These shall you abominate from among the birds, they may not be eaten - they are an abomination: the Chassidah. (Lev. 11:13)

Among the non-kosher birds is the chassidah - the stork. It is called chassidah because it displays kindness (chessed) toward others of its species by sharing food with them. According to the Ramban, the reason why the non-kosher birds are not kosher is because of their cruel nature. If so, the chassidah should have been a kosher bird - after all, it bestows kindness upon its companions!

Man finds it easy to love his fellow man if they are similar. If he learns in my school, if he dresses like I do, then I love him and I'll try to assist him whenever the need arises. If he's not like me, then I have no business with him and have no interest in helping him. However, the kosher form of chessed is to bestow kindness equally on all people, regardless of how similar they are to us. The chassidah acts kindly toward its companions, but only towards its companions. It does not act kindly towards anyone else. To Jews, that is not an admirable characteristic.(1)

Many great people were known for their love and care for every single Jew, whether they wore a black hat, white kippah or no kippah. Being kind to just your own kind is not kosher!

NOTES

1. Chidushei Harim.