Effects of urban environments on animals

Introduction:

Recent urban developments represent massive environmental changes.It was previously thought that only a few animals were suitable for city life,e.g. the crow because of its general adaptability and the pigeon because walls of city buildings are similar to cliffs. In fact, many urban animals are adapting with unsual speed.

Recent research:

• Emilie snell-Rood studied small urbanised mammal speciments from museums in Minnesota. She found the size of their brain had increased. She suggests this may be due to the need to locate new sources of food and to deal with new dangers.
• Catarina Miranda focused on the behabiour of urban and rural blackbirds. She found that urban birds were often braver, but were afraid of situations that were new.
• Jonathan Atwell studies how animals respond to urban environments. He found that some animals respond to stress by producing lower levels of hormones.
• Sarah Partan's team found urban squirrels use their tails to help them communicate.

Long-term Possibilities:

Species of animals may develop which are unique to cities. However, some changes may not be permanent.

Credit goes to

Cambridge IELTS