专题训练(三)AAlongtheriverbanksofAmazonandtheOrinocotherelivesabirdthatswimsbeforeitcanfly,flieslikeafatchicken,eatsgreenleaves,hasthestomachofacowandhasclaw(爪)onitswingswhenyoung
Theybuildtheirhomesabout4
6mabovetheriver,animportantfeature(特征)forthesafetyoftheyoung
Itiscalledthehoatzin
Inappearance,thebirdsofbothsexeslookverymuchalikewithbrownonthebackandcreamandredontheunderside
Theheadissmall,withalargesetoffeathersonthetop,brightredeyes,andblueskin
Itsnearestrelativesarethecommonbirds,cuckoos
Itsmoststrikingfeature,though,isonlyfoundintheyoung
Babyhoatzinshaveaclawontheleadingedgeofeachwingandanotherattheendofeachwingtip
Usingthesefourclaws,togetherwiththebeak(喙),theycanclimbaboutinthebushes,lookingverymuchlikeprimitivebirdsmusthavedone
Whentheyounghoatzinshavelearnedtofly,theylosetheirclaw