Big animals like to move. They need lots of space to find food and suitable mates. But animals around the world are increasingly finding it tough to get around as their habitats are being chopped up into small patches of protected reserves.
Chinese pandas, Florida panthers, Indian tigers, Africa's mountain gorillas, and now possibly jaguars in Central America are all getting swept into a biological black hole of shrinking spaces and smaller gene pools from which they can reproduce.
The latest battleground is in Nicaragua, where an environmental fight is brewing over a proposed deep-water shipping canal 170 miles across mountains, lakes and forests to link the Atlantic and Pacific coasts. Researchers say the canal could also sever an important "genetic highway" for the big cats as they travel throughout Central America.
"Nicaragua is one of those countries that is important to us to maintain that connectivity," said Howard Quigley, director of the jaguar program for Panthera, a New York based conservation group. "We're not opposed to development. We are opposed to development that doesn't take into account the jaguars in the long-term. In Nicaragua, the challenge is the development and construction of this new canal."
Over the past decade, conservation scientists have worked together with local groups and government officials to create the so-called "Jaguar Corridor" from Mexico all the way down to Brazil.
The corridor runs through verdant forests, as well as suburban areas, farms and around big hydroelectric dams. But the canal, proposed by a Chinese construction firm, would slice through prime jaguar habitat. It also makes it tougher for smaller populations of jaguars to connect and share genetic diversity.
This diversity is the only way to guarantee the survival of many large mammals.
In Florida, for example, a small population of Florida panthers has become an inbred, sickly group suffering from various ailments, including low sperm counts and kinked tails. Eight female panthers from Texas were introduced to the panthers south Florida habitat 20 years ago, and the population has risen to about 180, still well below the accepted minimal population of 500.
Africa's mountain gorillas face a similar vortex of shrinking space and smaller gene pool, according to a study by 23 scientists published in April in the journal Science. In Asia, tigers and pandas face similar fates: Small wildlife preserves set up by government officials isolate groups of animals from each other.
When it comes to creating nature reserves "we are looking for the Yellowstones that stand out for their charismatic beauty but aren't reflective of what's needed by the vast majority of animals," said Dennis Murray, a population ecologist at Trent University in Ontario. "We need to be more strategic in the way we are preserving land. If an area is critical in terms of linking up two other (protected) areas that should be a high priority."
Murray points to some other high-profile animals in North America that are also in danger of being fragmented by the loss of genetic corridors: the timber wolf in coastal southwest Alaska, the woodland caribou in northwest Canada and the red wolf in eastern North Carolina.
"Here we are approving a park here and a park there without taking a landscape ecology perspective," Murray said. "We are going at it piecemeal with a portfolio of small patches, they are really poorly designed."
Panthera's Quigley says that jaguars are pretty adaptable, but their territorial pathways are going to need to be considered by project developers. A new study by researchers at Panthera, Global Wildlife Conservation and Michigan State University identified two significant genetic pathways for jaguars and other species that may be bisected by the canal.
Without these pathways, three of Nicaragua's rarest large mammal species, jaguars, white-lipped peccaries, and Baird's tapirs, will struggle to find other individuals in neighboring populations for breeding, the researchers reported.
"Jaguars are good swimmers and we know they have crossed the Panama Canal," Quigley said. "In the (Nicaragua Canal) design, there are things that could mitigate the impacts. A bridge would be expensive and difficult. What would be simple would be to make sure that there is access to the edge of the water so it's not a high sided concrete wall."
Construction on the proposed Chinese canal is supposed to begin later this year, although some questions remain about both its route and financing, and whether a proper environmental impact study has been conducted, according to news reports.