According to PBS it is the Finch
Australian sparrow
The farmer had a prolific season this year. Sally was the most prolific contributor to her community. He knew that being prolific was a good thing.
Probably seagulls.
The 2nd largest bird on earth is the harpy eagle .
Arvind Gaur of Asmita Theatre is known as Most prolific theatre director of Delhi.
The most common bird on Earth is the domestic chicken (Gallus gallus domesticus), due to its widespread presence in farms and backyards worldwide.
England
A supercell is the most powerful variety of thunderstorm on earth. They are the most prolific produces of severe weather. Supercells are the primary produces of very large hail and strong tornadoes.
We the People
The Amazon River is the most prolific river in the entire world. In second place is the Nile River and in third place is the Mississippi River.
The most prolific species is the tapeworm.In every segment there are bunches of testes+ovaries-so an individual adult can finish up with 100s of gonads.
In the crust, Aluminum. However, the only economically viable form for mining is Aluminium-Bauxite which is not prolific, hence the higher cost of Aluminium.