1999 SPECIES REPORT CARD
The State of Colorado's Plantstand Animals 1999 Species Report Card
The mission of The Nature Conservancy is to preserve the plants, animals and natural commu nities that represent the diversity of life on Earth by protecting the lands and water they need to surVIve.
The mission of the Colorado Natural Heritage Program is to preserve the natural diver sity of life by contributing the essential scientific foundation that leads to lasting conservation of Colorado's biological wealth. Contents
Summary 2
Vanishing Assets 4
Life in Colorado: What We Know 6
Assessing Conservation Status 7
State of Colorado's Species 8
Where the Wild Things Aren't 14
Exploration: Ten Key Discoveries 16
Uncompahgre Fritillary 17
Smith Whitlow-Grass 18
Silky Pocket Mouse 19
Brandegee's Wild Buckwheat 20
Lesquerella Vicina 21
Mountain Plover 22
Preble's Meadow Jumping Mouse 23
Yellowfin Cutthroat Trout 24
Great Sand Dunes - Endemic Insects 25
Dalmation Toadflax 26
Raising Our Grades 27
Credits and Acknowledgments 29
1 Summary
oW are our state's plants The 1999 Species Report H and animals faring? Card assesses the condition of Which species are at approximately 4,350 species greatest risk and most in need of plants and animals, repre of special care to ensure their senting the most comprehen survival? Conservation of our sive appraisal available on the natural resources often conservation status of native requires difficult choices, and Colorado species. in an era of limited resources Healthy ecosystems we must have clear priorities The Good News are key to the survival of that provide answers to ques Colorado's native plants tions such as these. and animals, as a whole, are our native plants and ani doing better than species in mals and to the well The 1999 Species Report many other parts of the being of our economy. Card: The State of Colorado's United States. About 3,300 Plants and Animals addresses (76 percent) of our state's this need by providing the lat species and subspecies in this est figures on the condition of report card receive satisfacto- . our species from the scientific ry marks. These species databases of the Colorado appear to be relatively secure Natural Heritage Program at present, although for some (CNHP) at Colorado State there may be cause for long University and The Nature term concern. Conservancy of Colorado, in cooperation with the The Bad News Colorado Division of Wildlife. About one in five of Colorado's species and sub Healthy ecosystems are species are considered vulner key to the survival of our able or imperiled. Certain native plants and animals and groups are particularly affect to the well-being of our econ ed. Of the 19 species and sub omy. Unfortunately, these species of amphibians, nearly natural systems face mount 75 percent are considered ing pressures, and many of vulnerable, imperiled or extir the species that depend on pated. Freshwater fish have them have suffered serious been hit especially hard, with declines as a result. With our more than 22 percent of these state's population growing at species and subspecies of a rate twice the national aver global conservation concern. age, the impact of habitat Mammals and tiger beetles degradation and destruction also have a high proportion of looms as the biggest threat to their species and subspecies many species' survival. ranked as globally imperiled.
2 Key Discoveries ments that a significant num Ongoing biological ber of our state's flora and exploration is essential to fauna are at risk. improving our understanding of Colorado's plants and ani For the sake of both our mals, and to helping us pro wild companions and our tect these biological selves, we have a responsibili resources. This report card ty to set priorities for the con presents 10 key discoveries servation of these vanishing that are among the most assets. We also need to rededi important and interesting cate ourselves to the conser finds. Some bring goods vation commitment - public news. One species, the Smith and private - needed to raise whitlow-grass, was prevented these grades and provide last from being federally listed ing protection for our biologi after the Colorado Natural cal inheritance. For the sake of both Heritage Program conducted our wild companions and a biological inventory and ourselves, we have a found it to be more common than initially believed. New responsibility to set prior discoveries include the ities for the conservation Lesquerilla vicina, which a sci of these vanishing assets. entist found while visiting friends in Montrose. There are the native species that we won't ever see again, such as the yellowfin cutthroat trout. Then again, there are invasive weeds that we would be glad never to see again. The dal mation toadflax is one of these dastardly species, push ing out native grasses and perennials.
Raising Our Grades The 1999 Species Report Card reflects not only the condition of our state's plants and animals, but also how we as a society are doing at pro tecting our biological resources. While we are encouraged by the number of species that are relatively secure, this report card docu-
3 Vanishing Assets
panning the breadth and species of plants and animals. Sdepth of Colorado is a The tradeoff between the remarkable array of ecosys losses and the arrival of new tems and the plants and ani- species increased the overall mals that live here. From the diversity of life on our planet southwestern desert to the and developed the ecological windswept plains, and from systems on which we depend. foothills hogbacks to the rugged alpine peaks, our state We cannot be compla harbors an abundance of bio cent about the current rate of logically important areas. species losses. The pace of Our natural heritage has extinction now far exceeds inspired people to flock to anything seen in the fossil Colorado for hundreds of record since the dinosaurs years, but never at such an disappeared. Current extinc unprecedented rate as the tion rates are believed to be at current influx. least 10,000 times greater than historical levels. If there Our natural resources were an equally high rate of have provided much more species development, there than inspiration-they are the would be less concern; but basis of our economic health. creation of new species gener The same soils found on ally takes a very long time, some of our nation's farm usually thousands or millions lands support some of the last of years. Such a slow rate will remaining expanses of short not offset the loss of our bio grass and sands age prairies. logical assets, which has Unfortunately, these same occurred mostly within the We cannot be compla ecosystems are facing mount last few decades. cent about the current ing pressures as human activi rate of species losses. The ties take their toll. Bearing Extinction represents the much of the burden of this irretrievable loss of a species' pace of extinction now ecological deterioration are unique genetic, chemical, far exceeds anything seen the plants and animals that behavioral and ecological in the fossil record since depend upon these ecosys traits and contributions. Are tems for survival. Indeed, the these just hypothetical trends? the dinosaurs disap condition of Colorado's wild No! Extinction has already peared. species serves as an indicator occurred for at least 526 U.S. of the state's overall environ species. Forever gone from mental health. the world is our only native parakeet, the Carolina para Over the expanses of keet; the once abundant geological time there has human food source, the pas always been a loss of species, senger pigeon; and the beauti but this loss was counterbal ful Sexton mountain mari anced by the evolution of new posa lily.
4 Most of these extinctions improve decisions about con are not inevitable, but a servation and economic human choice. Those who development. Building on the have observed the large win long-term efforts of tering populations of bald Colorado's museums, univer eagles appreciate the inspira sity scientists and agency tion and fulfillment they pro partners, the Colorado vide. Yet, 20 years ago, this Natural Heritage Program The Nature species was on the brink of seeks to discover and docu Conservancy of Colorado extinction. Now populations ment the condition of the and the Colorado Natural are nearly recovered and state's natural diversity. As experts are envisioning full those data become available, Heritage Program are recovery. Such a remarkable we have an early-warning sys working together to make turnaround was possible not tem that identifies the species the best biological infor only with the support of many and ecosystems at highest risk agencies and experts, but also and the locations where they mation available to from a committed people. can be most effectively con improve decisions about This commitment resulted in served. conservation and eco protecting bald eagles and the nomic development. habitat they need to survive. The Nature Conservancy uses this scientific informa There are vigorous tion to identify critical natural debates occurring about the areas for protection. Working way in which we as a society with our Natural Heritage, should protect our natural agency and private partners, heritage, particularly our the Conservancy has created endangered species and the largest system of nature ecosystems. No matter what sanctuaries in the world. By the view, all sides agree that identifying, protecting and we should rely on the best sci managing important natural entific information. Such landscapes, the Conservancy knowledge is critical to a clear has protected more than understanding of the problem 310,000 acres in Colorado and to effective and efficient and 11 million acres in the solutions. With such informa United States and Canada. tion, the choices that balance conservation goals with human needs and aspirations become more apparent.
The Nature Conservancy of Colorado and the Colorado Natural Heritage Program are working together to make the best biological information available to
5 Life in Colorado: What We Know
tories of the numerous This report necessarily play dominant roles in our Sundiscovered species in addresses only the known ecosystems. Included are all the tropics and other species in Colorado. of the vertebrates, butterflies, remote regions of the Earth Vertebrates are well known skippers, freshwater mollusks, are familiar, stunning and and it is rare to find a previ dragonflies, damselflies and understandable to most peo ously unknown species in our tiger beetles. All vascular ple. But in Colorado, we state. But even with verte plants (except mosses) are assume that our state's species brates there are surprises. also included. are well known. We have sev Although still being reviewed eral major universities and by bird experts, sage grouse We are fortunate in colleges and two internation populations south of the Colorado to have a diverse ally recognized museums of Colorado River have recently natural landscape that pro natural history. Explorers been identified as distinctive vides homes for numerous have surveyed the state since and likely comprise a new other species. That there are the early 1800s. But the species! Plants, often more species not yet known is excit reality is that there are many cryptic in their appearances, ing for naturalists of all ages, gaps in our knowledge of are also well known in but it also encourages us to Colorado's biological her Colorado, but new species are take even greater care in itage. regularly described. For deciding the future of our example, in the past year, the natural heritage. Pueblo goldenweed was described in an area between We report here on the Pueblo and Canon City. conservation status of 1,266 Similarly, a previously animals and 3,088 plants reg unknown mustard was discov ularly occurring in Colorado. ered near Montrose. This represents 10 major groups of plants and animals Many of the invertebrate that have been classified and VERTEBRATES groups are very poorly studied in sufficient detail to Mammals 175 known, with new species fre allow comprehensive assess Birds 385 quently being found. Studies ments of the status for all of Reptiles 58 in the past decade around the their species (Table 1). This Amphibians 19 Great Sand Dunes revealed at information is drawn primari Fish 58 least five insects new to sci ly from the Colorado Natural ence. Even with such well Heritage Program databases, INVERTEBRATES known groups as butterflies supplemented by the and skippers, our evolving Butterflies/Skippers/selected Moths 388 Colorado Division of Wildlife Freshwater Mussels 33 knowledge of food plants, life databases. The museum and Dragonflies/Damselflies 106 histories and distribution natural history collections are Tiger Beetles 44 reveals new species almost particularly important sources annually. of information. Note that the PLANTS term "species" in this report Conifers and Flowering Plants 3,088 This report covers the is used in its broad sense, best known groups of organ referring to full species as well TOTAL 4,354 isms, many of which are as subspecies and varieties. familiar to Coloradans and
6 Assessing Conservation Status
hich species are thriving, whether a species' numbers population censuses, especial W and which are on the are increasing, stable or ly targeting those species brink of extinction? declining - is a key factor. thought to be imperiled or for These are crucial questions Extinction, after all, is simply which few existing data are for targeting conservation the ultimate decline in popu available. Most changes in action toward those species lation numbers. We must also status assessments tend to and ecosystems in greatest consider threats to the species reflect this improved scientific need. To answer these ques - human and natural - since understanding of the condi tions, the Natural Heritage these are important in pre tion of the species. Network and The Nature dicting their future decline. Conservancy have developed Designed to assist in set a method for evaluating the Conservation status ting research and protection health and condition of both ranks are based on a one-to priorities, these conservation species and ecological com five scale (Table 2), ranging status ranks are biological munities. This assessment from critically imperiled (G 1) assessments rather than legal leads to the designation of a to demonstrably secure (G5). categories. They do not con conservation status rank; for Species known to be extinct, fer legal protection, as do list species this provides an or missing and possibly ings under the U.S. approximation of their risk of extinct, also are recorded. In Endangered Species Act. extinction. general, species classified as vulnerable (G3) or rarer may Rare species are particu be considered to be "at risk." larly vulnerable to both human-induced and natural Conservation status hazards. As a result, rarity is assessments must be continu a key predictor of a species' ally reviewed, refined and risk for extinction. Although updated. During 1998 alone, GX PRESUMED EXTINCT rarity may seem a straightfor Colorado Natural Heritage Not located despite intensive searches ward concept, it is complex to Program and Nature GH POSSIBLY EXTINCT characterize. For this reason, Conservancy scientists re Of historical occurrence; still some Natural Heritage biologists appraised and updated the hope of rediscovery evaluate four distinct charac status of almost 1,400 species. G1 CRITICALLY IMPERILED teristics of rarity for each Natural Heritage biologists Typically 5 or fewer occurrences or species when assessing its rely on the best available 1,000 or fewer individuals conservation status: the total information in making and G2 IMPERILED Typically 6 to 20 occurrences or 1,000 population size, or number of documenting conservation to 3,000 individuals individuals of the species; the status determinations, includ G3 VULNERABLE number of different popula ing such sources as natural Rare; typically 21 to 100 occurrences tions or occurrences of the history museum collections, or 3,000 to 10,000 individuals species; the extent of its habi scientific literature, previously G4 APPARENTLY SECURE tat; and the breadth of the published reports, and docu Uncommon but not rare; some cause species' geographic range. mented sightings by knowl for long-term concern; usually more than 100 occurrences and 10,000 Scientists also factor in other edgeable biologists. To aug individuals considerations to determine ment this knowledge, G5 SECURE conservation status. For Heritage biologists conduct Common; widespread and abundant example, population trend - extensive field inventories and
7 State of Colorado's Species
Colorado's Unique Legacy tat ranging from altered - Species of Global stream flow to changes in Significance water quality, and to Just over one-tenth (11.2 hybridization and competition percent) of the 4,354 species with non-native species. and subspecies assessed in From watersheds throughout Colorado are of global con the state, stories of the demise servation concern (Figure 1). of Colorado's native fish are Eight of these plants and ani disturbingly common. The mals are presumed to be dramatic population reduc tions in the big-river fish of the mighty Colorado River - Figurel Global Ranks which hosts some of the con tinent's most unusual fish species such as the humpback chub (Gila cypha) and the Colorado pikeminnow (Ptychocheilus lucius) - have spawned a massive fish recov ery. In Colorado's high-alti tude streams and lakes, unique strains of cutthroat trout such as the Rio Grande cutthroat (Oncorhynchus clarki virginalis) and the greenback Secure/Apparently Secure cutthroat (Oncorhynchus clarki 76.1% stomias) remain only in a few extinct worldwide. In addi areas, just a fraction of their tion, 59 are classified as criti former ranges. And most cally imperiled, 107 as imper recently, the plight of the fish iled, and 309 as vulnerable. es adapted to the shallow, The 10 groups of plants and slow-moving rivers of the animals considered in detail plains has caught the atten here have fared very different tion of biologists who have ly. The proportion of species documented declines. at risk (GX-G3) in these groups ranges from a high of Tiger beetles and mam 22.4 percent for fish - repre mals also have high propor senting the worst overall con tions of their species and sub dition - to a low of 2.8 per species ranked as globally cent for dragonflies and dam imperiled. But the reasons selflies (Figure 2). for this are quite different from the factors affecting Colorado's native fish Colorado's fish species. A must cope with a variety of number of unique species impacts to their natural habi- have evolved within the multi-
8 tude of habitats found in the Proportion of Species at Risk Worldwide state, and represent a part of Colorado's natural heritage that can be found nowhere 20% else in the world. For exam ple, the Great Sand Dunes 16% tiger beetle (Cicindela theatina) lives among the 12% sparse vegetation in the vicini ty of Great Sand Dunes 8% National Monument. The 4% northeastern part of the San Luis Valley encompasses the entire range of this species. So, although the population of Great Sand Dunes tiger beetles may not have declined :? ;~'~. Vulnerable (G3) _Imperiled (G2) • Critically Imperiled (G1) • Presumed/Possibly Extinct (GXlGH) much from historic levels, its inherent rarity leads to its vul nerability. Significant habitat risk plant species represent destruction in the Great Sand almost 75 percent more Dunes area would mean seri species than the number of ous trouble for this species. at-risk vertebrate animals. Among the most conspicuous A few Of Colorado's features of our natural envi mammals are globally imper ronment, plants form the iled because of impacts to basis of the world's food their native habitat, such as chain. The more than 3,000 the Preble's meadow jumping species of flowering plants in mouse (Zapus hudsonius Colorado come in a dazzling preblez). This subspecies lives array of forms, from the wild only along the lower foothills flowers that brighten spring A number of unique time to the aspen groves that of the Rockies between species have evolved with Colorado Springs and enliven woodlands in autumn. Cheyenne, Wyoming. Its But because many wild plants in the multitude of habi dependence on streamside are adapted to very specific tats found in the state, soil types or habitats and willow habitats has left it vul and represent a part of nerable to land-use conver grow only in restricted areas, sions that are changing the they are especially vulnerable Colorado's natural her face of Colorado's Front to direct human disturbances. itage that can be found Range. nowhere else in the Plants, though, are the The good news is that organisms in greatest peril Colorado's native plants and world. when considering sheer num animals, on the whole, are ber of species of global con doing better than species in cern. The 12.4 percent of at- many other parts of the
9 United States. We have not concern within Colorado yet experienced the wholesale (Figure 3). In fact, nearly landscape changes that are one in five (18 percent) of common along both coasts, in Colorado's species and sub Hawaii, and throughout the species are considered vulner major eastern river valleys able or imperiled within the such as the Mississippi and state. Tennessee rivers. Coloradans have a responsibility to the Colorado's amphibians global community to manage have the highest percentage of our biological resources wise imperiled species and sub ly. If we recognize the issues species (figure 4), with nearly and act quickly to preserve 75 percent of the state's 19 areas of worldwide signifi species and subspecies con cance, there is still time to sidered vulnerable because of save vulnerable species and to small populations or few preserve our natural legacy occurrences. From the for future generations. diminutive Blanchard's crick et frog (Acris crepitans blan Our Own Backyard - chardz) to the somewhat hefti Species of Statewide er boreal toad (Bufo boreas Significance boreas), amphibians face many Species imperilment can challenges in Colorado. The also be viewed from a more wetland habitats needed by local perspective. A number these species are often few of species that are more com and far between because of mon elsewhere in North Colorado's arid climate. As a America are of conservation result, any loss of habitat has an impact on species survival in the state. In addition, although many amphibian Figure 3 State Ranks species are still relatively com mon globally, they have expe Critically Imperiled rienced dramatic population Presumed/Possibly Extirpated in Colorado 1.1% 7.8% declines in recent years. Scientists throughout the world are racing to under stand this phenomenon in the hopes of saving amphibians from a devastating series of extinctions.
10 Five species groups, of invasive non-native species, including fish, reptiles, tiger pollution and predator con beetles, mammals and mol trol. lusks, have nearly 40 to 50 percent of their species and The leading cause of If we recognize the subspecies ranked as vulnera imperilment is habitat degra issues and act quickly to ble within Colorado. Fish dation and destruction. While preserve areas of world have been impacted by water outright habitat destruction is use, while mammals and tiger usually quite obvious, alter wide significance~ there is beetles have a number of sub ation and degradation of sen still time to save vulnera species that have evolved sitive habitats can be subtle, ble species and to pre within relatively small areas often occurring over long defined by Colorado's diverse periods of time and escaping serve our natural legacy habitats. For the reptiles and notice. To the plants and ani for future generations. mollusks, their imperilment mals that depend on these reflects the fact that many habitats for survival, the species reach the edges of results may be just as fatal as their range near Colorado's complete habitat destruction. borders, so few individuals Degradation of habitats can can be found within the state. occur in various ways, includ Yet these populations are also ing direct alteration, fragmen valuable because they may tation, changes in the water contain unique adaptations quality or quantity in streams for surviving in habitats that and rivers, and the elimination are drier or otherwise more of key natural ecological extreme than the typical habi processes, such as periodic tat for the species. By helping burns in fire-adapted ecosys to conserve these peripheral tems. populations, we are ensuring that the genetic diversity of Non-native species pose these species is maintained. an especially serious but often under-appreciated threat. Causes of Imperilment These invasive species are While some species are indigenous to other countries naturally rare, many imperiled or regions, and- have been species were once more abun introduced beyond their nat dant and have declined ural ranges intentionally or because of human activities. inadvertently through human People have seriously affected actions. Invasive aliens can most ecosystems in Colorado, be particularly damaging to directly or indirectly influenc those native species that are ing the ability of native already vulnerable as a result species to thrive. The most of other factors. In some serious human impacts instances, they may provide include habitat destruction or the final push toward extinc degradation, the introduction tion.
11 Figure 4 Proportion of Species Imperiled in the State
80%
70%
60%
50%
40%
30%
20%
10%
0% Amphibians Fish Reptiles Tiger. Mammals Beetles 4t ttcc I 'I i' ~ ~\.
TOTAL 73.7% 46.5% 43.1 % 41 % 39.4%
State Vulnerable (S3) State Imperiled (S2)
12 This graph displays the percent of species of conservation concern in each of 10 major plant and animal groups. Species groups are arranged in order of relative risk, with those in greatest danger at left. Species at risk include those with a conservation status of vulnerable, imperiled, critically imperiled or extinct; intensity of color denotes severity of risk.
9.1% 11.2% 3.8% 5.4%
Mollusks Dragonflies/ Birds Butterflies/ Plants , Damselflies Skippers \. Y "' ~ State Critically Impaired (S1) Extirpated from State or Extinct (SXlSH)
13 Where the Wild Things Aren't
Gone Forever extinct (GH). The distinction Complete eradication of between the ranks of GX and Plants in Colorado tend a species from earth, or GH is tightly linked to the to be more poorly known extinction, is the ultimate intensity of inventory efforts. than animals. Thus, four of consequence of imperilment. the six GH species that once Documenting extinctions, Two taxa that are known occurred in Colorado are though, can be extremely dif to have occurred in Colorado plants, and we hope that ficult. In some ways it is like meet the stricter criteria of more intensive inventories searching a haystack for a presumed extinct worldwide: may still locate existing popu needle that isn't there any the Carolina Parakeet lations. These plants are the more. For this reason, we are (Conuropsis carolinensis) and Grand Junction cat's eye very cautious in ranking the yellowfin cutthroat trout (Cryptantha aperta), Colorado species as presumed extinct (Oncorhynchus clarki mac watercress (Rorippa coloraden (GX) unless exhaustive donaldi). The Carolina para sis), Mancos columbine searches of all suitable habi keet was primarily a resident (Aquilegia micranta var man tats have been carried out and of southeastern hardwood cosana) and small-flower there is no more cause for forests, but its range extend beardtongue (Penstemon parvi hope. Those species suspect ed as far west as New florus). None have been posi ed of being extinct but war Mexico and Colorado. This tively identified since the late ranting further searches are species was sensitive to habi 1800s, and each has its own ranked in the more conserva tat disturbances, and was interesting history. But a tive category of possibly hunted heavily for its common thread is that these plumage and value as a unusual plants probably have caged bird. It quickly disap very specific habitat needs peared from areas of human which confine them to very settlement. The last Carolina small areas. Combined with parakeet observed in the fact that the historical Colorado was in 1877, and records do not give precise the last known individual locations for the areas where died in the Cincinnati Zoo in the species were originally 1914. found, it becomes very diffi cult for scientists to know for The yellowfin cutthroat sure if they are even looking trout was native to Colorado in the right place when but its history is murky (see searching for any remaining Key Discoveries). Known populations. Targeted search only from high mountain es have been conducted for all lakes in Colorado, especially four of these species with no Twin Lakes and the lakes of success, but the wide range of Grand Mesa, the yellowfin possible areas to look holds cutthroat trout was unable to out the possibility that one hold its own in the face of day, maybe during the next widespread stocking of rain search, the species will be bow trout. It has not been found. seen since the mid-1930s, and is presumed extinct.
14 Local Losses Mammals represent the Ongoing Concerns At the local level, next most vulnerable group. These categories of Colorado is missing a num But here we see the strong species, the extinct and the ber of species that still hang emergence of an area effect. extirpated, represent the on, or even thrive, elsewhere Of the nine mammals pre most extreme examples of in the world. When a species sumed or possibly extirpated species imperilment in or subspecies is lost from a from the state, one-third (the Colorado. To protect our local area, such as Colorado, gray wolf, American bison natural heritage, we must the process is called extirpa and grizzly bear) are all focus our energy on keeping tion. As with global extinc large-bodied animals that the number of species in tions, we recognize two levels require big expanses of open these categories from getting of concern. Species are only space to survive. They have any higher. The flora and presumed extirpated (SX) also been heavily persecuted fauna that are known to be after there have been thor by people for economic, vulnerable need our help to ough searches of potential sport and predator control avoid the same path as the habitat that have not resulted reasons. In this regard, gray wolf. With foresight in documentation of existing Colorado's extirpations are and well-planned conserva populations. Otherwise, the typical of the kinds of species tion action we can protect more conservative rank of losses that are occurring in the habitat of these species, possibly extirpated (SH) is many places. Worldwide, their homes and communi used. large mammals have been ties, and ensure that future extirpated from extensive generations will enjoy the Once again, we can see areas of their former range. same richness of life in stark differences in the way Colorado that we do today. different types of species groups have fared in Colorado. Figure 5 shows the number of species from each taxonomic group that Figure 5 Numbers of Species and Subspecies Extirpated from Colorado fall into either the presumed or possibly extirpated cate 20 gories. Once again, plants have fared poorly. Each of these species or subspecies 15 has very specific habitat requirements that make sur vival difficult in the face of 10 habitat changes, or make it difficult for researchers to relocate small, poorly known 5 populations.
0
~ ~ 15 Exploration: Ten Key Discoveries he age of exploration is far effort are the institutions that T from over. While the undertake and support basic broad outlines of life on inventory and taxonomic clas Earth are now in focus, biolo- sification efforts, including We present here 10 gists continue to make discov universities, botanical gar key discoveries that add eries, large and small, filling dens, zoos, natural history out the fundamental knowl museums, and a variety of to the fabric of our edge about our fellow inhabi state and federal agencies. knowledge and help us tants on this planet. Natural Heritage programs better assess the state of and The Nature Conservancy Colorado's plants and Protecting plants and rely upon the findings of animals requires the work of these institutions and also animals. modern-day biological explor carry out extensive field sur ers to reveal the distribution, veys of their own to locate abundance and basic identity and document species of con of our nation's species. We servation concern. present here 10 key discover ies that add to the fabric of The 10 discoveries that our knowledge and help us follow represent a few of the better assess the state of most important and interest Colorado's plants and ani ing findings. Some bring mals. good news, such as the dis covery of new populations of Conservation efforts are a species that was previously only as effective as the knowl considered for protection edge on which they are based. under the Endangered Fortunately, a small but dedi Species Act. Other findings cated community of profes expand the frontiers of our sional and amateur biologists knowledge, including the dis is committed to furthering covery of a new species near knowledge about biodiversity. Montrose. Still other findings Especially important in this bode ill for Colorado's eco logical systems, such as the proliferation of yet another damaging alien pest, or reports of species that, while not yet gone, appear to be on a path toward extinction. On the whole, however, these dis coveries demonstrate the cen tral role that continued inven tory and exploration have in our ability to conserve Colorado's biological resources. 16 Research Brings New Hope The Uncompahgre Fritillary Conservation Status: IMPERILED Discovered only in 1978 and described as a new species in 1984, this listed endangered butterfly is endemic to the high alpine meadows of the San Juan Mountains in southwest- ern Colorado. Believed to be broadly distributed near glacial margins during the Wisconsin glaciation, the Uncompahgre fritillary (Boloria acrocnema) is now confined to small patches of habitat where glacier-like environments have persisted from the Holocene to the present. Intensive collecting pressure, improper grazing by domestic livestock, periods of pro longed drought conditions, mining activity, and an increase in alpine recreation coincided with its dramatic population decline and led to its listing as an endangered species under the U.S. Endangered Species Act in 1982. Listing the species led to extensive studies to develop knowl edge of its natural history, genetics and population trends, and prompted searches for new colonies. Prior to 1995, only two colonies of this butterfly were known to exist. Between 1995 and 1998, intensive inventory efforts by the Colorado Natural Heritage Program led to the dis covery of eight additional colonies, with the most recent being discovered in 1998. Monitoring techniques are being used to estimate population sizes of the colonies. Preliminary studies with maps, aerial photos and ground surveys indicate that numerous areas have high potential for additional colonies. Although there is much optimism with the discovery of these new populations, threats to this species still exist. Illegal collecting, increased recreation, and possible global warming all continue to threaten colonies of this butterfly. 17 Kept off the Endangered Species List Smith whitlow-grass Conservation Status: IMPERILED In this era of wrangling over whether species should or shouldn't be listed, it's encouraging when research keeps a species from federal listing under the Endangered Species Act. A case in point is the Smith whitlow-grass. In 1997, the Colorado Natural Heritage Program began conducting a bio logical inventory of the San Luis Valley. One of the targeted species was Smith whitlow-grass (Draba smithiz), a member of the mustard family that was first located in 1938 and not collected again until 1971. By 1996, the Smith whitlow grass was known from seven sites, all in Colorado. Of these sites, only one was known to harbor a population of at least 50 plants, and all of the other documented locations men tioned vague, if any, details about population size. By the end of the 1998 field season, CNHP's field staff had discovered the mother lode of Smith whitlow-grass in the San Juan Mountains. We currently know of 12 sites in four counties, with several of the larger occurrences harboring hundreds of individual plants. Not only have we found Smith whitlow-grass to be more common than initially believed, but we also have found that the threats are minimal since many of the populations are within Wilderness Areas that the U.S. Forest Service has designated. Although Smith whitlow-grass is far from being classified as common, it is exciting that the species, once nearly listed as endangered by the U.S. Fish & Wildlife Service, is secure enough not to warrant listing under the Endangered Species Act. 18 Rediscovered in a Unique Encounter Silky Pocket Mouse Conservation Status: CRITICALLY IMPERILED IN COLORADO Unrecorded in Colorado for over 30 years, the silky pocket mouse (Perognathus flavus sanluisz) made numerous appearances in the summer of 1997. This tiny, 8-gram mouse is endemic to the San Luis Valley of southern Colorado and northern New Mexico. It was first documented from southern Colorado in 1908 and had not been noted since the 1960s. It is possible that this subspecies had been captured recent ly by biologists working in the San Luis Valley, but there were no documented reports. Some accounts of this mouse mention that it is relatively uncommon and not easily trapped. Because the silky pocket mouse is so small, the smallest of Colorado's het eromyids, it may be too light to trigger traps that are set too tightly. In 1997, this subspecies was found to be fairly common in certain areas, when targeted for capture. It resides in a burrow system constructed at the base of shrubs such as greasewood, rabbitbrush, cactus or yucca in sandy soils or semiarid grass lands. It is a nocturnal seed-eater, as observed by Natural Heritage Program biologists who observed mouse tracks in the headlights while driving along a sandy road. After following tracks and searching with flashlights, a silky pocket mouse was found nibbling on Indian ricegrass seeds. Biologists found burrow systems throughout the area. This unique encounter seemed to indicate that this uncommon mouse was doing well at this location. While we know this mouse is still present in Colorado, we still have much to learn about its status, distribution, habitat pref erences and habits. 19 One of the World's Rarest Brandegee's Wild Buckwheat Conservation Status: CRITICALLY IMPERILED First described in 1917, Brandegee's wild buckwheat (Eriogonum brandegez) was collected for the first time in 1873 near the Garden Park Dinosaur Quarry just north of Canon City. For 50 years, this remained the only known location in the world of this species. Then in 1967, another collection was made a county away and across the Arkansas River canyon. Since then, scientists have conducted several thorough searches for this species. But its distribution remains as two separate pop ulations covering only about 16 square miles of habitat. In addi tion, the two populations are found on different geologic sub strates (Dry Union Formation and the Morrison Formation). The distribution may be puzzling, but it is quite clear that Brandegee's wild buckwheat is one of the world's rarest plant species. Not only is this species naturally rare, it is threatened by human disturbances such as recreational use, mining, fossil excavation and residential development. Many of the individual plants occur on Bureau of Land Management or Colorado State Forest properties. These organizations have teamed up with the Colorado Natural Heritage Program for the past several years to update information, continue additional surveys and work to create management practices that will allow for the long-term survival of this species. 20 Meeting a New 'Neighbor' Lesquerella vicina Conservation Status: IMPERILED Lesquerella vicina was first described as a new species in November, 1997. Because it is so new it doesn't even have a common name. Dr. James Reveal of the University of Maryland discovered the plant species while visiting friends in Montrose. The plants were discovered just over the fence on a neighbor's property, so he named it Lesquerella vicina, meaning "neighbor." Local botanists have been asking themselves why nobody noticed it before. One possible explanation is that it is a very early bloomer, setting seed before most botanists are out and about. (Colorado Natural Heritage Program staff found it in full bloom at the end of March.) It is a fairly mod est little mustard, the only white-flowered member of its genus in Colorado. By June, when the flowers have gone, it is almost identical to its common yellow-flowered relative Lesquerella rectipes, for which it has probably been mistaken. When CNHP's field staff began to look for it in earnest in 1998, in conjunction with the Uncompahgre Basin Biological Survey, it turned out to be more common than expected. It was found in both sagebrush and pinyon-juniper communities, from the south rim of the Black Canyon to the Uncompahgre Plateau. The Natural Heritage Program now knows of 14 occurrences in two counties. Some of these occurrences have thousands of individuals. Scientists expect to find many more populations as they spend more time searching. Presently, based on the known occurrences, it is ranked as a G2S2. 21 The Ghost of the Prairie Mountain Plover Conservation Status: IMPERILED During the past three decades, the mountain plover has been living up to its nickname, prairie ghost. Originally, the bird was given this moniker because it will turn from an observer and lie motionless, almost disappearing. But sadly, the mountain plover (Charadrius montanus) has been disappearing in other ways as well. Due to a history of over-harvest, habitat degrada tion and human disturbance, populations are declining. By some estimates the populations have been decreasing by 3 per cent annually since the 1970s. This decline has caused great concern for the welfare of this prairie specialist, which has been recommended for protection under the Endangered Species Act. Market hunters in the late 1800s took advantage of the plover's relatively tame demeanor, diminishing the numbers sub stantially. Historic accounts of mountain plover harvest depict hunters holding hundreds of birds each. Removal of prairie dogs, bison and pronghorn from some prairie environments has altered native grassland composition and negatively affected plover populations. Also, some farming practices in these areas have conflicted with the plover's nesting and ability to detect predators. But there is still hope for the mountain plover. Some habitat management practices have aided plover recovery. For example, in areas where grasslands are burned or grazed, plovers use the habitat in spring for nesting, and in fall and winter for night roosts. Scientists are conduct ing monitoring studies through out the plover's range to get a better handle on population trends. Through proper habitat manage ment, the prairie ghost may be return ing to some of its old haunts. 22 Of Mice and Men Preble's Meadow Jumping Mouse Conservation Status: CRITICALLY IMPERILED Much of our current concern for biodiversity has resulted from the impacts to natural diversity made by escalating human populations. In Colorado, the Front Range corridor from Fort Collins to Colorado Springs has been developing at an alarming rate, with at least one county ranking in the nation's top ten fastest growing. An inconspicuous resident of the Front Range riparian communities is the Preble's meadow jumping mouse (Zapus hudsonius preblez) , the namesake of naturalist Edward A. Preble. Because of its restricted range and the difficulty in locat ing substantial populations, the mouse was listed as threat- ened under the Endangered Species Act in May of 1998. This appealing mouse thrives in densely-veg etated riparian communities, and has become the poster species for the conservation of riparian communities along the Front Range. Preble's meadow jumping mouse is a physiological whirlwind, feeding voraciously and producing multiple litters before hiber nating for six months of the year. Hardly larger than a house mouse and usually weighing between 18-22 grams, this mouse will add an additional 20 percent of its weight to prepare for the long winter underground. During this time, the mouse is bulking up on arthropods, seeds, vegeta tion and fungi in grassland vegetation sur rounding willow habitats. True to its name, it has large hind feet and hind legs that allow it to leap distances of 5-6 feet. To counterbalance the mouse while it bounds through dense, herbaceous vegeta tion, it has a long tail that encompasses nearly two-thirds of its total length. With the growing concern over the conservation of the Preble's meadow jumping mouse and its habitat, scientists have completed more surveys and the known range for the mouse now extends north into southeastern Wyoming and as far south as Colorado Springs. A plan to integrate the conservation of this subspecies and growing development of Colorado's Front Range has been initiated in a cooperative effort between the U.S. Fish and Wildlife Service and the State of Colorado. 23 Gone from Waters Everywhere The Yellowfin Cutthroat Trout Conservation Status: EXTINCT The yellowfin cutthroat trout has got to hold the record for the shortest history of any modern vertebrate in Colorado. Evidence of this subspecies was lacking from the first accounts of trout from Twin Lakes, Colorado in 1877; the only mention of trout in the lakes referenced the smaller greenback cutthroats. A few years later, reports of 10-pound trout in the lakes started to emerge, and speculation surrounds the origin of these large trout. No one is sure whether they were transplanted (if so, from where?), or if they were simply missed in earlier catches. The 1885-1886 report of the Colorado Fish Commissioner represents the first official documentation of these silvery trout, which were named Oncorhynchus clarki macdonaldi after the U.S. Fish Commissioner, Marshall MacDonald. Following its nam ing, the road to presumed extirpation of the yellowfin cutthroat appears to have been short. Eggs from both greenback and yel lowfin cutthroat in Twin Lakes were used for propagation pur poses at the newly constructed Leadville National Fish Hatchery. This practice persisted from 1891-1897. In 1899, eggs were again taken, but this time from lakes on Grand Mesa. These trout were referred to as black-spotted trout and were presumed to be the same as yellowfins, but no specimens were ever preserved for scientific evaluation. Presumed yellowfin from these propagation efforts were stocked into waters in Colorado, Germany, Belgium and Wales. The concurrent stocking of rain bows in these same waters was also heavy over the years, and most definitely contributed to the extirpation of the yellowfin cutthroat trout. By the turn of the century, yellowfins had disappeared from Twin Lakes; rainbows were dominant, and the remaining greenbacks had hybridized with the rainbows. Greenbacks in Twin Lakes soon followed the fate of their yellowfin cousin. The last record of a yellowfin catch by an angler came from Island Lake on Grand Mesa in the 1930s. No evidence of yellowfins remains in any of the waters any where in the world. 24 A Hotspot of Biodiversity The Great Sand Dunes - A Haven for Endemic Insects Conservation Status: OUTSTANDING BIODIVERSITY SIGNIFICANCE The Great Sand Dunes system of southern Colorado is known to harbor at least six endemic species of insects. Perhaps the most well known insect is the Great Sand Dunes tiger beetle (Cicindela theatina). This beetle was formally described in 1944 and belongs to a group of tiger beetles restricted to sandy habi tats throughout North America. C. theatina is the only tiger bee tle in North America considered endemic due to a restricted geographical region, the Great Sand Dunes ecosystem. Two other endemic beetles are also sand-restricted and were described in 1998. These are Amblyderus werneri and Amblyderus triplehorni. These are more commonly known as ant like flower beetles as their small size and body shape give them an appearance similar to that of ants. Another endemic beetle is Eleodes hirtipennis, a circus beetle, which was described in 1964. This beetle is a scavenger uniquely adapted to its sandy habitat. There are also two undescribed species currently considered to be endemics of the Great Sand Dunes, as no other specimens have emerged in extensive museum searches or during field sur veys. One of these, Hypocaccus, is a beetle whose larvae live in sand at the roots of dune grasses and probably feed on the lar vae of weevils. The other, the only member of these inverte brates that is not a beetle, is Proctacanthus, an undescribed rob ber fly. This remarkably large and predacious fly will feed on other insects that match its own size. This unique assemblage of invertebrates indicates that the Great Sand Dunes has been a fairly stable system over time. Among all permanent sand dune systems of North America, that of the eastern San Luis Valley is considered to be one of the most remarkable. It resembles an island in some respects, as it is a very compact system that is geographically isolated, has rather harsh environmental conditions, and provides a variety of environmental influences responsible for the high level of endemic invertebrate species. Because of the uniqueness of the Great Sand Dunes system and its endemic invertebrates, it merits both conservation pro tection and well planned management. 25 Explosion in Slow Motion Dalmation Toadflax Conservation Status: NON-NATIVE IN NORTH AMERICA In the last decade, awareness of the threats non-native species pose to the integrity of natural areas has greatly increased among wildland managers. Over 60 percent of The Nature Conservancy stewards polled nationwide in 1992 indi cated weeds were among their top ten management problems. This increased understanding of the impact of weed species on biodiversity and ecosystem function has led natural area man agers to redefine weeds and pests, and to reassess management techniques and strategies. Most alien weeds are invasive, which is to say they move into an area and become dominant. Impacts of weed invasions can include significant alteration of ecosystem processes; elimi nation or reduced populations of native species; promotion of invasions and population increases by non-native animals, fungi, or microbes; and alteration of the gene pool. Some of these alien species have been accidentally intro duced through a variety of means such as agricultural products, while others have escaped from cultivated environments such as home gardens and are considered "escaped ornamentals." Dalmation toadflax (Linaria dalmatica) is an example of an escaped ornamental. Once established, its characteristics of high seed production and vegetative reproduction, as well as its exten sive root system, allow for rapid spread and high persistence. A native of the Mediterranean region, dalmation toadflax is now most common in the western United States and is listed as a noxious weed in Colorado, Arizona and New Mexico. In the Laramie Foothills along northern Colorado's Front Range, it has invaded shortgrass prairie and foothills sites. It has truly exem plified the weed concept of an "explosion in slow motion," with 400 percent increases in populations occurring on an annual basis. 26 Raising Our Grades he 1999 Species Report our rich natural diversity. Improve Understanding of T Card is a reflection of our Ecosystem approaches sustain Vanishing Flora and natural and cultural his biodiversity and support Fauna tory. Some species were responsible human uses of the Although the 1990s have never common. Other species same areas. Many resulted in enormous leaps in and natural communities have Coloradans have voiced a our understanding of become rare or imperiled with desire to protect their natural Colorado's natural heritage, Colorado's burgeoning popu heritage in such working there are many gaps in our lation. The condition of our landscapes. knowledge. What species exist natural areas is a strong indi in Colorado? Which ones are cator of how we value our Protect those species at at risk? Exactly where are they state. There is no longer any greatest risk found? What really threatens doubt that many of While focusing protec them? Limited resources have Colorado's species are declin tion on large ecosystems is an been spent in Colorado on ing or even extirpated or effective way of conserving answering these questions; yet extinct. This report docu many species, we should not the answers are imperative for ments that it has indeed hap forget the species or natural conducting effective conserva pened and is in danger of communities that are at high tion. Conservation activities repeating itself in every region est risk, such as the 3.9 per that are informed by good of the state. However, in cent of Colorado's species research on the taxonomy, almost every case there is that are ranked as imperiled distribution and ecology of ample time to stop or reverse or critically imperiled globally. our flora, fauna and natural these trends. What are the Another 9.1 percent are com systems will provide the basis actions that we as Coloradans mon elsewhere but imperiled for effective and efficient con can take to protect our rich in Colorado. These species servation. natural heritage? are known from relatively few locations with equally few Conseroe the Ecosystems options for survival. on Which Species Depend However, in many cases, the The most effective means local efforts required for pro of protecting Colorado's tection of the most imperiled many plant and animal species, mostly plants, are species is to conserve the small and cost-effective. For ecosystems that support the 7.1 percent of the globally them. Many of our species vulnerable species, many are known from the same other options are available. ecosystems, creating an effi In many cases, these species ciency in conserving many can be important in the iden plants and animals. With tification of high-quality destruction or degradation of ecosystems needed for the habitat being the leading conservation of more com cause of species losses and mon species. declines, conservation of ecosystems offers the only reasonable hope of protecting 27 Launch Searches to Remember the Little and drawn many of us here. This Relocate Missing Species Less Glamorous Creatures natural heritage has fueled the Some species, such as the Conservation efforts in development of one of the yellowfin cutthroat trout, have Colorado bring about images nation's healthiest economies. already disappeared from of peregrine falcons, lynx and Our cultural heritage relies on Colorado. For them it is too greenback cutthroat trout. our natural diversity, and our late. However, for several While these species are beau citizens have demonstrated species that have not been tiful and symbolic of wild their willingness to protect it. observed in several years, they places, the majority of species We in Colorado have played a may not yet be extinct. The are equally wondrous species leading role in the United boreal toad, once common in but less glamorous. These States in developing a conser Colorado, declined precipi species are often hidden from vation ethic and the accompa tously to the point that very view, small and even ugly (in nying tools for effective con few populations were known. a traditional sense); however, servation. However, concerted efforts by these species often play an many agencies, organizations invaluable role by pollinating, By recognizing private and individuals located sever recycling or merely providing landowners and government al previously unknown sites habitat for the better-known agencies as partners in con that are critical to successful species. In fact, our state's servation, Colorado has devel conservation. Clarifying a ecological fabric and econom oped such programs as the species' chance for survival as ic vitality depend on these Smart Growth Initiative, "too late" or "still a possibili species. Ignoring the condi Great Outdoors Colorado, ty" might not only prevent the tion and conservation of these and many local land trusts. loss of distinctive and highly less glamorous species and Leaders in conservation come imperiled elements of our their habitats because we can from the ranching, conserva natural heritage, but will also not ascribe a traditional dollar tion, government, natural increase our confidence that value is unwise, at best. resource, academic and busi conservation resources are not ness communities. However, being wasted. Instill a Commitment to as this report shows, a signifi Conseroation cant part of our natural diver Coloradans have discov sity is at risk. We now have ered our state's rich natural the responsibility, and still diversity; in fact, it is what has have the opportunity, to move ahead in an effective manner. We must renew our commit ment to conservation, public and private, and raise our conservation grades to ensure the perpetual conservation of our remarkable natural her itage. 28 Credits and Acknowledgments Credits Principal Authors: Mary Klein and Chris Pague Authors of "Ten Key Discoveries": Uncompahgre Fritillary - Phyllis M. Pineda Smith whitlow-grass - Renee Rondeau Silky Pocket Mouse - Renee Rondeau Brandegee's Wild Buckwheat - Kim Fayette Lesquerella vicina - Peggy Lyon Mountain Plover - Rob Schorr Preble's Meadow Jumping Mouse - Rob Schorr Yellowfin Cutthroat Trout - Mike Wunder Great Sand Dunes - Phyllis M. Pineda Dalmation Toadflax - Heather Knight Editors: Melinda Helmick and Linda Lee Design: Margaret Donharl Illustrations: All species illustrations by Paula Chandler except for tiger beetle on page 25 by Karolyn Darrow Acknowledgments This report card would not be possible without the work of the Colorado Natural Heritage Program, Nature Conservancy staff, and other scientific collaborators who assisted in develop ing the conservation status data used in this report. We would like to thank authors Mary Klein and Chris Pague for their tremendous contribution, and Kim Fayette, Heather Knight, Peggy Lyon, Phyllis M. Pineda, Renee Rondeau, Rob Schorr and Mike Wunder for writing the "Ten Key Discoveries." We are also grateful to Bruce Stein and Stephanie Flack, who wrote the national Species Report Card on which this report was based. A special thanks to Margaret Donharl for her generous donation of graphic design; Linda Lee for her hard work and sense of humor; Terri Schulz for her review and insightful com ments; and Paula Chandler and Karolyn Darrow for their won derful illustrations. The"~ Nature' C~~~~~~~cy. 303-444-2985 '; , ~.\jterit'We1.. ;;! \ COLo~ 970-491-1309