Firstly, the illustrations are top-notch. I’ve been looking for a good spider field guide for North America to complement my regional guide, and I think this could be my go-to in many instances. Below, I’ll discuss what I think are some fairly significant shortcomings of this work, but while species accounts in Princeton’s Spiders of North America, by Sarah Rose, are deeper and more comprehensive, that guide isn’t necessarily easy to use as a quick reference to narrow down identifications.
My biggest beef with the present guide is the organization: “The following accounts are organized in alphabetical order by family, and by genus and species within families… At this time there is no agreed upon taxonomic sequence for spiders. So in addition to being convenient, this is the same arrangement used in published checklists as well as the aforementioned manual.”
Granting that there’s no generally agreed upon sequence, this is still kind of a lame excuse. Firstly, Bradley’s reasoning is belied by the organization of the color plates. Mygalomorphs are grouped up front, followed by Araneomorphs with similar, often related, species close together. But for the species accounts, related species aren’t described in sequence. For instance, Foldingdoor trapdoor spiders (Antrodiaetidae) are nowhere near tarantulas (Theraphosidae).
And occasionally, related species aren’t depicted near each other in the color plates. Among family Hahniidae, there are only four species described in the book. One of these is shown on Plate 33, another on Plate 35, and the other two all the way over on Plate 81. Altogether, the poor choices made about sequencing contribute to a huge amount of flipping back and forth. This is mitigated in the ebook by linking between descriptions and illustrations, but this was of no use at all to me, because I had two copies of the book open, in order to read species descriptions while also looking at the illustration.
Each new family account begins with a general description of the family, along with the number of described species worldwide, and the number found north of Mexico. Relationships to similar families are usually not stated. Species accounts, again, are listed alphabetically, which means related genera might be widely separated within large families (like Araneidae, Salticidae, Lycosidae).
The title of the book is Common Spiders of North America, and nobody could expect to find illustrations or descriptions for all ~4,000 of the continent’s species north of Mexico. The book happens to include 469. Of course, many spiders can’t be distinguished for one another without examining microscopic features or through dissection. Thus, only the most physically distinctive species will ever be identified in the field. For this reason, genus-level descriptions would often be more useful than species-level, but this is missing in nearly all cases. Among the wolf spiders (Lycosidae), I’m rarely going to be able to identify Pardosa to species. Instead of labored descriptions of one Pardosa after another, how about explaining how to distinguish Pardosa sp. from Pirata sp.
None of these problems arise in (what is, for my money, the best spider field guide for folks in the Western U.S.) the Field Guide to the Spiders of California and the Pacific Coast States, by Adams & Manolis. Not only does that guide have color plates of comparable beauty, but the organization makes sense, and it provides description at the level that is most helpful to people wanting to learn about spider identification. We travel widely throughout the U.S., and I was hoping that the present guide would fill the same needs when away from the Pacific coast, but it often falls short of that high bar.
All that being said, I found the introduction instructive, and I especially appreciated the focus on web construction and the illustrated comparisons of different eye and spinneret configurations. Species accounts include information on seasonality, which is one bit of info lacking in the Adams & Manolis guide.
I haven’t yet had a chance for a deep dive into the new Princeton field guide Spiders of North America. Although that guide includes a greater number of species (which are accompanied by photographs, not illustrations), my first impression is that the present guide is a better entry-level guide, and easier for quickly flipping through pictures for anyone hoping to find a match to a spider they find in the field. I also found that the present guide provided clearer explanations in the introduction than in the Princeton guide. I’m sure I’ll continue to use all three of my field guides for different purposes, and the present guide certainly delivers on what it set out to do.