One of the most heartwarming sights for urban wildlife-lovers are hedgehogs traipsing around city gardens and parks. But the urban environment presents a host of obstacles for the small spiny creatures, including stone walls and fences that impede their nightly quests for food.

Two groups of aficionados, one in Israel and the other in the United Kingdom, are working to ensure that these creatures have the freedom of access they require to survive life in the big city.

In England, an organization calling itself Hedgehog Street has been active for about a year. Sponsored by the British Hedgehog Preservation Society and the People's Trust for Endangered Species, the group tries to encourage people to leave garden gates and other obstacles open for these little passersby. So far they have created passage through 5,000 gardens in various places in Britain.

In Israel, the project is more modest, sponsored by a Ramat Aviv group called Residents Forum for Urban Nature and Environmental Quality. Their goal is also to provide green corners that allow hedgehogs to enter and exit freely.

In England, awareness of the plight of hedgehogs arose after studies showed that their population had declined 25 percent over the past decade, mainly due to loss of natural habitats. Thus, the animals had become more dependent on cities, where they can still find food. But cities also present major obstacles to the animals, which can roam as much as two kilometers a night while foraging.

"The thing about hedgehogs is that they travel absolute miles. Lovely as it is to have them in the garden, if they've got no corridor to travel along, then they're not going to find enough food to eat - there's not enough food for them in one garden," famed nature-film producer David Attenborough told The Guardian when the British project was launched.

In addition to encouraging people to leave openings in their fences, the British effort urges home owners with ornamental pools to build them with shallow areas so the animals won't drown. Furthermore, Hedgehog Street advises, it's enough to remove one brick from the bottom of your garden wall, dig a tunnel under it, or plant a hedge to allow the animals to roam free.

One of the goals the Ramat Aviv group has set is to replace metal fences with hedges for the benefit of two subspecies: the northern and the long-eared hedgehog.

"There has recently been a trend in city neighborhoods to replace hedges with stone or metal fences that can't be breached," the forum's director, Galit Samuel explains.

According to Samuel, the group has reached an agreement with the Tel Aviv municipality that boundaries between public and private plots will be marked by fencing with openings allowing the hedgehogs to wander about freely.