California Department of Fish & Game's
Life History Accounts and Range Maps
Provides range maps and basic biology fact sheets for virtually every species of amphibian, reptile, bird, and mammal in California. There’s a tremendous amount of information here. The life history accounts are loaded with well-cited information and lots of references. This site’s a good starting point if you want to learn more about a particular species. All the fact sheets and range maps are also available as PDF files that you can easily save to your computer for research convenience.
Note: Some of the range maps are inaccurate, greatly exaggerated, and sometimes outdated. For instance, the range map for bighorn sheep shows them in the Warner Mountains and Lava Beds National Monument. Though reintroduced to these regions in the last century (Lava Beds in 1971; Warners in 1980), the areas’ bighorn populations have since died out with pneumonia from domestic sheep being the presumed cause. The DFG map also shows bighorns contiguously ranging across the Mojave Desert and into the Sierra in a wide swath. Bighorns do occur in the Sierra and Mojave Desert but in scattered, isolated patches of habitat.
As with any source of information, if you find something that doesn’t seem right or seems old, don’t hesitate to cross-check it with something else.
Cornell Laboratory of Ornithology's Bird Species Accounts
Provides species accounts, range maps, sounds, and videos of North American birds. Great resource with massive amounts of information. Bird species are listed alphabetically and taxonomically, so it shouldn’t be too hard to find what you’re looking for. The Cornell species accounts are also backed with citations for their information sources.
Northern Wild Sheep & Goat Council
Want loads of scientific papers about North American wild sheep and mountain goats? Yes? Then this is your site. According to their homepage: “The Northern Wild Sheep and Goat Council is a non-profit, international scientific and educational organization dedicated to the management and conservation of northern wild sheep and mountain goat populations and their habitats in North America. The Northern Wild Sheep and Goat Council was established in 1968 by a group of scientists from the U.S. and Canada.”
In terms of research credibility, this site looks about as legit as they get. I actually met one of the executive committee members (Craig Foster) in 2005 when I was on a trip to videotape California bighorns in Oregon. Foster is hard-working and has been involved with various action-packed bighorn capture-and-transplant operations. The scientific articles are available for free downloading as PDF documents and are on the site’s “Proceedings” page. There are articles from 1970 through 2006.
U.S. Forest Service’s Silvics of North America Manuals:
Volume I (Conifers) & Volume II (Hardwoods)
According to the Forest Service’s online glossary, silvics is “the study of the life history and general characteristics of forest trees and stands, with particular reference to environmental factors, as a basis for the practice of silviculture.” The glossary goes on to state that silviculture is “the art and science of controlling the establishment, growth, composition, health, and quality of forests and woodlands to meet the diverse needs and values of landowners and society on a sustainable basis.”
Basically, these documents (available as both webpages and downloadable PDFs) are impressively comprehensive (thousands of pages long) references covering the biology and management concerns for every major tree in the United States. Below is a description taken from the documents’ webpage.
“The silvical characteristics of about 200 forest tree species and varieties are described. Most are native to the 50 United States and Puerto Rico, but a few are introduced and naturalized. Information on habitat, life history, and genetics is given for 15 genera, 63 species, and 20 varieties of conifers and for 58 genera, 128 species, and 6 varieties of hardwoods. These represent most of the commercially important trees of the United States and Canada and some of those from Mexico and the Caribbean Islands, making this a reference for virtually all of North America.”
In addition to informative text, the silvics manuals boast fairly detailed species range maps with county outlines.