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Wild about homes: As spring nears, nature’s real estate market heats up

Ask the Expert Buying
Hermit-Crab-on-Sand
Hermit crabs will line up in hopes of trading up to a bigger shell. Adobe Stock

A severe housing shortage in Thailand last fall sent local officials scrambling to boost the supply of waterfront property. But it wasn’t more beachfront condos they needed — it was seashells.

A newly thriving hermit crab population around Koh Lanta National Park meant there were more of the crustaceans on the beaches than shells for the crabs to live in. And without the protection of a shell, the crabs can’t survive. So the Thai government solicited and received donations of empty shells from around the world, which they distributed on the beaches in December.

If only our human housing crisis were so easily remedied. But there are many parallels between nature’s housing market and our own. And for buyers braving the spring market, there are even some lessons to be learned.

Like humans, hermit crabs look to upgrade to bigger homes as they grow and need more space, said Monique Park, fish and invertebrates supervisor at Mystic Aquarium. When presented with a new shell, they may take several “house tours,’’ crossing back and forth between their existing shell and the new one to determine whether it’s worth moving. “You can actually see them testing it out, like they go on the walk-through, their own little housing inspector,’’ Park said. “It’s a big decision!’’

While it’s not always clear which shells hermit crabs will gravitate toward and why — individual preference seems to play a role — shells deemed more desirable than others can create a kind of bidding war. “The best shell is somewhat bickered over, so it’s a really tough housing market in their habitat at the aquarium,’’ Park joked. In fact, when a new shell hits the market in the wild (by washing ashore), it can attract a number of house-hunting crabs — even if it’s much too big for them. Smaller crabs will queue, from largest to smallest, waiting for a bigger crab to take the new shell so they can all trade up in a chain reaction.

Young buyers waiting for a starter home to free up can probably relate.

Just as people have different ideas about what makes a good home, “it’s the same thing with different animal species,’’ said Richard Primack, author of “Walden Warming: Climate Change Comes to Thoreau’s Woods’’ and a biology professor at Boston University. “Some animal species prioritize safety for themselves and for their young, and others prefer to live close to food. Some prefer to live in very dense colonies, some prefer to live by themselves.’’

And while some animals are content to move into existing housing — taking over an abandoned nest or burrow — others prefer new construction.

Beavers are particularly famed for their building prowess, bending the natural world to their will. These herbivores eat trees and twigs but are more comfortable and efficient in the water. So when they find a stream, they get to work, “using the most remarkable engineering capabilities imaginable to literally build a dam across the stream, which eventually begins to stop the water flow,’’ said Wayne Petersen, director of important bird areas for Mass Audubon. “As the water begins to back up and flood the adjacent woodland, they can have more ready access to the trees and shrubs.’’

Beaver-on-Top-Lodge
Beavers are particularly famed for their building prowess, bending the natural world to their will. —Adobe Stock

Not only are beaver dams structurally impressive, their lodges — where pups will live with their parents as a nuclear family for up to two years — are spacious and thoughtfully designed.

Beavers typically enter a freestanding lodge by swimming in from underneath. Inside, there are several different platforms and chambers at varying heights, Petersen said. “The lowest platform is their entry point when they first come in out of the water and shake themselves off,’’ he said. “It’s like a mudroom.’’ Outside the entrance, beavers store chewed-off branches underwater to keep the leaves and bark fresh, like a refrigerator.

When beavers create a pond, they’re essentially building a whole new ecological neighborhood. “As the beaver pond is created, other species of wildlife — like river otters, fish, muskrats, things that live in the water — will all take advantage of what the beavers have done,’’ Petersen said. Great blue herons, owls, and other birds will eventually nest in the dead, flooded-out trees. Call it Beaver Crossing: The latest mixed-use development for active waterfront living.

Woodpeckers are another important part of nature’s residential construction industry. While cavities form naturally in dead or decaying trees, woodpeckers are among the only species that can create nesting holes in live trees. “When a pileated woodpecker puts a hole into an 18-inch hardwood tree or pine tree, when they’re done using it, other large cavity dwellers are perfectly content to move in,’’ said Mariko Yamasaki, research wildlife biologist for the US Forest Service in New Hampshire. “There’s not a whole lot of redecoration required.’’

Indeed, hollows created by woodpeckers or natural decay are considered prime real estate for a number of animals, from squirrels to chickadees to smaller species of owl. “Tree holes generally are very valuable commodities,’’ Petersen said. Add to those cavities bird nests in the branches, and all kinds of insects and larvae living in the bark, and trees are like the apartment buildings of the natural world.

There are hot housing markets in the animal kingdom, too. For example, Primack said, birds will often space themselves out in a given area, establishing specific territories within which they can nest and have exclusive access to food. But in the most desirable habitats — those with an abundance of food and foliage — birds will settle for a smaller domain to be closer to the action.

“Generally, in the best habitat, the territories are smaller, because there’s more competition,’’ Primack said. And in marginal areas, with fewer resources and less competition, birds tend to live in larger territories. It’s reminiscent of how the price per square foot of real estate increases closer to Boston. “There are a lot of stores, restaurants, public transportation, cultural activities, employment opportunities, and so people are willing to accept a smaller living space because they have access to all these other resources,’’ Primack noted.

Woodchucks, prodigious diggers that they are, also add to the housing supply underground. Rabbits, skunks, and raccoons are among the animals that have been observed moving into woodchuck burrows, Petersen said, and abandoned foxholes are popular digs as well.

Chipmunk burrows are particularly elaborate, with separate chambers for storing food, sleeping, and nesting; there are even designated bathrooms. “They keep their nesting areas very clean, and they’re putting food waste and their droppings into these special waste chambers to keep the main part of the burrow clean,’’ Primack said. Housing safety inspectors would be happy to know that most burrowing animals also build secondary exits, “so that if they’re threatened in any way, they have an escape route to get away from any predator,’’ Primack said.

Chipmunks, beavers, and other creatures also spend quite a bit of time on home improvement. “Mice, for example, collect grass and make bedding of grass and straw and very fine material just to make their homes very comfortable, nice places for sleeping,’’ Primack said. “And they’re often cleaning them to remove dirt and to remove fleas and pests — they’re taking a lot of effort to keep them clean.’’

Octopuses also keep a tidy home — even if they move around more often than other animals. “They are neatniks, to an extent,’’ Park said, carefully disposing of midden (shells of animals they’ve eaten) to conceal their whereabouts. “They’ll actually use their siphon to clean the den every day, so all the refuse ends up outside. I mean, I wish I had that kind of cleaning ethic,’’ Park quipped.

They’re also known to dabble in interior design. “Here at Mystic Aquarium, our octopuses kind of redecorate their habitats pretty frequently,’’ Park said. “When you have a female, in particular, that nesting instinct is incredibly strong, and so they’ll actually ‘rearrange the furniture,’ we call it, inside the habitat.’’

Caribbean-Reef-Octupus
Octopuses keep a tidy home — even if they move around more often than other animals. —Adobe Stock

Park has seen an octopus move a 50-pound boulder, like an expectant mother preparing a nursery. “And this mother octopus is moving it around the habitat, stationing the rocks with the anemones on them so that they’re facing outwards and protecting that nesting ground that she’s created for herself,’’ she said. “It’s of the utmost importance to her at that point.’’

Like the Boston housing market, spring is prime time for animal house hunters as they prepare to breed and raise their young. And in many cases, we humans aren’t all that different: With kids on the horizon, things like backyards and schools start to factor more prominently in our housing decisions. “It’s common in the United States for people to move right around the time they’re thinking about having children,’’ Primack said.

Sometimes that means returning to what you know. Primack and his wife, for example, bought his parents’ old house in Newton. “For me, it was important to have that continuity of living in the same neighborhood that I grew up in. And there are some birds that are like that,’’ he said, such as woodpeckers, eagles, ospreys, and hawks.

“A very large number of animals are extremely faithful to the sites where they first established a nest,’’ Primack added. “They’ll just keep returning to the exact same place. And one reason is, if they were able to safely raise offspring in the past and find a mate, they’ll go back.’’

Choosing a place to live is a weighty decision. But while you may feel stressed out as you prepare to plunk down a lifetime of savings on a home this spring, maybe it helps to know that the stakes are even higher in the natural world. There’s a lot riding on where an animal chooses to live and raise its young, Yamasaki said. “If they don’t make a good choice, their genes don’t make it into the next generation.’’

Jon Gorey blogs about homes at HouseandHammer.com. Send comments to [email protected]. Follow him on Twitter at @jongorey. Subscribe to our free real estate newsletter at pages.email.bostonglobe.com/AddressSignUp.