Wild Rivers

By Steve Cary, July 31, 2020

Howdy New Mexico Butterflyers:

The latest newsletter of the Native Plant Society of New Mexico (NPSNM) arrived in my inbox this last week and I was happy to see it! I have been a member for decades, have given butterfly walks and talks at annual NPSNM conferences, and consider them one of the best investments of my tax-exempt charitable contributions in New Mexico.

One informative newsletter feature is the “Conservation Corner” and in this current edition, Rachel Jankowitz led off with a story about a plant that is essential for a very cool butterfly in New Mexico. The plant is Common Reed (Phragmites australis; Poaceae), a head-high grass that lives in emergent wetlands, on stream banks, on acequia banks, in marshes, and in other wet habitats in New Mexico and around the Southwest, actually nationwide, actually worldwide, hence the ‘common’ appellation.

Common Reed is the sole known larval host plant (that’s what its caterpillars eat) for Yuma Skipper (Ochlodes yuma). Yuma Skipper occurs in colonies throughout most of the American Southwest and Intermountain West, but colonies of Phragmites and Yuma are isolated and disconnected because the reed needs something that is scarce in the region: water. As a consequence of those habitat constraints, Yuma Skipper is confined to a very small area in New Mexico: the Rio Grande Gorge near Questa, in Taos County.

Dense stands of Common Reed (Phragmites australis) grow at Big Arsenic Springs, Rio Grande Gorge, Rio Grande del Norte National Monument, Taos Co., NM; August 14, 2017. (Photo by Steve Cary)

On July 23, 1984, my friend Jerry Jacobi invited me to join him and a small party of ecologists and hydrologists on a trip down into Taos County’s Rio Grande Gorge. The first 50 miles of the Rio Grande south from the Colorado border had been designated a National Wild and Scenic River in 1968, the first area in the US to be so designated. In 1984, we accessed the Gorge bottom on foot by way of a trail heading off the rim of the Taos Plateau southwest of Questa. Over the centuries, trails in and out of the gorge were created and maintained first by Native people, then by sheepherders, and subsequently by fishermen. Jerry and his colleagues were there on New Mexico Environment Department (NMED) business, checking the quality of water emanating from Big Arsenic Springs (its name does make a person wonder). Jerry invited me to join the group because he is a great friend with whom I would conduct dozens of entomological outings over the coming decades. Recently when I reminded him of this long-ago event, Jerry said it feels like it might as well have been back in 1884 — time does fly.

As a water resources professional myself, though between jobs at the time, I was interested in the water quality issues because the Molycorp mine and mill tailings complex was upstream. While helping NMED staff get their water samples, I followed my instincts and made note of the butterflies that were present (there was no rule against it — I checked). One in particular got my attention. I was only three years into my New Mexico butterfly avocation, but I studied them passionately and this skipper was unlike anything I had seen before, or even expected to see.

I returned on my own a couple of weeks later and captured a male and a female. After making some semi-educated guesses as to what they might be, I sent them to my Rocky Mountain butterfly guru at the time, Dr. Ray Stanford, in Denver. Ray looked at them and shared them with other experienced Colorado lepidopterists, who performed a quick microscopic examination of the genitalia, and they concluded it was Ochlodes yuma, the Yuma Skipper.

Male ‘Anasazi’ Yuma Skipper (Ochlodes yuma anasazi) in BLM’s Wild Rivers recreation Area, Taos Co., NM; August 9, 2016. (Photo by Steve Cary)

Yuma Skipper had never been seen in New Mexico before. Moreover, these Rio Grande Gorge Yuma Skippers looked somewhat different from Yuma Skippers in private and museum collections at the time. Standard Yuma Skippers from California and the Great Basin (the nominate subspecies) were unmarked bright yellow-gold on the underside and orange-gold above, with a few dark marks. The New Mexico version was more darkly marked on the upperside; undersides were frosted ochre with a faint band of a pale spots that were completely absent from the nominate subspecies.

Sensing we were onto something new, I read what I could to learn more about Yuma Skippers: eggs are placed on leaves of Phragmites australis and larvae cut, roll, and silk leaves together to engineer a hanging shelter where they spend nights and eventually pupate. Adults nectar at flowers, but rarely wander far from the host reeds. Our Gorge colony of Yuma Skippers matched the typical life history for the species as a whole, its one annual flight on the wing flying from late July into early September. With his encouragement, Ray and I described this as a new subspecies: Ochlodes yuma anasazi (Cary and Stanford 1995). In common parlance, call it ‘Anasazi’ Yuma Skipper or Anasazi Skipper.

As a geographer, I was and remain fascinated by the colony’s location in the depths of the Gorge. Phragmites occurs elsewhere in New Mexico without being chewed on by Yuma Skippers. The Gorge sustains the only Yuma Skipper colony in the Rio Grande drainage and the only colony in North America east of the Continental Divide. At 6,600 feet elevation, it persists at a higher altitude than any other known Yuma Skipper colony. This only provoked more questions. How extensive was the Gorge colony? How did it get there? What was it about that location that allowed them to live there?

In 2010, an opportunity arose to study the Anasazi Skipper colony in more detail. Back in 1997, friends John Pfeil, Randy Merker, and I formed a small non-profit, the Natural Resource Institute (NRI), which we used as a platform from which to obtain grants to conduct natural resource research and education activities on our own time. Biologist and GIS specialist Linda DeLay later joined the group and in 2010 we were funded by the New Mexico Department of Game and Fish to study what appeared to be a localized, rare creature that might warrant conservation attention: the Anasazi Skipper. After the Gorge was included in the new Rio Grande del Norte National Monument, the Taos Field Office of the U. S. Bureau of Land Management provided a second round of funding in 2015 in collaboration with the Institute for Applied Ecology, an fantastic local Santa Fe non-profit.

Those generous grants allowed us to spend a lot of field time in the spectacular Rio Grande Gorge tracking down and mapping patches of Common Reed, mapping occurrences of Anasazi Skipper, detailing its life history, studying its dispersal capabilities, and evaluating threats and risks it confronted. We hiked the difficult terrain and may have neared heat stroke a few times. Linda remembers “the thrill of navigating the Rio Grande in our white-water rafts, trying to keep one eye on the Phragmites that hugged the shore and one eye on the river. Who will be the first to find evidence of Anasazi Skipper among or near the reed? How exciting it was to rummage through the blades of leaves, once we did make a landing, to find a neatly rolled tent that a skipper larva made for a home.”

John said the other day: “It was a real joy to participate with NRI on the Anasazi Skipper study. Working with the crew in the Rio Grande Gorge . . . was a feast for the eyes and spirit; and strategizing how to protect our rarest butterfly was a challenge for the brain.”

We were able to confirm that although the Phragmites is more widespread along the Gorge, Anasazi Skippers occupy only a 15-mile reach of the Gorge. A mark/recapture study, staffed chiefly by awesome volunteers, allowed for a crude population estimate of 1,500 to 3,000 individual Yuma Skippers in 2018 (NRI 2019). The population seems to be centered at the Big Arsenic Spring complex which is fed by waters emanating from the Red River Fault and has the best patches of Common Reed in the Gorge. We never found a Skipper more than a mile from any Phragmites stand. With Anasazi Skipper so intimately linked to Common Reed, we concluded that its persistence into the future depended on persistence of large patches of the Reed, which relied in turn on a stable supply of water. As to the issue of why here, other than the presence of the Reed, we postulated that the dark basalt walls of the Gorge may foster a supportive (i.e., warmer) microclimate, while the presence of springs and Reed patches up away from the valley bottom might protect them from the coldest temperatures.

‘Anasazi’ Yuma Skipper (Ochlodes yuma anasazi) in BLM’s Wild Rivers recreation Area, Taos Co., NM; August 28, 2017. (Photo by Steve Cary)

Anasazi Skipper is one of the rarest butterflies in New Mexico and it is contained within one of the smallest habitat areas for any butterfly species in New Mexico. Nevertheless, Anasazi Skipper seems to be adequately protected in the Gorge. It persists now under a conservation-oriented land management program for the Rio Grande del Norte National Monument. Theoretically, an overly passionate butterfly collector could decide to go get all the Anasazi Skippers, but the difficult terrain in their breeding habitat should prevent a damaging take of specimens. Climate warming and drying is a larger concern.

And one additional threat is hard to gauge, as Rachel Jankowitz underscored in her excellent NPSNM “Conservation Corner” article. As a worldwide plant, Phragmites australis exists in multiple genotypes. The native genotype in the Gorge is one we know Anasazi Skipper larvae can eat just fine. Elsewhere in the US, however, exotic Old World Phragmites genotypes have been brought over from Europe or Asia, probably via ocean transports, and have become invasive, particularly in coastal estuaries. Local resource managers seek to protect their local ecosystems by reducing or eliminating the invasive Phragmites genotypes. I am as opposed to invasive exotic weeds as anyone else and I hope New Mexico resource managers are, too. We just need to be sure that resource managers for the Gorge do the appropriate genetic studies before taking any Phragmites management action that might make life difficult for Anasazi Skippers. NRI recommended that a baseline genotype analysis be done for Gorge Phragmites patches so their identity is known in advance. If a foreign Phragmites genotype were to invade the area, would we even recognize it? More importantly, would Anasazi Skipper caterpillars eat it?

If you want to see Anasazi Skippers, August is the time to make the effort and now you have some of the history and context. Follow directions to BLM’s Wild Rivers Recreation Area, a great location that typically allows camping, but probably not during the ongoing COVID pandemic. The driving route takes you north from Questa, west through the little settlement of Cerro, then south to the visitor center and camp loop. The road is paved the entire way. You’ll see campgrounds, pull-offs and trailheads along the west limb of the loop road, nearest the Gorge rim. Along the roadside there is usually a lot of nectar in the form of horsetail milkweed, which pulls in a lot of Anasazi Skippers. By late August, rabbitbrush is coming into bloom as milkweeds senesce. Things may be quite dry there this year, so I guarantee nothing except great views.

If you want to hike down to Big Arsenic Springs to see the Skippers in and around their Phragmites host plants, please think about it and prepare carefully. The hike is 2.4 spectacular miles from rim to Springs with easy, moderate and difficult portions and a net drop of 800 vertical feet. Climbing out can be a challenge on hot afternoons when heat radiating from black basalt canyon walls can roast your brain. Word to the wise: bring plenty of water and start your climb out well before noon. As a reward for making the journey to Wild Rivers, you might find Mead’s Wood-Nymph, too.

If you are not already a member of NPSNM, I strongly recommend you join up. If you like butterflies, you must like native plants, too. You don’t get the native flyers without the native photo-synthesizers.

Stay safe out there!

Cary, S. J., and R. E. Stanford. 1995. A new subspecies of Ochlodes yuma (W. H. Edwards) with notes on life history and historical biogeography. Bull. Allyn Mus. 140. 7 pp.

Natural Resource Institute. 2019. Studies of Anasazi Skipper (Ochlodes yuma anasazi) and Monarch Butterfly (Danaus plexippus) at Wild Rivers Recreation Area, Bureau of Land Management, Taos County, New Mexico.

Gettin’ the Blues

Blues are giving me complexes. Or are my complexes giving me the Blues?

By Steve Cary

Please allow me a moment to honor and remember the life of Linda Wiener Elmore, who recently and far too soon metamorphosed to the mysterious afterlife. There has been no greater bug lover than Linda, and that included butterflies, a passion we shared. Linda was one of my favorite New Mexico butterfly collaborators. It was she who undertook and carried out Santa Fe’s first butterfly counts. She was a keen observer in both senses of the word: sharp-eyed and enthusiastic. Linda had a way of looking at nature that helped others see the complexities from new angles, then she often threw in her hearty laugh as punctuation. I particularly remember two of her projects. Once she undertook to count the number of different spiders that shared her Santa Fe residential lot. Over a multi-year effort she found an eye-opening ~200 different spider species. Then consider the humble juniper tree . . . Linda spent the time and patiently invested the brain power to demonstrate that ~400 different invertebrate forms were occupying that tree-space, where I saw only Juniper Hairstreaks. Her educational skills were epic and she enjoyed sharing them professionally and avocationally. When I was a naturalist at the Randall Davey Audubon Center, she was happy to come to the property and deliver stimulating programs for the public. Linda brought her provocative blend of intellectual fizz and infectious laughter to whatever she did. That luminous bubble of energy was an unforgettable presence and all in her world were enriched by it. Happy trails, Linda, we will miss you.

For a while now, I’ve been envisioning a thread that confronts some of the more significant identification challenges for New Mexico butterflyers. One reader suggested that topic. Other correspondents regularly present photos wondering if the subject is species A or species B, and it can be a tough call. I think each of us has her/his own personal ID challenges that arise when two (or more) species look alike. Those ID challenges also seem to have a psychological component, nothing to do with the creatures themselves, but with the very understandable human desire to know what that insect is. For me to feel in control of my surroundings I need to make a species-level identification, to put a name on that picture file, to have a box into which I can place all of my experiences with that bug. (Geez, that quickly deteriorated from humans in general to me in particular . . . oh well, I’m no psychologist!)

I continue to struggle with Acmon and Lupine blues, whose different identities and diagnostic elements have long been a bugaboo for me. I have deftly dodged the issue for decades, but ongoing work by some professional colleagues looks like it may force me to face the music . . . eventually. Until that day of reckoning, however, this devilish duo continues to stalk me. Am I exaggerating? Please read on and you decide.

Recently at Eagle Nest Lake State Park I photographed a blue that was hanging around Redroot Buckwheat (Eriogonum racemosum). It behaved as if it were Spalding’s Blue, but it lacked the band of orange spots on the ventral forewing and so could not be. After considering the alternatives, I tentatively concluded it was my nemesis: Acmon/Lupine Blue. I took plenty of photos (they don’t cost anything) of male and female, dorsal and ventral, hoping that with some study I could finally learn the key characteristics and figure one of these species out on my own.

Male Acmon or Lupine Blue (Icaricia acmon or lupini) perching head-down atop a Redroot Buckwheat raceme; Eagle Nest Lake State Park, Colfax Co., NM on June 29, 2020 (Photo by Steve Cary).  

I studied my photos and researched my books, developed my opinion and then asked two accomplished, highly respected experts from Colorado, two fellows I am fortunate to call friends: Mike Fisher (author of Butterflies of Colorado) and Dr. Paul Opler (Assistant Director of the C. P. Gillette Museum of Arthropod Diversity at Colorado State University). My esteemed colleagues very kindly examined my photos and within a couple of days I had their thoughtful, well-reasoned, completely rational conclusions . . . which were totally opposite to each other. Mike was persuaded by the association with buckwheat that this was a Lupine Blue. (I know, why is a Lupine Blue hanging out on a buckwheat? Don’t get me started. It’s a longer story, which I intend to eventually tell on these pages.) Dr. Opler weighed in on the other side, explaining why he thought all the info was consistent with Acmon Blue. I sent each the note from the other, and each graciously conceded the other could be right.

Heartburn was not exactly the feeling I experienced. It was more like bemused hopelessness. I simply had to laugh! If they thought it could be either, what chance did I have of figuring it out? Dr. Opler did say something very sobering, however. He said it did not really matter what anyone thought they were because they were merely photographs. The implication was that people could debate the identity of images until the cows came home, but what truly mattered was the identity of the insects themselves, and that would only be revealed through more detailed scientific examination of specimens: genitalic dissection, DNA analysis to name a couple of routes to follow. And in fact, that work is being undertaken. Once the critters are successfully diagnosed, an effort must be made to pinpoint characters that can be observed in the field (or on photos) and used to distinguish one from the other. You go, Paul! Now I need to be patient, not something that comes naturally to me.

Considering all that’s going on in our world, what’s my best move? Well, obviously, I went to chase butterflies in the Zuni Mountains of Cibola County. The US Drought Monitor suggested that area was not as dry as locations more local to me and it’s a straight shot, 1 full gas tank, 2.5-hour drive from my house: out the door by 6:00 AM, feet on the ground by 8:30, home by 5:00 PM. No contact with potential super spreaders. Plus there are good canyons, good mudholes, a good hilltop, and good butterflies.

On that recent outing the first Blue I saw was “Spring” Azure (Celastrina ladon). They were fresh and numerous, which was a little surprising considering it was July 8. Southern New Mexico has two to three broods of azures each year. Northern New mexico typically has one, in the spring, but maybe our lengthening growing season will enable a second generation in some years.

Of late, some of you are calling these butterflies Echo Azures (Celastrina echo), but I have not given up on Spring Azure just yet. This and other localized Azure taxa, sometimes with specialized hostplants, have been described from various parts of the US. I consider their taxonomic status to be up for discussion. “Echo Azure” is part of a complex of Azures that bedevil taxonomists, so this name and arrangement are best considered tentative. Our New Mexico populations are assigned to subspecies cinerea (W. H. Edwards), but is it a subspecies of Celastrina echo or Celastrina ladon (Cramer)? or even of the more traditional Celastrina argiolus (Linnaeus)?

Which Azure did I see in the Zunis? I won’t pretend to know, but I’m calling it ‘Spring Azure complex’ as suggested by Brock and Kaufman (2003). Spring Azure is a “complex” of organisms, whether species, subspecies, or forms, and no one really knows which is what. Experts have staked out hypotheses and educated opinions which will stimulate continued investigation that will lead us inexorably to the truth, within my lifetime, one hopes, though perhaps not. Until then, “Spring Azure complex” is a properly descriptive container for these beautiful creatures.

On to other Blues, for which evaporating mudholes are magnets on summer days because precious salts accumulate along their drying perimeters. Next in view was another expected species: Western Tailed-blue. A quick preview of my photos, however, did not look quite right. It had patches of orange in places that made me think it was an Eastern Tailed-blue, which I did not expect. Richard Holland’s report on his multi-year butterfly survey in the Zuni Mountains during the 1970s listed Western Tailed-blue, but not its Eastern cousin.* As a very careful collector and observer who was born and raised back East, he undoubtedly knew the difference.

Both species occur in southwest New Mexico, but were they both in the Zunis, too? Easterns usually have more orange in the hindwing false head, especially on the underside, whereas the orange is much more limited on the Westerns. There were quite a few tailed blues sipping contentedly at a local salt lick along Forest Road 504, so I took a bunch of photos hoping to get enough evidence to be able to figure out what was there (does that sound familiar?). One individual of unknown gender, below, displayed more ventral orange than any tailed-blue I’ve ever seen, even up onto the forewing margin. Compare it to the subsequent photo of Western Tailed-blue taken in the Zunis back in May 2008, for which orange on the ventral hindwing is limited to two cells near the tail.

Eastern Tailed-blue (Cupido comyntas) in the Zuni Mountains, Cibola Co., NM on July 8, 2020 (Photo by Steve Cary).
Western Tailed-blue (Cupido amyntula) in the Zuni Mountains, Cibola Co., NM on May 31, 2008 (Photo by Steve Cary).

If we examine upperside characters, consider the two images that follow. The first, taken in the same area in the Zunis on May 4, 2020, shows a male with distinct smudges of orange in two cells near the tail. This is consistent with Eastern Tailed-blue. For comparison I offer the second photo below showing a standard male Western Tailed-blue dorsum with no orange whatsoever. For the sake of time, but with some misgivings, I’ll pass over the same analysis for females . . .

Eastern Tailed-blue male (Cupido comyntas) in the Zuni Mountains, Cibola Co, NM on May 4, 2020 (Photo by Steve Cary).
Male Western Tailed-blue (Cupido amyntula) in Sugarite Canyon State Park, Colfax Co., NM on May 25, 2016 (Photo by Steve Cary).

Dorsal and ventral images collectively support the idea that Eastern Tailed-blues are present in the Zunis, at least this year, if not before. This was not something I expected. When venturing into New Mexico’s bigger mountains I always expect to find Western Tailed-blues, not Easterns, and this is based on decades of experience.

Are Western Tailed-blues still in the Zunis? Brock and Kaufman (2003) explained that where these two species overlap in the West, Easterns tend to occupy lower habitats and Westerns inhabit higher sites. That has held true in New Mexico. The Zunis are not particularly high, topping out at a mere 9,200 feet. Places where I found Easterns this year were in the higher portions of Zunis, from 7,800 to 8,800 feet elevation on the slopes of Mt. Sedgwick, the highest peak in the range. There were no higher habitats in which to search for Western tailed-blues. If Westerns were there, I think I would have come across at least one. Perhaps our warming climate is allowing Easterns to penetrate the Zunis, while making life difficult there for Westerns.

The closest thing I’ve seen to a Western tailed-blue, so far is shown in the photo below. This male looks at first glance to have no orange on the hindwing, a la Western, but if you look closely (maybe tilt your computer at the right angle?) you can see a small glint of pink/orange in the cell near the tail. Is this a Western Tailed-blue or a lightly marked Eastern?

Eastern or Western Tailed-blue (Cupido sp.) in the Zuni Mountains, Cibola Co., NM on May 29, 2020 (Photo by Steve Cary).

Brock and Kaufman (2003, p. 124) said that male Easterns usually show one or two orange spots near the tail while Westerns usually lack orange near the tail, implying there are exceptions. Does this male show enough orange to call it an Eastern? Glassberg (2017) put it right out there and stated that it is unknown how to separate these two blues “with certainty.” One then wonders, where they co-occur, can the two tailed-blue species identify each other with certainty when it comes to breeding? Is it hybridization that produces the intermediate amount of orange? More study clearly is needed. Documentation of what you see can be important, especially regarding tailed blues in the Zuni Mountains. Perhaps they will join the fun and become their own complex! A second brood of tailed blues can be expected in August.

After Spring Azure and Eastern Tailed-blue, the last Blue species I encountered while butterflying in the Zunis last week was, yes, you guessed it — that squishy Acmon/Lupine thing again. That complex does occur statewide, so clearly it is tag-teaming me. Hey, just because one is paranoid does not eliminate the possibility that one is being harassed.

Female Acmon or Lupine Blue (Icaricia acmon or lupini) in the Zuni Mountains, Cibola CO., NM on July 8, 2020 (Photo by Steve Cary).

For the time being, the only way I can manage the anxiety is to call Acmon/Lupine Blues a complex. What better word to describe our ignorance or perhaps the reality of life on the ground? Our taxonomic framework of well-defined boxes might work for my brain, or your brain. It may even be accurate in many situations, but there must be circumstances in which two organisms are incompletely separated, whether geographically, temporally, or reproductively. For most of us butterfly watchers, gardeners, and photographers, our knowledge of some butterflies will never attain that degree of specificity. In those cases, I suggest we embrace the complex. Why not accept it as an opportunity, even a privilege, stemming as it does from the majestic, inscrutable, perhaps never fully knowable, Nature?

August is on the horizon (where did summer go?). If you can be safe doing so, in-state, I invite you to seek out Wild Buckwheats and their inscrutable herbivores! Go get your own Dotted Blues! And do your rain dance.

  • Holland, Richard. 1984. Butterflies of Two Northwest New Mexico Mountains. Jour. of the Lepid. Soc. 38(3):220-234.

Hairstreaks on the Move?

June 27, 2020

By Steve Cary

Before I leave the topic of subtropical stray butterflies, I want to place the Buckeye situation in a larger context. The great state of New Mexico is adjacent to the great American subtropics, that is, Mexico. Species that breed in Mexico but not in New Mexico can occasionally be found here, even if only as unusual vagrants or strays. Some even breed seasonally, like Monarchs and Painted Ladies. Usually by March, warm weather allows wandering species to enter the US, find nectar, maybe even mates, and possibly complete a generation or two during the warm season.

Those of you along our southern border are in the best position to see some of these oddballs in your gardens or on your local outings. The more routine examples include Sleepy Orange, Texas Crescent, Queen, Mexican Yellow, Cloudless Sulphur, Southern Dogface, and American Snout. As I write this blog post, for example, I learned that James Lofton recently photographed a Gulf Fritillary near Portales, NM. All these explorers may be frozen out come winter, but while here they contribute to our ecosystems via pollination or by becoming prey to insectivorous birds, insects, spiders, or lizards. Vagrants, strays, and seasonal breeders make up a substantial portion of New Mexico’s 320 butterfly species and they are important components of the butterfly fauna for all border states from Texas to California.

Among the butterflies, hairstreaks (Lycaenidae: Theclinae) strike me as perhaps least likely to wander very far from their ‘home’ turf, where they did their munching as larvae. They are small, seem fragile, and most have lifestyles that keep them near their host-plant, on nearby hilltops or in local nectar patches. How many wingflaps would it take for a tiny, dime-sized hairstreak to cover as much distance as her royal highness the Queen could manage in one? Strangely enough, however, 2020 is becoming a standout year for subtropical hairstreaks in New Mexico. Below are three examples.

The Leda Ministreak (Ministrymon leda) includes southern New Mexico in its breeding range, where it places eggs on various mesquites (Prosopis spp.; Fabaceae). This year, it already has been seen a few times well north of its normal breeding range. It is known to wander north from time to time, so it’s not a total shock, but it always seems implausible up here considering its miniature size. This year, Rebecca Gracey and Joe Schelling photographed it near Quemado on the high plateau of northern Catron County on May 24, then repeated the feat on June 12 in the Sandia Mountains northeast of Albuquerque, where it was a new species for Sandoval County! I photographed one on May 27 that was at 9,500 feet elevation in the Sangre de Cristo Mountains below the Santa Fe ski resort — the second report ever for Santa Fe County and possibly the highest altitude ever for that species. The photo below shows it is a little worn, but it still has all its delicate tails, two long and two short, so we know it has not flown in from, say, Lordsburg. Could it be breeding locally? My Arizona butterfly compadres say Leda is all over that state, too. Will Colorado be next?

Leda Ministreak (Ministrymon Leda) found at 9,500 feet elevation in the Sangre de Cristo Mountains of Santa Fe County, NM. This butterfly was seen here on May 27, 2020. (Photo by Steve Cary)

One of the most unexpected subtropical strays already this young season has been Silver-banded Hairstreak (Chlorostrymon simaethis). In Las Cruces, Rob Wu found two individuals nectaring at his Woolly Butterflybush (Buddleia marrubifolia), a desert native down there, back on May 22. One was in pretty good condition, suggesting it had not flown too terribly far (see photo below). That was only the second confirmed report ever from New Mexico, the other being a sighting by NABA legend Jeff Glassberg from Otero County in 1998. To extend the amazement, yet another Silver-banded Hairstreak was seen and photographed in Silver City a few weeks later. That observer graciously posted her photo to BAMONA for all to see. So Silver-bandeds have not been a mere ‘one-time wonder’ this year. Again, my Arizona butterfly colleagues confirmed that multiple Silver-banded Hairstreaks were being seen in southern Arizona this year, too. That is another hairstreak species to keep an eye on through the year. I wonder . . . will it be able to reproduce in southern New Mexico?

A Silver-banded Hairstreak nectaring in a Las Cruces garden on May 22, 2020. (Photo by Robert Wu)

I never expected a sighting that would top Silver-banded Hairstreak, but perhaps most surprising so far (it’s only June!) was a report on June 18 of Tailless Scrub-hairstreak (Strymon cestri) from Socorro County. Matt Brown, a bird and butterfly guide out of Patagonia, Arizona, and his girlfriend, Abbie, were exploring the San Mateo Mountains when eagle-eyed Abbie spotted an odd hairstreak on a yellow flower and took a photo. Matt shared it with Arizona butterfly expert Rich Bailowitz, who confirmed the identification: Strymon cestri. At about 8,500 feet elevation well up in the San Mateos, this is an unusual spot for a vagrant or stray. Normally they like watercourses where terrain is more amenable to long distance movement. Field Guides place this Mexican species only as far north as the Lower Rio Grande Valley of Texas, straying occasionally to southeast Arizona. Matt was justifiably excited by this find: it was only the second documented occurrence in New Mexico.

I had seen that same species back in May 2016, perhaps 50 miles to the southwest in Sierra County in the eastern foothills of the Black Range. My photo (below) shows a rather worn male defending a juniper on a hilltop at about 6,100 feet elevation. It was a wake-up call for me to see it, but the moment passed and I had not thought too much about it since then. Now, however, Matt and Abbie’s more recent sighting in Socorro County certainly makes me wonder . . . is Strymon cestri already a breeding resident in southern New Mexico? Has it set up camp in New Mexico’s part of the Rio Grande Valley? We need more eyes on the ground looking for it in southern New Mexico, especially in the desert mountain ranges bordering the Rio Grande.

A very worn Tailless Scrub-hairstreak (Strymon cestri) in Sierra County, NM, on May 11, 2016. (Photo by Steve Cary)

In the old days before global warming, such subtropical oddities were nice enhancements to the butterflying experience in New Mexico. One never expected to see any particular subtropical wanderer, so whatever turned up was always a surprise — a lagniappe, as they might say in New Orleans, a little something extra for making the effort to go butterflying in the first place. There have been some amazing finds over the years: Zebra Longwing in Eddy County, Polydamas Swallowtail south of Deming, Broad-banded Swallowtail in Harding County (thanks Christopher!), to name a few.

Now, however, I feel a strong and growing temptation to conclude that the subtropical butterfly waves are getting stronger, more frequent, more diverse and more routine. Perhaps I imagine it, but this year . . . it may not be my imagination. Winters here seem warmer, or perhaps ‘not as cold’ is a more accurate description. Years ago, when I was asked to forecast effects of climate warming on New Mexico butterflies, one of my two principal working hypotheses was that subtropical species would gain a greater presence. My Arizona colleagues might agree that it was frigid overnight winter low temperatures that kept the door closed to subtropical butterflies. Is that door now opening?

What was my second hypothesis regarding effects of global warming on New Mexico butterflies? I’ll weigh in on that in another post in the near future, as soon as I remember it.

Thanks for tuning in, stay safe, and happy butterflying!

Steve Cary, Santa Fe

A Tale of Two Buckeyes

Dear New Mexico Butterfly Admirers,

Last year’s Los Alamos Butterfly Count produced a big surprise: a ‘Dark’ Tropical Buckeye, which was new for Los Alamos County and the farthest north it had ever been seen in New Mexico (see photo below). Little did we know then what it foretold. This year, Rozelle Wright and others have been spotting Buckeyes in various forms including another Tropical Buckeye, in early May no less. Rozelle wanted to understand what she was seeing and she would not let me skate with a superficial reply.

First Dark Buckeye spotted in Los Alamos County (Photo by Rozelle Wright, July 27, 2019)

Buckeyes are of modest size but they display beautiful eye-shaped markings, called ocelli. Behaviorally, Buckeyes patiently patrol watercourses, wet or dry, flying up one stream bank for a while, then turning around and returning — up one side, down the other, no more than a few feet above ground level, hoping to encounter a potential mate. Buckeyes stop frequently to bask in the sun or take nectar from floodplain flowers. With wings spread, they make tantalizing photographic targets.

Traditionally, New Mexico and the greater Southwest have been home to what was called Common Buckeye (Junonia coenia), the same species that prevails in the eastern United States, easily identified by the prominent white band angling across the upperside of each forewing and enclosing a eyespot (see photo below). However, recent DNA studies1,2 first revealed and then confirmed the western, white-banded buckeye as a cryptic species, a visual dead ringer for eastern J. coenia, but now understood to be the genetically distinct western sister species known as Gray Buckeye (Junonia grisea).

Gray Buckeye (Junonia grisea), formerly thought to be Common Buckeye (Junonia coenia) (Photo by S. J. Cary, July 9, 2007 taken in the Sacramento Mountains, Otero Co., NM)

Gray Buckeye, as we now must call it, has long been a routine component of butterflying in southern New Mexico, a regular presence along creeks and arroyos from Hobbs and Portales to Lordsburg and Silver City. As with many southern species prone to wandering, Gray Buckeyes would occasionally be spotted farther north, especially during or after the summer monsoons, whose southerly air flow brought moist air, thundershowers, and southern butterfly species. But eventually winter would descend and Gray Buckeyes would be frozen out. They might re-invade the following year, depending on circumstances, but penetrations north of Albuquerque were few and far between.

The second character in this gripping drama (it’s OK, just remember to breathe) also has suffered an identity crisis. It’s now called Dark Buckeye (Junonia nigrosuffusa) and by comparing photos you can see that, while sharing several Gray Buckeye markings, it is missing the distinctive white band on the forewing. On the hindwing, a bright orange stripe near the margin is obvious on Gray Buckeye, but largely absent on Dark Buckeye. For many years the Dark Buckeye masqueraded as the ‘Dark’ subspecies of the Tropical Buckeye (Junonia genoveva nigrosuffusa), but recent DNA studies1,2 showed that it is not a subspecies of Tropical Buckeye, but its own full species.

Butterfly watchers had never seen a Dark Buckeye in northern New Mexico because it comported itself like a truly subtropical critter. Indeed, Dark Buckeyes were scarce even in southern New Mexico. For decades, my few sightings of Dark Buckeye occurred only during trips to New Mexico’s Bootheel or to southern Arizona.

Dark Buckeye (Junonia nigrosuffusa), formerly ‘Dark’ Tropical Buckeye (Photo by S. J. Cary; July 27, 2019; Apache Canyon, Santa Fe County, NM).

All those geographical constraints on Gray and Dark buckeyes, which I took for granted right along with a stable climate, have now been blown out of the water. Gray Buckeyes have materialized farther north with each passing year, or so it seems. Then in 2019, Dark Buckeyes were seen in several Northern New Mexico counties for the first time ever. Already this year (it’s barely June), northern observers are reporting Gray Buckeyes and Dark Buckeyes. These butterflies are not transcontinental, round-trip migrants like Monarchs or Painted Ladies, but by patiently following New Mexico’s best north-south river corridor, the Rio Grande, over successive generations, they are able to work their way pretty far north at least until winter cold. Shockingly, however, our recent winter failed to freeze out Buckeyes of any kind and now we must expect further expansion of Buckeyes through the 2020 warm season. I’ve already seen it above 9,000 ft elevation in the Sangre de Cristo Mountains above Santa Fe.

In addition to the two named forms, Gray and Dark, we are seeing a range of intermediate forms (see two examples below). Butterfly observers on the Colorado Front Range are seeing the very same mix of Dark, Gray, and intermediates. This suggests that breeding boundaries between the two species are not very effective. Given that they have very similar behaviors in the landscape, they no doubt encounter each other frequently, inter-specific matings do occur, and offspring may have reasonably high viability and fertility. It seems that DNA analyses in the laboratory may be able to tease out distinct species, but in the realities of living nature, these two species seem incompletely separated at best. Gray Buckeyes are occasionally hybridizing with Dark Buckeyes.

Junonia intermediate. (Photo by S. J. Cary; November 12, 2016; Dona Ana Co., NM)
Junonia intermediate. (Photo by S. J. Cary; July 12, 2017; Socorro Co., NM)

Many subtropical butterflies that find their way to northern latitudes are lost, confused, vagrant individuals that have no chance of finding a mate or reproducing. Pipevine Swallowtails (Battus philenor), for example, are occasionally seen in Northern New Mexico, but there are no pipevines (Aristolochiaceae) growing here and thus no satisfactory places for females to put eggs. Subtropical vagrants are fun to see, glimpses of butterfly diversity in more exotic climes, but they and their DNA are goners.

Buckeyes, in contrast, are finding mates and places to put eggs in Northern New Mexico. Buckeyes oviposit on plants in the Plantain Family (Plantaginaceae), for which there are a few native species and some introduced, non-native species that may naturalize. Los Alamos’s Marc Bailey recently watched a Gray Buckeye ovipositing on new shoots of what is thought to be Purple Toadflax (Linaria purpurea), a Mediterranean forb sold in some nurseries. A butterfly’s act of placing an egg is usually furtive, near the ground, quick, and hard to photograph, but see Marc’s photo below and note abdomen curled to place egg on the plant.

A female Gray Buckeye (Junonia grisea) placing an egg on what may be Purple Toadflax in Los Alamos, NM. (Photo by Marc Bailey)

So it seems that Buckeyes, both species and everything in between, are on a journey of expansion in the Southwest. Wherever you are in New Mexico, you are in good position to watch and document it as it unfolds over the coming months and perhaps years. This year’s spring Buckeyes are mating and placing eggs. Those eggs should produce a new generation of adults in summer, and there could easily be yet another generation in flight come autumn. Keep your eyes peeled, as they used to say, your lens caps off, and let’s see how things eventuate!

Steve Cary, Santa Fe

1. Melanie M.L. Lalonde and Jeffrey M. Marcus. 2018. Getting western: biogeographical analysis of morphological variation, mitochondrial haplotypes and nuclear markers reveals cryptic species and hybrid zones in the Junonia butterflies of the American southwest and Mexico.

2. Qian Cong, Jing Zhang, Jinhui Shen, Ziaolong Cao, Christian Brevignon and Nick V. Grishin. 2020. Speciation in North American Junonia from a genomic perspective.