Warbler Guy, where do I learn about "reading" warbler songs (sonograms or spectrograms)? Is Warbler song easy to "read?"

Kathy, there's a one-stop shopping venue for all your edification needs: earbirding.com

Here, Nathan Pieplow, an erudite sound recordist and expert birder, highlights many "ear birding"
elements, including ways for you to easily read sonograms/spectrograms.

Please see his web site: earbirding.org and his recent book's are excellent on this subject: a) Petersen Field Guide to Bird Sounds of Western N. America and b) Petersen Field Guide to Bird Sounds of Eastern N. America.

The above web site is so good that it gets a top rating from Warbler Guy's advisory panel: me, myself, and I.

Seriously, reading and interpreting sonograms/spectrograms takes practice, but after a while you can
see the elements upon the page that originally looked like gibberish make sense.

Ergo, you'll quickly have no problems identifying a song sparrow classic song via its sonogram in comparison to a common yellowthroat's, and so on.

Other resources for identifying birds by sound and "ear birding" abound.....Some of my favorite are books by Dr. Donald Kroodsma, who authored the classic:
The Singing Life Of Birds.

Is warbler song easy to read on sonograms? Some people find them easier to comprehend than others. I think the above resources will help. My opinion is that some sonogram songs are easy to understand and others are more incomprehensible.

Warbler Guy, where are the most different kinds of warblers found? How many types or species of warblers exist? Are all warblers migratory or do some stay “close to home”...?

New World wood-warblers (that are not closely related to the various Old World warblers in the Eastern Hemisphere (e.g., Europe, Asia) are often identified to number as 112-115 species, occurring among 24-26 genera. The centers (or “epicenters”) of their breeding areas occur in eastern North America, the West Indies, Mexico and Central America, and Andean South America.

The majority of northern-latitude breeding species migrate, but many island and tropical species are sedentary. Many of these latter species remain close to their birthing areas or perform short-distance, post-breeding altitudinal/elevation migrations.

As for myself, I often see 20-30 wood-warbler species during early May when I return to homecoming birding forays in the Midwest (and, concurrently, attend the annual Wisconsin Society For Ornithology conference). This year, I was lucky to visit Wisconsin again on another week-long June jaunt similar areas in Door County, but achieved merely a single digit wood-warbler total. Likewise, my birding efforts in southern Wisconsin on my recent visit provided challenging warbler conditions, with Milwaukee County nearly devoid of warbler detections, except for probable nesting species such as American Redstart, Mourning Warbler, Bay-breasted Warbler, and Yellow Warbler.

In contrast, my n. CA residency, yields more warbler species during the breeding season — a result that surprises many people because the West is thought to host far fewer warbler species. For example, in Marin County (Bay Area) where I live, I often detect at least eight warbler species annually and, in the Sierra Nevada Mountains (near Yuba Pass and/or amid the Gold Lakes country off of Highway 49 near Bassetts), I sometimes successfully sleuth out nine warbler species.