Climate change may affect the way birds behave. Higher temperatures encourage them to choose habitats further north as the old ones grow less favorable due to changing weather patterns. Global warming is also the reason behind the disappearance of wetlands, which poses deadly threat to bird species whose lives depend on them. Besides, some migratory birds don’t have to travel as far as they used to because climate in closer locations has become mild enough for them to winter. The farther they fly, the more energy they need so it is only reasonable to stay as close as possible to breeding habitat. Some birds choose not to migrate; a Robin has already spent two winters in my backyard (it is so easy to tell it from other birds that come to the bird table, such as Great and Blue Tits, Tree Sparrows or Greenfinches, by its shape – it looks like a little ball with dropped wings). Winter habitats are also affected by climate change – droughts make it very tough for birds to survive in Sub-Saharan Africa. In spring, birds tend to return earlier. They also tend to build nests and lay eggs earlier. Whether they are successful in raising nestlings depends on how much food (larvae of insects, plants) is available. However, particular elements of the environment may adapt to rising temperatures at different rates and, as a consequence, the hatching of young birds may not coincide with the abundance of larvae.