Bull studied taxidermy in Rochester, New York and is known for his illustration of wildlife.

[2] Bull's first job at the age of 16 was preparing animals for mounting at the Ward's Museum in Rochester, New York.

He later worked as a taxidermist in Washington, D.C., specializing in anatomy of birds and animals.

He made many trips to Central and South America studying wildlife in their natural surrounding.

Stories and illustrations for this trip were published in his book, Under the Roof of the Jungle.