When I first started teaching at Hocking College, back when commuters came by horse and buggy (okay, it only FEELS like that long ago!), we had an influx of students who were interested in pursuing only historical interpretation. They often complained about having to take Ornithology, Dendrology, Field Biology, etc. Likewise, there were others who wanted to be only naturalists, and initially balked at the requirement to "dress up" and present living history at Robbins Crossing. To defend the curriculum, we touted the need to be "marketable" graduates, and to have a variety of experiences on a resume.
The real value, however, of requiring both content areas goes much deeper. Interpreters are storytellers, and a good story is not predicated on the depth of knowledge in only one or two areas, but rather a breadth of knowledge that allows connections to the interest(s) of the visitor. Most of our ancestors knew the properties of different trees, the importance of seasonal changes, and the flora and fauna all around them. For many, survival depended on it! Likewise, there are very few plants and animals that have not been affected by human history- from domestication and farming to habitat destruction and climate change. An old foundation of a house in a park may offer as much to a Naturalist as to an Historical Interpreter.
Perhaps most importantly, an interpreter should possess an insatiable curiosity. The best interpreters are constantly learning new things, changing their programs, and developing fresh ideas for future stories. Some of my best learning experiences have come from participants sharing their knowledge, and not from me sharing my research. If I could magically grant every student one quality, it would be a sense of wonder. Even the most mundane tasks would be fodder for inquiry. The morning tube of toothpaste could present endless possibilities.
Many of the students who successfully took the classes they complained about, later admitted to begrudgingly gaining appreciation for the opportunity. After practicing and presenting a station at Robbins' Crossing, several students would join in the wood-stove-cooked meal and admit that they "could get into this living history stuff". One student (an accomplished historical reenactor) who had complained about Ornithology class, later followed it up by eagerly identifying hawks from the back of a van on a field trip. I spun around in astonishment. "Okay", he sheepishly grinned and admitted, "I get it!"
I hope we all do.