Most of the trends reported in these volumes are, unsurprisingly, negative: declines in the numbers of individual species, declines in habitats such as wetlands. But there are surprises. In the section on grasslands, running up the center of the country from Texas to Canada, there are maps of the ranges of endemic bird species. The maps are color-coded, with shades of purple indicating declines and shades of green for increases.
On the maps, most of the birds appear to be holding their own, and some, photogenic ones like the ferruginous hawk and the Mississippi kite, are increasing across parts of their range. Some of it has to do only with shifts in where they breed, but it's nice to look at the maps and see more green than purple.
Nature isn't all handsome birds of prey. In the section on the Southwest, I came across cryptobiotic crusts found in arid lands: living layers on top of what would otherwise be bare soil. It never would have occurred to me that this crunchy stuff was alive, but apparently it is a community of blue-green algae (now also known as cyanobacteria), lichens, mosses, microfungi and bacteria. The "crust" is created whenever there's enough moisture for the algal filaments to move through the soil, leaving behind a mucilaginous substance that binds loose dirt particles. The crusts reduce wind erosion, store water when it rains, and add nitrogen and organic matter — both always in short supply in desert soils — to the ecosystem.
Pleasant little surprises pop up here and there. In the references for the section on Puerto Rico and the Virgin Islands, the name T. A. Wiewandt appears. This is Tom Wiewandt, a first-rate photographer whose work has appeared in this magazine. The reference is to his 1977 doctoral dissertation, "Ecology, behavior, and management of the Mona Island ground iguana, Cyclura stejnegeri." (Mona Island is a 13,633-acre wildlife refuge off the west coast of Puerto Rico.)
For the people who manage our natural resources, Status and Trends is an important beginning. For amateur naturalists, it is somewhere between a reference book and a travel guide. It is something I never thought I'd say of a government report: hard to put down.
By John P. Wiley, Jr.