 The rails are a large and very widespread family , with nearly 150 species . They are small to medium @-@ sized , terrestrial or wetland birds , and their short bodies are often flattened laterally to help them move through dense vegetation . Island species readily become flightless ; of 53 extant or recently extinct taxa restricted to islands , 32 have lost the ability to fly . 
 The rails <a href='drop_aux' title='1'><mark>are</mark></a>a large and very widespread family , with nearly 150 species . They <a href='drop_aux' title='2'><mark>are</mark></a>small to medium @-@ sized , terrestrial or wetland birds , and their short bodies are often flattened laterally to help them move through dense vegetation . Island species readily become flightless ; of 53 extant or recently extinct taxa restricted to islands , 32 <a href='been_done' title='3'><mark>have</mark></a> lost the ability to fly . 
The rails a large and very widespread family , wid nearly 150 species . They small to medium @-@ sized , terrestrial or wetland birds , and their short bodies are often flattened laterally to help them move thru dense vegetation . Island species readily become flightless ; of 53 extant or recently extinct taxa restricted to islands , 32 done lost the ability to fly .