Doves: love, hope, peace, the divine.
Hummingbirds: happiness and delicate beauty.
Swan: loyalty and grace.
Cardinal: fresh perspective.
Bat: death & rebirth, nurturing and sensitivity.
Cliptomania.com has 500+ non-pierced earrings including birds and other Animals including Creatures of the Air. We also have other "birds" and flying creatures clip on earring located throughout the website. To find them, simply go to the elongated seach products here box.
One "bird" designer in particular is Bamboo. Search for Bamboo under the Designer filter.
Sources:
symbolism.wikia.com/wiki
www.whats-your-sign.com
www.animal-symbols.com