“Assisting Migration” Could Be Aiding Extinction

Candice Gaukel Andrews January 2, 2011 10

Climate shift will be fastest over flat areas, such as marshes. ©John T. Andrews

As our 2010 calendars now come down off the walls and we look at the crisp, new, blank pages of 2011, we can’t help but wonder what this New Year has in store for the world and for us. The early days of January tend to fill us with hope for the next 12 months; visions of uplifting news headlines, solutions to vexing problems, and imaginative new technologies that will make our jobs and lives even easier. But there’s at least one thing that I hope won’t distinguish the year 2011 as we look back upon it next December—I hope it doesn’t become The Year the First Species Went Extinct Due to Climate Change.

Just a little more than two years ago, scientists reported that the white lemuroid possum was missing from its only home in the mountain forests of north Queensland, Australia. It hasn’t been seen there for almost four years. A slight temperature rise (of only one or two degrees) is postulated as the likely reason: the possum typically dies in as little as four or five hours at 86 degrees Fahrenheit.

Researchers, such as Dr. Chris Thomas of the University of Leeds in England, believe that even under midrange global-warming scenarios, 15 to 37 percent of our terrestrial species could become extinct by 2050. And that’s just the threat from climate change, without taking into account the added dangers of habitat loss and the migration barriers posed by cities and highways.

“Desperate times call for desperate measures,” or so the proverb goes. That’s why some nature enthusiasts are refusing to wait for the slow wheels of government to turn and are participating in an activity called “assisted migration” (or “managed relocation”).

By 2050, 15 to 37 percent of our terrestrial species could become extinct due to climate change, habitat loss and the migration barriers posed by highways and development.

Moving day

“Assisted migration” is defined as “the practice of deliberately moving members of a species from their present habitat to a new region with the intent of establishing a permanent presence there.” Usually, assisted migration projects are conducted in response to the destruction of natural habitats caused by human actions: most notably, climate change.

In past episodes of global warming, many plants were able to keep up, evolving and moving in concert with the temperatures. But the unprecedented speed of climate change today has almost made that impossible. A study published in the science journal Nature predicted that, on average, climates would shift about a third of a mile per year in the 21st century. It will be fastest—about three-quarters of a mile per year—over flat areas, such as deserts, mangrove swamps and marshes. And it could be as much as six miles per year in extreme situations. Without human help, some say, countless species will die.

For example, one group of concerned citizens, the Torreya Guardians, moved 31 seedlings of the endangered Florida torreya, a conifer tree, 400 miles north of its current natural range in Florida to two sites in the North Carolina mountains. In Los Angeles, fans of the quino checkerspot butterfly—a tiny, brown, red-and-black insect that doesn’t like it too hot and dry—carried a few cocoons north beyond the city and into the mountains. The hope is that these species will re-establish themselves in their new habitats.

The vast majority of our plants have not evolved for rapid locomotion. ©John T. Andrews

In most cases of assisted migration, people act on their own without much paperwork or bureaucracy. And for some, that’s the problem.

Slower is better

Many conservation biologists argue that assisted migration is not helping to save the world’s biodiversity; in fact, quite the contrary. By taking the fate of rare and vulnerable species into their own hands, citizen activists are inadvertently harming them at a time when invasive, nonnative plants and animals pose one of the gravest threats to natural areas—to the flora and fauna already living there.

Instead, say those who oppose assisted migration, people should work under the supervision of botanic gardens and government agencies, which are approaching relocations cautiously and methodically. Some gardens are now collecting seeds of threatened plants for use in future reintroduction efforts. In order to preserve a species’ genetic diversity, these entities are careful to include samples from a wide variety of populations. Government agencies, they say, have been moving more vigorously to purchase lands in order to create “migration corridors,” large continuous tracts that enable plants and animals to successfully rearrange themselves. And both have been redoubling their efforts to control invasive species.

In the Midwest, where I live, the Chicago Botanic Garden is now beginning to test the feasibility of assisted migration for the threatened (federal and state) dune thistle. This imperiled wildflower with puffy, cream to pinkish-tan summer blossoms and blue-green leaves has been driven by development and drought from much of its habitat along the western Great Lakes. In recent years, the garden has been collecting seeds from different parts of the dune thistle’s range and using growth chambers in labs and special germination tables to test the plant’s response to different conditions—and thus to help choose the best places to relocate it in the wild.

Eco-vigilantes or species-saviors?

Botanic gardens are approaching assisted migration cautiously. ©Candice Gaukel Andrews

Those who believe in assisted migration, however, say that “potted” plants is the botanical equivalent of “caged” fauna. Cultivated plants could be far different from their counterparts in the wild if they were propagated from stock at commercial nurseries that have long been in cultivation. Such plants may have adapted to the “easy life,” including regular watering and a lack of competition from other plants and animals. And as climate change intensifies, it’s likely that public monies and scientific manpower will be stretched to the limit just managing species that play major ecological roles. The fate of many other plants and animals may depend on a few friends willing to help them move—people like you and me.

If a species is getting close to extinction, do you think it’s okay for concerned citizens to help it move to a better habitat, or would it be wiser to wait for organized institutions to step in?

Here’s to finding your true places and natural habitats,



  1. John Howard Gaukel January 4, 2011 at 10:43 am - Reply

    I wonder if having individuals or groups of people participating in assisted migration,on their own, of plants and animals from their area to another area could become a form of assisted invasive migration? Maybe, sense we seemed to have caused the global-warming problem we shouldn’t compound the problem further. Let the scientist do their job and wait for their recommendations. In the meantime, try and do what you can to prevent further global-warming.

  2. Art Hardy January 4, 2011 at 10:09 am - Reply

    Wow, that’s a really tough question. You never want to sit idly on the sidelines and watch a species become extinct, and later realize that some action on your part might have helped to prolong its existence. But, on the other hand, how many times have we heard of good intentioned naturalists trying to solve one species’ problem only to create some new challenge to a different local species.

    I’d error on the side of not messing with Mother Nature.

  3. NineQuietLessons January 4, 2011 at 10:07 am - Reply

    Well-intentioned measures that are executed poorly can do more harm than good. It’s better to let the professionals handle it.

  4. Kit Nordeen January 3, 2011 at 10:13 am - Reply

    No reply right now.

  5. jack January 2, 2011 at 7:19 pm - Reply

    If I were a quino checkerspot butterfly, I’d be worried about what species of birds are waiting for me in the mountains.

  6. Kris January 2, 2011 at 5:49 pm - Reply

    I think it would be wiser for organized institutions to manage it…but I think it’s our duty to stay informed and show support for these organizations, helping if needs be.

Leave A Response »