Bethany B. writes: I have an Eisenhower Silver dollar dated 1971 that has what looks like a bird stamped into the coin right behind Eisenhower’s  head. Could you please tell me something about it. Thanks.
This kind of alteration is called “punching” or “re-engraving”. It is an alteration that was done after a coin has left the Mint and therefore has no official connection to the issuing body.
Altering coins for fun or profit has been around for many years. For example, during the epoch between the turn of the 19th century and the beginning of WW II, talented hobos and others, would artistically alter the Indian or Liberty head on a nickel and trade their art work for food and shelter. A whole genre of collecting was established for “hobo nickels” and for other coins with messages or symbols punched into the coin’s surface.
I can’t tell you what the specific meaning of the stylized bird is but punched and reengraved coins have been used for advertising, membership cards, awards and security devices. Discovering the meaning of the alteration is the fun part of collecting these interesting coins. Let me know if you find the meaning of this symbol. See: Re-engraved Cents