South-central Arizona Research Articles

Precipitation and time effects on vegetation change in Southern Arizona abandoned farmland

Farmland abandonment represents a significant issue globally, and in arid environments reclaiming ecosystems is challenging. In the Sonoran Desert, much irrigated farmland has been abandoned since 1950. Our objective was to compare changes in vegetative (canopy) cover and species over a 26-year period on abandoned farmland and unfarmed controls in southcentral Arizona (precipitation <300 mm/year). We evaluated time since abandonment and precipitation effects on these variables between 1976 and 2003 with point frame methods on eight farmland sites using stepwise multiple regression. Results suggest antecedent precipitation (AP) is more important than time since abandonment in explaining cover changes. On 26 abandoned sites, we used non-parametric ANOVA to show that vegetative cover (point frame and line intercept methods) declined by about 43% from 1977 to 2023, which was greater than on non-farmed controls. Few farmlands had cover and species composition like reference communities in 2003. Paired farmland-control sites exhibited similar vegetation in 1977 and 2003 suggesting local factors (e.g., soil chemistry, roadways) may have overwhelmed that of farming. Uninterrupted (natural) surface water flow may predict where revegetation was most successful. Our research indicates that farmland may exist in alternative states, and passive revegetation will not reestablish native Sonoran Desert communities on most abandoned farmland sites.

Ecological-niche modeling reveals current opportunities for Agave dryland farming in Sonora, Mexico and Arizona, USA.

For centuries, humans occupying arid regions of North America have maintained an intricate relationship with Agave (Agavoideae, Asparagaceae). Today Agave cultivation, primarily for beverage production, provides an economic engine for rural communities throughout Mexico. Among known dryland-farming methods, the use of rock piles and cattle-grazed areas stand out as promising approaches for Agave cultivation. Identifying new cultivation areas to apply these approaches in Arizona, USA and Sonora, Mexico warrants a geographic assessment of areas outside the known ranges of rock piles and grasslands. The objective of this study was to predict areas for dryland-farming of Agave and develop models to identify potential areas for Agave cultivation. We used maximum entropy (MaxEnt) ecological-niche-modeling algorithms to predict suitable areas for Agave dryland farming. The model was parameterized using occurrence records of Hohokam rock piles in Arizona and grassland fields cultivated with Agave in Sonora. Ten environmental-predictor variables were used in the model, downloaded from the WorldClim 2 climate database. The model identified potential locations for using rock piles as dryland-farming methods from south-central Arizona to northwestern Sonora. The Agave-grassland model indicated that regions from central to southern Sonora have the highest potential for cultivation of Agave, particularly for the species Agave angustifolia. Results suggest that there are many suitable areas where rock piles can be used to cultivate Agave in the Sonoran Desert, particularly in the border of southeastern Arizona and northwest Sonora. Likewise, cattle-grazing grasslands provide a viable environment for cultivating Agave in southern Sonora, where the expanding bacanora-beverage industry continues to grow and where different Agave products (e.g., syrups, fructans, saponins, and medicinal compounds) can potentially strengthen local economies.

Rio Grande cultural remains on the middle Gila River, Arizona: The Pueblo Revolt and the Eastern Puebloan diaspora

Data recovery investigations in the Blackwater area along the middle Gila River in south-central Arizona identified ceramic and lithic artifacts derived from the Rio Grande region. These remains were collected from GR-1425, which is located at the heading of the Blackwater canal system within the Gila River Indian Community. The site lacks evidence for permanent occupation, and instead only short-term habitation occurred. Extensive evidence for weapon manufacturing suggests that the temporary relocation was associated with conflict, and radiocarbon dates suggest that the cultural remains were deposited after the Hohokam Classic period ended circa CE 1450. The most parsimonious explanation for the data from GR-1425 is that a group of Eastern Puebloans temporarily moved to the middle Gila River around the time of the Pueblo Revolt in CE 1680. As a result of increased interactions of disparate populations brought together by the extensive population movements that occurred at this time, substantial changes in regional ceramic traditions occurred, and data from GR-1425 suggest the extent of these interactions was more wide-scale than previously recognized.

Survival and fidelity of translocated and resident burrowing owls in Arizona

AbstractGiven the rapid pace of urbanization, mitigation translocations are increasingly being used to reduce human‐wildlife conflicts, especially to move animals out of the path of land development. Burrowing owls (Athene cunicularia) are commonly subjected to translocations because of their association with flat, open lands that are attractive to development. But outcomes of burrowing owl translocations and the effects they have on their demographic parameters are seldom documented. From 2017–2019, we tracked the fates of 42 resident (non‐translocated) burrowing owls and 43 translocated owls using very high frequency radio‐telemetry across 4 release sites in southcentral Arizona, USA. Translocations were conducted by Wild At Heart (WAH), a non‐profit raptor rehabilitation program, and owls were moved from areas with planned development activities to release sites that contained artificial burrows. Each year, WAH held translocated owls in groups of 6–10 owls with varying male to female ratios in aviaries prior to taking the owls to release sites where the owls stayed in soft‐release tents for an acclimation period of 30 days before release. Resident owls were located at or near the 4 release sites. We used the joint live encounter and dead recovery model to evaluate differences in survival and fidelity probabilities between resident (non‐translocated) and translocated burrowing owls and to assess factors that influenced these probabilities including sex, year, site, captivity duration, and the number of males in release cohorts for translocated owls. Annual survival was consistently lower for translocated owls (0.35, 95% CI = 0.10, 0.61 and 0.01, 95% CI = 0.00, 0.03 for 2017 and 2018, respectively) compared to resident owls (0.68, 95% CI = 0.45, 0.92 and 0.69, 95% CI = 0.47, 0.90 for 2017 and 2018, respectively). Annual fidelity was lower for translocated owls (0.05, 95% CI = 0.00, 0.15) compared to resident owls (0.79, 95% CI = 0.57, 1.00) in 2018, but fidelity did not differ significantly between translocated (0.54, 95% CI = 0.19, 0.89) and resident owls (0.62, 95% CI = 0.37, 0.87) in 2017. For translocated owls, the number of males in release cohorts negatively affected survival ( = −0.74, 95% CI = −1.07, −0.40) and fidelity ( = −0.73, 95% CI = −1.17, −0.29). Our results indicate the need for substantial changes to the current translocation methodology for burrowing owls in Arizona. Breeding season releases that included owl groups and multiple males within cohorts resulted in agonistic interactions, high mortality, and low fidelity. Translocations of this territorial species should be restricted to male‐female pairs or single individuals. Earlier releases may allow owls time to become established on release sites prior to the breeding season, which could promote fidelity. We recommend these changes be implemented and evaluated along with an examination of other release methods.

Antelope Jackrabbit (Lepus alleni) Habitat Characteristics in a Former Rangeland

Semi-desert grasslands in the southwestern United States have undergone significant ecological changes as a result of anthropogenic activities beginning in the 1800s. As efforts to restore semi-desert grasslands continue, importance should be placed on understanding the habitat requirements of species, and their relationships with other plants and animals. We examined habitat characteristics of antelope jackrabbits (Lepus alleni Mearns 1890) at Buenos Aires National Wildlife Refuge in south-central Arizona. We examined antelope jackrabbit habitat in relation to endangered Pima pineapple cacti (Coryphantha scheeri Kuntz var. robustispina Schott) and available freshwater sources. Dominant vegetation type and cover were measured at 247 points in antelope jackrabbit home ranges between October 2015 and December 2015. Additionally, we documented the proximity of antelope jackrabbit locations to Pima pineapple cacti and available water sources to determine whether antelope jackrabbits have a spatial relationship with this endangered cactus or water availability.Antelope jackrabbits did not select for habitat based on the vegetation characteristics we measured, proximity to Pima pineapple cacti or based on water availability (P > 0.05).Some jackrabbit species have indicated habitat structure preferences, and while antelope jackrabbits are most commonly associated with tropic-subtropic savannas, our study did not show that antelope jackrabbits select for specific vegetation types or a specific vegetation density, nor native grasses over non-native grasses. Antelope jackrabbits may encounter and eat Pima pineapple cactus opportunistically, as opposed to selecting habitat where Pima pineapple cactus occur. Additionally, antelope jackrabbits did not choose habitat based on the location of freshwater sources which may be because they do not need to drink water to survive and instead get their water needs from their food. Little information exists on how antelope jackrabbits select habitat. This study concluded that there is no relation between vegetation factors previously thought to influence antelope jackrabbit habitat selection and habitat use. Future studies based on larger-scale variables, like topography or predator pressure, may help in understanding the factors that influence how this species uses man-altered landscapes.

Masked Bobwhite Recovery: The Need for a Multifaceted Approach

Masked bobwhite (Colinus virginianus ridgwayi) is a critically endangered quail historically found in the Sonoran grasslands of southern Arizona, USA and Sonora, Mexico. Native populations of masked bobwhite may already be extinct in the wild, but captive populations exist in the United States at G. M. Sutton Avian Research Center (Oklahoma, USA), Buenos Aires National Wildlife Refuge (Arizona, USA), and various zoos. The 47,000-hectare Buenos Aires National Wildlife Refuge, located in south-central Arizona, was established primarily for reintroduction of this bird. Recovery efforts within the refuge boundary in the 1980s and 1990s were initially successful but suffered debilitating setbacks that ultimately resulted in failure. Substantial releases were suspended in 2005. Improved habitat restoration efforts and promising conditioning and release techniques led to the belief that reintroductions could again be attempted and successful. In 2016–2017 plans were developed to increase captive propagation and reinitiate release efforts. Releases began in 2018. Over-winter survival of birds released in 2018–2019 was encouraging, and reproduction of wild birds was documented in 2019. An existing base of wild birds established from these releases could help masked bobwhite populations recover in the state. Habitat restoration, better methods of rearing, release, and conditioning, and improved production from captive facilities also inspire hope that a full recovery of the species in Arizona is possible.

Quantifying the impact of cropland wind erosion on air quality: A high-resolution modeling case study of an Arizona dust storm

Dust storms fueled by wind erosion of desert and cropland soils in south-central Arizona have caused numerous highway accidents and health risks by creating hazardous air quality conditions. Despite much speculation that a major fraction of windblown dust during these storms originates at an active or abandoned cropland surface over the region, its quantification is largely missing in the literature. This study estimated the contribution of cropland wind erosion to the regional air quality degradation, in terms of concentration of particulate matter with diameter 10 μm and smaller (PM10), during a typical springtime dust storm, by conducting high-resolution (1 km horizontally) simulations utilizing the Weather Research and Forecasting-FENGSHA (a dust emission model)-Community Multiscale Air Quality (WRF-FENGSHA-CMAQ) modeling framework. The dust model for this study employed up-to-date and very high-resolution data on land use, soil texture, and vegetation index. The modeling system used in this study simulated reasonably well a regional dust storm (that raised concerns for air quality and highway safety) of 08–09 April 2013 compared against ground (station) observations of PM10 and satellite observations of dust optical depth and vertical structure of aerosol subtypes. The model evaluations also included the use of radar observations.Furthermore, the model results from this study revealed that the cropland wind erosion was responsible for 55% and 51% of total PM10 over Phoenix (33.35°N–33.85°N, 112.36°W–111.485°W) and western Pinal County (32.50°N–33.35°N, 112.2°W–111.2°W), respectively, during the simulated dust storm. The large contributions suggest that the inclusion and accurate representation of cropland dust sources are crucial in preparing emission inventories and in air quality modeling for the region. Such representation is particularly important in view of the projected future aridity over this region (that is already under a long-term drought), which may lead to fallowing of currently active farmlands, making them potential hotspots of dust emission. The modeling approach developed for this work can be used to carry out more comprehensive studies, over extended spatial and temporal extents, to identify the sources of windblown dust and quantify their climatological dust emission potentials for this region or elsewhere. Such studies are highly desirable to help decision-making processes to reduce windblown dust and the associated health and safety risks.

FIRST RECORD ON HOST PLANTS AND TAXONOMICAL DESCRIPTION ON Aptopus opata (ELATERIDAE: CARDIOPHORINAE: CARDIOPHORINI) FROM SINDH PAKISTAN

Aptopus Eschscholtz is a native of the Mexico sonar light trap Huachuca Mountain of south central Arizona. This species has been first time observed from district Khairpur Sindh province of Pakistan from (March 2018 to October 2019), these observation represent first record of this species from Sindh or Pakistan. This description and illustrations are provided for easy identification, they cause significant damage to crops, they are pest species and omnivores feeder, especially on maize crops, potatoes, tomatoes and germinating seeds, weeds and small grasses overall in worldwide, its larva is yellowish to brown in color, from damage use the granules insecticides at planting time will prevent from wireworm, Aptopus opata is a differ from the closely allied species on the basis of genitalial and morphological characteristics body lengthened, dark brown to blackish with densely punctuations, prontal angles lengthened, pointed, scutellum blackish spot like, legs lengthened, aedeagus wider than longer, base broader, lateral lobe parameres slightly bigonal, with have golden hairs, at apex, median lobe parameres, broad at basal, rapidly narrowing apically, hairs like structure view from the ventral aspects.

ARGAS (PERSICARGAS) GIGANTEUS SOFT TICK INFECTION WITH RICKETTSIA HOOGSTRAALI AND RELAPSING FEVER BORRELIA ON WILD AVIAN SPECIES OF THE DESERT SOUTHWEST, USA

Changing climatic conditions and the northward expansion of ticks and pathogens are of immense importance to human, animal, and environmental health assessment and risk management. From 2014 through 2015, a wildlife rehabilitation center in south-central Arizona, US noted soft ticks (Argasidae) infesting 23 birds, including Cooper's Hawks (Accipiter cooperii), Gray Hawks (Buteo plagiatus), Harris's Hawks (Parabuteo unicinctus), Red-tailed Hawks (Buteo jamaicensis), Great Horned Owls (Bubo virginianus), Common Ravens (Corvus corax), and a Greater Roadrunner (Geococcyx californianus), during the late summer seasonal rainy seasons. The parasites numbered in the hundreds on individual birds. Infested birds were moribund, obtunded, or paralyzed on presentation, with no prior histories of illness or evidence of trauma. Tick and avian blood samples were collected for vector-borne pathogen analysis focusing on the molecular detection of Rickettsia and Borrelia species. Ticks were identified as the neotropical species of soft tick, Argas (Persicargas) giganteus; their occurrence in the southern US on raptors represented an expansion of host range. Pathogen testing of ticks showed that 41% of 54 ticks were infected with Rickettsia hoogstraalii and 23% of 26 ticks were infected with a relapsing fever Borrelia; both agents are associated with uncertain health consequences. Among the blood samples, one was infected with the same Borrelia spp.; this Red-tailed Hawk also had Borrelia-positive ticks. With supportive therapy, the majority of birds, 74% (17/23), recovered and were released or permanent residents. The management of soft tick-infested birds and mitigation of future disease risk will require additional characterizations of these poorly studied soft ticks and their associated pathogens.

Seasonal Changes in the Home Range of the Antelope Jackrabbit (Lepus alleni)

In the face of climate change, more research is needed to understand how animals adjust to dynamic ecosystems. Seasonal environments offer a unique opportunity to observe how animals use the landscape in a fluctuating system. The antelope jackrabbit (Lepus alleni) is an understudied lagomorph found in the Sonoran Desert of Arizona, USA and Mexico. Basic ecological information on this species is lacking beyond historical responses to rangeland conditions. Using radio telemetry, we collected data on home range size and seasonal ranges of antelope jackrabbits on the Buenos Aires National Wildlife Refuge in southcentral Arizona. Male and female antelope jackrabbit mean home range size differed slightly, though not significantly. Within a seasonal landscape of semidesert and Sonoran savanna grasslands, antelope jackrabbits seasonal range size did not change but the home range usage percentage differed across seasons and degree of interseason similarity was low. Antelope jackrabbit home ranges are comparable to range sizes reported for the widespread black-tailed jackrabbit (Lepus californicus) as well as the closely related Tehuantepec jackrabbit (Lepus flavigularis). This study is the first to document antelope jackrabbit home range, and our results permit a better understanding of how these hares use the landscape in a complex arid environment.

Self-Fashioning for Survivance: Akimel O'odham Story and History in the Hispanic and Early American Periods

Self-Fashioning for Survivance:Akimel O'odham Story and History in the Hispanic and Early American Periods* Jennifer Bess (bio) The earth is spinning aroundThe earth is spinning aroundAnd my people are spinning around with the earth.The earth is spinning fasterThe earth is spinning fasterAnd my people are spinning faster with the earth.At that time when Siuuhu was singing these songs, that is a sign that some day we'll find out that the earth is turning around all the time. —Julian Hayden, Juan Smith, and William Allison Smith, "Pima Creation Myth"1 The legends I have told were told by the old Pimas many, many years ago to entertain and instruct their children. Today, these old stories are almost forgotten by the younger Pimas. I don't think they should be forgotten. They are a part of Pima tradition. They show what life was like in those old days and what bothered the people such as floods and drought and old Ho'ok's bad manners. They show what our ancestors thought was important. They help us to understand what is important today. —George Webb, A Pima Remembers 2 [End Page 725] At the height of deliberations dividing Akimel O'odham (River People, also called Pima) and Anglo-American farmers over the life-sustaining waters of the Gila River in south-central Arizona in the early twentieth century, 444 "Indians of the Pima Tribe" repeated in their testimony before the U.S. Senate a refrain dating back at least two generations: "We Pimas…have always been the white man's friend."3 Between 1848 and 1854, they had proven their friendship through the respite their grandfathers offered to 60,000 migrants crossing Arizona on their way to California.4 Providing safety from Apache assaults, forage for animals, and food and water for travelers, the eight Akimel O'odham villages stretching along 12 to 15 miles of the middle Gila River marked the junction at which four southern trails to California converged.5 As fortyniner Benjamin Butler Harris remarked in regards to this hub of activity, "So many 'Pilgrims' of different companies accumulating here at one time caused disintegration and new combinations of companies."6 They came to this oasis in the Sonoran Desert trading clothing, whiskey, and weapons for cotton blankets, corn, wheat, tobacco, pumpkins, melons, and other foodstuffs. As Cave Johnson Couts limned, due to the fact that the "Gila bottom…surpasses anything we have ever witnessed for fertility," the Akimel O'odham were able to be generous.7 "The Pima," wrote George Webb a century later in A Pima Remembers, "have always been known for their hospitality. If you came to the home of another Pima, no matter what time of day, the first thing placed before you would be some kind of food…. In those days the Pimas always had plenty."8 This era of prosperity and generosity, witnessed by Anglo-Americans and eulogized by Webb, illustrates one of many chapters in a local history characterized by adaptation, innovation, and co-creation. And as demonstrated below, the "spinning" world of the Akimel O'odham sacred stories provided them with a lens through which to interpret the past, see opportunities in the present, and build the future. The following study draws from the fields of oral narrative theory, archaeology, history, religion, and anthropology to provide necessary foundations in order to explore the importance of adaptation, innovation, and "world-building" in Akimel O'odham sacred story and history.9 Inspired by the studies of anthropologist William Roseberry and historian Colleen O'Neill, both of whom illustrate the reciprocal nature of culture and history, this essay reveals the mutually reinforcing and dynamic relationship between the philosophies articulated in the sacred stories and the lived history of their guiding messages.10 Along the two axes of [End Page 726] storytelling and history, this study seeks to bring into relief three interrelated points: the importance of sacred story and oral history as complements to written history and archaeology in understanding the past; the value of storytelling as an interpretive lens to that history; and the example that the Akimel O'odham provide of Native adaptability...

Blackwater Village at the Turn of the Twentieth Century: Akimel O’Odham Perseverance and Resiliency

Much of what is known regarding Historic period Native American communities is based on studying documents that were written by non-indigenous peoples. However, archaeological excavations in a portion of the Blackwater Village within the Gila River Indian Community provide another perspective on Native American life ways within south-central Arizona during the late 1800s. The latter nineteenth century was a pivotal time for the Akimel O’Odham (i.e., Pima) who have long lived within the Phoenix Basin, and they experienced dramatic changes in their subsistence strategies, settlement patterns, craft production, and other cultural practices during this time. These recent investigations demonstrate that the Akimel O’Odham were not passive recipients of Euroamerican culture, and instead they chose to adopt some aspects of non-native practices while at the same time retaining important traditions. As a result, the Akimel O’Odham have successfully maintained their society in the face of tremendous hardships, and Blackwater Village remains a vibrant settlement to this day.

Hohokam Lost Crop Found: A New Agave (Agavaceae) Species Only Known from Large-scale pre-Columbian Agricultural Fields in Southern Arizona

For over thirty years archaeologists have provided evidence that southern Arizona pre-Columbian Native Americans, the Hohokam, extensively cultivated agave. However, no archeologists reported finding living agaves growing in the rock-piled or gridded Hohokam fields, therefore researchers could only speculate about the species cultivated. Our work expands upon a recent publication noting several agaves growing in prehistoric dry-farmed fields on terraces overlooking the San Pedro River. These agaves have affinities to A. phillipsiana W. C. Hodgs. and A. palmeri Engelm. based on flower color but differ by their gray-green leaves with thick bases and conspicuous bud imprinting. They are extremely rare, reproduce asexually via rhizomatous offsets with no apparent fruit set, have relatively uniform intra- and inter-population morphology, grow only with archaeological features and are unknown from natural settings: all characteristics expected in a domesticated crop. Here we describe Agave sanpedroensis, provide a key to distinguish it from other agaves in south-central Arizona and propose that it is a clonal, relictual crop grown from ca. A.D. 800–1450 by the Hohokam, and thus represents a ‘lost crop’ as sought by archaeologists. The extensive size and wide distribution of Hohokam agave fields that transformed the landscape and are still visible today indicates the crop's importance in the Hohokam economy. The question of where and when this agave originated has implications for North American domestication centers. Our discovery emphasizes the importance of collaborative research between archaeologists and botanists whose distinctive data can provide a richer understanding of how the Hohokam developed and then sustained one of the American Southwest's largest prehistoric populations.

Simulating the meteorology and PM10 concentrations in Arizona dust storms using the Weather Research and Forecasting model with Chemistry (Wrf-Chem)

ABSTRACTNine dust storms in south-central Arizona were simulated with the Weather Research and Forecasting with Chemistry model (WRF-Chem) at 2 km resolution. The windblown dust emission algorithm was the Air Force Weather Agency model. In comparison with ground-based PM10 observations, the model unevenly reproduces the dust-storm events. The model adequately estimates the location and timing of the events, but it is unable to precisely replicate the magnitude and timing of the elevated hourly concentrations of particles 10 µm and smaller ([PM10]).Furthermore, the model underestimated [PM10] in highly agricultural Pinal County because it underestimated surface wind speeds and because the model’s erodible fractions of the land surface data were too coarse to effectively resolve the active and abandoned agricultural lands. In contrast, the model overestimated [PM10] in western Arizona along the Colorado River because it generated daytime sea breezes (from the nearby Gulf of California) for which the surface-layer speeds were too strong. In Phoenix, AZ, the model’s performance depended on the event, with both under- and overestimations partly due to incorrect representation of urban features. Sensitivity tests indicate that [PM10] highly relies on meteorological forcing. Increasing the fraction of erodible surfaces in the Pinal County agricultural areas improved the simulation of [PM10] in that region. Both 24-hr and 1-hr measured [PM10] were, for the most part, and especially in Pinal County, extremely elevated, with the former exceeding the health standard by as much as 10-fold and the latter exceeding health-based guidelines by as much as 70-fold. Monsoonal thunderstorms not only produce elevated [PM10], but also cause urban flash floods and disrupt water resource deliveries. Given the severity and frequency of these dust storms, and conceding that the modeling system applied in this work did not produce the desired agreement between simulations and observations, additional research in both the windblown dust emissions model and the weather research/physicochemical model is called for.Implications: While many dust storms can be considered to be natural, in semi-arid climates such storms often have an anthropogenic component in their sources of dust. Applying the natural, exceptional events policy to these storms with strong signatures of anthropogenic sources would appear not only to be misguided but also to stifle genuine regulatory efforts at remediation. Those dust storms that have resulted, in part, from passage over abandoned farm land should no longer be considered “natural”; policymakers and lawmakers need to compel the owners of such land to reduce its potential for windblown dust.

Coccidioidomycosis Dynamics in Relation to Climate in the Southwestern United States.

Valley fever is endemic to the southwestern United States. Humans contract this fungal disease by inhaling spores of Coccidioides spp. Changes in the environment can influence the abundance and dispersal of Coccidioides spp., causing fluctuations in valley fever incidence. We combined county‐level case records from state health agencies to create a regional valley fever database for the southwestern United States, including Arizona, California, Nevada, New Mexico, and Utah. We used this data set to explore how environmental factors influenced the spatial pattern and temporal dynamics of valley fever incidence during 2000–2015. We compiled climate and environmental geospatial data sets from multiple sources to compare with valley fever incidence. These variables included air temperature, precipitation, soil moisture, surface dust concentration, normalized difference vegetation index, and cropland area. We found that valley fever incidence was greater in areas with warmer air temperatures and drier soils. The mean annual cycle of incidence varied throughout the southwestern United States and peaked following periods of low precipitation and soil moisture. From year‐to‐year, however, autumn incidence was higher following cooler, wetter, and productive springs in the San Joaquin Valley of California. In southcentral Arizona, incidence increased significantly through time. By 2015, incidence in this region was more than double the rate in the San Joaquin Valley. Our analysis provides a framework for interpreting the influence of climate change on valley fever incidence dynamics. Our results may allow the U.S. Centers for Disease Control and Prevention to improve their estimates of the spatial pattern and intensity of valley fever endemicity.

Survival of the Endangered Pima Pineapple Cactus: Does Clearing Before Prescribed Fire Alter Survival Postfire?

Federal land managers and ranchers often use prescribed fire as a tool to reduce invading woody plants within desert grasslands of the arid southwestern United States. Managers must evaluate the threat of the burn toward the health and survival of plants of concern including how preemptive clearing before prescribed fire might benefit these species. One example is the endangered Pima pineapple cactus (Coryphantha scheeri var. robustispina), a small hemispheric cactus of desert scrublands and grasslands of south-central Arizona and northern Sonora, Mexico. In 2014, we examined survival of Pima pineapple cactus documented in 2009 or 2010 within grasslands of Buenos Aires National Wildlife Refuge in Arizona. Of the 72 sites observed, 35 had no burn after documentation and 37 experienced prescribed fire. Refuge staff removed vegetation between 0.3 and 3.0 m from the cactus preburn. We found that Pima pineapple cacti in areas subjected to prescribed fire and with preemptive clearing had the same survival statistically as cacti from sites that were not burned.

Population and colony structure and morphometrics in the queen dimorphic little black ant, Monomorium sp. AZ-02, with a review of queen phenotypes in the genus Monomorium.

The North American little black ant, Monomorium sp. AZ-02 (subfamily Myrmicinae), displays a dimorphism that consists of alate (winged) and ergatoid (wingless) queens. Surveys at our field site in southcentral Arizona, USA, demonstrated that only one queen phenotype (alate or ergatoid) occurred in each colony during the season in which reproductive sexuals were produced. A morphometric analysis demonstrated that ergatoid queens retained all specialized anatomical features of alate queens (except for wings), and that they were significantly smaller and had a lower mass than alate queens. Using eight morphological characters, a discriminant analysis correctly categorized all queens (40 of 40) of both phenotypes. A molecular phylogeny using 420 base pairs of the mitochondrial gene cytochrome oxidase I demonstrated that alate and ergatoid queens are two alternative phenotypes within the species; both phenotypes were intermixed on our phylogeny, and both phenotypes often displayed the same haplotype. A survey of the genus Monomorium (358 species) found that wingless queens (ergatoid queens, brachypterous queens) occur in 42 of 137 species (30.6%) in which the queen has been described. These wingless queen species are geographically and taxonomically widespread as they occur on several continents and in eight species groups, suggesting that winglessness probably arose independently on many occasions in the genus.

ANCESTRAL O'ODHAM: AKIMEL O'ODHAM CULTURAL TRADITIONS AND THE ARCHAEOLOGICAL RECORD

Archaeologists have long used the prehistoric inhabitants of the Phoenix Basin in south-central Arizona as an example of a failed or collapsed society, and most prehistorians still assert that Hohokam material culture patterns ended at the close of the Classic period (circa A.D. 1150–1450). Although researchers are increasingly recognizing connections between prehistoric and modern indigenous people, little consensus exists regarding the cause or causes of the dramatic alterations in material culture patterns that occurred in the region. Most archaeologists who have studied the changes at the end of the Classic period, however, have not fully considered the implications of previous and subsequent conditions, including similar and seemingly abrupt shifts in cultural practices that occurred both before and after this time. This paper uses Akimel O'Odham (i.e., Pima) cultural knowledge to contextualize the “Hohokam Collapse.” We show that this perspective of culture history explains the relationship between prehistoric and historic populations and answers many of the long-standing questions regarding cultural variation in the Phoenix Basin.

Notes on the distribution of Cylindropuntia fulgida var. mamillata (Cactaceae- Opuntioideae) in India

Cylindropuntia fulgida (Engelm.) F.M.Knuth var. mamillata (A.Schott ex Engelm.) Backeb. (Cactaceae), a native of south-Central Arizona in the USA, is reported for the first time for India from Nagarjuna konda Island of Andhra Pradesh. Detailed description, photo plate and relevant notes are provided.

Ecology of the antelope jackrabbit (Lepus alleni)

The antelope jackrabbit (Lepus alleni) is a lagomorph indicative of Neotropic savanna and thornscrub in south-central Arizona, west-central Sonora, and western Sinaloa <1,200 m elevation. We found populations in Arizona are most abundant in tropic–subtropic areas of low relief, characterized by velvet mesquite (Prosopis velutina) with an herbaceous understory (= Sonoran savanna grassland), and receiving a mean annual rainfall of between 200 and 450 mm, >90 mm of which falls as summer precipitation. In Mexico, this hare most commonly occurred in savanna grasslands or thornscrub interrupted by open areas receiving between 200 and 450 mm of precipitation per annum. Cacti were important habitat components for the hares and mean annual temperatures were >18°C with <60 d a year having temperatures below 0°C. Although sympatric with Lepus californicus over portions of its range, the two species preferred different habitats and rarely occurred together, and L. alleni was more prone to occur in groups than was L. californicus. We calculated the distributional range of L. alleni as ca. 102,000 km2 in Arizona and Mexico.