I would like to clarify and correct some of the above postings.
- Zoologists study animals, pure and simple, any aspect (classification, ecology, behavior) of animals from bees to birds to humans. Biologist is a term that encompasses both zoologists and botanists (scientists who study plants).
- Taxonomists study classification - a taxonomist that studies mammals would consider themselves a mammalian taxonomist. Likewise for a plant taxonomist or an avian taxonomist.
- Preservationists are rarely scientists. To preserve means to maintain something in its exact state without letting anything change. Most scientists that are interested in saving endangered species are conservationists - which means they want to make a species (or group or subspecies) maintained but are willing to allow it to naturally change (perhaps in genetic structure or prey selection or whatever - essentially they allow the group to naturally evolve).
- Not all wildlife biologists travel or work in the field (a term used to indicate any site where study occurs outside of the lab) and not all zoologists are lab people. I would say equal numbers of wildlife biologists and zoologists are field people, and equal numbers are lab people.
All scientists that study animals are Zoologists, but many prefer to use more specific terms to identify what they study. For example, I am a zoologist that studies the evolutionary relationships and evolutionary histories of South American rodents. So when I label myself (especially to other scientists), I would say I am a mammalian systematist. Rodents are mammals and the study of evolutionary relationships is referred to as systematics. When I name a new species or reclassify an existing genus, I am a taxonomist. When I evaluate the traits of an organism (number of offspring, lifespan, etc), I am a natural historian. When I evaluate coat color, hair thickness, number of teeth, I am a morphologist. If I study behavior, I am a behaviorist. And so on and so on.
It seems nearly every scientists can label themselves in some way that makes them almost unique - how many mammalian molecular systematist that specialize in Akodontine rodents of South America do you think there are out there? It just depends on how specialized you want to be and how specialized you want to define yourself.
Wildlife biologists study what are consider game species - think things that people hunt and eat like deer, elk, turkeys. These studies could include anything from lab studies of feces or isotopes in teeth to radio-collaring and tracking.
Me - I'm a PhD student that sequences the DNA of lots of mice collected from South America (my lab work) and I also go to South America to collect them (my field work - and to lots of places in North America to collect mice that have nothing to do with my PhD).