Bird strike assessment is still part of FAR 25 certification of Transport catagory Aircraft
Government regulatory organizations have reacted to the wildlife-strike problem by promoting airworthiness standards that address the ability of aircraft to safely withstand bird strikes—particularly during the critical flight phases of takeoff and climb, and approach and landing. The following list presents organizations responsible for these standards, as well as names of the regulations they enact:
United States Federal Aviation Administration Federal Aviation Regulations (FARs)
Canada Transport Canada Canadian Aviation Regulations (CARs)
Europe The Joint Aviation Authorities Joint Aviation Regulations (JARs)
Mass of Ingested Birds Number of Ingested Birds Bird Impact Requirements
3-ounces Maximum of 16 birds in rapid succession Impacts may not cause more than 25% power or thrust loss, require engine to be shut down within 5 minutes, or result in a hazardous situation
1.5 pound Maximum of 8 birds in rapid succession Impacts may not cause more than 25% power or thrust loss, require engine to be shut down within 5 minutes, or result in a hazardous situation
4 pound 1 Engine is not to catch fire, burst, or lose the capability to be shut down
I like the last one which would approximate a chicken.
Bet that was more than you wanted to know..................