1.1 Background
1.2 Setting
1.3 Information Needs
1.4 Purpose
2.1 Previous Studies
2.2 Interview Process
2.3 Supplemental Information
3.0 SPECIES EXTIRPATED FROM PIMA COUNTY
5.0 HABITATS OF CONCERN AND TARGET PLANT COMMUNITIES
8.1 ESA Conservation vs. Unlisted Species Conservation
8.2 Conservation of Species vs. Habitat Conservation
8.3 Species vs. Subspecies
8.4 Taxonomic Uncertainties
8.5 Other Issues
NUMBER TITLE
PAGE
1 Location Map 1-8
NUMBER TITLE
PAGE
1 Federally Listed, Proposed and Candidate Species 1-2
2 People Interviewed for Species of Concern 2-2
3 Species Extirpated from Pima County 3-2
4A Species of Concern - Status 1 4-2
4B Species of Concern - Status 2 4-4
4C Species of Concern - Status 3 4-6
4D Species of Concern - Status 4 4-8
5 Habitats of Concern & Target Plant Communities 5-2
A Additional Species & Interview Process Forms A-1
B Other Species Discussed B-1
C Exotic Species in Pima County C-1
1.1 Background
In October of 1998, the Pima County Board of Supervisors directed staff
to develop the Sonoran Desert Conservation Plan. The Sonoran Desert Conservation
Plan (SDCP) is a major conservation planning effort with the following goals:
(1) define urban form and prevent urban sprawl though protection of natural
and cultural resources; (2) provide the basis of a natural resource protection
and environmental element for the Comprehensive Plan; (3) protect habitat
for and promote recovery of the endangered cactus ferruginous pygmy-owl;
(4) preserve an interconnected system comprised of the range of native vegetative
communities needed to provide habitat for the diverse array of species native
to Pima County and thereby prevent the need for future listings; and (5)
obtain a Section 10 permit under the Endangered Species Act for a regional,
multi-species conservation plan.
The regulatory backdrop for the SDCP is provided by the federal Endangered
Species Act (ESA). Section 9 of the ESA prohibits the "take" (harm,
harassment, significant alteration of habitat, etc.) of any federally listed
animal species. Section 10 of the ESA allows permits to be granted for incidental
take of a listed species if an adequate conservation plan is developed.
Applications for these permits are submitted to the U. S. Fish and Wildlife
Service, which is responsible for reviewing and approving, or denying, species
conservation plans.
In Pima County, there are eighteen species which have been federally
listed as threatened or endangered under the Endangered Species Act. These
are described within Table 1, along with four additional species which are
considered candidates for federal listing, two species proposed for listing,
and one species which has been petitioned for listing under ESA. At a minimum,
we assume that the protection of these species will be addressed by the
SDCP.
Another goal of SDCP is to provide protection to species and habitats,
not covered by ESA, whose existence in Pima County may be in jeopardy or
should be considered because of their ecological or social importance. To
accomplish this goal, the SDCP is being designed as a regional program with
six elements that reflect a wide range of community values including:
| SCIENTIFIC NAME | COMMON NAME | STATUS | LOCATION IN PIMA COUNTY | DISTRIBUTION | HABITAT NEEDS | COMMENTS |
| Panthera onca | Jaguar | Endangered | Eastern/Western | Widely distributed south of Arizona | Range throughout a variety of habitats from Sonoran Desert to conifer forests | Sightings near Mexico/Arizona border and south central AZ (confirmed with photographs) |
| Felis yagouaroundi tolteca | Jaguarundi | Endangered | ? | Widely distributed south of AZ | Variety of habitats: deciduous forests, riparian areas, swampy grasslands, upland dry savannahs, etc. | Sightings in southern AZ (unconfirmed) |
| Felis pardalis | Ocelot | Endangered | Eastern | Widely distributed south of AZ | Humid tropical and sub-tropical forests, savannahs and semi-arid thorn scrub (dense cover) | Sightings in southern Az (unconfirmed) |
| Canis lupus baileyi | Mexican Gray Wolf | Endangered | Eastern (historically) | May still persist in Mexico; was formerly wide in distribution | Chapparal, woodland, and forested areas; may cross desert areas | Unconfirmed reports of individuals in southern AZ; experimental nonessential population introduced in Blue Primitive Area |
| Antilocapra americana sonoriensis | Sonoran Pronghorn | Endangered | Western | Also occurs in Mexico in Pinacate Biosphere Reserve | Broad, Intermountain alluvial valleys with Creosote-Bursage & Palo Verde-Mixed Cacti Associations | Historic range probably larger than exists today; formerly ranged east to near Tucson |
| Leptonycteris curasoae yerbabuenae | Lesser Long-nosed Bat | Endangered | Eastern/Western | Widely distributed | Desert scrub habitat with agave and columnar cacti present as food plants; day roosts in caves and abandoned tunnels | Species is migratory |
| Falco peregrinus anatum | American Peregrine Falcon | Endangered | Eastern/Western | Widely distributed in United States | Cliffs and steep terrain usually near water or woodlands with abundant prey | Breeding birds are year-round residents; other birds winter and migrate through AZ; species endangered due to pesticides |
| Haliaeetus leucocephalus | Bald Eagle | Threatened | Eastern | Widely distributed | Large trees or cliffs near water (reservoirs, rivers and streams) with abundant prey | Some birds are nesting residents while a larger number winters along rivers and reservoirs |
| Glaucidium brasilianum cactorum | Cactus Ferruginous Pygmy-Owl | Endangered | Eastern/Western | Widely distributed south of AZ | Mature Cottonwood/Willow, mesquite bosque, and sonoran desert scrub | Few documented sites; surveys are needed |
| Colinus virginianus ridgewayi | Masked Bobwhite | Endangered | Eastern | Limited distribution in Mexico | Desert grasslands with diversity of dense native grasses, forbs and brush | Presently only known from reintroduced population in Buenos Aires |
| Strix occidentalis lucida | Mexican Spotted Owl | Threatened | Eastern/Western | Specific habitat needs | Nests in canyons and older forests with multi-layered foliage structure | Saguaro National Park; Coronado National Forest |
| Empidonax traillii extimus | Southwestern Willow Flycatcher | Endangered | Scattered | Distribution restricted to riparian corridors | Cottonwood/Willow and tamarisk vegetation communities along rivers and streams | Migratory riparian obligate species that occupies breeding habitat from late April to September |
| Charadrius montanus | Mountain Plover | Proposed threatened |
? | ? | Open arid plains, short grass prairies and scattered cactus | Listed proposed/threatened in February 1999 |
| Coccyzus americanus occidentalis | Western Yellow-billed Cuckoo | Petitioned | Eastern | ? | Riparian areas | Petitioned for endangerment; declining throughout its range |
| Kinosternon sonoriense longifemorale | Sonoyta Mud Turtle | Candidate | Western | Also found in Rio Sonoyta, Sonora, Mexico | Ponds and streams; prefers mud or sandy bottoms | Known only from Organ Pipe Cactus National Monument |
| Rana chiricahuensis | Chiricahua Leopard Frog | Candidate | Eastern | Streams, rivers, backwaters, ponds and stock tanks that are free from introduced fish, bullfrogs and crayfish | ||
| Cyprinodon macularius | Desert Pupfish | Endangered | Western | Formerly occurred in Santa Cruz River |
Shallow springs, small streams, and marshes; tolerates saline and warm water | Two subspecies are recognized: Desert Pupfish and Quitobaquito Pupfish |
| Poeciliopsis occidentalis occidentalis | Gila Topminnow | Endangered | Eastern | Upper Cienega Creek; Santa Cruz River near Tubac | Small streams, springs and cienegas with vegetated shallows; backwaters of large rivers | Historically occurred in backwaters of large rivers |
| Gila intermedia | Gila Chub | Candidate | Eastern | Scattered Statewide; also found in Sonora, Mexico | Pools, springs, cienegas and streams | Multiple private landowners including TNC, Audoubon Society, BLM and others |
| Sonorella vespertina | San Xavier Talusnail | Proposed endangered |
Eastern | Only one known population | Talus slopes | Petition to be removed from listing due to conservation agreement still pending |
| Lilaeopsis schaffneriana ssp recurva | Huachuca Water Umbel | Endangered | Eastern | Populations in adjacent Sonora, Mexico and Fort Huachuca Military Res. | Cienegas, perennial low gradient streams; wetlands | Found in Pima County in Empire Ranch; formerly in Santa Cruz River at Sentinel Peak |
| Amsonia Kearneyana | Kearney's Blue Star | Endangered | Western | Narrowly distributed | West-facing drainages in the Baboquivari Mountains; grow in stable, partially shaded, coarse alluvium | Protected by Arizona Native Plant Law |
| Echinocactus horizonthalonius var nicholii | Nichol's Turk's Head Cactus | Endangered | Western/Eastern? | Found in unshaded microsites in Sonoran desert scrub on dissected alluvial fans at the foot of limestone mountains and on inclined terraces and saddles on limestone mountainsides | ||
| Coryphantha scheeri var. robustispina | Pima Pineapple Cactus | Endangered | Eastern (Santa Rita Exp. Range, flanks of the Santa Rita Mountains) | Narrow distribution | Sonoran Desertscrb or semi-desert grassland communities; alluvial valleys or on hillsides in rocky, sandy or silty soils | Impacted by grazing and loss of habitat (urban development); Lehmann's Lovegrass is a major problem; recovery in the initial planning stage |
| Echinomastus erectocentrus acunensis | Acuna Cactus | Candidate | Western | Well drained knolls and gravel ridges in Sonoran Desertscub |
Implicit within all of these elements is the tangible objective of developing
a natural, open space and preserve system capable of protecting the full
spectrum of biological diversity that characterizes this region. Adopting
a region-wide perspective covering a variety of elements of natural resource
planning will allow Pima County to avoid the fragmentation resulting from
piecemeal efforts. The SDCP will also reduce or eliminate the expense and
disruption that is occurring nationwide, when communities do not put species
protection into effect until the point of listing under ESA.
1.2 Setting
Pima County can be divided into two eco-regions as defined by Omernik
(1987) (Figure 1). The central and western portions of Pima County are lower
in elevation and are characterized by Sonoran desert vegetation, while the
eastern portion of the county possesses a number of high, forested areas
surrounded by either desert or grassland vegetation.
To understand the biologic diversity of Pima County, we must understand
the broader geographic and evolutionary setting in which our county is situated.
Pima County is located between the subtropics and temperate climatic zones
of North America. As a result of this location, and evolutionary happenstance,
Pima County spans two of the world's floristic realms, the Neotropic and
the Holarctic (Warshall 1995). Our coniferous forests and broad-leafed deciduous
riparian woodlands are part of our temperate heritage, while our desert
and oak woodland vegetation is a legacy of the tropics (Brown 1982). Pima
County's position at the edge of the tropics is also reflected in the fauna,
as many species are at the northern limits of their range within this region
(Felger 1995). Relatively few animals and plants are at their southern limits
here because of the presence of high elevations farther south in Mexico.
Elevations in Pima County range from a low point of 660 feet west of
Ajo, to a high point of 9157 feet above mean sea level in the Santa Catalina
Mountains north of Tucson (Figure 1). The Santa Catalina, Santa Rita, Rincon
Mountains, and, to a lesser degree, other ranges in the County have served
as a refuge for animals and plants that would have otherwise disappeared
during warm, inter-glacial periods such as that which has prevailed the
last 10,000 years. These mountain ranges, known as "sky islands,"
also nurture perennial streams with a unique fish fauna. During glacial
periods, the floral and faunal constituents of the mountains and streams
extended farther down into the valleys.
Pima County's biological diversity is attributable in part to its physical proximity to the Sierra Madre Occidental of Mexico, and indeed the sky islands are considered its northern outlier. The Sierra Madre has been identified as one of the three "megadiversity" centers of the planet (Warshall
1995).
Pima County experiences great variation in weather patterns. Average annual rainfall generally increases from west to east, as does the amount of summer rainfall, but annual rainfall totals vary greatly from year to year and place to place. The summer monsoonal rains reduce water stress during the hottest portion of the growing season, which is one reason why the Sonoran Desert is more diverse than the Mohave Desert, which is dominated by winter rainfall alone. In the warmest region, southwestern Pima County, nearly frost-free conditions permit the growth of tender plants found nowhere else in the United States, such as the organ pipe cactus.
Pima County is also geologically diverse. Rock types run the gamut from
acidic volcanic and intrusive rocks, to limestone, basalt, andesite and
metamorphic schists. Wide, sloping, alluvial piedmonts derived from erosion
of the mountains are a dominant landform. Substrate diversity on these alluvial
slopes is enhanced by great variation in the type and degree of soil formation.
Over time, dust accumulating on these surfaces creates distinctive subsurface
zones of clay and calcium carbonate which profoundly affect the character
of the vegetation. Associated with the valley floors are extensive bottomlands
of deep, fine soils. Where bedrock outcrops occur in present-day valleys,
sites are created for high groundwater tables to persist during long periods
of aridity.
1.3 Information Needs
To accomplish the goal of protecting biological diversity under the SDCP,
we must first determine which species are in danger of being lost from Pima
County and understand the habitats and efforts needed to protect them. In
addition, it is important to note those native species which have already
been lost from Pima County and which could potentially be restored. This
report presents a guide to assist the Science and Technical Advisory Team
(STAT) in determining plant and animal species which should be addressed
by the SDCP. Combined with data on the federally listed species mentioned
in Table 1, this information will provide the basis for future biological
investigations, which will be guided by STAT and planned for by the SDCP
Steering Committee.
1.4 Purpose
The purpose of this report is to make preliminary recommendations for unlisted species, plant communities and habitats for conservation in Pima County. The assumption that listed species will be accorded highest priority for conservation led us to focus on prioritizing unlisted species during our interviews with species experts. This report summarizes information obtained regarding species of concern for Pima County. The Science Technical Advisory Team will review and adopt a revised set of focal species, plant communities and habitats for the Sonoran Desert Conservation Plan. These species will be protected under the conservation plan in addition to the federally listed threatened and endangered species, candidate species and species currently petitioned for listing under the Endangered Species Act.
2.1 Previous Studies
Three previous investigations provided a basis for our interviews. The
Nature Conservancy's (TNC) 1998 eco-regional workshop materials identified
sensitive plants, animals and plant communities for the Sonoran desert,
as did The Wildlands Project's "State of the Biome" report (Nabhan
and Holdsworth 1998). Both these efforts treat a broad area which includes
part of Pima County, excluding the Sky Islands eco-region. The Coalition
for the Sonoran Desert Protection Plan compiled a preliminary list in July
1998 specifically for Pima County. Their list was based on an evaluation
of sensitive species lists from Arizona Game and Fish Department (AGFD)
and the Coronado National Forest (Andy Holdsworth, personal communication).
A fourth source of information was used only for our final interview
concerning plants. Ms. Sabra Schwartz generated a list of plant species
in the AGFD Heritage Data Management System for Pima County. Ms. Sue Rutman
reviewed this list during the course of her interview.
2.2 Interview Process
Interviews of biological experts were conducted to obtain information
on various species of concern within Pima County. Personal interviews were
conducted in lieu of holding a workshop for several reasons. First, an experts
workshop had been recently conducted by The Nature Conservancy to identify
conservation priorities for the Sonoran Desert eco-region, which includes
a large portion of Pima County (see section on Previous Studies). This workshop
included developing an extensive list of species and habitats considered
to be threatened within the study area. Holding another workshop to go over
these same issues would be considered redundant by most experts, and they
may not be interested in participating. Second, holding personal interviews
streamlined the process of gathering information by allowing each individual
to set a time and place to meet that was convenient to their own schedules.
Finally, interviews with individual experts allowed the interview team to
hold discussions in greater detail and depth than a workshop would allow.
Many of the species listed in The Nature Conservancy and The Wildlands
Project reports are not found in Pima County or the United States. Those
that do range into Pima County were generally discussed during our interviews.
On a number of occasions, we asked the experts about certain species mentioned
in previous investigations. This was particularly true of species in the
Coalition list, since this was the only previous list focused on this county's
biodiversity.
Interviews were conducted with thirteen people based on their knowledge and expertise regarding six different taxa of animals including mammals, birds, herpetofauna (reptiles and amphibians), fish, invertebrates and plants/plant communities. A list of those interviewed is displayed in Table 2.
| NAME | AFFILIATION | DATE | SPECIES |
| Mr. Phil Rosen | University of Arizona School of Renewable Natural Resources |
3/4/99 | Reptiles & Amphibians |
| Mr. Jeff Simms | Bureau of Land Mgmt. | 3/15/99 | Fish |
| Dr. Carl Olson | University of Arizona Dept. of Entomology |
3/12/99 | Invertebrates |
| Dr. Bill Mannan | University of Arizona School of Renewable Natural Resources |
3/12/99 | Birds |
| Dr. Peter Warren | The Nature Conservancy | 3/18/99 | Plants & Plant Communities |
| Dr. Lendell Cockrum | University of Arizona Dept. Of Ecology and Evolutionary Biology |
3/19/99 | Mammals |
| Mr. Steve Prchal | Sonoran Arthropod Studies Institute | 3/19/99 | Invertebrates |
| Dr. Robert McCord | Mesa Southwest Museum | 3/22/99 | Invertebrates |
| Dr. Steve Russell | University of Arizona Dept. Of Ecology and Evolutionary Biology |
3/22/99 | Birds |
Dr. Wendell Minckley (faxed materials only) |
Arizona State University Department Of Biology |
3/24/99 | Fish |
| Dr. Yar Petrszyn | University of Arizona Dept. Of Ecology and Evolutionary Biology |
3/24/99 | Mammals |
| Mr. Jeff Howland | U. S. Fish and Wildlife Service | 3/29/99 | Reptiles & Amphibians |
| Ms. Sue Rutman | Organ Pipe National Monument | 4/2/99 | Plants & Plant Communities |
A series of forms were mailed to each individual for them to fill out
prior to the interview (see Attachment A in Appendix A). The forms were
designed to obtain basic information on species such as common and scientific
names, current State or Federal status, habitat and management needs, and
the general location and distribution of the species within Pima County.
These forms were useful in helping staff organize and prioritize each
individual species described during the interviews. Since the SDCP has been
broken into two regions, Eastern and Western Pima County(1),
it is necessary to identify the location or locations where the plants and
animals can be found. This way, each species will be planned for within
the proper phase of the SDCP. Distribution within its range is useful to
determine the status of each individual species and direct conservation
planning activities. Species which are narrowly distributed will have different
protection and recovery needs than those that are more widely distributed.
Interviews were held on an individual basis. Dr. William Shaw from the
University of Arizona and Julia Fonseca and David Scalero from the Pima
County Flood Control District were responsible for conducting the interviews
of each biological expert. Interviews were performed in person, when possible,
or over the phone. Information gathered was placed on the form shown in
Attachment B, located in Appendix A.
2.3 Supplemental Information
After completion of the interviews, supplementary information was gathered to help fill in some of the data gaps. Scientific and common names of plants and animals were determined using the Heritage Data Management System database (AGFD), faxed data sheets from people interviewed and other references. Plant communities were identified using "Biotic Communities of the American Southwest" (Brown, 1982) and information provided during the interviews. Draft tables were reviewed for accuracy by the U. S. Fish and Wildlife Service.
As many as 13 species are believed to have been extirpated from Pima
County (see Table 3). Most of these species no longer exist in Pima County
due to the loss of habitat which they depended upon for survival. The Mexican
Gray Wolf and Grizzly Bear are exceptions, because they were purposefully
extirpated in Pima County through bounty hunting and government trapping
programs The Mexican Gray Wolf and Grizzly Bear are the only species in
this table which are listed under the Endangered Species Act.
A disproportionate number of species were extirpated through loss of
aquatic habitat. In Pima County, several streams have entirely ceased to
flow during much of the year, most notably the Santa Cruz River and Rillito
Creek. In addition, many other streams and springs have been diverted or
developed for human or livestock use in a manner incompatible with the existence
of native species.
| SCIENTIFIC NAME | COMMON NAME | LOCATION IN PIMA COUNTY | HABITAT NEEDS | COMMENTS |
| Canis lupus baileyi | Mexican Grey Wolf | Eastern | Large areas of mountain and grassland terrains | Last record in 1952 on southern side of Catalina Mountains |
| Ursos arctos | Grizzly Bear | Eastern | Large upland montane areas with riparian habitat | Last seen in the 1920's in Catalina and Rincon Mountains |
| Castor canadensis | Beaver | Eastern | Aquatic | Formerly at Ft. Lowell |
| Ondatra zibethicus | Muskrat | Eastern | Aquatic | |
| Falco femoralis | Aplomado Falcon | |||
| Rana tarahumarae | Tarahumara Frog | Eastern (Santa Rita Mtns.) | Canyons | Last record in 1983 |
| Catostomus insignus | Sonoran Sucker | Eastern | Aquatic | May occur periodically in the Santa Cruz River outside Pima County |
| Catostomus clarki | Desert Sucker | Eastern | Aquatic | May occur periodically in the Santa Cruz River outside Pima County |
| Rhinichthys osculus | Speckled Dace | Aquatic (bottom) | Taxonomic uncertainties: surveys needed in Buehman Canyon, etc. | |
| Speyeria nokomis caerulescens | Blue Silverspot Butterfly | Eastern | Mountain Cienegas; violets as food source |
Extirpated in the U. S.; Mt. Lemmon population extirpated due to water diversion |
| Anodonta californensis | California Floater (clam) | Possibly extirpated | ||
| Tryonia protea | Snail | Possibly extirpated | ||
| Dalea tentaculoides | Gentry Indigobush | Western (Baboquivari & Tohono O'Odham) | Mountain Riparian |
Based on the interviews, a list was developed for species of which there
is some concern regarding their status in Pima County. This list was divided
into four groups according to the following criteria:
Information for each species is displayed in Tables 4A, 4B, 4C or 4D according to the criteria above. This list provides the focal point for discussions on species to be included within the Sonoran Desert Conservation Plan.
| SCIENTIFIC NAME | COMMON NAME | LOCATION IN PIMA COUNTY | DISTRIBUTION | HABITAT NEEDS | COMMENTS |
| Pipilo aberti | Abert's Towhee | Eastern/Western | Limited distribution in Mexico; Found along Santa Cruz, Gila & Western Colorado River | Riparian habitat along surface water | High priority since range exists mostly within Pima County |
| Melospiza melodia | Songsparrow (subspecies) | Eastern/Western | Limited distribution in Mexico; range mostly within Pima County | Riparian communities along water | High priority for subspecies; subspecies has lighter shading |
| Aimophila carpalis | Rufous-winged Sparrow | Eastern | Northern edge of its range; distribution limited in Mexico | Desert grasslands (2400-3200 ft elevation) | Santa Rita Experimental Range has greatest populations |
| Chionactus occipitalis klauberi | Tucson Shovel-nosed Snake | Eastern | Formerly in Avra Valley | Upland valley floors at low elevation | Subspecies of Western Shovel-nosed Snake; last record in 1981 |
| Sonora semiannulata | Ground Snake (valley form) |
Western | Tobosa Grassland on Tohono O'Odham Nation | Desert grassland with clay loams or heavy silty clay loams | May be a subspecies; small numbers in Pima County occur with more common forms |
| Chionactus palarostris | Organ Pipe Shovel-nosed Snake | Western (Organ Pipe National Monument) | Very local in distribution | Subspecies of Sonoran Shovel-nosed Snake | |
| Tryonia quitobaquitae | Quitobaquito Tryonia | Western (Quitobaquito and a few nearby springs) | Narrow distribution | Aquatic | |
| Sonorella xanthenes | Talus Snail | Western (Tohono O'Odham Nation) | Narrow distribution | Talus slopes | |
| Sonorella papagorum | Papago Talus Snail | Talus slopes | |||
| Sonorella baboquivariensis berryi | Talus Snail | Eastern | Narrow distribution (1 known site) | More surveys and better taxonomy is required to better understand status | |
| Zaitzevia parvula | Santa Rita Water Beetle | Eastern | Narrow distribution | Aquatic | Family Elmidae |
| Argia sabino | Sabino Creek Damselfly | Eastern | Narrow distribution | Aquatic | Family coenagrionidae |
| SCIENTIFIC NAME | COMMON NAME | LOCATION IN PIMA COUNTY | DISTRIBUTION | HABITAT NEEDS | COMMENTS |
| Lasiuris borealis | Red Bat | Eastern | Broad range, but not very common | Foothills Riparian | Always has been low in numbers |
| Peromyscus merriami | Merriam's Mouse (Mesquite Mouse) | Eastern/Western (Papago & Quitobaquito) | Small range in Pima County; widespread elsewhere | Mesquite bosque | Numbers have plummeted in Pima County; more common in Mexico |
| Dasypterus egaxanthinus | Yellow Bat | Eastern/Western | Palm fronds | Little is known; some concern due to low #'s | |
| Sorex arizonae | Arizona Shrew | Eastern (Santa Rita Mountains) | Very localized | Arizona springs in mountain ranges (5000-7000 ft) | Santa Rita population is gone, Very small numbers |
| Athene cunicularia | Burrowing Owl | Eastern | Widespread in range; local in distribution | Agricultural areas; Levees and Dikes | Declining numbers in Pima County |
| Buteo swainsoni | Swainson's Hawk | Eastern | Widespread; migratory | Grasslands for nesting | |
| Rana yavapaiensis | Lowland Leopard Frog | Eastern | Range has been reduced | Streams and ponds | AGFD sensitive and protected by State; threatened by loss of habitat, disease, and exotic species (bullfrogs) |
| Terrapene ornata luteola | Desert Box Turtle | Eastern | Desert Grasslands/Chihuahuan Desert Scrub | Still present at Buenos Aires National Wildlife Reserve and Empire Cienega Ranch as far north as I-10 | |
| Cnemidophorus burti stictogrammus | Giant Spotted Whiptail Lizard | Eastern | Formerly abundant in Sabino Canyon; extirpated from Santa Cruz | Riparian areas on flanks or flats | AGFD sensitive list |
| Cnemidophorus burti xanthonotus | Red-backed Whiptail Lizard | Western | Ajos, Tabletop and Javelina Mountains | Rocky slopes from 2000 to 4000 feet elevation | AGFD sensitive list |
| Thamnophis eques | Mexican Garter Snake | Eastern | Perennial aquatic habitat with dense vegetation (cienegas and riverine marshes) | Likely to be listed as endangered; Extirpated from Colorado River and Yuma area; threats include loss of habitat and introduction of exotics | |
| Pantosteus clarki | Desert Sucker | Eastern (formerly) | Aquatic | Occurred in Pima County in Santa Cruz River | |
| Sonorella bagnarai | Bagnara's Talus Snail | Eastern (Rincon Mountains) | Talus slopes | ||
| Sonorella pupela | Talus Snail | Eastern (Whetstones) | More surveys and better taxonomy is required to better understand status | ||
| Sonorella pyrgulopsis | Talus Snail | More surveys and better taxonomy is required to better understand status | |||
| Echinomastus erectocentrus var. erectocentrus | Needle-spined Pineapple Cactus | Eastern | Ls rock outcrop or alluvium derived from Ls | Rare, but not likely to be listed | |
| Muhlenbergia dubioides | Box Canyon Muhly | Eastern (Box Canyon) |
"Sky islands" (mountains) | Very rare plant; also found in Huachuca Mountains | |
| Tumamoca macdougalii | Tumamoc Globeberry | Western; Tohono O'Odham Nation; Eastern | Bajadas with fine sandy or clayey loams; needs good summer rainfall | Delisted species; reduced habitat due to introduction of exotics (fountain grass, lovegrass); 5 year monitoring period |
| SCIENTIFIC NAME | COMMON NAME | LOCATION IN PIMA COUNTY | DISTRIBUTION | HABITAT NEEDS | COMMENTS |
| Choeronycteris mexicana | Mexican Long-tongued Bat | Eastern | Northern end of its range | Roost and maternity sites along perennial and intermittent streams | Not very common, low numbers |
| Buteo nitidus | Grey Hawk | Eastern | Widespread; Northern edge of range | Riparian areas | 15 to 20 pairs in Pima County |
| Caracara cheriway | Crested Caracara | Western/Eastern | Northern edge of range; widespread south of Az; also common in Texas | Sonoran Desert uplands | Breeding sites in Sells and Tohono O'Odham Nation |
| Buteo albonotatus | Zone-tailed Hawk | Eastern | Northern edge of range | Canyon Riparian areas | |
| Caprimulgus ridgwayi | Buff-colored Nightjar | Eastern (Catalina Foothills; CDO; TV) | Widespread | Riparian and riparian uplands | Abundant elsewhere |
| Progne subis | Purple Martin | Eastern | Widespread | Saguaro/Pinyon Pine communities | Cavity nests needed; at risk in Pima County |
| Trogon spp. | Trogon | Eastern/Western | Northern edge of range | Canyon riparian areas | |
Senticolis triaspis (Elaphe triaspis) |
Green Rat Snake | Widespread; common in Mexico and farther south | Productive riparian areas in mountains | ||
| Lampropeltis getulus nigritus | Black Kingsnake | Eastern | |||
| Neovansia striata | Dahlia Rooted Cereus | ||||
| Stenocereus thurberi | Organ Pipe Cactus | Western (Organ Pipe National Monument) | Widely distributed south of Pima County | ||
| Lophocereus schottii | Senita | Western (Organ Pipe National Monument) | Widely distributed south of Pima County | Less common in U. S. than the Organ Pipe Cactus; easy to cultivate; provides food for Long-nosed Bats | |
| Triteleiopsis palmeri | Blue Sand Lily | Western (Cabeza Prieta; Pinta Sands) | Very narrow distribution; more common in Mexico | Sand dunes | Habitat invaded by exotics (Sahara Mustard); important culturally |
| SCIENTIFIC NAME | COMMON NAME | LOCATION IN PIMA COUNTY | DISTRIBUTION | HABITAT NEEDS | COMMENTS |
| Colaptes auratus | Gilded Flicker | Eastern/Western | Endemic | Saguaro communities (needed for breeding) | Must use saguaro cavities created by others |
| Toxostoma lecontei | LeConte's Thrasher | Western | Local in distribution (Avra Valley & Cabeza Prieta) | Creosote flats; lower bajadas and desert lowlands with fine grained soils | Status is unknown due to no recent observations |
| Gopherus agassizii | Desert Tortoise | Eastern/Western | Widespread | Thermally buffered Sonoran Desert bajadas | Protected by State of Arizona; major problem is collection and release by humans; public education is recommended |
| Heloderma suspectum | Gila Monster | Eastern/Western | Widespread | Same as Desert Tortoise | |
| Capsicum annuum var. glabriusculum | Chiltepin | Eastern | Riparian overstory of mesquite and hackberry | Foodplant; cultural importance | |
| Agave murpheyi | Hohokam Agave | Western (Tohono O'Odham) |
Found in gardens within Tohono O'Odham Nation; food-plant; cultural importance |
Table 5 displays a list of habitats of concern and target plant communities
for conservation within Pima County. Target habitats were determined though
discussions during the interviews. Target plant communities were based on
supplemental information provided by the Coalition for the Sonoran Desert
Protection Plan with additions made by Pima County staff.
Aquatic habitats, wetlands and riparian woodlands are considered to be
a high priority for conservation planning based on discussions during the
interviews. These ecosystems are rapidly disappearing throughout the United
States, including Pima County. Diversion of water and desiccation of these
habitats has caused extirpation of at least five fish species in Pima County.
A large number of species listed within this report either live in aquatic
or riparian habitats, or utilize them in some way. Primary threats include
groundwater pumping, which has reduced water tables needed to sustain these
ecosystems, and the establishment of exotics or "invader species"
which inhibit growth of native species.
Native grasslands were also mentioned by our informants as important
to protect within Pima County. Grassland communities are rapidly disappearing
throughout Pima County due to development pressures and poor land and fire
management. Development causes fragmentation throughout these communities
which depend on large tracts of undeveloped land to maintain a healthy existence.
Introduction of exotics, lack of fire, and other activities (e.g. grazing
livestock) have degraded grasslands and reduced species diversity. One specific
grassland type mentioned by our informants as a conservation target is the
big galleta grass (Hilaria rigida) association.
Although common in many areas of the Southwest, saltbush communities
are another important habitat within Pima County which is gradually disappearing
due to development pressures and agriculture. Saltbush (Atriplex polycarpa
and A. canescens) occur within valley floors, where silty soils prevail.
They provide good cover for small animals such as the shovel-nosed snake,
and are a palatable browse for larger animals like the Sonoran Pronghorn.
Some habitats contain "indicator species" which identify climates,
soil conditions, etc. that are favorable to listed and unlisted species
mentioned within this report. Ironwood and Saguaro are two examples of indicator
species mentioned in Table 7. Ironwood communities indicate areas that are
thermally buffered, providing a suitable climate and habitat for species
such as the desert tortoise. Saguaro communities indicate areas suitable
for cavity nesters such as the Cactus Ferruginous Pygmy-owl and Gilded Flicker.
Several informants recommended that attention should be focused on these
indicator species and communities when determining critical habitat for
listed and unlisted species in the SDCP.
Target Plant Communities (Brown, Lowe and Pase Classification)1
Target Habitats for Conservation2
1. This list based on Ecoregion Workshop (TNC, 1998), Coalition for Sonoran
Desert Protection Plan and additions made by Julia Fonseca
2. Based on interviews
Appendix B contains a list of a number of species which were discussed in the interviews, for which those interviewed had little concern regarding their status in Pima County. Most of the species on this list are commonly found in Pima County or are commonly found elsewhere and were never common in Pima County. A majority of these species would benefit under a conservation plan designed for threatened and endangered species (Table 1) and species of concern (Table 4)
A list of exotic species which occur in Pima County is located in Appendix C. This information is included within the report to highlight the need for proper management practices of our natural lands and for public education regarding the potential harm of introducing exotics to native ecosystems. Many of these species are associated with humans and human modified environments. Some of them can take over environments, creating monocultures which are very harmful to natural settings (i.e. Buffel Grass, Red Brome and Lehmann's Lovegrass are capable of changing fire frequency).
Efforts such as cargo inspections of imported agricultural products, investigations of methods to reduce introductions through CAP water usage, and public education on the harms created by release of pets can help combat the invasion of exotics into Pima County's natural environment.
8.1 ESA Conservation vs. Unlisted Species Conservation
By adopting a broad conservation plan designed to protect unlisted species,
not just those who are federally listed, Pima County would help prevent
the need for future listings under the ESA. Many of Pima County's rare and
unique habitats are slowly disappearing due to pressures by development
and poor land management. Although some of these natural communities would
be protected through the ESA, a majority would be left unprotected due to
the lack of endangered species present. Planning for a wide range of plant
and animal species will help insure protection of these other habitats and
preserve the biological diversity which makes Pima County a unique place
to live.
8.2 Conservation of Species vs. Habitat Conservation
The best way of protecting individual plant and animal species is by
preserving the habitats upon which they depend. Interactions between the
various plant and animal species that make up each specific ecosystem play
a vital role in the health of those ecosystems. The loss or reduction of
one species could greatly impact others in one way or another, thus changing
the character of the environment in which they live. When species also depend
on certain processes such as fire or floods to maintain their habitats,
maintaining these processes or managing habitats will also be necessary.
8.3 Species vs. Subspecies
Some of the animals considered for protection under the SDCP are subspecies.
Subspecies represents a taxonomic group below species which have developed
some morphological or behavioral attributes that differ from the species
due to geographical isolation. In many cases, the overall species is doing
quite well, but the subspecies is in jeopardy of extirpation due to a smaller
range and distribution. The ESA provides for protection of subspecies of
plants and animals and even distinct population segments of vertebrate species.
This brings up an important question of whether or not we should protect
unlisted subspecies.
As mentioned above, subspecies have some different characteristics based on their isolation from other populations of the same species. These changes have evolved to allow the particular population of the species to adapt to the area in which it inhabits. Without the adaptations, the species could no longer exist in these isolated areas. By including subspecies within conservation planning, we not only protect these unique groups of plants or animals, but we also provide protection for the diversity that is the essential building block for evolutionary processes.
8.4 Taxonomic Uncertainties
For some species and subspecies, determining the status can be difficult
due to the lack of current information available. This is especially true
for snails, which were last known to be extensively collected for genus
studies in the 1930's. Most of the records are considered to be poor, since
the standards used then are inferior when compared to current methods. The
lack of quality information has provided uncertainties when trying to distinguish
between one particular genus and the other. For example, the San Xavier
Talusnail is found to exist on one particular hillslope in Eastern Pima
County. Another hillslope close by contains a population of talusnail which
could be the same genus or might be a different one. (Bob McCord, personal
communication).
8.5 Other Issues
Under Section 9 of the Endangered Species Act, the "take" of
any federally listed animal is prohibited. However, there are no such protections
for plant species listed under ESA. Outside federal lands, plants such as
the Pima Pineapple Cactus can be removed or harmed without any penalty by
federal law. For this reason, plant species could be given high priority
under the Sonoran Desert Conservation Plan. Taking measures to conserve
these plant species under SDCP will help provide the protection to them
which is absent under the ESA. These measures might include local ordinances,
changes to the Arizona Native Plant law, pre-listing agreements and changes
to local, state or federal management.
In some cases, regulations brought forth by the ESA have hampered the
recovery of federally listed animal species. This is especially true for
the fish species, where reintroduction of unlisted species is easier than
listed species which are less commonly found in the wild (Jeff Simms, personal
communication). Provisions could be made within the SDCP to help insure
and quicken the process of recovery of our threatened and endangered species,
and to recover unlisted species though pre-listing agreements or local or
federal management activities.
Exotics or "invader species" are of great concern when developing conservation measures designed to protect listed and unlisted species. Many invader species which establish themselves in the wild provide strong competition to native populations and, in many cases, completely take over the natural habitat. This can change ecosystems which are rich and diverse in plant and animal life to a sterile monoculture containing very few species and very little diversity. A majority of these invaders are established in developed areas (i.e. roadsides, urban ponds, agriculture, etc.) and expand into natural settings. Proper land management practices and public education would be key components added to the SDCP which could help combat problems associated with exotic species.
Brown, D.E., 1982. The biotic communities of the American Southwest--United States and Mexico.
Desert Plants (14): 1341.
Brown, D. E. and R. Davis, 1995. "One Hundred Years of Vicissitude: Terrestrial Bird and Mammal Distribution Changes in the American Southwest, 1890-1990" in Debano, L. F. et al., Biodiversity and management of the madrean archipelago: the sky islands of southwestern United States and northwestern Mexico. Sept. 19-23, 1994, Tucson, AZ. Gne. Tech. Rep. RM-GTR-264. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, 669 p.
Felger, R.S. and M.F. Wilson, 1995. "Northern Sierra Madre Occidental and Its Apachian Outliers: A Neglected Center of Biodiversity" in DeBano, L.F. et al., Biodiversity and management of the madrean archipelago: the sky islands of southwestern United States and northwestern Mexico. Sept. 19-23, 1994, Tucson, AZ. Gne. Tech. Rep. RM-GTR-264. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, 669 p.
Nabhan, G.P. and A.R. Holdsworth, 1998. State of the Desert Biome: Uniqueness, Biodiversity, Threats and the Adequacy of Protection in the Sonoran Bioregion. The Wildlands Project, Tucson, Arizona.
Omernik, J.M., 1987. Ecoregions of the conterminous United States. Map suppl. Annals of the Assoc. Fo Amer. Geographers (77): 118-125.
The Nature Conservancy and Instituto del Medio Ambiente y el Desarrollo Sustentable del Esado de Sonora (IMADES), 1998. Sonoran Desert Experts Workshop.
Warshall, Peter 1995. "The Madrean Sky Island Archipelago: A Planetary Overview," in DeBano, L.F. et al., Biodiversity and management of the madrean archipelago: the sky islands of southwestern United States and northwestern Mexico. Sept. 19-23, 1994, Tucson, AZ. Gne. Tech. Rep. RM-GTR-264. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, 669 p.
1. Eastern Pima County is defined as all land located to the east of the Tohono O'Odham Nation. Sixty-four percent of Eastern Pima County is in private or State (and therefore potentially private) ownership, making this area a top priority for conservation efforts. Western Pima County includes the Tohono O'Odham Nation, and substantial federal land along with private holdings to the west of the Nation. Western Pima County federal land is considered more protected from development, making it a lower priority for conservation. Eastern and Western Pima County landscapes also reflect largely different eco-regions, with the transition from Sonoran Desert vegetation to grassland vegetation occurring across the eastern third of the County.
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