WINGS

THE XERCES SOCIETY FALL 2007

ESSAYS ON INVERTEBRATE CONSERVATION

Introduction: Invertebrates and Global WarmingScott Hoffman Black

Page 3.

Wetland Invertebrates:What Happens When the Pond Is Half-Empty?John H. Matthews

Water temperature and volume, both critical to the development and emergenceof dragonfly larvae in wetlands, are changing as global warming increases. Page 5.

Bleached Out: Coral Reefs Under StressDavid Obura

Tropical coral reefs are one of the first ecosystems to show significant changes dueto changing climate. Page 11.

Beer for Butterflies: Tracking Global WarmingMatthew L. Forister

As scientists study the impacts of global warming upon butterflies, patterns areemerging of both shifts in range and changes in the timing of life-history events.The consequences for these tiny creatures may be enormous. Page 15.

For Marine Worms, Timing Is EverythingAndrew Lawrence

Marine worms are a hugely important link in the food chain of intertidal areas. In-creasing water temperatures place their future breeding success at risk. Page 19.

Impacts of Global Warming on PollinatorsDavid Inouye

Climate change is altering the phenology of both plants and their insect visitors,breaking the link between the two and putting at risk the essential service of pol-lination. Page 24.

Xerces NewsProtecting native bumble bees and other pollinators, wetland conservation efforts,and a Butterfly-A-Thon; and new staff members join the Xerces Society. Page 28.

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CONTENTS

Not long ago, as I was hiking along aroaring stream on my way up to Col-orado’s Red Cloud Peak, my mind wan-dered back to the summer of 1995. I hadbeen hired by the Colorado NaturalHeritage Program to help organize asearch for the Uncompahgre fritillary(Boloria improba acrocnema). With fewknown populations and multiple threatsincluding sheep grazing, potential over-

collecting, and a prolonged droughtthat was thought to be drying out thehabitat, this butterfly had recently beenlisted as an endangered species.

The Uncompahgre fritillary livesonly in alpine meadows. Thought tohave been broadly distributed near gla-cial margins during the last ice age, thebutterfly is now confined to smallpatches of habitat above thirteen thou-

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Introduction: Invertebrates and Global Warming

Scott Hoffman Black

The San Juan Mountains of Colorado are home to the Uncompahgre fritillary (Boloriaimproba acrocnema), one of many alpine insects that are vulnerable to climate destabi-lization. Warming climate may spell extinction for many of these species. Photographby Scott Hoffman Black.

sand feet in the San Juan Mountains ofsouthwestern Colorado, where cool andwet environments have persisted to thepresent.

On my recent trip, I was heading upto see how things had changed in thelast twelve years. Although it was a lit-tle late in the year, I hoped to see a fewlate-season stragglers. The area lookedmuch the same as it did in 1995. Snowwillow (the Uncompahgre fritillary’s lar-val hostplant) was still abundant. Therewere bumble bees, flies, and several spe-cies of butterflies including the arcticfritillary (Boloria chariclea), Uncompah-gre’s sister species.

I carefully made my way throughthe habitat hoping to spot an adult Un-compahgre. I thought about the com-plexities and uncertainties confrontingus. Global warming will not lead to uni-form change across the landscape. Someplaces will be hotter and drier whileothers may be wetter; in still others theweather may simply be more variable.It may affect plant communities andcause seasonal shifts that put species outof synchrony with their food sources.

After a fruitless search, I decided tohike the last few hundred feet to theridge to take in the magnificent view.Just as I reached the very limit of thehabitat, a familiar sight met my eyes. Afaded and battered Uncompahgre fritil-lary fluttered across the trail to land ona rock a few feet away. I sat down nextto the butterfly, noting that its life wasnear an end. I then looked up and real-ized that this species really has nowhereto go as the climate changes. It cannotlive in the rock and ice at the top of thepeak. I thought about what future gen-erations will see when they come upthis mountain. It might look the same,

but will it really be the same without aspecies that has resided here for thou-sands of years?

The Uncompahgre fritillary is notthe only invertebrate facing a changingenvironment. In this issue of Wings, weexplore multiple aspects of climate de-stabilization from the perspective of in-vertebrate conservation. Included are es-says on how warming temperatures arealready leading to bleaching corals andshifts in butterfly ranges. You will seethat global warming may lead to the ex-tinction of some butterflies and aquat-ic invertebrates. It may also lead to theloss of some marine worms that are animportant food source for many birdsand marine animals. In short, globalwarming is already having a profoundimpact on both terrestrial and marineecosystems.

It is interesting to note that the firstspecies thought to have been driven ex-tinct by global climate change was asnail. Does it matter that one snail goesextinct or that the Uncompahgre fritil-lary may follow? There has been talklately of taking action to protect someof the species that have been led to thebrink of extinction by global warming.Some scientists have floated the idea of assisted migration (helping speciesmove to habitat where they were nevernative). For most species this option isneither feasible nor wise. What we needto do is to take heroic efforts as a soci-ety to curb the impact of global warm-ing. We must find the societal and po-litical will to take the actions that areneeded to curb this global threat.

To find out some changes that youcan make as an individual, go to www. climatecrisis.net/takeaction/whatyoucando/index6.html.

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In May 2003, I stuffed my car withcamping and collecting equipment, saidgood-by to my wife, and began a twelve-hundred-mile drive north from centralTexas. On the front seat next to me sata well-thumbed photocopy of a 1970Ph.D. dissertation about dragonflies,written by a University of Toronto stu-dent named Robert Trottier. And thetopmost page had a fuzzy photographof a pond in Caledon, Ontario.

I was headed to Caledon to begin amulti-year study of the relationship be-

tween climate change and the aquaticmacroinvertebrates found in small wet-lands. Given the diversity and abun-dance of life they hold, these wetlandsare both under-studied and beneath theradar of the public and policy makers.Most small wetlands are ephemeralaquatic habitats (that is, they dry up ona regular basis), but even “permanent”wetlands swing wildly in their annualwater volume. Since many fish are in-tolerant of large shifts in volume, thesefish-free habitats are typically rich in in-

FALL 2007 5

Wetland Invertebrates: What Happens When the Pond Is Half-Empty?

John H. Matthews

Common green darners (Anax junius) are found at lakes, ponds, and wetlandsacross much of North America. Male, photographed in Texas by John C. Abbott.

vertebrate diversity. Indeed, the top car-nivore positions held by fish in largerbodies of water tend to be occupied bydragonfly or beetle larvae in such wet-lands. But most of these wetlands areviewed as insignificant and marginalecosystems, and many countries offerthem little or no protection. In my longdrive to Caledon I had time to ponderthe question of just how sensitive thesewetlands are to shifts in climate.

Climate change has been generallyviewed through the lens of air temp-erature, a bias reinforced by the term“global warming.” However, in additionto air temperature, many aspects of cli-mate such as wind speed, cloud cover,and relative humidity have been shift-ing over the past century. The majority

of the water in most small wetlandscomes from precipitation. And in recentdecades, the timing, form, and amountof precipitation have been changing.Less snow is falling. Globally, precip-itation amounts are increasing andindividual precipitation events on av-erage are becoming more intense. Butbecause air temperatures are also gener-ally warmer, evaporation rates are high-er. The effect is even stronger in aridand semi-arid regions, where, for themost part, precipitation is decreasingwhile evaporation rates are rising. As aresult, many places—even those receiv-ing more rain—are actually drier moreof the time. To make the matter worse,the timing of precipitation is changingin many areas. As every gardener knows,

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When mating, the male dragonfly grasps the female behind herhead, and she curls her abdomen around to accept sperm. Com-mon green darners, photographed in Texas by Giff Beaton.

the timing of rain matters. Annual in-creases in mean precipitation are shift-ing at a monthly or seasonal scale in bi-ologically significant ways. And all ofthese changes are likely to intensify incoming decades.

There are two major effects on smallwetlands that could come from shifts inprecipitation patterns. First, the timingor seasonality during which ephemeralwetlands hold water (their hydroperiod)is likely to alter. Such changes are im-portant because many wetland inverte-brates depend on a regular and pre-dictable hydroperiod for their life cycle.If there’s no water, they might need tospeed up their rate of development ortry to leave that wetland in search of an-other with a longer hydroperiod. If theycan’t disperse very well, they might haveto survive harsh drying conditions, per-haps by entering a resting state. Or theymight simply die, causing a local popu-lation to go extinct. For insects withaquatic larvae, such as stoneflies, dia-pause and death are the two most com-mon responses to desiccation.

Second, water volume is also asso-ciated with temperature. Water is muchharder to heat or cool than air becauseit has a lot of thermal mass. While large

bodies of water such as rivers and lakestend to change volume (or temperature)slowly, even small changes in precip-itation regime can radically alter thevolume of small wetlands, and thus the temperature of their water. Lesswater volume means warmer water,since there is a smaller thermal mass.And more water means cooler water, be-cause of the larger thermal mass.

Temperature matters to all organ-isms, especially invertebrates. Metabo-lism, development, activity level, re-production rate, the ability to find preyor escape predation, and many otherbasic processes are influenced directlyby temperature. Thus, changes in watervolume that result in water temperatureshifts should also alter behavior.

At least, these were my thoughts asI pulled into Caledon with Trottier’s dis-sertation. Research into biological im-pacts from climate change faces somebasic hurdles. Many of these studies arephysiological, experimentally testingthe tolerances of organisms to particu-lar environmental variables like tem-perature or humidity. However, thesestudies have proven too difficult to gen-eralize. Even closely related members ofthe same genus of butterfly or flower

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Changes in water volume and temperature can impact thedevelopment and emergence of dragonfly larvae. Commongreen darner larva, photographed by John C. Abbott.

can have very different physiological re-sponses to the same stimulus. Moreover,outside of the laboratory, multiple cli-mate variables are changing simultane-ously, and there is no guarantee that theselected variable in a laboratory will bevery important in a natural setting. His-torical studies that compare current be-havior to an earlier period are an effec-tive way to observe species’ responsesover time, which can then help us un-derstand what further changes we canexpect in coming decades.

Unfortunately, historical studieshave been rather limited for inverte-brates. Although insects make up thelargest number of species on the planet(and have one of the largest biomasses),there are very few baseline datasets forstudies on the impact of historical cli-mate change. Which is why I had Trot-tier’s dissertation with me in Caledon.

As a graduate student in the late

1960s, Trottier had no awareness ofanthropogenic climate change. He wasinterested in untangling the develop-mental cycle of the common green darn-er (Anax junius), a species of dragonflyfound from southern Canada to the Yu-catan peninsula of Mexico whose larvaecannot survive outside of the small wet-lands they favor. To explore their de-velopment, Trottier tracked emergence,the process of metamorphosis from lar-val stage to adult. When a green darnermetamorphoses, the larva crawls fromthe water onto some projection such asa stick or cattail and then the adultemerges and flies away, leaving behindthe empty exoskeleton.

Trottier hired a young field assistantnamed Mike McCormick, set up somefencing around the perimeter of a pondin Caledon as an emergence substrate,and waited. Trottier also brought somegreen darners into his Toronto labora-

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Due to their small size and seasonally variable conditions, ponds and wetlandsmay be impacted by changes in both rainfall and temperature. This is the Cale-don, Ontario, research site studied by the author. Photograph by John Matthews.

tory where he found that he could altertheir rate of development by changingthe temperature of their ambient water.Developmental rates were quite plastic,varying by factors of two to three oversmall temperature ranges.

I saw Trottier’s emergence datafrom the late 1960s on the timing ofemergence as a potential baseline forcomparison, particularly since his re-search ended just before a period of rel-atively rapid climate change began.Starting around 1974, many climate var-iables began to shift swiftly worldwide.Moreover, Trottier had documented theimportance of temperature on the de-velopment rate of green darners.

While in Caledon, I was especiallylucky to meet the grown-up Mike Mc-Cormick, and he and his wife, Darleen,provided access to a pond that was verysimilar to the original site. With threeyoung and excited field assistants of myown, I began four years of emergenceand environmental monitoring at the McCormick pond. Following Trottier’smethod, we set up an emergence sub-strate. We found both that the timing

of emergence had changed since the1960s, and that these changes wereclosely associated with decade-scale in-creases and decreases in precipitation.We believe that changes in thermalmass and hydroperiod in this wetlandhave significantly altered the timing ofdragonfly emergence in Caledon overjust the past thirty-five years.

How important are these resultsfrom a more general conservation per-spective? Ontario is a relatively wet re-gion in the northern temperate zone,and small shifts in dragonfly emergencemay not be critical there. Except duringdrought years, there are abundant wet-lands in eastern Canada of many sizesand thermal masses.

However, the implications of theseresults should be of serious concern inregions where surface water is more lim-ited. In semi-arid regions, small ephem-eral wetlands are often the most impor-tant and widespread type of freshwaterhabitat. For instance, across most of theGreat Plains and the Great Basin ofNorth America, small wetlands—oftencalled prairie potholes or playa lakes at

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Many birds rely on adult aquatic insects for food. Tree swallows (Tachycineta bicolor), photographed in Quebec by Michel Bordeleau.

the northern and southern ends of theGreat Plains, respectively—are criticalhabitat and contain a different inverte-brate fauna from nearby reservoirs andrivers. Many climate models suggestthese regions will become drier in com-ing decades.

Therefore, in these regions changesin hydroperiod and thermal mass arelikely to have a strong effect, and notjust on dragonflies. Precipitation-drivenchanges in habitat are also likely to af-fect mayflies, stoneflies, caddisflies, dip-terans (such as mosquitoes and midges),and many other groups. The impacts onthese species will not be limited to fresh-water taxa. Many bird species, for in-stance, specialize on the adult terrestri-al stage of aquatic insect species. DavidWinkler of Cornell University believesthat continental-scale changes in thetiming of egg laying in tree swallows(Tachycineta bicolor) is an indirect effectof shifting climate on the emergencetiming of aquatic dipterans, their pri-mary prey. Given that many species aresensitive to the timing of behaviors inother species—think of the importanceof the coordination between floweringtime and a specialist pollinator —evenminor changes can alter complex inter-species relationships. I fear that ephem-eral small wetlands may be one of thetypes of habitats most endangered byclimate change.

For the next decade, there are prob-ably two broader lessons to keep inmind about global warming and fresh-water invertebrates in small wetlands.First, few studies have focused on howclimate change is altering wetlands, somore research should be conducted onthis topic while more formal protectionis enacted to reduce wetland destruc-

tion. In the United States, small wet-lands are under growing pressure be-cause recent judicial reviews of theClean Water Act have eroded the abili-ty of federal agencies to protect non-flowing freshwater systems.

Second, there are grounds for hopefor small wetlands and the species theyhouse if we can commit to their pro-tection. These wetlands should be ex-cellent candidates for protective legisla-tion and active resource management.Particularly in regions projected to be-come drier in future decades, relativelysmall modifications to the shape andsize of small wetlands can alter their surface-to-volume ratio, reducing therate of evaporation and shifting thethermal regime. We need to give thesespecies some more time to adapt duringa period of intensifying climate change.In some cases, more small wetlands mayneed to be created at higher latitudes sothat the ranges of species can move astheir preferred climate “envelope” shiftsspatially.

These wetlands are little worlds inthemselves, full of life and activity. Ifind them beautiful and compelling.Our care for them and their inhabitantsmay tell us something about how pre-pared we are to help organisms in morecomplex habitats respond to our plan-et’s emerging new climate.

John Matthews is a freshwater climatechange specialist with the World WildlifeFund in Corvallis, Oregon. He continues towork on issues related to aquatic inverte-brates, though occasionally he has to spendtime on vertebrates as well. John thankshis Caledon field assistants, Nathan Bur-nett, Kieran Samuk, and Marie Riddell.

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Objects of great beauty in themselves,coral reefs are home to immeasurablydiverse communities of marine life.Often described as “tropical forests ofthe sea,” or “gardens of paradise,” reefssupport a tourism industry worth a bil-lion dollars, and tens of millions of peo-ple living along tropical coasts are de-pendent directly on them for transportnetworks, building materials, fisheries,and the protection of coastlines.

Corals are closely related to seaanemones. The major difference is thatmany corals produce a cup-shaped skel-eton of calcium carbonate, within whichthe anemone-like coral polyp lives. It is

this skeleton that gives stony (or scler-actinian) corals their name. A few stonycorals are solitary polyps that may reachten inches (twenty-five centimeters)across, but the great majority are tinypolyps, usually less than an eighth of aninch (three millimeters) across, and livein vast, reef-building colonies.

Stony corals cannot successfully liveon their own. For survival they rely ona symbiotic relationship with zooxan-thellae, single-cell algae that live with-in the polyps. The relationship is clear-ly mutually beneficial. Indeed, it hasevolved to the point of being effectivelyobligate in nature for the coral: the

FALL 2007 11

Bleached Out: Coral Reefs Under Stress

David Obura

Healthy corals form reefs of many different colors and shapes. This coral garden wasphotographed in Papua New Guinea by Tammy Peluso.

two can survive apart in controlledlaboratory conditions but in the realworld, coral species that are normallysymbiotic are incapable of maintainingthemselves alone against competitionand infection.

Through photosynthesis, zooxan-thellae capture energy into chemicalform, a large part of which they pass tothe coral polyp. This provides the fuelfor cellular functions within the polyp,including the creation of its calcium car-bonate skeleton, which leads to the ac-cretion of reef structures as new coralsgrow on the skeletons of previous gen-erations. In return, the zooxanthellaeare physically protected by living with-in the polyp, and the reef structure pro-vides them with access to light, whichthey require to survive. They also re-quire water temperatures greater thansixty-eight degrees Fahrenheit (twenty

degrees Celsius), so reefs are almost ex-clusively restricted to tropical seas lessthan 150 feet (50 meters) deep. The part-nership between corals and zooxan-thellae is one of the most successful onthe planet; this relationship has existedfor more than four hundred millionyears and the resulting reefs are the onlybiogenic structures visible from space.

Over the years, a picture has devel-oped of coral reefs as highly sensitivenetworks of species in a delicate equi-librium. Cold temperatures have longbeen known to be inimical to reef sur-vival, but in the 1970s evidence accu-mulated that showed corals have uppertemperature and light limits as well aslower limits. By the 1980s, scientistswere witnessing large-scale “bleaching”and mortality of corals believed relatedto warming seas associated with in-creasing levels of greenhouse gases in

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The purple areas of this Pocillopora coral are normal, while the pinkand white areas are in successive stages of bleaching. The brown areasare dead. Photographed in the Mariana Islands by David Burdick;courtesy the National Oceanic and Atmospheric Administration.

the atmosphere and perturbation ofocean-atmosphere oscillations such asthe El Niño and La Niña cycles. Sincethat time, bleaching and mortality haveincreased rapidly.

It is now widely accepted amongcoral reef scientists that coral bleachingrepresents a last-ditch attempt by coralsand zooxanthellae to resist stressful con-ditions. A wide range of stress causesthem to separate, and the departure ofthe pigmented zooxanthellae from thecoral tissue leaves the tissue transparent,revealing the bright white skeleton be-neath. Under not-too-stressful condi-tions, the partners can often rejoin andcontinue growing; however, when con-ditions are too severe, bleaching is usu-ally followed by mortality.

Excessive temperature and light in-tensities are the main causes of stress inthe polyp-zooxanthellae symbiosis, andthese two factors are increasing globally.Background levels of both are rising,

and peak fluctuations are being pushedhigher than ever. Corals in all regionsappear to be adapted to a late-summerpeak of temperature and light when thesun is at its local zenith. However, anyincrement above seasonal norms push-es corals and zooxanthellae over theiradaptive limit—and around the worldtemperature and/or light are beginningto exceed their historic summertimemaxima. In 1998 alone, during the hot-test year on record, coinciding with anEl Niño peak in the Pacific and a similarclimate peak in the Indian Ocean, 16percent of the world’s reefs were judgedto be severely degraded.

The implications of continuingstress are dire for coral reefs. Althoughfew species on a reef rely directly onstony corals for food or energy, thestructure that corals provide enables therest of the reef community to exist. Thedecline in coral diversity and cover onsome reefs has resulted in lower diver-

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Completely bleached corals are white; as they bleach they can takeon fluorescent hues of purple, blue, green, or yellow. Acropora coral,photographed in the Mariana Islands by David Burdick; courtesythe National Oceanic and Atmospheric Administration.

sity and abundance of obligate associ-ates of coral, those crustaceans and fishthat live in spaces among branchingcorals, or fish that feed only on corals.If coral growth does not resume, theframework of the reef itself erodes, re-sulting in still lower diversity and abun-dance of fish, including many fisheriesspecies of economic importance. In theGalapagos, where only small reefs everbuild up, near-total death of corals inthe El Niño of 1983 resulted in completeerosion of some local reef frameworkswithin the next twenty years.

Quantifying the potential loss ofbiodiversity from declining reef healthis probably impossible. What would itmean if the area of healthy reefs de-clines to less than 10 percent of what itwas a few decades ago? What is the like-lihood of coral species going extinct?

The majority of coral reef scientists,managers, and enthusiasts, includingthe scientists on the United Nation’sIntergovernmental Panel on ClimateChange and the team that put togeth-er last year’s Stern Review for the Britishgovernment, believe that coral reef de-cline is a harbinger of decline in otherecosystems. Others who minimize thesignificance of coral reef declines pointto the coral species that bounce backquickly after bleaching. These species,however, are mainly widespread gener-alists and not representative of all spe-cies on a reef, much as weeds and cock-roaches are not representative of allplants or insects. Their ability to survivechanging conditions masks the impactof such change on global coral diversity.

Of course no one can precisely pre-dict the future for corals, but some out-comes are more likely than others. Theclimate-change debate is fueling new re-

search on coral and zooxanthellae evo-lution and physiology as well as reef dy-namics, and it is clear that with two part-ners interacting, each with their owngenomes, there are levels of adaptationand acclimation available to corals thatwe don’t yet understand. Coral reef sci-entists are split between those who havemeasured very limited capacity for ad-aptation, and those who offer evidencefor considerable capacity for adaptation.

In my view there will be many sur-prises, but it is hard to imagine that anecosystem knocked down to just 10 per-cent of its historic extent by conditionsthat are predicted to become increas-ingly hostile, can have much chance offunctional or widespread survival. Per-haps a few locations will retain func-tional coral reefs, and in fifty years we’llhave to travel to South Africa or Japanto see the corals that make it fartherfrom the equator as seas continue towarm. People may debate the details ofcoral declines but, for those who de-pend on coral reefs to earn enoughmoney to support their families, it is notfair to say “no problem, no action need-ed,” when we really don’t know. Thereare many challenges that need our at-tention and that will benefit from a pre-cautionary rather than a laissez-faire ap-proach to climate change.

David Obura coordinates CORDIO EastAfrica, supporting activities in mainlandAfrica and the island states, including re-search, monitoring, and capacity buildingof coral reefs and coastal ecosystems. He has studied sediment stress and coralbleaching and life-history strategies, andhas a primary research interest in climatechange and the resilience of coral reefs.

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The cabbage white butterfly (Pieris ra-pae) is so common and plain as to be oflittle interest to most butterfly enthusi-asts. However, under certain conditionsa cabbage white butterfly can be cashedin for a pitcher of beer. For more thanthirty years, Dr. Art Shapiro of the Uni-versity of California, Davis, has held a“Beer for a Butterfly” contest. A pitcherof beer goes to the person who nets thefirst cabbage white within California’sSacramento, Solano, or Yolo countieson or after the first of the New Year.Since he has the ability to think like abutterfly, Dr. Shapiro usually wins. Itried, but never came close.

Around the turn of this century, asI was pursuing my graduate studies in

Dr. Shapiro’s lab, biologists were com-ing to a consensus that contemporarychanges in our climate were havingequally contemporary and dramaticchanges on the plants and animalsaround us. For butterflies, much of thediscussion was coming from northernEurope (England in particular), while weknew relatively little about the samephenomena at lower latitudes. This ge-ographical disparity in our knowledgeinspired us to examine the results fromthe “Beer for a Butterfly” contest. Wefound that the beer had been handedout earlier and earlier over the course ofthe previous three decades. In fact, thefirst cabbage white of the year was now appearing on average almost three

FALL 2007 15

Beer for Butterflies: Tracking Global Warming

Matthew L. Forister

The cabbage white (Pieris rapae) is a European species naturalizedin North America. Because of warming temperatures it nowappears nearly three weeks earlier in the spring in some areas.Photographed in California by Henk Wallays.

weeks earlier, as were many of its fellowbutterflies in the same region. Thesechanges appeared to be related to warm-ing and drying climatic conditions inthe region.

Results like these from the cabbagewhite and its neighbors are all too com-mon. Similar effects are turning up onevery continent and with many differ-ent kinds of creatures.

Of species’ varied responses to cli-mate change that have been observed,shifts in geographic range and in thetiming of life-history events (phenol-ogy) are of fundamental importance.Both kinds of changes follow from thefact that organisms depend on cuesfrom their environment to determinewhen, where, and how to live out theirlives. When conditions become warmeror drier (or colder or wetter), the envi-ronmental cues change and the biologyof plants and animals may or may notchange in response. It has become veryclear (at least in temperate regions) thatthe phenology of butterflies is changingin predictable ways. In particular, thedate when the first butterfly of manyspecies is observed is coming earlier inthe season.

Why does this happen? In regionswith strongly seasonal climates, mostbutterflies spend at least part of the year in a dormant phase. This part ofthe year is often winter but in somecases, it’s the heat of summer. Butterflieshave a variety of ways of spending thesedormant times: as different life-historystages and in different states of inactiv-ity. For many butterflies, entry into dor-mancy is controlled by photoperiod(day length), and may or may not be in-fluenced by temperature, while emer-gence from dormancy is largely tem-

perature controlled. Consider a butter-fly that spends the winter as a caterpil-lar in arrested development. In the heartof winter, a succession of cold days caus-es the caterpillar to “break” dormancyand resume normal metabolic activityin preparation for spring. After that,subsequent growth and emergence maybe dramatically affected by temperature:with a very warm spring, the caterpillarswill grow more rapidly and the firstadult butterflies will be seen earlier thanin a year with a cold spring.

The other side of the coin is move-ment in space. Studies by scientists,including Camille Parmesan of the Uni-versity of Texas and Jane Hill of the Uni-versity of York, have shown that but-terflies across Europe are shifting north-ward. In particular, a study of thirty-fivenon-migratory species found that, dur-ing the twentieth century, the ranges of nearly two-thirds of the species ex-panded northward by between 35 and240 kilometers (22 and 150 miles). Insome but not all cases, the southern edgeof the range has also shifted northward.

An instructive example of similarmovement comes from the westernUnited States, and the work of Lisa Cro-zier of the National Oceanic and Atmos-pheric Administration. The sachemskipper (Atalopedes campestris) has re-cently expanded the northern edge ofits range from northern California tosouthern Washington. Through exper-iments in which caterpillars were ex-posed to a range of environmental con-ditions, Crozier was able to show thatwinter temperatures were the primaryfactor affecting the recent expansion.Pacific Northwest winters warmed byroughly three degrees Celsius (five anda half degrees Fahrenheit) in the second

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half of the twentieth century. Before the1990s, winter temperatures in Wash-ington were generally below a criticalsurvival threshold for overwinteringcaterpillars; the threshold appeared tobe average January minimum temper-atures of minus four degrees Celsius(twenty-five degrees Fahrenheit). Oncetemperatures on average warmed abovethat point in the 1990s, the skipper wasable to rapidly expand its range and isnow a regular member of the Washing-ton fauna.

A comparable phenomenon is theupslope movement of butterflies onmountains in response to warmingconditions. In France, populations of amontane butterfly, the Apollo (Parnas-sius apollo), have gone extinct at lowerelevations but, as described by HenriDescimon at the Université de Pro-vence, in Marseille, they persist on pla-teaus at higher elevations. Where thelower-elevation populations are close to

suitable higher-elevation habitat, but-terflies colonize the higher locationsand establish new, viable populations.Robert Wilson of Madrid’s UniversidadRey Juan Carlos reports similar behav-ior among numerous species in themountains of central Spain.

So what’s the problem with all thisshifting around in space and time? For changes in space, the consequencesmay be painfully obvious. Montanepopulations can be pushed only so farupslope or poleward along a mountainchain: if warming continues, they mayrun out of mountain. The consequencesof shifting in time are more subtle. Thelife cycles of many butterflies, particu-larly those with a single spring genera-tion, are tightly timed to the phenolo-gy of their hostplants, the ones that thecaterpillars depend on for food. Cater-pillars may, for example, need to eatnewly unfolded leaves, which are notonly tender but also relatively free of the

FALL 2007 17

The Sachem skipper (Atalopedes campestris) is found acrossthe United States. On the West Coast its range has recentlyexpanded northward into Washington state. Photographedin Virginia by Preston Scott Justis.

toxins that accumulate as the leaf de-velops. If the butterfly’s flight period isshifted either forward or backward, theadults may lay eggs but caterpillars willnot find optimal foliage. It is also possi-ble that the phenology of plants maychange, but there is no particular reasonto think that a shift in plant phenologywill perfectly match a shift in butterflyphenology. Of course, climate changedoes not result in uniform warming.Many areas are receiving increased win-ter precipitation, which may delay de-velopment or even increase mortalitythrough mold or disease; even if notkilled outright, stressed larvae becomeless healthy adults.

If changes in range and phenologycan lead to such problems, why don’torganisms adapt to changing conditionsand just stay put? After all, it is clear thatbutterflies have adapted to almost allmanner of environments because wefind them in the hottest deserts and onthe highest mountains. Although thefact is that we know relatively littleabout the evolutionary responses ofbutterflies to climate change, examplesare accumulating of one intriguing pos-sibility: dispersal facilitated by adap-tation. Populations at northern rangeboundaries may evolve greater dispersalability (in response to newly availablehabitat), and, in the case of the brownargus (Aricia agestis), populations at anorthern range boundary have colo-nized a novel hostplant, which subse-quently facilitated range expansion, asdescribed by Chris Thomas at the Uni-versity of Leeds.

But what if there is nowhere to go? Is adapting to new conditions pos-sible? The answer is certainly yes: weknow of few true constraints on the evo-

lutionary process, but there are daunt-ing issues of chance and time that alladapting populations face. For specieswith nowhere to go it seems likely thatmany will simply go locally extinct, in-cluding not only species on mountains—such as the Apollo butterflies trappedon warming plateaus—but also species in extremely localized or fragmentedhabitats.

Given the possibility of extinctionin some cases, and phenological or spa-tial shifts in others, it’s interesting toconsider what your favorite butterflycommunity, in your backyard or localpark, will look like in ten, twenty, orfifty years. It is quite possible that youwill see one or two species that you havenever seen before as they colonize fromlower latitudes, and you might evenspot a few tropical gems. It’s equallypossible that some species may be gone,either locally or globally, and that newecological interactions may arise asplant and predator communities arealso shifting around the butterflies. Out-comes will also depend on many fac-tors not related to climate change, suchas regional habitat destruction. In anyevent, the coming decades may be bothintriguing and disheartening for ob-servers of butterflies. Perhaps we shouldall have a “Beer for a Butterfly” contest,and raise a glass or two for the butterfliesas they come and go in space and time.

Matthew Forister is a research assistantprofessor in the Department of Natural Re-sources and Environmental Science at theUniversity of Nevada, Reno. His researchinvolves the ecology and evolution of her-bivorous insects, particlarly issues of speci-ation and ecological genetics in butterflies.

18 WINGS

Let me begin by asking you to removeyour watch, close your calendar, turnoff your TV or radio, throw away yournewspaper, and not speak to anyone.How long do you think that it would bebefore you lost track of time—the pre-cise time of day, day of the week, ormonth of the year? And, if you wereasked to keep track of time, how mightyou try to do this?

What if I said that you have thechance to meet the man or woman ofyour dreams at 7:00 in the evening ofOctober nineteenth and that, if youmeet, you will enjoy a night of passionleading to the birth of your only child?Do you think that you would be able tomake the meeting? And, if I said that

you will die the next day, do you thinkthat your genes would have been passedon to the next generation?

This is the challenge facing manyinvertebrates. Lucky then for the is-landers of Samoa and Fiji that the palo-lo worm has managed to solve this puz-zle. Each year, millions of worms releasetheir epitokes, their rear sections full ofsperm or eggs, which swarm at the seasurface to reproduce. The islanders havebeen able to predict the date and timeof day of this phenomenon for cen-turies. At dawn on the day before andthen on the actual day of the moon’slast quarter in October or November,people row or wade out to sea with netsready to catch the animals for the brief

FALL 2007 19

For Marine Worms, Timing Is Everything

Andrew Lawrence

During their annual swarm, palolo worms (Palola siciliensis) releaseepitokes, rear sections filled with eggs or sperm. The male epitokes aretan, those of females a darker gray-green. Photographed in AmericanSamoa by Stassia Samuels; courtesy the National Park Service.

period that they are available. The palo-los are considered a delicacy and eatenraw or cooked, and their arrival is oftenfollowed by festivals.

The palolo worm is one of the mostdramatic examples of an animal thatcoordinates its reproductive cycle tolunar periodicity. However, spawning is only the final stage in a complexprocess of gamete (eggs or sperm) de-velopment and maturation, and inorder for the worms to be able to spawn,the gametes have to be ready at the ap-propriate time. This too requires precisesynchronization.

The most commonly used cues toregulate breeding are environmental:photoperiod and temperature. Of these,photoperiod (length of day) is the mostaccurate predictor of time of year and itis often used to entrain an animal’s in-

ternal clock mechanism, which in turncontrols the animal’s annual cycle ofactivity or physiological processes (bio-rhythm). Temperature is a secondarycontrol. While it also follows seasonalcycles, it can show significant variationon a yearly basis and may cause onset ofcertain phases of development at in-appropriate times if it is used as themain cue.

Cueing to environmental cycles inorder to synchronize reproduction iswidespread in invertebrates, but someof the best examples are seen in the ma-rine worms in the class Polychaeta.

Ragworms (genus Nereis; also calledsandworms or clamworms in NorthAmerica) are widespread in intertidalareas across the Northern Hemisphere.Up to twelve inches (thirty centimeters)long, they are found mostly in muddy

20 WINGS

Intertidal mudflats may appear featureless and barren, but under the surface is a richcommunity of invertebrates waiting for the returning tide. England’s Humber Estuary,photographed by Alan Clements.

estuarine areas and may live for one tothree years in temperate waters. When the tide goes out they retreat to U- or J-shaped burrows in the sand or mud. Dur-ing high tide they emerge from their bur-rows as active, fast-swimming predators.

Ragworms are among the most im-portant food sources for shorebirds andare preferred prey in Britain for birdssuch as dunlin, bar-tailed godwit, greyplover, and redshank. With burrow den-sities that may exceed several hundredper square yard, ragworms are a hugefood resource, and consequently someestuaries are of national or internation-al importance as migratory stopovers forbirds. The Humber Estuary, for example,on the east coast of England, is one ofEurope’s key sites for wintering wildfowland may host more than 175,000 birds.Its importance is recognized worldwide.

Ragworms are different from manyother polychaetes in that they are sem-elparous—that is, breeding only once,after which the adult dies. Synchroniz-ing the timing of reproduction is there-fore essential and must be tightly con-

trolled, not only within the individualbut also across the population.

The two most important factorscontrolling the development of eggsand sperm in ragworms are water tem-perature and photoperiod. In the kingragworm (Nereis virens), for example, eggdevelopment is initiated by the switchto short winter days —a day length ofeight hours is essential to promote egggrowth—but it is temperature that con-trols the speed of egg development. Lowtemperatures speed up development sothat eggs starting to develop later in thewinter grow faster at the lower temper-atures they experience and catch up tothose eggs that began development dur-ing the milder conditions earlier in theseason. All eggs are ready for spawningin early spring.

Temperature has also been linkedwith spawning. For example, the rag-worm Nereis diversicolor spawns in thespring after a period of low winter tem-peratures. In this species it seems thatthe rise in temperature from winter to early spring is highly important in

FALL 2007 21

Ragworms in the genus Nereis are agile predators whenthe tide covers their mudflats. Photographed in theNorth Sea by Edgar Donkervliet.

aiding the synchronization of gametematuration and spawning. Further syn-chrony is imposed as mature animals re-lease their gametes only with the springtides, which occur on the semi-lunarcycle of 14.8 days and coincide with thefull and new phases of the moon.

Scaleworms (genus Harmothoe) areanother group of polychaete worms that utilize photoperiod and water tem-perature to synchronize reproduction.Like ragworms, they are widely distrib-uted across the Northern Hemisphereand are an important food source forshorebirds, but they differ from rag-worms in behavior, habitat, and lifecycle. They are sit-and-wait predators ofrocky shores, using cryptic coloration tohide in crevices or under stones or sea-weed holdfasts, and are iteroparous,which means they reproduce once ayear and may live for several years.

One species, Harmothoe imbricata,actually produces two batches of eggseach year, with the spawning of theseoccurring just weeks apart. The processbegins in autumn when the first batchof eggs grows during the winter beforebeing spawned in March. After this, thesecond batch of eggs develops rapidlyand is spawned approximately threeweeks later. Spawning is linked to cal-endar date and H. imbricata exhibits anannual reproductive cycle in whichphotoperiod sets the clock. The animalsmust be exposed to at least six weeks ofcontinuous short days (thirteen hoursor less of daylight) for successful egg de-velopment. Falling temperatures duringthis period also help to synchronize ga-mete progression to maturity. A finalrapid growth phase is accelerated by lowtemperatures combined with longer daylengths as winter transitions to spring,

but only in those animals that have ex-perienced at least fifty short days.

Scaleworms and ragworms, alongwith many other marine creatures, relyon a delicate balance of day length and temperature to control breeding. Ifone of these two environmental cuesfails them, the worms may not be ableto breed successfully. If an individualmisses the spawning period, its indi-vidual genes may be lost from the pop-ulation forever. If a population missesthe spawning period, then the conse-quences will be more severe, not just forthe worms themselves but also for theother animals that are reliant on themas a seasonal food source. Global warm-ing makes this more than just a possi-bility. The United Nations’ Intergovern-mental Panel on Climate Change pre-dicts higher surface temperatures, withthe change 50 percent higher duringwinter in northern temperate regionsthan elsewhere, so it is likely that therelationship between photoperiod andtemperature will be broken or fall out of phase.

For the species discussed here, theimpact of climate change could be dra-matic. The photoperiod cues will remainthe same, so gamete development willbe initiated and spawning will occur atthe same time, but higher winter tem-peratures will slow the rate of develop-ment, leading to a significant reductionin the number and quality of gametesready to spawn. Dissynchronous spawn-ing between individuals has been seenin populations of Nereis diversicolormaintained in constant high tempera-tures. It may also lead to the time ofspawning becoming uncoupled fromthe best time of year for larval survival.While this may not ultimately lead to

22 WINGS

species extinctions, it could lead to thelocal extinction of some populations orthe significant collapse of populationsfrom some areas. Their survival will de-pend on the speed at which they canadapt to climate change.

Recent events in the seas aroundnorthwest Europe have shown thatchanges in environmental conditionsduring the winter can have significantimpacts on marine invertebrate repro-duction. Ecological responses to theclimatic effects of the North AtlanticOscillation have included changes inthe timing of reproduction, populationdynamics, abundance, and spatial dis-tribution of marine invertebrates. In ad-dition, unseasonable climatic events inthe Baltic Sea have lead to high losses ofshearwaters due to a collapse in theirfood supplies.

The structure and function of ma-rine ecosystems are intimately linked to the atmosphere, and the impact ofclimate change on these and other in-

vertebrates is likely to go beyond justthe individual species. Because poly-chaetes are one of the most importantcomponents of the estuarine sedimentcommunity, loss of these animals mayhave a significant impact on the ecol-ogy of these systems. For some estuar-ies, any significant loss of invertebratebiomass could result in the loss of birdpopulations.

So finally, going back to your bignight on October nineteenth, wouldyou have made the meeting? Do youthink that you would have noticed thatthis is the night of the third quarter ofthe moon in North America? I suspectthat most of us would miss the date.

Andrew Lawrence has been studying ma-rine worms and impacts of climate changefor more than twenty years. He is a seniorlecturer in marine ecology at the Universityof Hull, a couple of miles from the northshore of the Humber Estuary.

FALL 2007 23

Invertebrates of intertidal areas provide a vital food resource for mi-grating or overwintering shorebirds. Photographed at the HumberEstuary, England, by Paul Glendell; courtesy Natural England.

The global climate is changing. Al-though many of the finer details haveyet to be revealed, the overall picture isone that portends trials and changes forinvertebrate species generally and forpollinators specifically. Pollinators willface multiple challenges to their sur-vival—many of them have complex lifecycles that include dependence on dif-ferent resources at different stages ofgrowth, some have life spans of multi-ple years, and for others migration is afactor as well. Pollinators seem mostlikely to respond to a warming envi-ronment in two ways, through changesin phenology (the timing of life-cycleevents), and through changes in theirgeographic distribution.

Phenology of both pollinators andthe plants on which they feed is an im-portant ecological factor that is chang-ing in response to global, regional, andlocal climate changes. Key phenologicalevents in pollination, including polli-nator emergence or arrival and timingof flowering plants, generally appear tobe happening earlier than in previousyears in temperate regions of the world.Some of the clearest examples comefrom Britain. Data from the United King-dom’s Butterfly Monitoring Schemeshow that the first appearances of mostbutterflies have advanced in the last twodecades. These changes were stronglyrelated to earlier peak appearances and,for multi-brooded species, longer flightperiods. Models using these data suggestthat climate warming on the order of

one degree Celsius (one and three-quar-ters degrees Fahrenheit) could advancefirst and peak appearance of most but-terflies by two to ten days. This sort ofchange is not limited to butterflies. Al-though they are not pollinators, Britain’sdragonflies and damselflies have beenemerging about three and one-thirddays earlier for every degree Celsius ofwarming in temperature since 1960.

It also appears that the general ar-rival of spring has advanced in recentdecades. Where detailed studies havebeen conducted on more local scales,earlier flowering is a common patternfor many species. A danger for pollina-tors comes from the loss of synchronybetween their life cycles and those ofthe plants upon which they depend, ei-ther as hostplants or nectar and pollenresources.

My own research has been focusedprimarily on montane and alpine en-vironments, particularly in Colorado,where I have worked for almost fourdecades at the Rocky Mountain Biolog-ical Laboratory. Here the emergence ofMilbert’s tortoiseshell (Nymphalis mil-berti ), a butterfly that overwinters as anadult, has not been changing in concertwith the flowering of early spring wild-flowers, suggesting a loss of synchronybetween their need for nectar and theavailability of their customary floralresources. If this pattern turns out to be more widespread—if overwinteringbumble bee queens or emerging solitarybees, beetles, or flies respond differently

24 WINGS

Impacts of Global Warming on Pollinators

David Inouye

than do spring wildflowers to changesin environmental cues (such as snow-melt dates and warming soil tempera-tures in temperate habitats) —it raisesthe possibility that changes to manyhistorical plant-pollinator relationshipsare on the way.

A second prediction of the conse-quences of global warming is that somespecies will move their ranges to high-er latitudes in the Northern Hemisphereor to higher altitudes in mountains.There is now evidence that some speciesof butterflies have already undergonesuch latitudinal changes, which match-es the observation that some species ofbirds, fish, other insects, and plantshave also expanded their latitudinaldistributions. It would be surprising ifother pollinators don’t also respond towarming temperatures by moving to-ward the poles; there is already evidenceavailable of bumble bees moving tohigher mountain elevations.

One ongoing research project at theRocky Mountain Biological Laboratoryis an investigation of potential shifts in the altitudinal distribution of bum-ble bee (Bombus) species. In 1974 and1975 Graham Pyke and I were graduatestudents at the Laboratory and both ofus looked at the distribution of thesebumble bees along altitudinal transectsthat spanned up to about 1,500 verti-cal feet (460 meters). The bees typicallysorted out by a combination of pro-boscis length (short, medium, long) andaltitude (high, medium, low). Consis-tent with the predictions for globalwarming, we have anecdotal evidencethat species in this habitat are movingtheir ranges up in altitude. This summerwe brought Dr. Pyke back to the Labo-ratory from Australia, where he nowworks, to help relocate his original tran-sects from 1974. The students who thenre-surveyed the transects last summerobserved at least one of the bumble bee

FALL 2007 25

Global warming is changing the timing of flower bloom and but-terfly emergence, in some cases breaking synchrony betweenspecies. Milbert’s tortoiseshell (Nymphalis milberti ), photographedin Wisconsin by Mike Reese.

species about fifteen hundred feet high-er than we had reason to expect to findit. The results of our recent census willprovide both insight into any signifi-cant changes in distribution and an-other baseline for future studies.

Pollinators are dependent on plantspecies for nectar and pollen as sourcesof carbohydrate and protein, so it makessense to consider how their interactionswith plants may be affected by climatechange. In some cases these are very spe-cific relationships, with insects visitingonly a single species of plant, or perhapsa group of related species, while otherpollinators may be much more catholicin their diets. Perhaps the former strat-egy is the one most at risk under sce-narios of climate change, for if the onespecies of plant a pollinator depends onshifts its distribution, or if its abundancedecreases, the pollinator would have toduplicate the range shift or face a cer-tain decline. Pollinators dependent ona suite of flowering plant species may

also face problems if gaps develop in thetemporal sequence of resources theyneed. For example, bumble bee coloniesare started early in the spring by queensemerging from overwintering underground, but new reproductives aren’tproduced until the end of the summer,so a whole series of plant species mustbe available to sustain this long periodof colony development.

In addition to changes caused by in-creasing global temperatures, the effectsof increasing carbon dioxide could haveimplications for pollinators. In an ex-perimental study in Britain, elevatedcarbon dioxide levels had an effect onflowering phenology and nectar pro-duction of some butterfly hostplants. Inanother experimental study, a changeof food-plant preference was found forcaterpillars under elevated carbon diox-ide, and development took longer withincreasing levels of carbon dioxide.

Yet another prediction of some cli-mate-change scenarios is that there will

26 WINGS

Pollinators are key components of terrestrial ecosystems, yet little researchhas been done on the impacts of global warming on bees, flies, and bee-tles. A bee fly on valerian, photographed in Colorado by David Inouye.

be increased variability in precipitation.At Stanford University’s Jasper RidgeBiological Station, a nearly four-decade-long study of bay checkerspot butterflies(Euphydryas editha bayensis) found evi-dence that such variability may haveamplified population fluctuations, lead-ing to their local extinction. Modelingstudies also suggest that rapid extinc-tion could result from precipitation-amplified fluctuations in butterfly pop-ulations. Precipitation is also importantfor both the abundance of floweringand the abundance of nectar; in droughtyears plants may lose flower buds andthe flowers that are produced may notproduce nectar.

To date, butterflies have been thefocus of most climate-change and pol-linator research for a variety of reasons.They are easy to observe, there are oftengood historical records of distributionand abundance, and they seem to res-onate with the public more than manyother invertebrate species. But they arenot necessarily representative of all pol-linators; it is likely that many less mo-bile invertebrate species could face evengreater challenges in responding to fu-ture changes in temperature, precipita-tion, and phenology.

The recent report on the status ofpollinators in North America sponsoredby the National Research Council point-ed out that little is known about theecology, the population biology, or eventhe distribution of most pollinators.This lack of information hampers bothour ability to forecast the changes thatare undoubtedly ongoing and our abil-ity to plan for conservation. The kindsof changes predicted in phenology orrange due to climate change present achallenge for the goal of protecting

habitat for pollinator species. If we pro-tect habitat where pollinators occurtoday, what will happen in the future astheir ranges change? The growing real-ization of the economic and ecologicalsignificance of pollinators may help tospur the research that is needed to in-crease our understanding of the changesthey are facing and provide better strate-gies for protecting these vital creatures.

David Inouye is a professor of biology atthe University of Maryland, College Park.He has worked at the Rocky Mountain Bi-ological Laboratory since 1971, studyinghummingbirds, pollination biology, ant-plant mutualisms, bumble bees, and thephenology and demography of wildflowers.Inouye was a member of the National Re-search Council committee on the status ofpollinators in North America.

FALL 2007 27

Over the last three decades the range of at least one species of bumble bee in theColorado Rockies has moved fifteen hun-dred feet higher in elevation. Bombus flavi-frons on lupine (Lupinus argenteus), pho-tographed in Colorado by David Inouye.

tion. This coincidental timing suggeststhat an exotic disease is the cause for thewidespread loss, although this hypoth-esis is still in need of validation.

The Xerces Society is collaboratingwith a bumble bee expert, Dr. RobbinThorp, to learn the former and currentranges of these species. We are solicitinginformation from the scientific litera-ture, museum collections, and expertsacross the country to document thebees’ former range and abundance; andwe are conducting background researchon each species’ biology, ecology, androle in crop pollination. This informa-tion will help determine the best way toprotect the populations that remain.

We are also working to raise public

FEATURE

28 WINGS

XERCES NEWS

Seven years ago, bee taxonomists beganto notice a decline in the abundanceand distribution of several very com-mon bumble bee species across theUnited States. Three bee species, Bombusoccidentalis (the western bumble bee), B.affinis (the rusty-patched bumble bee),and B. terricola (the brown-tipped bum-ble bee), were once very common andimportant crop pollinators across NorthAmerica, but are now only rarely found.A fourth species, B. franklini (Franklin’sbumble bee) may already be extinct.

The decline of these species is cor-related with a crash in the laboratorypopulations of commercially raisedbumble bees that were distributed acrossNorth America for greenhouse pollina-

Conserving Our Most Important Native Pollinators

An introduced disease carried by commercially raisedbumble bees may be the cause of decline in native spe-cies, including Franklin’s bumble bee (Bombus franklini ).Photographed in Oregon by Dr. Peter C. Schroeder.

of these bees and to solicit informationabout their current distribution.

In addition to protecting the popu-lations of these declining bumble bees,we hope to prevent the unregulatedtransport of bumble bees (and their dis-eases) in order to prevent future declinesin other bumble bee species.

Funding for this project comes fromthe CS Fund. To find out more aboutthis effort please visit www.xerces.org/bumblebees.

In the past century, millions of acres ofwetlands in North America have beenlost due to agriculture or urbanization.Many of the remaining wetlands sufferfrom a variety of human impacts, in-cluding pollution, changes in waterflow, and invasive species.

Wetlands are important elements ofwatersheds, providing such valuableecosystem services as water filtration,flood control, erosion control, and crit-ical habitat for animals and plants.Quality wetland habitat is essential tonative and endangered species; abouthalf of all federally listed endangeredanimals rely on wetlands for survival,including over 50 percent of America’s

protected migratory bird species. In the Pacific Northwest, many wet-

lands are severely compromised but fewhave been studied thoroughly and littleinformation is available on their bio-logical integrity (their ability to supportlife). While there are a variety of tech-niques available to assess the biologicalcondition of rivers and streams, evalua-tion of the biological attributes of wet-lands and their responses to human dis-turbances has lagged behind. An in-creasing number of watershed councilsin the Northwest are taking on wetlandrestoration projects, but lack the toolsto assess wetland quality and evaluaterestoration success.

FALL 2007 29

Xerces Works to Understand and Protect Wetlands

awareness about these species, their rolein pollination of crops and naturalareas, and the threats they face. We arecreating a series of “Wanted” posters tosend to bee researchers and entomolo-gy and ecology departments across thecountry, as well as to annual meetingsof groups such as the Entomological So-ciety of America and the Society forConservation Biology. The purpose ofthe posters is to educate the public andscientific community about the decline

For five years we have been building aprogram focused on pollinator conser-vation in agricultural landscapes. OnJuly 20, 2007, the Xerces Society signeda memorandum of understanding withthe Natural Resources Conservation Ser-vice that is helping us to expand ouroutreach to a broader segment of theagricultural community.

We are working with NRCS officesacross the country to provide pollinatorconservation and management trainingand to help NRCS staff incorporate pol-linator conservation into existing farmbill programs. This effort has been fund-ed by Xerces members together with theTurner Foundation and other privatefoundations.

Partnership with the Natural Resources Conservation Service

The Xerces Society is working to de-velop an invertebrate-based biologicalassessment tool that can be used to as-sess wetland quality. With funding fromthe Environmental Protection Agencyand the Mountaineers Foundation, wecompleted a pilot project to identify theinvertebrates in one class of wetland andhave begun developing this assessmenttool for the Pacific Northwest. Next yearwe hope to expand the project to in-clude additional classes of wetland.

The information and recommenda-

tions drawn from background researchand our pilot study have been incorpo-rated into a CD-ROM guide to wetlandinvertebrate identification in the PacificNorthwest. The guide has family-levelkeys for aquatic invertebrates encoun-tered in Northwest wetlands, and gen-eral information on invertebrate mon-itoring in still water habitats. To pur-chase the CD-ROM Aquatic Invertebratesin Pacific Northwest Freshwater Wetlands:An Identification Guide and EducationalResource, please go to www.xerces.org.

3030 WINGS

Throughout 2008, noted lepidopteristand writer Robert Michael Pyle will beundertaking a historic journey to find,experience, and identify as many spe-cies of butterflies as possible in the Unit-ed States and Canada. The literary fruitsof this project will be published byHoughton Mifflin as a book entitled

Swallowtail Seasons: The First Butterfly BigYear. The project is also a fundraiser,and you can participate in this effort bymaking a pledge for every butterflyspecies that Bob encounters, as part of a“Butterfly-A-Thon.” All proceeds fromthe Butterfly-A-Thon will go towardsthe Xerces Society’s work to preserve

Support Butterfly Conservation: Pledge the Butterfly-A-Thon

Sarina Jepsen, Xerces Society senior conservation associate, uses a dipnet to collect aquatic invertebrates as part of our effort to develop a bi-ological assessment tool for wetlands. Photograph by Logan Lauvray.

FALL 2007 31

and protect rare and endangered but-terfly species.

During his travels, Bob will be seek-ing to find as many as he can of thenearly eight hundred butterfly speciesrecorded in North America north ofMexico, although the numbers will besecondary to his actual encounters withthe butterfly fauna. To update partici-pants on his progress, he will be postingregular updates from the road on a But-terfly-A-Thon blog.

Bob Pyle founded the Xerces Soci-ety in 1971. He has published fifteenbooks, including such butterfly classicsas the Audubon Society Field Guide toNorth American Butterflies, the Handbookfor Butterfly Watchers, and The Butterfliesof Cascadia, as well as award-winning lit-erary works, including Wintergreen andSky Time in Gray's River.

To make a pledge or to find outmore about the Butterfly-A-Thon, pleasevisit www.xerces.org.

WINGS, Fall 2007 Volume 30, Number 2

Wings is published twice a year by the Xerces Society, an international, non-profit organization dedicated to protecting the diversity of life through theconservation of invertebrates and their habitat. A Xerces Society member-ship costs $25 per year (tax-deductible) and includes a subscription to Wings.

Copyright © 2007 by the Xerces Society. All rights reserved. Xerces Exec-utive Director: Scott Hoffman Black; Editors: Scott Hoffman Black, Adair Law,Matthew Shepherd, and Mace Vaughan; Design and Production: John Laursen.Printed on recycled paper.

For information about membership and our conservation programs fornative pollinators, endangered species, and aquatic invertebrates, contact us:

THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION4828 Southeast Hawthorne Boulevard, Portland, OR 97215

telephone 503-232-6639 fax 503-233-6794 info@xerces.org www.xerces.org

We are delighted to have two new staffmembers at Xerces.

Celeste Mazzacano joins us as aconservation associate. Celeste holds aPh.D. in entomology from the Univer-sity of Minnesota. She has more thantwelve years of experience in research,education, and conservation, and hasworked extensively with aquatic inver-tebrates. At Xerces she is currently de-

veloping assessment tools for wetlandsof the Pacific Northwest.

Lisa Schonberg is our new conser-vation assistant. She recently complet-ed her M.S. in entomology at EvergreenState College, researching ants in thecloud forests and lowland forests ofCosta Rica. Lisa will be working on a va-riety of pollinator conservation and en-dangered species projects.

New Staff Members at the Xerces Society

THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION4828 Southeast Hawthorne Boulevard, Portland, OR 97215

Board of Directors

May R. BerenbaumPresident

J. Kathy ParkerVice President

Linda CraigTreasurer

Sacha SpectorSecretary

Michael J. BeanScott E. Miller

Counselors

Paul R. EhrlichClaire KremenJohn LoseyThomas LovejoyJerrold MeinwaldMichael G. Morris

Piotr NaskreckiPaul A. OplerRobert Michael PyleCharles L. RemingtonMichael SamwaysCheryl Schultz

Scientific Advisors

Thomas EisnerE. O. Wilson

A $25 per year Xerces Society membership includes a subscription to Wings.

Our cover photograph shows an Apollo butterfly (Parnassius apollo). Butterflies are oneof the best studied insects with respect to the impacts of climate change; the range ofthis species has shifted due to global warming. Photographed in Italy by Angie Sharp.

Individual coral polyps are usually tiny, but in colonies can form massive stonyformations, such as this brain coral (Oulophyllia crispa). Coral reefs are amongthe first ecosystems to display signs of significant damage due to global warming.Photographed in Tanzania’s Songo Songo archipelago by David Obura.