The second-most expensive purchase of my time as a birder cost $1,950. Only my newest Nikon 35mm digital camera cost more.

I bought 716 printed booklets, each detailing a North American bird species. These were published by the Cornell Lab of Ornithology, a series titled The Birds of North America.

Fifteen years ago, I was very excited about my purchase, eager for delivery. The set was available at a few libraries and on certain college and university campuses. I wanted the information at my elbow because I intended to and do use the booklets often.

(I once considered reading all, 716 cover to cover. I changed my mind.)

Today, the contents of those booklets and much more is available on-line from Cornell.

Aside: Electronic is a production method with endless possibilities, but staying power determined by technology, subject to change at any moment.

That is the thought of someone of a certain age, a print guy. In today's reality, this much information can't be done any way. other than electronic.

Contents can be described as basically everything known about a particular species. The accounts are written by ornithologists familiar with that bird.

Today, there are no delivered boxes. You subscribe. The cost is $42 for one year, $75 for two, $100 for three, or $5 for 30 days (the latter perfect for school projects).

I've found my set of paper volumes invaluable. I have used them often as I research one bird or another. I'm working on Golden-winged Warblers today. My Golden-winged Warbler booklet, 15 pages of text, a range map, and one photo, is beside me as I type.

The electronic version Cornell now makes available at its Web site has more text, a photo gallery, a video gallery, an audio gallery, and various graphs, drawings, and tables. It is an amazing resource. I have subscribed. Coming now are days when the information I want will be in front of me as I type.

You subscribe to this extraordinary resource on the Cornell Lab web site, bna.birds.cornell.edu/bna/. This is available to anyone with a credit card, and, I suppose, an interest in birds.

You also can go there for a preview. Chose a bird, any bird, and the introductory material for that species is available, no charge.

I'm going to keep the printed versions, of course. You can buy your own printed set from Buteo Books http://www.buteobooks.com/category/BNA.html. It acquired the remaining inventory from Cornell, and still offers both complete sets for $1950 as well as individual booklets.

Aside: Printing is a technology unlikely to change for hundreds of years.