Natural History Goals

We’ve just returned from a 12-day camping trip, visiting west Texas and the southern reaches of New Mexico, Arizona, and California. On this trip, wedged between two birding tours to South America, we reached a milestone that has me thinking about the various natural history goals that Eileen and I have had over the years. These goals have heavily influenced where we have traveled and the types of field work we have done.

Mohavea confertiflora, Fossil Cyn, Imperial Co, CA
Above: Mohavea confertiflora (Ghostflower), Fossil Canyon, Imperial Co., CA.  

Our first goal, effectively adopted when we were married in 1986, was to see 700 native species of birds in the Continental United States and Canada (hereafter, CONUS+CAN). This is a reasonable biogeographic region that is adopted by many popular field guides such as those for birds, mammals, butterflies, etc. There is even a flora in progress for the region, though it will fill 30 volumes rather than a single book. The goal of 700 was a good aspiration in that it involved seeing nearly all the regular breeding species in the region, plus a few dozen visitors from elsewhere. I reached this milestone with Black-capped Gnatcatcher in Southeast Arizona on Nov. 26, 2002, and Eileen did so with Crescent-chested Warbler, also in Southeast Arizona, on May 7, 2020. The difference in these dates is partly because I started birding about 20 years before Eileen did.

Allen's Hummingbird, Famosa Slough, Pt. Loma, San Diego Co, CA
Above: Allen’s Hummingbird, Famosa Slough, Point Loma, San Diego Co., CA.

Our second natural history goal, prompted by the publication of Volume 2 of the Flora of North America in 1993, was to see all 98 species of conifers in CONUS+CAN. It took 14 years but we completed the quest on July 24, 2007, in Plumas National Forest in California, where we saw magnificent examples of the cypress Cupressus bakeri.

Above: Posing with our last conifer in CONUS+CAN, Cupressus bakeri (Baker Cypress), Plumas National Forest, CA, July 2007. 

We had started in 2003 to systematically look for the 22 adorable species of chipmunks in CONUS+CAN, and that was completed relatively quickly with a sighting on Aug. 8, 2008 of Gray-collared Chipmunk in Gila National Forest in New Mexico. This naturally led to working more broadly on our mammal list in CONUS+CAN, targeting 50% of the 445 native species then recognized. We devoted particular attention to bats, learning to make ultrasonic recordings of their echolocation calls, so it is not surprising that we both broke the 50% mark with bats: Eastern Small-footed Myotis on Aug. 31, 2016, in Mammoth Cave National Park, KY for me; and Northern Yellow Bat on Feb. 6, 2018 in Apalachicola National Forest, FL for Eileen.

Linanthus dianthiflorus, Pt. Loma, San Diego Co, CA
Above: Linanthus dianthiflorus (Fringed Desert-Trumpets), Point Loma, San Diego Co., CA.

During the decade 2006 – 2016, we undertook some rather comprehensive botanical goals in California, the state with the highest plant diversity. I had to develop extensive custom database software on a personal digital assistant (PDA)  to even deal with the large numbers of species, and we still use a descendant of that software on our smartphones today. Initially we sought to find 99% of the 162 native families (two were thought hopeless), 90% of the 993 genera, and 50% of the 6505 taxa (species, subspecies, and varieties) of vascular plants found in California. We ultimately located all the native families (finishing with the aquatic Pontederiaceae along the Pit River in Modoc County on July 11, 2014). Later that year, on Oct. 11, we  hit 50% of the taxa, finding caper family member Cleomella palmeri in the Palen Dunes of Riverside County. Having had such fun tracking down 90% of the genera, we revised our goal upward to 95%, and on Aug. 18, 2015, reached that milestone by finding Howellanthus, a type of phacelia, in Shasta National Forest in Siskiyou County.

Brian looking for Aphanisma, Pt. Loma, San Diego Co, CA
Above: Brian looking for new genus Aphanisma in the mist, Point Loma, San Diego Co., CA.

After retiring in 2016, it was time to come up with some new goals, covering wider geographic regions than California. The overarching focus for the first few years was for me to reach 10,000 lifetime species of plants and animals, worldwide, and that effort has been described in earlier postings in this blog. The milestone species was an onion, Allium schoenoprasum, on Sept. 2, 2019, in Waterton Lakes National Park, Alberta. But at the same time we were building on our efforts in California and trying to find as many of the remaining native vascular plant families of CONUS+CAN as possible. There are 239 families, about half a dozen of which I felt were pretty much hopeless, so we were shooting to reach 97%. With families petering out, in 2021 we started in on the 2108 native genera and that has been our primary focus since; we are hoping to reach 90%.

Hesperocallis undulata, Organ Pipe NM, AZ
Above: Hesperocallis undulata (Desert Lily), Organ Pipe National Monument, AZ.

Which brings us to the present. During the 12-day trip we just finished, we looked for a dozen genera and found ten of them, an excellent result. But most importantly, one of the plants we found was Glinus radiata, an obscure annual that grows in mud exposed by drying ponds. This genus is in the family Molluginaceae, and with this success – north of Phoenix, Arizona, on Mar. 8, 2023 – we have now seen every native plant family in the region! In fact, thanks to our efforts on genera, and some targeted efforts in 2022, we actually have seen at least half the native genera in each and every family in CONUS+CAN!! This represents an impressive sampling of the region’s plant biodiversity, if I do say so myself.

Glinus radiatus seeds, Maricopa Co, AZ
Above: Seeds of Glinus radiatus (Spreading Sweetjuice), N of Phoenix, AZ. The engraved scale is in millimeters. The white structures are called arils and usually indicate that seeds are dispersed by ants. The smooth, shiny surface of the seeds is the best way to distinguish this species from a similar non-native species, which has bumpy seed surfaces. This find completed our quest to see all the native vascular plant families in CONUS+CAN. 

What about future goals? Worldwide, Eileen has seen 3870 birds out of about 10,776 (36%) and 462 mammals out of about 6615 (7%). My lists are at 3988 (37%) and 486 (7%). We would like to move these numbers appreciably, and so are stepping up international travel, hoping to take two to three birding tours per year while our health holds out. It would be highly satisfying to reach 50% of the bird species and 10% of the mammals, which might require something like twenty such trips. We’ve talked about other possible goals, but for now, these two, plus finding 90% of plant genera in CONUS+CAN, should suffice.

Western Shovel-nosed Snake, Cabeza Prieta NWR, AZ
Above: Western Shovel-nosed Snake (subspecies annulata), Cabeza Prieta National Wildlife Refuge, AZ. This striking species lives in dunes, where it is proficient at burrowing in the sand.

Appendix: The Toughest Plant Families

I have listed below, with comments, what I believe are the dozen most challenging vascular plant families, in terms of finding at least half their native genera in CONUS+CAN. These days a rare plant species can suddenly become relatively straightforward to find, by virtue of a single published record containing precise coordinates. So to make this list as stable and meaningful as possible, I have rated families based on the difficulty of finding their genera without the use of highly specific location information. We have only found two of these families ourselves without such information. The families are listed alphabetically, as I really cannot rank them precisely. For each family, I list the number of native genera and species in CONUS+CAN, and give an idea of the distribution based on Biota of North America (BONAP) software, which is the taxonomic authority we use.

Anacampserotaceae: One species, in 8 counties in TX and NM. Talinopsis frutescens (Arroyo Fameflower) occurs mostly in very rugged and remote terrain, has a short flowering period, and is inconspicuous. Combined with its small range, these factors make it quite a challenge.

Clusiaceae: One species, believed native in 5 counties in FL. Clusia rosea (Autograph Tree) is planted everywhere in Florida, so the problem is not finding one, but becoming convinced that a plant is native. We were finally satisfied with a venerable specimen having seven trunks, growing with mangroves, its roots inundated by the ocean at high tide. It was hard to imagine someone planted it there many decades ago.

Gleicheniaceae: One species, in 10 counties in FL. Dicranopteris flexuosa (Drooping Forked Fern) is essentially a vagrant fern in the U.S., its spores occasionally being brought in from the Caribbean by hurricanes. Sometimes these lead to isolated colonies that survive for a few years or decades.

Hymenophyllaceae: Five genera, 9 species, in 25 states and one province. The Filmy Fern family is quite fascinating. It is primarily tropical and in the U.S. is mostly restricted to protected, humid habitats such as cave-like overhangs, cracks in rocks, or deep fissures in thick bark. Most species are small and closely resemble mosses, liverworts, or algae. Seven of the nine species are considered rare, and the other two – Vandenboschia boschiana (Appalachian Fern) and Crepidomanes intricatum (Weft Fern) – are darned uncommon, so finding three genera in this family (to meet the 50% criterion) is very challenging.

Lindsaeaceae: One species, in one or two counties in FL. Odontosoria clavata (Club-shape Parsely Fern) is rare on limestone in Miami-Dade Co., with only a few publicly accessible areas to try searching.

Lomariopsidaceae: One species, in one county in FL. Lomariopsis kunzeana (Holly-Leaf Fringed Fern) is very rare on limestone in Miami-Dade Co., mostly on private property.

Orchidaceae: This family has 66 extant genera, and occurs in all states and provinces. It may surprise readers to see this family listed, as there are many orchid genera that are frequently encountered. However, 30 of the 66 genera, almost half, are only found in Florida, and the vast majority of those are very difficult to find, making it a real challenge to see 50% of the genera.

Molluginaceae: One species considered native by BONAP, in 11 counties in AZ and CA.  Glinus radiata (Spreading Sweetjuice) occurs mostly on private ranches with stock ponds that dry out early in the summer. Seeds are required for positive identification, but they can be hard to secure because the plants usually occur in areas inundated shortly after fruiting by monsoonal rains.

Nitrariaceae: One species, in 6 counties in TX. The first two U.S. iNaturalist records of  Peganum mexicanum (Garbancillo) were from just five months ago.

Piperaceae: One genus, 5 extant species, in 15 counties in FL. All five species of Peperomia are rare. We had to wade a fair distance in thigh-deep water, watching for alligators, to see one.

Schizaeaceae: Two genera, 2 species, in 4 states and 4 provinces. Tiny ferns with very limited distributions.

Stemonaceae: One species in 40 counties, mostly in AL. Croomia pauciflora, a southeastern endemic, is classified as rare in three states, and extinct in a fourth.

It is interesting to note that five of the twelve families listed are ferns, and five families are found only in Florida.

One thought on “Natural History Goals

  1. Mammoth goals you two have set and managed to achieve – and now you have set a new bar. Envy you your travel – just so happy we did ours when we had the taste for it! Enjoy your journey, as you always manage to do! Love, Connee and Bob ________________________________


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