Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
perch [pəːtʃ] n (for bird) насе́ст
n inv (fish) о́кунь*m
vi
to perch (on)(bird) сади́ться*(сесть*perf) (на +acc) ; (person) приса́живаться (присе́сть*perf) (на +acc)
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: