[philipov]

It raises the question - begging the question is something else.

As for the question, it probably has to do with the gender of the noun. I bet 'deer' derives from a neuter-gendered word in Anglo-Saxon, while 'bird' does not.

Noun gender is the system used by many languages to categorize words that have different declension rules. It's atrophied in English, but is implicitly still present in the various "inconsistencies" that pop up.

[joenot443]

https://en.wikipedia.org/wiki/Begging_the_question I actually had no idea about that distinction, appreciate it.

Noun gender makes a lot of sense.