passage 9 Easter ( 复活节 ) is still a great day for worship, candy in baskets and running around the yard finding eggs, but every year it gets quite a bit worse for little rabbits. And no, not because the kids like to pull their ears. The culprit is climate change, and some researchers found that rising temperatures are having harmful effects on at least five species of rabbit in the US. Take the Lower Keys Marsh rabbit, for instance. An endangered species that lives in the Lower Florida Keys, this species of rabbits is a great swimmer -- it lives on the islands! -- but it is already severely affected by development and now by rising sea levels. According to the Center for Biological Diversity, an ocean level rise of only 0.6 meters will send them jumping to higher ground and a 0.9-meter rise would wipe out their habitat ( 栖息地 ) completely. The snowshoe hare, on the other hand, has a color issue. Most of these rabbits change their fur color from white in the wintertime to brown in the summer, each designed to give them better cover from predators (食肉动物) . As the number of days with snow decreases all across the country, however, more and more little rabbits are being left in white fur during brown dirt days of both fall and spring, making them an easier mark for predators. Researchers know that the color change is controlled by the number of hours of sunlight, but whether the rabbit will be able to adapt quick enough to survive is a big question. The National Wildlife Federation has reported that hunters have noticed their numbers are already noticeably down. American rock rabbits, a relative of rabbits and hares, might be the first of these species to go extinct due to climate change. About 7-8 inches long, pikas live high in the cool damp mountains west of the Rocky Mountains. As global temperatures rise, they would naturally migrate to higher ground -- but they already occupy the mountaintops. They can't go any higher. The National Wildlife Federation reports that they might not be able to stand the new temperatures as their habitat heats up. The volcano rabbit has the same problem. These rabbits live on the slopes of volcanoes in Mexico, and recent studies have shown that the lower range of their habitat has already shifted upward about 700 meters, but there are not suitable plants for them to move higher, so they are stuck in the middle. Scientists are concerned about their populations. Native to the US, pygmy rabbits weigh less than 1 pound and live in the American West. They are believed to be the smallest rabbits in the world. Their habitats have been destroyed by development. Several populations, such as the Columbia Basin pygmy, almost went extinct and were saved by zoo breeding programs. Pygmy rabbits also rely on winter cover by digging tunnels through the snow to escape predators, but lesser snowfall is leaving them exposed. All of this gives new meaning to dressing up in a giant bunny costume this Easter.