DURHAM, N.C. - Permeable fencing could help make solar-energy facilities in North Carolina more wildlife-friendly.

The Nature Conservancy, along with the North Carolina Pollinator Conservation Alliance and other groups, has teamed up with solar companies to figure out how to better integrate solar farms into the landscape. Around 40,000 acres of land in the state are being used to harvest solar energy, a number that is expected to increase. On these sites, hundreds of solar panels generate electricity that's fed into a grid, supplying consumers with clean energy.

"We identified that there are a bunch of practices out there that could be applied to solar farms, so people could install things like this wildlife-permeable fence, which is a fence with larger holes in it than a traditional chain-link fence," said Liz Kalies, director of science at the Nature Conservancy's North Carolina chapter. "The idea is that it allows for small- to medium-sized animals to move freely through the fence."

Charlotte-based developer Birdseye Renewable Energy was the first to install permeable fencing at one of its facilities in Tennessee. Footage from motion-sensitive cameras revealed that raccoons, rabbits and other critters are able to move safely through the fencing. Based on this evidence, Pine Gate Renewables in Asheville installed permeable fencing at sites in Johnston and Moore counties. North Carolina is a leader nationwide in solar-energy capacity, along with California and Arizona.

Kalies said the solar farms where the permeable fencing is installed are located near dense forests that are home to diverse wildlife populations. She said she hopes the fencing will catch on as a tool to ensure that animals don't get squeezed out of their habitats.

"We're going to be putting in more and more solar farms and, at some point, that amount of habitat removal, that amount of habitat loss, is going to matter," she said. "We don't know what that number is, and so we need to start preparing for it and mitigating against it."

As the need for clean-energy solutions increases, Kalies pointed out that permeable fencing, along with other techniques such as planting pollinator vegetation, could help balance out the environmental impact of solar farms.

This week, in honor of World Otter Day, conservation groups are looking to raise awareness about efforts to restore sea otters along more areas of the California coast.

Right now, sea otter populations are mostly concentrated on the Central Coast, between Santa Barbara and an area just south of San Francisco, hemmed in by predatory white sharks.

Andy Johnson, California representative for Defenders of Wildlife, said they used to live all the way up the north coast.

"We'd like to, at some point, maybe shift some otters northward and get them into cooler waters, where sea otters used to be before they were hunted to near extinction," Johnson explained. "Let them maybe help restore some of the kelp along the north coast, and improve the biodiversity of those habitats."

The Monterey Bay Aquarium's surrogacy program has successfully reintroduced sea otters in nearby Elkhorn Slough.

The U.S. Fish and Wildlife Service is due to release a report to Congress this summer on the feasibility of expanding the program. Otters save kelp beds by eating sea urchins, which can devour the kelp if not kept in check.

Johnson noted the otter population has rebounded over the past century, but has a long way to go to fully recover.

"We think that there were between 16,000 and 20,000 otters historically on the California coast," Johnson reported. "Right now, there are about 3,000 animals. There were only about maybe 50 otters back in the early 1900s."

This week, the California State Assembly also passed a resolution to proclaim the 20th annual Sea Otter Awareness Week, which takes place Sep. 18-24.

The Colorado General Assembly has passed legislation to fund wildlife road-crossing projects across the state.

Rep. Julie McCluskie, D-Gunnison, said Senate Bill 151 has broad support from sportsmen and women, land and wildlife conservation groups, and community leaders from both parties. She argued safe passages work, and pointed to a successful program developed in Summit County.

"Our safe passages in Summit County have been able to reduce the number of wildlife and vehicle collisions by more than 92% in the five years since they were originally constructed," McCluskie reported.

Each year, wildlife-vehicle collisions kill thousands of animals, at a cost of more than $80 million in property damage and related expenses. The "Safe Crossings for Colorado Wildlife and Motorists" bill will use state funds to tap matching federal dollars for a list of shovel-ready projects, starting with stretches of roads and highways with high rates of wildlife-vehicle collisions.

Outdoor recreation contributes more than $62 billion to Colorado's economy. But Colorado Parks and Wildlife estimated more Western Slope mule deer does are killed each year in vehicle collisions than from hunting.

Rep. Perry Will, R-Carbondale, said the measure will help protect critical wildlife resources.

"We lose thousands of deer and elk and other wildlife across the state each year," Will noted. "This bill is important; that we can save those, plus the safety of the motoring public. There's some really bad accidents with wildlife and vehicle strikes on the roadways."

Colorado has been a leader in the West for wildlife-crossing solutions. There are currently 64 bridges, culverts or tunnels, and fencing projects to help move animals away from traffic and to safe crossings. McCluskie said the measure will help preserve Colorado's rich outdoor experiences.

"Nothing is more special about Colorado than our great outdoors," McCluskie stressed. "When we protect wildlife, we protect that very pristine, special, unique part of our entire state and culture."

Saturday is World Migratory Bird Day, and bird experts said it is a great time to be on the lookout for types of birds you may not see every day in your community.

Up to 300 species of birds have been identified in and around the Gulf of Maine during migration season, and this year's theme for the awareness day is the impact of light pollution on birds.

Nicholas Lund, advocacy and outreach manager for Maine Audubon, noted roughly one million birds die per day from running into glass. At night, the lights from within make glass invisible to birds, and during the day it reflects their habitat.

"Birds don't know what glass is," Lund explained. "They fly accidentally into windows when they are drawn in by lights, which also may disorient them as they're traveling or draw in the insects that they're trying to eat."

In addition to risks of collision, disorientation can cause birds to circle and deplete their energy resources, making them more vulnerable to predators.

Lund recommended turning out lights at night during migration, which is now through the first part of June, and then again in September and October. He said if you cannot keep your lights off, light fixtures can help, and you can treat the glass on your windows to make it more visible to birds.

Lund added while Saturday is the day selected to celebrate migratory birds, millions of birds are flying up to Maine every night from their wintering grounds in the south, looking for places to breed.

"The trees in your backyard are going to be full of colorful songbirds," Lund pointed out. "The shores and the mud flats will be full of shorebirds moving, the skies full with raptors. I mean, this is migratory bird month, for sure."

Lund emphasized for those who want some guidance, birders and experts are leading walks across the state - including at Fields Pond near Bangor on Saturday, as well as all this week and next at Evergreen Cemetery in Portland.

Also on Saturday, staff naturalist Doug Hitchcox will host a "Big Day," trying to find as many bird species as possible from Bangor to Kennebunkport.