Studies in Avian Biology No. 32:2–9

TIDAL : HOME FOR THE FEW AND THE HIGHLY SELECTED

RUSSELL GREENBERG

WHY STUDY TIDAL MARSHES? adaptive challenges of tidal , and in what ways we can act to conserve these Tidal marshes consist of grass or small shrub- small but unique tidal marsh faunas. dominated that experience regular Studies of tidal-marsh faunas have signifi - tidal inundation. In subtropical and tropical cance far beyond understanding the vagaries of regions, marshes give way to this particular habitat. Tidal marshes, with their dominated by a small number of salt-tolerant abrupt selective gradients and relatively simple tree species. Tidal marshes can be fresh, brack- biotic assemblages, provide a living laboratory ish, saline, or hyper-saline with respect to salt for the study of evolutionary processes. The concentrations in water. In this volume we following are just a few of the major concep- focus on marshes (not [Rhizophora, tually defi ned fi elds within biology that have Avicennia, and Laguncularia]) that are brack- focused on tidal marshes as a model system: (1) ish to saline (5–35 ppt salt concentration). evolutionary biologists seeking to investigate Tidal saltmarshes are widely distributed along systems where morphological changes may most continental coastlines (Chapman 1977). have evolved in the face of recent colonization Although found along thousands of kilometers and gene fl ow between saltmarsh and of shorelines, the aerial extent of tidal marsh is inland populations, (2) ecologists interested in quite small. We estimate that, excluding arctic how life history and behavior may shift in the marshes and tropical salt fl ats, tidal marshes face of a local, but strongly divergent environ- cover ≈45,000 km2 which, to put this in perspec- ment, (3) physiological ecologists, wishing to tive, would cover a land area merely twice the see how different organisms cope with the abi- size of the state of New Jersey. To place this otic factors governing successful colonization fi gure further in an ecological context, the total of saltmarshes, (4) biogeographers interested area of another threatened , tropical in patterns of diversity in endemism in this rain forest, is approximately 14,000,000 km2 or habitat along different and in different >300 times greater than the amount of tidal continents, and (5) conservation biologists, marsh even after ). Although the because of the disproportionately high fre- area covered by tidal marsh is small, this eco- quency of endangered and threatened taxa that system forms a true ecotone between the are endemic to tidal marshes. and land, and therefore plays a key role in both Many of us have spent years in tidal marshes marine and terrestrial ecological processes. In in pursuit of our particular study species. We the parlance of modern conservation biology, came together for this project because we began the tidal-marsh ecosystem provides numer- to think beyond our particular study species ous critical ecological services, including and study marsh, , or . It became protecting shorelines from erosion, providing apparent to us that tidal marsh vertebrates face nursery areas for fi sh, crabs and other marine a number of severe environmental threats that organisms, and improving water quality for might best be understood by gaining a more . global and less local estuary-centric perspec- Tidal saltmarshes are primarily associated tive. Furthermore, although tidal marshes pro- with the large estuaries of mid-latitudes, in vide a laboratory for studying local ecological North America, Eurasia, and southern South differentiation, the mechanisms and ultimate America, with some in Australia and South factors shaping this local divergence can best Africa. Tidal marshes are highly productive yet, be understood by studying common adaptive in some ways, inhospitable to birds and other challenges and their solutions in a more com- vertebrates. Surrounded by a highly diverse parative manner. As we contacted vertebrate source fauna from the interior of the continen- zoologists working around the globe, it became tal land mass, relatively few species cross the apparent that few tidal-marsh researchers think threshold of the maximum high- line and beyond their particular coastline. We believed colonize intertidal wetlands. In this volume, that if we could provide the catalyst for a more we discuss myriad approaches to understand- holistic and global thinking about tidal marsh ing which species have colonized the land- vertebrates, that would be an important step ward side, how they have evolved to meet the forward.

2 TIDAL MARSHES—Greenberg 3

In October 2002, we held a symposium at greatly throughout the Pleistocene (Malamud- Patuxent National Wildlife Research Center to Roam et al., this volume). Perhaps because of this, bring researchers together from different coasts the current fauna is a mosaic of species with old and marshes. But we took one step further. Both and very recent associations with this habitat during the organization of the symposium and (Chan et al., this volume). In North America, the the subsequent preparation of this volume, we fauna consists of repeated invasions from spe- made a concerted effort to go beyond our orni- cies in a few select genera of which sparrows thological roots and to pull together research (Ammodramus and Melospiza), shrews (Sorex), from other vertebrate groups, as well as voles (Microtus), and water snakes (Nerodia) are more process-oriented tidal-marsh ecologists. the most frequently involved. On the other hand, Including other classes of terrestrial vertebrates tidal marshes are inhabited by a few ancient taxa, has opened our collective eyes and we appreci- such as the diamondback terrapin (Maloclemys ate the cooperation of the editors of Studies in terrapin), that have evolved in estuarine habitats Avian Biology to allow so much non-avian mate- since the Tertiary. A plethora of recent work on rial in our publication. molecular phylogenies of these species allows Tidal marshes are among the most produc- us to examine the pattern and time of invasions tive ecosystems in the world, with high levels of by new taxa. Furthermore, we can examine the primary production created by vascular plants, nature of adaptation of taxa with older and more phytoplankton, and algal mats on the substrate recent associations with tidal marshes (Grenier (Adam 1990, Mitsch and Gosselink 2000). and Greenberg, this volume). Abundant plant and animal food resources are Because of this high level of differentiation available through both the terrestrial vegetation of tidal marsh taxa, the restricted distribution of and the marine food chains associated with tidal this habitat, and its location in some of the most channels. It is small wonder that saltmarshes heavily settled areas of the world, it is not sur- often support high abundances of the species prising that many populations are very small that live there. and have shown rapid declines. Tidal marsh On the other hand, the fauna and fl ora associ- vertebrates face the continuing challenges of ated with salt and brackish marshes are depau- fragmentation, ditching and impoundment, perate. Our attention is drawn to tidal-marsh reduction in area, pollution, and the establish- systems not primarily for the diversity of birds ment of invasive species (Daiber 1982). In addi- and other terrestrial vertebrates, but for the tion, sea-level rise will not only infl uence the high proportion of endemic taxa (subspecies or extent and zonation of tidal marshes (Erwin et species with endemic subspecies). In the course al. 1994, this volume), but the and per- of preparing this volume, we have identifi ed haps the frequency of storm surges as well. 25 species of mammals, reptiles, and breeding Given the enormous pressures on delicate birds that are either wholly restricted or have coastal ecosystems, it should not be a surprise recognized subspecies that are restricted to tidal that the 25 species and the close to 50 subspe- marshes (Table 1). cies that they represent are disproportion- Tidal marshes present enormous adaptive ately endangered, threatened, or otherwise of challenges to animals attempting to colonize heightened conservation concern (Table 1). One them. The vegetation is often quite distinct from saltmarsh subspecies of ornate shrew from Baja adjacent upland or habitats. California (Sorex ornatus juncensis) may already Perhaps more severe are the challenges from be extinct. Federally endangered taxa include the physical environment (Dunson and Travis the harvest mouse (Reithrodontomys 1994). In particular, animals must cope with the raviventris), three western subspecies of the salinity of the water, the retained salinity in the Clapper Rail (Rallus longirostris), and the food supply, the regular ebb and fl ow of , Florida meadow vole (Microtus pennsylvanicus and the less predictable storm surges. Less obvi- dukecampbelli). The Atlantic subspecies of ous differences include basic geochemical pro- the salt marsh water snake (Nerodia clarkia tae- cesses, which, among other things can alter the niatus) is listed as threatened by the USDI Fish dominant coloration of the substrate. How these and Wildlife Service. Although only seasonally challenges shape individual physiological, mor- associated with saltmarshes, the Orange-bellied phological and behavioral adaptations has often Parrot (Neophema chrysogaster) of Australia and been the focus of excellent research, but efforts the Saunder’s Gull (Larus saunderi) of Asia, may to integrate the effect of these environmental be added to the global list of species that may factors are far fewer. depend upon saltmarshes. Many of the other The availability of tidal-marsh habitat as a subspecies listed in Table 1 are on various state setting for evolution and adaptation by colo- and regional lists for threatened or vulnerable nizing terrestrial vertebrate species has varied species. 4 STUDIES IN AVIAN BIOLOGY NO. 32

TABLE 1. VERTEBRATE TAXA RESTRICTED TO TIDAL MARSHES.

Species Subspecies Distribution Status Diamondback terrapin (Malaclemys terrapin) terrapin Atlantic coast of Endangered in centrata North America Massachusetts, tequesta threatened in Rhode rhizophorarum , species of macrospilota special concern in pileata six other states. littoralis saltmarsh snake (Nerodia clarkii) clarkii Gulf of Mexico and taeniata is taeniata Atlantic coast of threatened. Florida Carolina water snake (Natrix sipedon) williamengelsi Carolina coast of State species of North America concern. Northern brown snake (Storeria dekayi) limnetes Gulf of Mexico, North America Black Rail (Laterallus jamaicensis) a jamaicensis Atlantic, Gulf of Species of coturniculus Mexico, and Pacifi c conservation coasts of North concern (USDI Fish America and Wildlife Service 2002). Clapper Rail (Rallus longirostrus) obsoletus group Atlantic, Gulf of Populations in crepitans group Mexico, and Pacifi c California are coasts of North endangered. America Willet (Catoptrophorus semipalmatus) semipalmatus Atlantic coast of None North America Common Yellowthroat (Geothlypis trichas) sinuosa San Francisco State species of concern. Marsh Wren (Cistothorus palustris) palustris Atlantic coast of C. p. griseus and C. p. waynei North America marianae subspecies griseus of conservation marianae concern in Florida. Song Sparrow (Melospiza melodia) samuelis San Francisco Bay State of California pusillula subspecies of maxillaris concern. Sparrow (Melospiza georgiana) nigrescens Mid-Atlantic North Maryland subspecies American coast of concern. Savanna Sparrow (Passerculus sandwichensis) rostrata group Western Mexico Threatened in beldingi group and Southern and California. Baja California Seaside Sparrow (Ammodramus maritimus) Atlantic Coast Atlantic and Gulf One subspecies group of Mexico coasts endangered (A. m. Gulf Coast group mirabilis), one subspecies extinct (A. m. nigrescens). Species of national conservation con- cern (USDI Fish and Wildlife Service 2002). Salt Marsh Sharp-tailed Sparrow caudacutus Atlantic coast of Species of national (Ammodramus caudacutus) diversus North America conservation con- (non-breeding) cern (USDI Fish and Wildlife Service 2002). Nelson’s Sharp-tailed Sparrow subvirgatus Atlantic and Gulf Species of national (Ammodramus nelsoni) alterus of Mexico coast of conservation con- North America cern (USDI Fish and (non-breeding) Wildlife Service 2002). TIDAL MARSHES—Greenberg 5

TABLE 1. CONTINUED.

Species Subspecies Distribution Status Slender-billed Thornbill (Acanthiza iradelei) rosinae South coast of None Australia Masked shrew (Sorex cinereus) nigriculus Tidal marshes at None mouth of Tuckahoe river, May, New Jersey Ornate shrew (Sorex ornatus) sinuosus San Pablo Bay, State of California salarius Monterey Bay, subspecies of salicornicus Los Angeles Bay, concern. Extinct? juncensis El Socorro marsh, Baja California. Wandering shrew (Sorex vagrans) halicoetes South arm of San State of California Francisco Bay subspecies of concern. swamp rabbit (Sylvilagus aquaticus) littoralis Gulf coast Salt marsh harvest mouse raviventris San Francisco Bay Both California and (Reithrodontomys raviventris) halicoetes federal endangered species. Western harvest mouse distichlis Monterey Bay, No status. State of (Reithrodontomys megalotis) limicola Los Angeles Bay California subspecies of concern. California vole (Microtus californicus) paludicola San Francisco Bay, Subspecies sanpabloenis San Pablo Bay, sanpabloenis and halophilus Monterey Bay, stephensi are stephensi Los Angeles coast California sub- species of concern. Meadow vole (Microtus pennsylvanicus) dukecampbelli Gulf Coast, Federally nigrans Waccasassa Bay in endangered. Levy County, and Suwannee National Wildlife Refuge, Florida; East coast Chesapeake Bay Area White-tailed deer (Odocoileus virginianus) mcilhennyi Gulf coast None a Black Rail is included, although small populations of both North American subspecies can be found in inland freshwater marshes (Eddleman et al. 1994).

THREATS TO TIDAL SALTMARSHES http://spo.nos.noaa.gov/projects/population/ population.html). The im p act of human popu- As we have suggested, the threats to the lations around major navigable estuaries where already local and restricted saltmarsh taxa are most tidal marsh is found is undoubtedly higher a bellwether of the overall threats to the integ- than random sections of coastline. In particular, rity of salt marsh ecosystems. The following the fi lling and development of the shoreline of represents some of the major environmental tidal estuaries such as the San Francisco and issues facing the small amount of remaining Chesapeake bays and the Rio Plata has led to tidal marsh. the direct loss of large areas of saltmarsh. The loss of >80% of the original wetlands around San DEVELOPMENT Francisco Bay is of particular concern (Takekawa et al., chapter 11, this volume), since its three Coastal areas along protected temperate major embayments support more endemic tidal shorelines are prime areas for human habitation. marsh taxa than any other single coastal locality. By the end of the last century, 37% of the world’s population was found within 100 km of the coast GRAZING AND AGRICULTURE (Cohen et al. 1997). At the same time, 42% of the U.S. population lived in coastal counties along Marshes are often populated by palatable the Pacifi c, Atlantic, and Gulf of Mexico (NOAA and nutritious forage plants and hence have 6 STUDIES IN AVIAN BIOLOGY NO. 32 been directly grazed or grasses have been Meadowlands in the Hudson River estuary harvested for hay. Harvesting salt hay for for- (Sipple 1971). On an even larger scale, the bal- age and mulch was an important industry in ance between fresh-water fl ow and salt-water marshes along the east coast of North America intrusion has been the subject of considerable in the 18th and 19th centuries (Dreyer and interest in the estuaries of the Suisun Bay and Niering 1995). Although no longer a common lower Sacramento-San Joaquin deltas of the San practice in North American tidal marshes, the Francisco Bay area (Goman 2001). The California use of coastal wetlands to support livestock Water Project has doubtlessly infl uenced this, still occurs in the maritime provinces of Canada but early Holocene shifts in plant composition and is common in Europe and parts of South suggest natural variation in the pattern of salt America. water incursion has been profound. Apart from grazing and haying over the On a micro-scale, saltmarshes have been var- course of human history, large and unknown iously ditched for insect control (Daiber 1986) areas of tidal marsh have been diked and and opened with large water impoundments to converted to agricultural use, such as the low provide habitat for insect control and to provide countries of Northern Europe (Bos et al. 2002), habitat for waterfowl (Erwin et al. 1994, Wolfe areas of rice farming in Korea and China, and 1996). In some areas, human engineering of salt production. water distribution and vegetation in marshes A more profound change than the addition has all but replaced the natural engineering of grazing livestock to many marsh systems is of wildlife—particularly the muskrat (Ondatra the loss of large grazing animals towards the zibethicus; Errington 1961). end of the Pleistocene (Levin et al. 2002). We know from studies of reintroduced horses, that MARSH BURNING tidal marsh grasses—particularly smooth cord- grass (Spartina alternifl ora)—are highly palat- Lightning fi res can be an important source of able and preferred forage (Furbish and Albano natural disturbance to coastal marshes, occur- 1994). In many marshes the largest vertebrate ring at particularly high frequencies along the herbivores have shifted from ungulates to micr- southern Atlantic and Gulf coasts (Nyman otine and cricitid rodents. Nowadays, the most and Chabreck 1995). The frequency of marsh important herbivores in some marshes may be burning has increased due to human activities, snails and snail populations are controlled by including the purposeful use of fi re as a man- crabs (Sillman and Bertness 2002). But in the agement tool to increase food for waterfowl and Tertiary and Pleistocene, large mammals might trappable wildlife. However, the effect of such have been keystone herbivores in tidal marsh management on non-target organisms and eco- systems. It would be fair to say that the ecologi- system function is just beginning to be evalu- cal and evolutionary impact of the loss of such ated (Mitchell et al., this volume). herbivores is not fully understood (G. Chmura, pers. comm.) INVASIVE SPECIES

DITCHING, DEVELOPMENT, AND CHANGES Coastal ecosystems have been on the receiv- IN HYDROLOGY ing end of human-caused introductions that have resulted in species invading and chang- Tidal marshes have borne the brunt of an ing tidal marshes. The most critical inva- array of management activities that either sions have consisted of dominant tidal-marsh directly or indirectly affect their functioning. plants, because as they take over marshlands, Barriers to or canalization of tidal fl ow can they change the face of the habitat. Species disrupt natural cycles of inundation. The reduc- of Spartina have been prone to establishing tion of tidal fl ow has been implicated in major themselves on foreign (West Coast of vegetation changes in tidal marshes in Southern the US, China, parts of Northern Europe, New California (Zedler et al. 2001). Water manage- Zealand, and Tasmania). Even along its native ment projects for creating shipping navigation shoreline, smooth cordgrass is spreading as a channels have had a particularly large impact result of nitrifi cation and other environmental on the coastal marshes of the Mississippi Delta changes (Bertness et al 2002). The common (Mitsch and Gosselink (2000). On the other reed (Phragmites australis), a native species, has hand, upstream impoundment of water may spread in the high marshes of eastern North reduce the input of freshwater and induce salt America, often creating large barren monocul- water incursions into freshwater systems. Shifts tures (Benoit and Askins 1999). towards higher salinity over the past 150 yr We have focused on how invasions of have been documented for the marshes of the dominant plant species change the basic habitat TIDAL MARSHES—Greenberg 7 structure and productivity in many, as yet communities allows marsh invasion. Depending poorly understood, ways. Major changes have upon the shape of the estuarine basin and the occurred in the benthic fauna of major North land use on the lands above the maximum American estuaries (Cohen and Carlton 1998) high-tide line, the possibility of upland expan- and the effect this has had on the feeding ecol- sion may be curtailed along many coastlines. ogy of tidal marsh vertebrates has not been well Estimates for coastal loss as a result of documented. Vertebrate species themselves are sea-level rise range from 0.5–1.5% per year. often invasive, and the tidal-marsh fauna itself Global warming may result in other, less has been dramatically changed through human obvious impacts on coastal marsh systems. introductions. Species of Rattus and the house Perhaps of equal concern as the loss of marsh- mouse (Mus musculus) are now distributed in land is the change in salinity resulting from marshes around the world. The rats, in particu- salt-water intrusion into brackish-marsh sys- lar, are known to be important nest predators and tems. The actual warming itself may favor the are hypothesized to have a negative impact on spread of lower latitude species into higher endangered taxa, such as the Clapper Rail. Other latitude coastlines. Warmer conditions may predator populations, including red fox (Vulpes also favor the increase in the seasonal activity vulpes) and Virginia opossum (Didelphis virgin- of mosquitoes and other disease-transmitting iana), have spread through human introductions insects and help the spread of associated dis- and activities. The nutria (Myocastor coypus) has eases. Finally, increases in atmospheric carbon spread throughout the southeastern US resulting dioxide (CO2) have a demonstrable impact on in severe levels of grazing damage. Although we the productivity and transpiration of salt-marsh know of no introduced breeding bird species, a plants. These effects vary between species and variety of reptiles have colonized mangroves may shift the mix of tidal marsh dominants. and subtropical saltmarshes of Florida. Already it has been demonstrated that increases 3 4 in CO2 favor the spread of C versus C plants TOXINS, POLLUTANTS, AND AGRICULTURAL RUN-OFF (Arp et al. 1993).

Estuaries receive run-off from agricultural WHAT THIS VOLUME IS ABOUT fi elds and urban development spread over large watersheds. Tidal marshes are often In this volume, the authors collectively sprayed directly with pesticides, a practice that provide a sweeping view of what we know will probably increase under the threat of emer- about vertebrates—primarily terrestrial verte- gent mosquito-borne diseases, such as West brates—in the highly threatened tidal-marsh Nile virus. In addition, tidal marshes that fringe systems. The contents provide a broad view of estuaries also bear the brunt of any oil or chemi- tidal-marsh biogeography, more focused dis- cal spills into the marine environment that drift cussions of adaptations of different taxa to the into the shores. The effects of pollution are both challenges of tidal-marsh life, and a compre- acute and long term; the latter including the hensive account of the major conservation and effects of increased nutrient loads into the tidal- management issues facing marshes and their marsh ecosystem and the former comprised of wildlife. The following provides a brief guide to the toxic effects of chemicals to the vegetation the narrative trail we explore. and wildlife (Clark et al. 1992). The impact on dominant vegetation of increased nitrogen BIOGEOGRAPHY inputs into tidal marshes has been documented, at least for marshes along the Atlantic Coast of We examine what is known—from both North America (Bertness et al. 2002). direct evidence and inference—about the changes in the quantity and distribution of INCREASE IN CARBON DIOXIDE, SEA-LEVEL RISE, tidal marshes from the Tertiary to recent times, CHANGES IN SALINITY, AND GLOBAL WARMING with a focus on the San Francisco Bay estuar- ies, home of the greatest single concentration Sea level is rising in response to global of endemic vertebrate species and subspecies. increases in atmospheric temperatures. If, on Having set the historical stage, we examine a local scale, coastline accretion does not keep the distribution of tidal marshes and their pace with this rise, then the leading edge of vertebrate biota throughout the world. The coastal marshes will become permanently disparate distributional literature for mammals inundated and lost as wildlife habitat. Over and birds, and as much as possible, reptiles and time, becomes middle and then amphibians has been sifted through to deter- with increasing sea levels. New high mine which species of these taxa occupy tidal marsh forms after major disturbance of upland marshes along different coasts and on different 8 STUDIES IN AVIAN BIOLOGY NO. 32 continents. Emphasis is placed on the distri- change. We fi nally turn to more synthetic treat- bution of differentiated taxa (subspecies and ments of environmental issues outlined above species) that occupy tidal marshes in different with chapters focusing on sea-level rise, inva- regions. Distributional patterns are synthesized sive species, toxins (focusing on Clapper Rails), and some preliminary hypotheses to explain the and the effect of active salt-marsh management, distributions are proposed. In addition, some of including burning, open-water management, the features that characterize successful colo- and mosquito-control efforts. nists of tidal marshes are explored. If nothing else is accomplished, we hope In recent years, molecular phylogenies of that we will bring greater attention to the con- groups that feature tidal-marsh taxa have been servation of the tidal-marsh endemics. The fi rst developed and the genetic structure of tidal step towards a more concerted conservation marsh taxa has been detailed as well. This new effort is a systematic source of information on information allows us to begin to estimate the the population status and long-term trends of length of historical association of various taxa saltmarsh vertebrate populations. To catalyze and how this has affected adaptation to tidal this, we provide a collaborative chapter outlin- marshes. ing approaches to the long-term monitoring of tidal-marsh birds. Future collaborations should ADAPTATION TO TIDAL MARSHES focus on establishing similar systems for mam- mals and, in some areas, snakes and turtles. Tidal marshes present myriad adaptive Such monitoring programs are only a fi rst opportunities and challenges to the few species step. We hope they will provide the backbone that colonize them. In a series of chapters, adap- to an active research program on tidal-marsh tation to tidal marsh life is explored from a vari- vertebrates. ety of perspectives. Focusing on nesting biology We end the volume with a menu of exciting of birds, we explore the role of tidal cycles and and important areas for both applied and basic fl ooding events in shaping this central feature research. By following these research leads, we of avian ecology. Adaptations to saline environ- will achieve the ability to better manage and ments are examined by focusing on the physiol- protect the healthy, restore the degraded, and ogy of salinity tolerance in sparrows, a group reestablish the lost marshlands, while achieving that is not generally known for its maritime a greater understanding of how animals adapt distribution. In the course of focusing in on to this unique environment. sparrow adaptations, we review the different behavioral, physiological and morphological ACKNOWLEDGMENTS adaptations of vertebrates in brackish to salty environments. The volume further explores This publication grew from a symposium shared adaptations to the tropic opportunities held in October 2002 at the Patuxent Wildlife with emphasis on the bill morphology of spar- Visitors Center which brought together scien- rows and background matching coloration of a tists from throughout North America to focus suite of terrestrial species. Finally, we examine on the scientifi c and conservation issues fac- shifts in communication, demography and ing vertebrates in tidal marshes. We thank J. social organization that accompany successful Taylor and the USDI Fish and Wildlife Service occupation of tidal marshes. and the Smithsonian Migratory Bird Center for providing fi nancial support to the symposium. CONSERVATION BIOLOGY: ANTHROPOGENIC We also would like to extend our appreciation ENVIRONMENTAL IMPACTS ON TIDAL MARSHES OF THE to the Friends of Patuxent and the staff of the PREVIOUS AND NEXT CENTURY visitor center and the Smithsonian Migratory Bird center for logistical support. We received Tidal marshes have already been reduced in incisive reviews of all of the manuscripts from area, fragmented, ditched, and altered by the 36 subject-matter experts and this has greatly damming of streams and rerouting of water improved the quality of the publication. The sources. To place the environmental issues authors of papers in the volume were encour- facing saltmarsh vertebrates in context, we aged to revise their contributions to make will provide regional reviews of four North them as inductive as possible. This involved American tidal-marsh areas—Northeast, a good deal of time and patience over and Southeast, San Francisco Bay, and southern beyond what is normally expected contribu- California—that together present the range tors and we (the editors) appreciate this extra of conservation issues. Two chapters address effort. I thank S. Droege, M.V. McDonald, and species specifi c approaches to evaluating both M. Deinlein for comments on a draft of the local- and landscape-level effects of habitat introduction. The following provided funds to TIDAL MARSHES—Greenberg 9 support publication of this volume: Canadian of California, Berkeley; University of South Wildlife Service; Migratory Bird Center, Dakota; USDI Fish and Wildlife Service; USGS, Smithsonian Institution; The National Museum Alaska Cooperative Fish and Wildlife Research of Natural History, Smithsonian Institution; Unit; USGS, Western Ecology Research Center; Biology Department, Northwestern State Department of Biology, University of South University; USGS Patuxent Wildlife Research Dakota; and Department of Biological Sciences, Center; Department of Geography, University Wright State University. BIOGEOGRAPHY AND EVOLUTION OF TIDAL-MARSH FAUNAS

Bay-capped Wren-spinetail (Spartonoica maluroides) Drawing by Julie Zickefoose