Photo via International Rhino Foundation

Finding love is hard enough when you're a certifiably sexy eco-celebrity--but when you're an endangered bug-eyed mammal with razor-sharp claws, a giant rhino, or a panda on display, your chances are even slimmer.

For species in the wild, dwindling populations mean less chance of a love connection, while animals in captivity deal with infertility, performance anxiety, and other mating problems. Read on for seven endangered species who have more than a little trouble scoring at their local watering hole -- meaning the babies needed to get them off the endangered list are few and far between.

1. Sumatran Rhino

Love comes in all shapes and sizes--which is a relief if you're a 2000-pound, hairy Sumatran rhino. After years of coordination, Ratu and Andalas, residents of Indonesia's Sumatran Rhino Sanctuary in Way Kambas National Park, are expecting their first bundle of joy in May 2011. (The father, Andalas, is one of only three of the breed born in captivity in more than a century.) But their fellow rhinos still in the wild face a bigger challenge when it comes to finding true love: Only about 200 still run free -- added to the less than a dozen of the rhinos in captivity worldwide, this is one seriously endangered animal.

2. Aye Aye

Photo via Zoo Borns

We'll admit the aye-aye is one of the world's weirder-looking endangered species, but when it comes to love, isn't it supposed to be what's on the inside that counts?

Still, with its numbers decreasing in its home country of Madagascar--blame deforestation and hunters for that--the aye-aye's chances for reproduction are becoming increasingly scarce, and even those in captivity aren't going at it too frequently; only two of the animals have ever been born in North America, the second at the Denver Zoo last spring. But modern medicine has a backup plan: German zoologists are keeping stem cells from the aye-aye frozen for their potential in cloning projects.

3. Vancouver Island Marmot

Photo via The Vancouver Island Marmot Recovery Foundation

Considered Canada's most endangered species--and one of the rarest mammals in the world--the inquisitive-looking marmot is found in just one place: Vancouver Island in British Columbia.

By 2001, the population had dwindled to just 75 marmots total, a result of logging and attacks from bigger predators, and only a third of those were living in the wild. These days, the numbers are growing: about 100 remain in the wild, and the Vancouver Island Marmot Recovery Foundation raised 71 weaned pups last year. And while both parents stay involved by watching the pups for the first year, the species depends on the creation of new colonies--so marmots that are lucky enough to find their soulmates will leave their homes to create a new colony together.

4. Ugandan Mountain Gorilla

Photo via African Wildlife Foundation Ugandan mountain gorillas are Mother Nature's answer to tall, dark, and handsome--but that doesn't always mean the males are able to catch the eye of any female they'd like. Sure, the dominant silverback in each group has unlimited access to any of the females, but sub-adult males get their mating opportunities only with the silverback's permission--usually not before they're teenagers--and the decreasing numbers of these animals (scientists believe that only 720 remain in the wild) mean that other options are few and far between. Female gorillas give birth to, on average, one baby every four years, which makes it hard for the population to recoup at the same rate it's affected by hunting, poaching, and deforestation.

Discover More Endangered Species We Can't Believe Are Single on Page 2