If a liger is a cross between a lion and a tiger, then a higer must be ... well, in the English language, it’s most often a typo for the word higher. There are 54 entries for this high-probability error in the OhioLINK database. Many are actually correct, because Higer is also a surname. Others occur in transcribed fields and would have to be checked.
(Female and male ligers, from Wikimedia Commons)