( ( The ( ear coverts ) ) ( are ( ( ( small feathers ) ( behind ( ( the ( bird 's ) ) eye ) ) ) ( which ( ( cover ( the ( ear opening ) ) ) ( -LRB- ( ( ( ( the ear ) ( of ( a bird ) ) ) ( has ( no ( external features ) ) ) ) -RRB- ) ) ) ) ) ) )
(ROOT (S (NP (DT The) (NN ear) (NNS coverts)) (VP (VBP are) (NP (NP (JJ small) (NNS feathers)) (PP (IN behind) (NP (NP (DT the) (NN bird) (POS 's)) (NN eye))) (SBAR (WHNP (WDT which)) (S (S (VP (VB cover) (NP (DT the) (NN ear) (NN opening)))) (PRN (-LRB- -LRB-) (S (NP (NP (DT the) (NN ear)) (PP (IN of) (NP (DT a) (NN bird)))) (VP (VBZ has) (NP (DT no) (JJ external) (NNS features)))) (-RRB- -RRB-))))))))
The ear coverts are small feathers behind the bird's eye which cover the ear opening (the ear of a bird has no external features)
(ROOT (S (NP (DT The) (NNS ears)) (VP (VBP are) (NP (NP (DT an) (JJ external) (NN feature)) (PP (IN in) (NP (JJ human) (NNS beings))) (SBAR (S (VP (VBZ is) (ADJP (JJ responsible) (PP (IN for) (NP (NN balance))))))))) (. .)))