The birds and bees -- and the mammals, insects and amphibians -- that share the state with humans don't vote or pay taxes. But since this latest conservation movement began nearly 40 years ago, endangered and threatened species have had a "voice" and been afforded at least some protection from the seemingly relentless pressures of development, erosion and habitat changes.

The official list of species with declining numbers is revised every five years or so by state Department of Environmental Protection biologists, and last year development, disease, new predators and even carelessly discarded pets got many once-common creatures listed for the first time.

Take, for example, the painted turtle. The DEP is observing The Year of the Turtle in 2011 to call attention to several native species in sharp decline, including painted turtles.

"The turtles you buy in a pet store are red-eared sliders, and they are not native to Connecticut," said Julie Victoria, a DEP wildlife biologist. "People let them go when they don't want them anymore, and they are taking over areas that had been used by painted turtles, pushing them out."

Although Connecticut doesn't have the equivalent of a snail-darter, the tiny fish that held up the construction of a Tennessee River dam for years, development here has been affected by the presence of endangered or threatened species. The Eastern box turtle has been a species "of special concern" for years, and the presence of just a few of them in one location has sometimes been enough to delay a construction project or force it to be redesigned.

When a new mobile home park was being developed in Milford in the 1990s, about 18 Eastern box turtles were found on the site. After an environmental impact study, the layout of the park was reconfigured to preserve a pond and to move building farther way from it.

An upgrade of Route 7 south in Danbury a few years later was redesigned when Eastern box turtles were found along the route, said Adam Whelchel, director of conservation programs for the Nature Conservancy of Connecticut. Changes to culverts that preserved the turtles' access to fresh water allowed the project to move forward, he said.

The Eastern box turtle can live for up to 100 years, Victoria said, "but it has a very small home range. They don't move very far from where they were born and they don't recognize things like roads."

Sometimes, man and nature can co-exist with just a few simple accommodations or modifications. A new boardwalk that opened this month to connect Walnut Beach in Milford to Silver Sands State Park was relocated several feet south of its original location, after DEP biologists found that it would otherwise encroach on a nesting area for piping plovers, rare shore birds that lay their eggs on the sand.

The Nature Conservancy, working with the Aquarion Water Co., installed lamps underwater to guide eels on the Aspetuck River away from treatment plants. Eels avoid light and the lamps route the eels around the plant's intake vents and toward a dark pool with a siphon that carries them safely over the reservoir's spillway, officials said on the water company's website.

The 50-year-old conservancy also builds fish ladders and other measures to help alewives and other small fish cross spillways, Whelchel said. The Eastern spadefoot toad is an endangered species on both the state and federal wildlife lists, giving it a double layer of protection, he said. The blue-spotted salamander is endangered in Connecticut and the Northern spring salamander is considered "threatened," a less-severe status, according to the DEP's latest list.

Sometimes a species may be thought to be endangered because no accurate count exists, biologists said. One solution has been the "Bio-Blitz," in which several hundred volunteers from state and local conservation groups, the DEP and zoology students from Connecticut College in New London conduct a thorough canvass of a habitat.

"They'll count every living thing in a small area," said Whelchel of the Nature Conservancy. "The most recent bio-blitz was done in the Trap Rock Ridge area of Middletown."

Accurate counts may help dispel rumors of wolves, mountain lions and other creatures that have not been documented in Connecticut in centuries.

Victoria, the state wildlife biologist, said one reported mountain lion turned out to be an exotic pet, kept illegally. "There is a whole layer of exotic pets that the department is trying to get a handle on. But the last mountain lion documented in the wild in Connecticut was in the 1890s. There haven't been wolves here for centuries; the Colonists pretty much declared war on them."

Bears and coyotes are increasing in numbers, as are bald eagles, Victoria said.

Bobcats are too, she said, though they were always here and never endangered. "They're secretive so you don't see many bobcats. But we have them."

The biggest threat to the state's biodiversity right now is "white nose syndrome," a fungal infection that is decimating the bat population, said Christina Kocer, a DEP wildlife technician. "Since this was first documented in Connecticut in 2008, we've lost 99 percent of the Northern long-eared bats that winter here, and 96.6 percent of all little brown bats. Right now, we have no long-term means to address it, but there has been some talk of a captive breeding program. That won't be easy to do, with a hibernating species," she said.

It's just not the bats' noses that are covered in the powdery white fungus, but its fur and feet, Kocer said. "When they are close to death, they are almost completely engulfed in it. This is one case where it isn't habitat loss that's affecting their numbers. Bats do pretty well with people; they are part of the landscape and they can even live in attics. But bats eat insects, and while other factors also affect the number of insects, you can infer that with so many fewer bats, the numbers of mosquitoes will increase sharply."

Another problem, the introduction of invasive species, is behind the sharp drop in the number of freshwater mussels in the Housatonic and Connecticut rivers and their tributaries, said Victoria of the DEP. Zebra mussels, native to Russia and originally brought to North America in the ballast of ships on the St. Lawrence Seaway, are smothering the freshwater mussels that line the bottoms of rivers, she said. "They grow right on top of them, and they smother them."

Colony collapse syndrome, a mysterious condition in which honeybees abandon their hives, has led to several bee species making the DEP's list for the first time in 2010. At the same time, several species of moths and invertebrates came off the list, Victoria said. Common ravens also lost their protected status; they are expanding their range into Connecticut, biologists said.

One of the biggest success stories is the return of the osprey, said Victoria, who supervises the DEP's annual count of shore birds.

"Earth Day has been a success, beginning with the Clean Water Act and Clean Air Act in the early 1970s," she said. "Ospreys had been decimated by (the pesticide) DDT; we had only nine nesting pairs in the whole state in 1974, two years after DDT was banned nationwide. We had 290 pairs last year, all along the coast from Greenwich on down. Ospreys once had been found only at the mouth of the Connecticut River in Old Saybrook."

The species has been "de-listed" in light of its comeback.