A Survey Conducted 1996-1998
Between September 1996 and October 1998, we conducted a survey of the butterflies of Coronado National Memorial under National Park Service Contract #1443CX860196007. The survey included sixteen separate days of field observation by four different individuals. Since most butterflies are seasonal in occurrence, we attempted to make observations every three to four weeks between the months of March and October. All records represent sightings only; no specimens were collected during the survey. Close focusing binoculars were used to confirm identification on some occasions. In one instance, a photograph was used to confirm the field identification of the Tropical Leafwing.
RESULTS
100 species of butterflies were observed during the two-year period. Of these, only four species are considered to be strictly non-residents since their larval foodplants do not occur within the Memorial. Another six are of questionable status due to their rarity of occurrence or unknown larval foodplants. Two of the butterflies recorded (Rosita Patch and Elissa Roadside Skipper) are new to the Huachuca Mountains. In addition, two larval foodplants were found that are not on the Coronado National Memorial plant list. They are Pipevine, Aristolochia watsoni and Desert-honeysuckle, Anisicanthus thurberi. Numerous individuals of these species are growing near the east entrance to the Memorial.
DISCUSSION
Considering topography, plant diversity and permanent water availability in the Memorial, we anticipated recording about 110 species. Compare this with the 180 species of butterflies recorded from the Huachuca Mountains and surrounding area, or the 145 species reported just from Garden Canyon, a mid to high elevation canyon with permanent water. The total of 100 species recorded for the Memorial is a pleasant surprise. We believe that an additional ten to fifteen species can be added to the count with two to three years of additional observations.
The species we anticipate include:
Rita Blue
|
Euphilotes rita |
Nais Metalmark
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Apodemia nais |
Fulvia Checkerspot
|
Thessalia fulvia |
Canyonland Satyr
|
Cyllopsis pertepida |
Golden-banded Skipper
|
Auctocton cellus |
Meridian Duskywing
|
Erynnis meridianus |
Scudder's Duskywing
|
Erynnis scudderi |
Edward's Skipperling
|
Oarisma edwardsii |
Snow's Skipper
|
Paratrytone snowi |
Taxiles Skipper
|
Poanes taxiles |
Huachuca Giant-Skipper
|
Agathymus evansi |
One factor contributing to the high diversity within the Memorial is its location on the Mexican border, a region easily accessible to wandering and otherwise non-residential butterflies with origins to the south in Mexico. Also, its proximity to the San Pedro River, a natural corridor for northward straying butterfly species as well as a haven for native riparian lepidoptera, increases the odds of adding species to the park list.
Two factors limit butterfly diversity within the Memorial; absence of high elevation habitat and associated plants, and the absence of a good permanent riparian area. For example, the State of Texas seep was a Mecca for butterflies during the survey. If permanent water were to stretch the length of Montezuma Canyon, there could easily be five more resident species and this type of habitat would be more of a magnet for additional strays. With that said, one could expect the butterfly list to approach 125 or 130 over a ten-year span of intensive observations, especially in wetter years.
Normally, a butterfly survey requires the use of a butterfly net. At the request of the Memorial's staff, a net was not used since the authors were familiar with the fauna being surveyed. With all identifications being made by sight and with the land area involved in the survey, it was imperative that locations of high butterfly densities be found.
Butterfly density is usually higher on hilltops, in gullies, around high concentrations of good nectar flowers, and at isolated patches of standing water. Those areas found to have more butterflies were repeatedly sampled due to their seasonal nature.
HILLTOPS
Males of certain species of butterflies use hilltops for mate location. Many of these species are only present during the morning or early afternoon while others show up only in the late afternoon. Therefore, it is useful to observe butterflies at different times of the day.
Stratification of species also occurs on hilltops. Some butterflies perch on the ground. Others perch on both the ground and small shrubs while others only land on branches of the highest trees. One species, the Great Purple Hairstreak repeatedly landed on the ramada atop Coronado Peak.
During the survey, Coronado Peak was determined to be an excellent site for butterfly observations. Other high points along the ridge running immediately south were not as productive on an individual basis but very good collectively.
The small hilltops just north and east of the east park entrance were also productive. A viable colony of the Arachne Checkerspot was located there. However, a search for Desert Orangetips was unsuccessful. Other hilltops were searched including the limestone outcrops behind the park residences. There were past reports of the Fulvia Checkerspot occurring there but repeated trips failed to yield any specimens. Montezuma Peak remains unsurveyed because inclement weather canceled plans for July observations.
WATER COURSES
There are numerous drainages or gullies within the Memorial. Gullies and small canyons also serve as mate location areas for the males of many species of butterflies. Since these butterflies are mostly different from those on hilltops much observation time was spent in these types of locations. Many species like the Orange Skipperling and the Caicus Skipper repeatedly patrol small areas. They fly back and forth in a given area and often return to the same perch.
There is also a time factor involved with gully fliers. Some species such as the roadside skippers, are only active on early summer mornings and late summer afternoons. Therefore it was necessary to make observations throughout the day as long as temperatures stayed warm. The Elissa Roadside Skipper, a new record for the mountain range, was found before 7:30 A.M.! Some butterflies do not set up territories until the heat of the day.
The best gullies were those near the east entrance to the park, those along Joe's Canyon trail, and Montezuma Canyon and nearby washes. Montezuma Canyon was the largest and proved to be an excellent lookout for patrolling butterflies. It is also a natural corridor for wandering species and there is usually nectar available nearby.
With the exception of desert broom, Baccharis sarathroides, excellent nectar sources were difficult to find. The October blooms of desert broom were a tremendous help in making butterfly observations. Unfortunately, there was a lack of comparable nectar sources the rest of the year. Often, other attractant flowers were found but never in high enough concentrations to be as useful as desert broom. Some of these were milkweed, Sarcostemma; buckwheat, Eriogonum wrightii; buckbrush, Ceonothus fendleri; loosestrife Lythrum californicum and various members of the sunflower family (Asteraceae).
SPECIES ACCOUNTS
The 100 butterfly species observed during the survey are illustrated here with photos of living butterflies taken by the authors. Many of these photos were taken in the Memorial.
The common names used are those of the North American Butterfly Association as listed in their Checklist and English Names of North American Butterflies (NABA, 1995). Taxonomy and scientific names follow Bailowitz and Brock in Butterflies of Southeastern Arizona (SASI, 1991).
The accounts of the butterflies recorded during the survey contain the four categories; General, Flight, Foodplant and Status. In the General category, we provide information about the species habits and habitat preferences. Where useful, we also provide information to help the casual observer distinguish from similar species. Flight refers to the times during the year when adults of each species can be seen flying. Foodplant is that of the larval stage; adults may sip nectar at many species of plants. Status describes whether the species is a permanent resident within the Memorial or considered a stray, primarily from farther south in Mexico.