Urban wildlife is wildlife that can live or thrive in urban environments. Some urban wildlife, such as house mice, are synanthropic, ecologically associated with humans. Some species or populations may become entirely dependent on humans. For instance, the range of many synanthropic species is expanded to latitudes at which they could not survive the winter outside of human settlements. Other species simply tolerate cohabiting with humans and using the remaining green spaces, in some cases gradually becoming more accustomed to the new habitat over time and eventually synanthropic. These species represent a minority of the creatures that would normally inhabit an area. For example, a 2014 compilation of studies found that only 8% of native bird and 25% of native plant species were present in urban areas compared with estimates of non-urban density of species.