of three other ungulate species: guanaco in the Patagonian Steppes in Argentina, caribou in the arctic tundra of Canada and Alaska and moose in temperate forests in Massachusetts. SCBI's primary role in collaboration with University of Maryland was to provide the remote and statistical analysis, while other partners organized and executed the field work in each of the areas.

After determining how far each species migrated and whether individuals moved together or independently from each other in different directions, the scientists compared these results to 25 years of satellite data from the showing seasonal and annual changes in landscape dynamics. They found that the species that moved the largest distances (caribou and gazelle) live in areas where vegetation (their food source) varies over large scales, while those that moved shorter distances (guanaco and moose) live in areas where the vegetation varies at a much smaller scale.

They also found that Mongolian gazelles, which move independently in different directions compared to one another other, live in habitats with the least predictable landscape dynamics.

"What this indicates is that while it may be appropriate to put barriers around landscapes where endangered species stay in herds as they migrate, species that migrate as individuals require conservation strategies that facilitate long-distance movements across the entire landscape," said Scott Derrickson, deputy director of SCBI. "We now know some of the landscape factors that we can look at to determine the best way to manage habitat for endangered or threatened species."

SCBI will spearhead the next steps in the research: expanding the number of species and the number of study regions and refining the statistical methods quantifying how individuals move relative to one another. The researchers also want to understand how the animals know how to navigate the landscapes—whether through memory or through other sensory mechanisms—and if those mechanisms differ between the that migrate as herds or as individuals.

Explore further: Disquieting times for Malaysia's 'fish listener'

add to favorites email to friend print save as pdf

Related Stories

Study of guanacos launched in Chile

Jun 10, 2008

The Wildlife Conservation Society has launched a study in Chile's Karukinka reserve on Tierra del Fuego to help protect the guanaco – a wild cousin of the llama that once roamed in vast herds from the Andean ...

We're off then: The evolution of bat migration

Nov 20, 2009

(PhysOrg.com) -- Not just birds, but also a few species of bats face a long journey every year. Researchers at Princeton University in the U.S. and at the Max Planck Institute for Ornithology in Radolfzell, ...

Wiping out the world's mass migrations

Jun 01, 2009

Densely packed wildebeests flowing over the Serengeti, bison teeming across the Northern Plains—these iconic images extend from Hollywood epics to the popular imagination. But the fact is, all of the world's ...

Asia's odd-ball antelope faces migration crisis

Mar 17, 2008

Take a deer’s body, attach a camel’s head and add a Jimmy Durante nose, and you have a saiga – the odd-ball antelope with the enormous schnoz that lives on the isolated steppes of Central Asia. Unfortunately, ...

New study reveals large scale conservation essential

Jun 10, 2008

Scientists were surprised with findings of a recent study that reveals many animal species believed to persist in small contained areas actually need broad, landscape level conservation to survive.

Recommended for you

France fights back Asian hornet invader

50 minutes ago

They slipped into southwest France 10 years ago in a pottery shipment from China and have since invaded more than half the country, which is fighting back with drones, poisoned rods and even chickens.

Tide turns for shark fin in China

1 hour ago

A sprawling market floor in Guangzhou was once a prime location for shark fin, one of China's most expensive delicacies. But now it lies deserted, thanks to a ban from official banquet tables and a celebrity-driven ...

Manatees could lose their endangered species status

13 hours ago

About 2,500 manatees have perished in Florida over the last four years, heightening tension between conservationists and property owners as federal officials prepare to decide whether to down-list the creature to threatened ...

User comments : 0