This from WOFS.com, the first on-line fung shui magazine (click title for link),
"most things associated with birds tend to spell good fortune, such as when birds fly to your home and start making nests in and around your house. While bats bring abundance, birds bring good news and opportunities. The next time a flock of ravens, pigeons or magpies come to your home, feed them with bird seeds. Birds are also said to be powerful protectors and guardians. Even crows are said to be messengers of the Gods. So welcome birds with open arms."
My mother loved to see Cardinals in the yard and would make an effort to point them out whenever she saw them. She grew up in the State of Ohio whose state bird is the Cardinal. Upon her death, we decided to have a Cardinal etched in her gravestone. On the stone, the Cardinal is resting on a White Pine, the state tree of Michigan - which is where she spent most of her adult life. Now, whenever I see a Cardinal, I think of her.
Probably too much information, but never forget to look for clues and symbols from nature in our everyday life, they can serve as powerful reminders or confirmations.