Studies in Avian No. 19:2-26, 1999.

CONSERVATION OF IN THE WESTERN HEMISPHERE

PETER D. VICKERY, PABLO L. TUBARO, Jo& MARIA CARDOSO DA SILVA, BRUCE G. PETERJOHN,JAMESR. HERKERT, AND ROBERTOB. CAVALCANTI

“The sweeping vista of the worlds’ natural -be they steppes, savannas, range- lands, punas or prairies-occupy nearly seven billion hectares; over half of the earths’ land surface. Add to that figure the vast area converted to of low intensity agriculture and grasslands become second only to the oceans in terms of direct dominance of the planets’ ecosystems. They govern, directly, the livelihoods of hundreds of millions of neoole.” -C. Imboden (i988:vii).

Research on and interest in grassland birds usual adaptations, such as large body size and have increased considerably in the past 20 yr. cursorial habits, have evolved in grassland birds. There are several reasons for this heightened in- And the ability to readily observe many behav- terest. Foremost, it is clear that populations of iors makes these ideal for research (e.g., many grassland birds have declined sharply Wheelwright and Mauck 1998). throughout the Western Hemisphere (e.g., Buch- er and Nores 1988, Cavalcanti 1988, Fjeldsg GRASSLAND HABITATS IN THE 1988, McNicholl 1988, Knopf 1994, Peterjohn WESTERN HEMISPHERE and Sauer 1999). In , populations of at least 13 species of grassland birds declined Grassland ecosystems occur in a variety of significantly between 1966 and 1995 (Peterjohn forms and are affected by geology, geography, and Sauer 1999). And as a group, North Amer- moisture, soil type, elevation, , and dis- ican grassland birds have experienced “steeper, turbance regime (Kantrud 1981, Vickery et al. more consistent, and more geographically wide- in press). In this volume, we define a grassland spread declines than any other behavioral or as any extensive area that is dominated ecological guild,” largely because of habitat loss by more than 50% grass () or sedge (Cy- and degradation (Knopf 1994:251). Similar de- peraceae) cover and that generally has few scat- clines are also occurring in , tered shrubs (< 4 m high) and trees. We have where species such as Pampas Meadowlark generally excluded habitats that are dominated (StumelZu dejilippii; Tubaro and Gabelli 1999), by more than 50% shrub cover, such as chap- Saffron-cowled Blackbird (Agelaius jlavus; Fra- arral. ga et al. 1998), and (Silva In addition to such obvious grassland habitats 1999) have declined in the past 20 yr. Indeed, as tallgrass and shortgrass prairies, pampas, and Collar et al. (1992:35) describe the “near-total Patagonian grassland, we include sedge-domi- destruction of open grasslands in south-east Bra- nated , alpine ridges and barrens, puna, zil . . and in the vast central planalto . . as one and paramo. We also include the longleaf of the great ecological catastrophes in South (Pinus palustris) ecosystems of the southeastern America.” and the pine (Pinus spp.) Another reason for the increased research in- and savannas of because it is clear that terest in grassland birds is changing agricultural several species of birds, among them Bachmans’ practices. For example, the U.S. Department of Sparrow (Aimophih aestivalis), Striped Sparrow Agricultures’ Conservation Reserve Program (Oriturus superciliosus), and Sierra Madre Spar- (CRP), which has taken more than 14 million ha row (Xenospiza baileyi), have adapted to the of cropland out of production under IO-yr con- graminoid ground cover beneath these forests. tracts, has made it possible to examine regional, Although these ecosystems are generally viewed and even continental, effects of changing land- as forests, the above species appear to occupy scapes on grassland birds (e.g., Lauber 1991, them as a form of grassland, not , habitat. Reynolds et al. 1994, Herkert 1998). Addition- Bachmans’ Sparrow, for example, continues to ally, the CRP has provided excellent opportu- occupy clear-cut glades after forest removal nities to study colonization, habitat use, and (Dunning 1993). In North America, we also in- nesting success in different regions and under clude as grassland wet-mesic upland habitats different ecological conditions. Finally, grass- where the soil is often saturated but not inun- land birds are also fascinating from ecological dated for long periods; we do not include fresh- and evolutionary perspectives. Distinctive or un- water, brackish, and saltwater wetlands where

2 INTRODUCTION-Vickery et al. 3

FIGURE 1. Distribution of major grassland ecosystems in North America and Mexico prior to European settlement.Alpine zonesabove tree line have not been depicted. This map was adapted and modified from two primary sources, Risser et al. 1981 and Environment 1998. standing water is present for long periods, how- grasslands in southern and and ever. pampas in eastern Argentina, , and Native grasslands in the Western Hemisphere southernmost . Brushier savanna grass- extend from high- sedge meadows in the lands include chaco, cerrado (particularly “cam- tundra of North America to pampas and Pata- po limpo” and “camp0 sujo” in central Brazil), gonian grasslands in southern South America Beni savannas, Amazonian savannas, Guianan (Figs. 1 and 2). In North America, a mosaic of savannas, and espinal. Native South American tundra/barrens habitats forms the northernmost grasslands also include such mesic ecosystems grassland component. In the temperate region, as the llanos of and and the the most extensive grasslands historically in- of southwestern Brazil, where seasonal cluded the shortgrass prairie and southern mixed flooding for several months each year is fol- prairie of the western Great Plains and the tall- lowed by pronounced dry seasons when most grass prairie and northern mixed prairie of the surface water disappears (Soriano 1991, Diner- midwestem United States and Canada (Knopf stein et al. 1995, Stotz et al. 1996; Fig. 2). 1988; Fig. 1). Although they were less exten- sive, bunchgrass shrubsteppe (including palouse DEFINING GRASSLAND BIRDS prairie) and California grasslands in the west, “The difficulty in defining grassland species desert grasslands in the southern United States results from the fact that grassland itself is not and Mexico, and palmetto (Serenoa repens) dry easy to define precisely. How small may a prairie prairie in were historically all major be before it is a mere opening? Where does grass- grassland types in North America (Fig. 1). land stop and very open woodland begin? In South America, major native grassland How much sage is required before grassland be- comes some form of desert scmb?” ecosystems include high-altitude paramo and -R. M. Mengel (1970:283) puna grasslands (listed as Andean grasslands; Fig. 2) and mid-elevation monte grasslands (Fig. Few would argue that species such as Lesser 2). Low-elevation grasslands include Patagonian (Rhea pennatu), Spragues’ (Anthus STUDIES IN AVIAN BIOLOGY NO. 19

FIGURE 2. Distribution of major grassland ecosystems in South America prior to European settlement. Puna and paramo grasslands have been classified as Andean grasslands. This map was adapted and modified from two primary sources, Cabrera and Willink 1980 and Dinerstein et al. 1995. spragueii), McCowns’ Longspur (Calcarius alized that grasslands extend along a moisture mccownii), and Wedge-tailed Grass- (Em- gradient-from arid prairies to wet meadows berizoides herbicola) are completely adapted to and marshes-and that defining the limits of this grassland habitats and should be considered gradient in relation to the birds that occupy these grassland specialists. Classification seems obvi- habitats can be, and is, somewhat arbitrary. In ous in these cases, as all of these species use addition, he noted that grassland ecosystems fre- grassland habitat for all their life-history needs. quently intergrade with forested and other hab- But for many other species, determining which itat types, making it difficult to define the limits ones should be considered grassland birds quick- of some grassland types. In the Cerrado of cen- ly becomes complicated and invariably some- tral Brazil, for example, “camp0 limpo,” or what subjective. Are Western Kingbirds (Tyrun- open grasslands, are interspersed with “camp0 nus verticalis), Red-winged Blackbirds (Age- sujo,” or grasslands with scattered trees and Zuius phoeniceus), and Blue-black Grassquits shrubs; and campo sujo may blend into “cerra- (Volutinia jucarinu), for instance, also grassland dHo,” which is even more densely forested (Ei- birds? What about jaegers (Stercorurius spp.)? ten 1972). In the United States, tallgrass prairie Although each of the three jaeger species spends intergrades into (Quercus) savannas in the 9 mo a year on the open ocean, all require open Midwest, and in the Southeast the dry palmetto tundra for nesting. And nest success in Pomarine prairies of central Florida merge into longleaf Jaegers (S. pomarinus), as in Snowy Owls (Nyc- pine savannas, called “flatwoods.” Consequent- tea scandiucu), depends strongly on collared ly, it is often difficult to delineate where grass- lemming (Dicrostonyx torquatus) populations land ends and forest begins. Furthermore, dif- (Pitelka et al. 1955). ferent species of birds may respond differently Mengel (1970) recognized the difficulties in- to the same ecotone. In Florida, Grasshopper herent in trying to define grassland birds. He re- Sparrows (Ammodrumus suvannurum Jloridan- INTRODUCTION-Vickery et al. 5 us) breed only on treeless palmetto prairies and lands, although [were] not restricted to them” do not occupy savanna flatwoods. Bachmans’ (Mengel 1970:283). This geographic emphasis Sparrows, however, breed commonly in both created ecological inconsistencies. Wilsons’ habitats. From the perspective of these two sym- (Phalaropus tricolor) and Franklins’ patric grassland sparrows, the definition of Gull (Larus pipixcan), for instance, were con- grassland habitat is quite different. sidered “primary” grassland species, but the This process is further complicated by the fact ecological connections to grassland habitat for that some grassland species use different habi- either species are limited. Wilsons’ Phalarope, tats in different parts of their ranges. Savannah for example, generally breeds along the edges of Sparrows (Passerculus sandwichensis) are prairie potholes and open marshes but makes lit- known to use an extraordinary array of open tle use of the surrounding grassland habitat. habitats throughout their extensive range We prefer an ecological basis for defining (Wheelwright and Rising 1993). In eastern Tex- grassland birds. We thus define a grassland bird as, Bachmans’ Sparrows typically breed in open as any species that has become adapted to and pine forests, but in central Florida they com- reliant on some variety of grassland habitat for monly breed on treeless palmetto prairies (Dun- part or all of its life cycle, be it breeding (either ning 1993, Shriver et al. 1999). Although there nesting or feeding), migration, or wintering. are similarities in these habitats, notably the pre- Grassland birds often, but not necessarily, nest dominant graminoid ground cover, the differ- on the ground. Thus, we consider Swainsons’ ences are also obvious and striking. Hawk (Buteo swainsoni), Mountain Plover Finally, the fact that so many grassland hab- (Charadrius montanus), and Long-billed itats have been severely altered by modern ag- (Numenius americanus) to be grassland birds, ricultural practices further complicates efforts to despite the fact that Swainsons’ Hawks nest in define grassland birds. Many grassland species trees and that often use a variety of in- in the Western Hemisphere are presently occu- tertidal habitats in the nonbreeding seasons. pying artificial habitats that did not exist 200- Along the moisture gradient, we include as 300 yr ago. For example, Northern Harriers grassland birds four species of South American (Circus cyaneus), Short-eared Owls (Asio jkzm- geese (Chloephaga spp.), Sedge Wren (Cistotho- meus), Henslows’ Sparrows ( hen- rus platensis), Henslows’ Sparrow, and Le slowii), and many other grassland birds now Contes’ Sparrow (Ammodramus leconteii), but breed on reclaimed surface coal mines in west- we exclude birds that normally breed over or em Pennsylvania, West Virginia, Ohio, and In- adjacent to standing water, among them Swamp diana. These newly created “prairies” did not Sparrow ( georgiana), Nelsons’ exist 100 yr ago, but they appear to be providing Sharp-tailed Sparrow (Ammodramus nelsoni), important refugia for threatened species in these Seaside Sparrow (A. maritima), some waterfowl regions (D. Brauning, pers. comm.). Conversely, (), and most rails (Rallidae) and herons some steppe or forest birds are invading open (Ardeidae; but see Sample and Mossman 1997 habitats because as early settlers cleared the land for a different perspective). Along the shrub gra- for agriculture, they provided the perches and dient, we consider Rufous-winged Sparrow refuges these species require (Gochfeld 1979, (Aimophilu carpalis) and Lark Sparrow (Chond- McNicholl 1988). Thus, it is necessary to have estes grammacus) to be grassland birds but not some understanding of habitat preferences prior Brewers’ Sparrow (Spizella breweri). We ex- to European settlement to determine whether clude species that occur commonly in grassland present-day habitat use reflects long-term evo- habitats but do not use the graminoid compo- lutionary patterns. nents of these habitats; examples include Pinyon Given the complexities in defining grassland Jay (Gymnorhinus cyanocephalus), which feeds habitats, how does one define the birds that use almost exclusively on shrub seeds, and aerial in- this variety of habitats? Are there common sectivores such as swifts (Apodidae) and swal- threads that help define grassland birds? And are lows (Hirundinidae), which only feed over these similarities consistent spatially and across grasslands. taxa? Finally, we include species that occupy wet- In midwestem North America, Mengel (1970) land, shrub, and forest edges adjacent to grass- recognized two groups of grassland birds based land habitats only when they make regular use on distribution and habitat selection. He relied of the grassland habitat away from edge (> 100 on limited geographic range and endemism to m). For example, we consider the American Bit- determine “primary” grassland birds, which tern (Botaurus Zentiginosus), which nests in prai- were restricted to the central Great Plains. He rie fragments and fields, and the various puddle identified as “secondary” grassland birds those that nest in upland fields far from wet- species that had “strong affinities with the grass- lands to be grassland birds. 6 STUDIES IN AVIAN BIOLOGY NO. 19

OBLIGATEAND FACULTATIVEGRASSLAND BIRDS Tierra de1 Fuego; the (Athene cuniculuria) breeds from southern Canada and Within our ecological definition of grassland Florida to the southern pampas of Argentina; birds, two groups can be reasonably separated. and the Sedge Wren, currently classified as a sin- Obligate grassland specialists are species that gle, widely distributed species, occurs from east- are exclusively adapted to and entirely depen- em North America to southern South America dent on grassland habitats and make little or no (AOU 1998). Only seven obligate grassland spe- use of other habitat types. Examples include cies in North America breed in both arctic/alpine Lesser Rhea, Bairds’ Sparrow (Ammodramus and temperate regions (Table 1). bairdii), and Pampas Meadowlark (Tables 1 and Although there are differences between arctic/ 3). Obligate grassland birds would almost cer- alpine breeders in North America (e.g., ptarmi- tainly become extinct without the appropriate gan [Lagopus spp.], jaegers, and buntings [Plec- grassland habitat. trophenax spp.]) and temperate or steppe breed- Facultative grassland specialists use grass- ers (e.g., prairie-chickens [Tympanuchus spp.], lands as part of a wider array of habitats. In sparrows [ spp.], and meadowlarks general, these species are not entirely dependent [Sturnella spp.]), the similarities between grass- on grasslands but use them commonly and reg- land birds of these regions are pronounced. ularly. If the appropriate types of grassland hab- Many genera are shared between the arctic/al- itat were destroyed, populations of some facul- pine and temperate regions, despite the fact that tative grassland birds would diminish but prob- the breeding ranges of most species are restrict- ably would not completely disappear. Examples ed to either the arctic/alpine or temperate region of facultative grassland birds include Barn Owl (Table 1). For example, McCowns’ Longspurs (Tyto alba), Loggerhead Shrike (Lank ludovi- and Chestnut-collared Longspurs (Calcarius or- cianus), Clay-colored Sparrow (Spizella palli- natus), both of which occur in shortgrass and da), and Blue-black Grassquit (Tables 2 and 4). mixed prairies, are replaced by Smiths’ Long- The number of obligate species found in spurs (C. pictus) and Lapland Longspurs (C. grasslands is not especially great compared with Zapponicus) farther north. The same allopatric other habitats. In North America, Mexico, and relationships are found among hawks (Buteo the , for example, there are 59 species spp.), falcons (Falco spp.), plovers (Charadrius of obligate grassland species from 35 genera spp.), curlews (Numenius spp.), (Limosa (Table 1) compared with more than 180 species spp.), shrikes (Lanius spp.), and . of obligate forest-dwelling species. With 124 In South America, taxonomic affinities be- species from 59 genera (Table 3), South Amer- tween high-altitude and lowland temperate birds ica supports many more obligate grassland spe- occur in hawks (Bureo spp.), caracaras (Phal- cies than do North America, Mexico, and the coboenus spp.), (Attagis and Thino- Caribbean. Not surprisingly, facultative grass- torus spp.), doves (Metriopelia and Zenaida land species are more numerous than obligates; spp.), tyrant flycatchers (Tyrannidae), and seed- there are 97 species of facultative grassland eaters (Emberizinae). It should be noted that the birds in North America, Mexico, and the Carib- geographic scope of research in this volume is bean (Table 2) and 164 in South America (Table limited to birds that breed in the temperate 4). regions of North, Central, and South America. DISTRIBUTION OF GRASSLAND BIRDS In North America, the geographic separation between arctic/alpine and temperate breeders Obligate grassland specialists have a wide largely disappears in the nonbreeding season. geographic distribution. They occur from north Although a few species such as ptarmigan are of the to the southern tip of Ar- largely resident, many arctic/alpine species mi- gentina and Chile and as far offshore as the Islas grate medium to long distances and can be found Malvinas () and, 1770 km east wintering with temperate grassland breeding of Tierra de1 Fuego, South Georgia Island (Ta- birds. A few arctic breeders, such as American bles 1 and 3). As a , pipits (Anthus spp.) Golden-Plovers (Pluvialis dominicus) and Eski- have the widest breeding range of any Western mo Curlews (Numenius borealis), join more Hemisphere , extending from arctic temperate breeders such as Upland Canada (American Pipit [A. rubescens]) to South (Bartramia longicauda) and Bobolinks (Doli- Georgia Island (South Georgia Pipit [A. antarc- chonyx oryzivorus) to winter on the pampas in ticus]). Argentina and southern Brazil. Only three obligate grassland species are widely distributed across the Americas, howev- LOSS OF GRASSLAND HABITAT er. The Short-eared Owl breeds discontinuously Since the early 1800s most grassland ecosys- from the arctic regions of Canada and to tems in North America have been profoundly INTRODUCTION-Vickery et al. 7

altered by agricultural activities, and many are pastures and to deter aboriginal Indians trans- now among the continents’ most endangered formed the Pampas and were commented on by ecosystems (Table 5; Noss et al. 1995). In most Darwin (1876). The most profound changes, areas, habitat loss has exceeded 80% (Samson however, occurred after 1890 with the expansion and Knopf 1994, Noss et al. 1995) and where of agriculture in South America. During the first soil and topography are well suited for crops, quarter of the twentieth century, the negative ef- less than 0.1% of native prairie remains (Samson fect of agriculture on grassland species such as and Knopf 1994). Since 1850, for example, the the Strange-tailed Tyrant (Alectrurus risoru) be- decline of tallgrass prairie (estimated to be 88- came evident (Wilson 1926). Since 1970, in- 99%) exceeds that reported for any other major creased use of agrochemicals and technology ecosystem in North America (Samson and has contributed to the intensive use of grass- Knopf 1994, Noss et al. 1995). Similarly, in lands. In the northern Pampas, silviculture is Florida only 19% of the original palmetto dry also reducing grassland area. prairie remains, with most of this habitat having In Brazil, more than 50% of the Cerrado has been converted to citrus groves and improved been converted for human uses since 1950 (Sil- cattle pastures since about 1950 (Shriver and va 1995), and today the region is seen as a Vickery 1999). promising area for “carbon bank” mitigation Native temperate grasslands in the Western (planting trees to absorb and convert carbon di- Hemisphere have experienced major, sometimes oxide) against deforestation in Amazonia (Cav- profound, losses from agriculture, range man- alcanti 1999a). The trend in the Cerrado is an agement, and urban development. Some grass- ever-growing rate of destruction of natural hab- land species, however, notably Picazuro Pigeon itats. Recent estimates indicate that approxi- (Columba picazuro), Spot-winged Pigeon (C. mately 75% of this biome can be converted to maculosa), Eared Dove (Zenaidu auriculatu), pastures and agriculture fields to produce about Grasshopper Sparrow, Dickcissel (Spizu ameri- 100 million ton of crops and meat annually (Ma- cana), Bobolink, and meadowlarks have adapted cede 1994). An analysis of satellite images from successfully to these modified landscapes (Gra- 1987 to 1993 covering the entire Cerrado region ber and Graber 1963, Bucher and Nores 1988, showed that 67% of the land surface (excluding Rodenhouse et al. 1995, OConnor’ et al. 1999). non-Cerrado habitats) was in a disturbed or In the midwestem United States, agricultural highly disturbed condition as a result of human lands have provided adequate breeding habitat activity (Mantovani and Pereira 1998). for many species, but in the past 50 yr conver- In the Pampas, less than 5% of the land was sion of pastures and hayfields into rowcrops used for agriculture in 1890, but in high, mesic (e.g., corn [Zeu mays] and soybeans [Glycine areas that figure is now greater than 50%. In the mux]) and shortened cutting rotations of hay more arid and lowland areas of the Pampas, till- have made much of this habitat unsuitable and age agriculture represents less than 10% of the have become major threats to grassland bird land use, but cattle grazing over seeded or nat- populations (Herkert 1991, 1997; Warner 1994; ural pastures is widespread (Leon et al. 1984). Herkert et al. 1996). It is clear that similar rates of habitat loss have In Canada, approximately 25% of native taken place elsewhere in Central and South grasses remain, but losses continue; 570,000 ha, America, from northern Mexico (Manzano-Fi- or approximately 6% of what remained, were scher et al. 1999) to Argentina (Collar et al. lost between 1991 and 1996 (Statistics Canada 1992, Dinerstein et al. 1995, Tubaro and Gabelli 1997). Southeastern Alberta and southwestern 1999). It is distressing that conversion of native Saskatchewan contain much of the remaining grasslands for agricultural purposes in South native prairie, and several grassland bird species, America has been “so utterly neglected as an among them Bairds’ Sparrow and Spragues’ Pip- international conservation issue” (Collar et al. it, are abundant there (Price et al. 1995). Grazing 1992:35). In Brazil, remnants of native grassland pressure has generally increased on remaining are now largely restricted to national parks (Col- native grasslands (Gayton 1991). lar et al. 1992). In Argentina, there is no national In South America, modernization and me- park protecting a representative sample of pam- chanical changes in agricultural practices have pas (Burkart and Valle Ruiz 1994). Moreover, a had similarly adverse effects on breeding birds recent attempt to create a national park in the (Bucher and Nores 1988, Cavalcanti 1999b, Tu- Pampas failed because the landowner plowed baro and Gabelli 1999). Horses and cattle were and destroyed the grassland on his hacienda introduced to the Pampas in 1535, and by 1750 when he realized the government was consid- feral populations were so common that they sup- ering appropriating the area (I? Tubaro, pers. ported a growing industry of exporting hides. comm.). The most acutely imperiled grasslands The effects of grazing and burning to improve in Central and South America are the Cerrado, 8 STUDIES IN AVIAN BIOLOGY NO. 19

TABLE 1. OBLIGATE GRASSLAND BIRDS OF NORTH AMERICA, MEXICO, AND THE CARIBBEAN

Breeding distribution

Sub- AUXICI tropical/ alpine Temperate Mexico Caribbean

Hawks Accipitridae Northern Harrier Circus cyaneus Swainsons’ Hawk Buteo swainsoni Ferruginous Hawk Buteo regalis Rough-legged Hawk Buteo lagopus Falcons Falconidae Aplomado Falcon Falco femoralis Partridge, , Old World quail Rock Ptarmigan Lagopus mutu.s White-tailed Ptarmigan Lqopus leucurus Sharp-tailed Grouse Tympanuchus phasianellus Greater Prairie-Chicken Tympanuchus cupido J Lesser Prairie-Chicken Tvmpanuchus pallidicinctus J Odontophoridae Montezuma Quail montezumae Ocellated Quail Cyrtonyx ocellatus Stone curlews Burhinidae Double-striped Thick-knee Burhinus histriatus Plovers, American Golden-Plover Pluvialis dominica Pacific Golden-Plover Pluvialis filva Mountain Plover Charadrius montanus Shorebirds Scolopacidae Upland Bartramia longicauda Eskimo Curlew* Numenius borealis Bristle-thighed Curlew Numenius tahitiensis Long-billed Curlew Numenius americanus Marbled Limosa ,fedoa Bairds’ Sandpiper bairdii Buff-breasted Sandpiper Tryngites subruficollis Gulls, jaegers Laridae Pomarine Jaeger Stercorarius pomarinus Parasitic Jaeger Stercorarius parasiticus Long-tailed Jaeger Stercorarius longicaudus Owls Strigidae Nyctea scandiaca Burrowing Owl Athene cunicularia J J J Long-eared Owl Asia otus J Short-eared Owl Asio frammeus J ; J Larks Alaudidae Homed Lark Eremophila alpestris J J J Wrens Troglodytidae Sedge Wren Cistothorus platensis J J Pipits American Pipit Anthus rubescens J J Spragues’ Pipit Anthus spragueii Emberizids Emberizidae Ruddy-breasted Sporophila minuta J Sicalis jlaveola Grassland Yellow-Finch Sicalis luteola J J INTRODUCTION-Vi&~ et al. 9

TABLE 1. CONTINUED

Sub- APZICI tropicaV Family alpine Temperate Mexico Canbbean

Cassin’s Sparrow Aimophila cassinii J Bachman’s Sparrow Aimophila aestivalis J Botteri’s Sparrow Aimophila botterii Striped Sparrow** Oriturus superciliosus :: Vesper Sparrow Poorcetes gramineus J Lark Calamospiza melanocorys Passerculus sundwichensis J j $ Grasshopper Sparrow Ammodramus savannarum J Baird’s Sparrow Ammodramus bairdii Henslow’s Sparrow Ammodramus henslowii 5 Le Come’s Sparrow Ammodramus leconteii J Sierra Madre Sparrow** Xenospizu baileyi J McCown’s Longspur Calcarius mccownii J Calcarius lapponicus Smith’s Longspur Calcarius pictus s Chestnut-collared Longspur Calcarius ornatu.7 J Snow Bunting nivalis J McKay’s Bunting Plectrophenax hyperboreus J Cardinals and allies Cardinalidae Dickcissel Spiza americana J Meadowlarks, blackbirds Icteridae Bobolink Dolichonyx oryzivorus Eastern Meadowlark Sturnella magna J Western Meadowlark Sturnella neglecta

Note: Tbn list wac derived from numerous ~ou~cec. mcludnng Bond 1971 Johnsgard 1981; Hayman et al. 1986; Raffaele 1989; Howell and Webb 1995; AOU 1998: and J L. Dunn. per\. comm. * Posibly extinct. ** Autecology poorly known chaco savannas, Pampas, and Beni savannas of grassland birds in North and South (), and more regionally, the savannas America (Collar et al. 1992, Knopf 1994, Her- near Veracruz and Tehuantepec, Mexico (Diner- kert et al. 1996, Stotz et al. 1996, Vickery et al. stein et al. 1995). in press). In South America, excessive hunting Although habitat loss is frequently viewed and illegal trapping have also contributed to primarily as conversion to cropland or other some grassland bird declines (Bucher and Nores uses, it also includes more subtle forms of deg- 1988, Collar et al. 1992, Fraga et al. 1998). radation, among them unnatural grazing re- In North America, most grassland bird popu- gimes, planting of exotic grasses, and succession lations have been declining for half a century to shrublands (Vickery et al. in press). In Pata- (Askins 1993, Peterjohn and Sauer 1999). Pop- gonia, overgrazing by sheep has degraded tall- ulations of at least 13 grassland species declined grass habitats (FjeldsH 1988), and in the western significantly between 1966 and 1996, whereas pampas of Argentina it is contributing to the populations of only 3 species are known to have spread of chaiiar trees (Geoffroea decorticans; increased during that period (Peterjohn and Anderson 1977). In North America, shortgrass Sauer 1999). There is additional concern be- prairie is adapted to intensive grazing by native cause these declines have prevailed across much herbivores, but contemporary cattle management of the continent. It is unlikely that there is a emphasizes rotations that maintain moderate single underlying cause of these declines; in- ground cover, which is less suitable for some stead, multiple causes are probably responsible. rare species such as Mountain Plover (Knopf It is clear, however, that these declines are not and Rupert 1999). local, isolated phenomena (Peterjohn and Sauer THE IMPETUS FOR GRASSLAND BIRD 1999). AND HABITAT CONSERVATION Similar declines have taken place throughout Habitat loss and degradation have been the South America, especially in lowland grasslands two most important factors influencing the de- (Bucher and Nores 1988, Fjeldsa 1988, Caval- 10 STUDIES IN AVIAN BIOLOGY NO. 19

TABLE 2. FACULTATIVE GRASSLANDBIRDS OF NORTH AMERICA,MEXICO,AND THE CARIBBEAN

Breedingdistribution

Sub- Arctic/ tropical/ Family alpilE Temperate Mexico Caibkan

Herons Ardeidae American Bittern Botaurus lentiginosus Cattle Egret Bubulcus Storks Ciconiidae Jabiru Jabiru mycteria New World vultures Cathartidae Turkey Vulture Cathartes aura Lesser Yellow-headed Vulture Cathartes burrovianus Waterfowl Anatidae Greater White-fronted Goose Anser albifrons Emperor Goose Chen canagica Snow Goose Chen caerulescens Rosss’ Goose Chen rossii Canada Goose Branta canadensis Brant Branta bemicla Gadwall Anas strepera American Wigeon Anas americana Mallard Anas platyrhynchos Blue-winged Teal Anus discors Northern Shoveler Anus clypeata Northern Pintail Anas acuta Green-winged Teal Anus crecca J :: Falcons Falconidae Crested Caracara Carcara plancus J American Kestrel Falco sparverius :: J Merlin Falco columbarius J :: Gyrfalcon Falco rusticolus Peregrine Falcon Falco peregrinus Prairie Falcon F&o mexicanus Partridge, grouse, Old World quail Phasianidae Gray Partridge* Perdix perdix J Ring-necked Pheasant* Phasianus colchicus Willow Ptarmigan Lagopus lagopus J :; New World quail Odontophoridae Scaled Quail squamata Elegant Quail Callipepla douglasii Northern Bobwhite virginianus J ; J* Black-throated Bobwhite Colinus nigrogularis Crested Bobwhite Colinus cristatus Rails Rallidae Yellow Rail Cotumicops noveboracensis Cranes Gruidae Sandhill Crane Grus canadensis J J Whooping Crane Grus americana Plovers, lapwings Charadriidae Black-bellied Plover Pluvialis squatarola Killdeer Charadrius vociferus J Shorebirds Scolopacidae Lesser Yellowlegs fravipes Willet Catoptrophorus semipalmatus Whimbrel Numenius phaeopus J INTRODUCTION-Vi&q et al. 11

TABLE 2. CONTINUED

Breeding dlstnbution

Sub- Arctic/ tropical/ Family alpine Temperate MeXlCO Caribbean

Hudsonian Godwit Limosa haenmstica Surfbird Aphriza virgata Red Knot Calidris canutus Sanderling Calidris alba Semipalmated Sandpiper Calidris pusilla Western Sandpiper Calidris maw-i Least Sandpiper Calidris minutilla White-rumped Sandpiper Calidris fuscicollis Pectoral Sandpiper Calidris melanotos Purple Sandpiper Calidris maritima Rock Sandpiper Calidris ptilocnemis Dunlin Calidris alpina Short-billed Limnodromus griseus Long-billed Dowitcher Limnodromus scolopaceus Common gallinago Wilsons’ Phalarope Phalaropus tricolor Gulls Laridae Franklins’ Gull Larus pipixcan Doves Zenaida macroura Common Ground-Dove Columbina passerina J :; Barn Owls Tytonidae Barn Owl Tyto alba J J Owls Strigidae Striped Owl Pseudoscops clamator Goatsuckers Caprimulgidae Lesser acutipennis Common Nighthawk Chordeiles minor Common Poorwill Phalaenoptilus nuttallii Tyrant flycatchers Tyrannidae Says’ Phoebe Sayornis saya Ash-throated Flycatcher Myiarchus cinerascens Cassins’ Kingbird Tyrannus vociferans Western Kingbird Tyrannus verticalis Eastern Kingbird Tyrannus tyrannus Scissor-tailed Flycatcher Tyrannus forjcatus Fork-tailed Flycatcher Tyrannus savana Shrikes Laniidae Loggerhead Shrike Lank ludovicianus Northern Shrike Lank excubitor Crows, jays Corvidae Chihuahuan Raven Corvus cvptoleucus Thrushes Turdidae Eastern Bluebird Sialia sialis Western Bluebird Sialia mexicana Mountain Bluebird Sialia currucoides Thrashers Mimidae Bendires’ Thrasher Toxostoma bendirei J Wood-Warblers Parulidae Common Yellowthroat Geothlypis trichas 12 STUDIES IN AVIAN BIOLOGY NO. 19.

TABLE 2. CONTINUED

Breeding distrlbutlon

Sub- Arctic/ tropical/ Famdy Zdp,Ile Temperate Mexico Caribbean

Emberizids Emberizidae Blue-black Grassquit Volatinia jacarina Yellow-bellied Seedeater Sporophila nigricollis J :: Yellow-faced Grassquit Tiaris olivacea J Canyon Towhee Pipilo fuscus :: Rufous-winged Sparrow Aimophila carpalis Rufous-crowned Sparrow Aimophila ru$cep.ps s ; Oaxaca Sparrow** Aimophila notosticta J Clay-colored Sparrow Spizella pallida J Worthens’ Sparrow** Spizellu wortheni Lark Sparrow Chondestes grammacus J ::: Meadowlarks, blackbirds Icteridae Red-winged Blackbird Ageluius phoeniceus J J Brewers’ Blackbird Euphagus cyanocephalus :: Shiny Cowbird Molothrus bonariensis Bronzed Cowbird Molothrus aeneu Brown-headed Cowbird Molothrus ater Fringillidae Gray-crowned Rosy-Finch Leucosticte tephrocotis Black Rosy-Finch Leucosticte strata Brown-capped Rosy-Finch Leucosticte australis

Nore: Thi\ list was derived from numerou* SOUICCS. including Bond 1971 : Iohnsgard 1981: Hayman et al. 19X6; Raffaele 1989; Howe,, and Webb 1995; AOU 1998; and J. L. Dunn. pen. comm. * Introduced. *= Autoecology poorly known.

canti 1999a, Tubaro and Gabelli 1999). Accord- responsible for maintaining tallgrass prairies in ing to Wege and Long (1995), 12% of the Neo- the Midwest and native grasslands in the North- ’ threatened bird species live in grasslands east. In Florida, lightning was the primary dis- and savannas. At least 34% of the grassland bird turbance that helped maintain prairie habitat. species rank as high conservation priorities, and Prescribed fires have generally been conducted 80% of the campos grassland birds are at risk in winter, however, whereas natural fires bum (Stotz et al. 1996). primarily in summer-and research has demon- strated that at least two species of grassland CONSERVATION STRATEGIES birds, Florida Grasshopper and Bachmans’ spar- People involved in grassland bird conserva- rows, generally prolong their breeding activities tion efforts need to recognize the historical dy- after summer bums (Shriver et al. 1996). In cen- namics under which these unique habitats tral Brazil, Parker and Willis (1997) reported evolved. Where feasible, management should in- that several grassland birds shift their habitats corporate the ecological processes that have gen- every few years in response to local fires: tall- erated and maintained these distinctive ecosys- grass species (e.g., Sharp-tailed Grass-Tyrant tems. The timing, intensity, and seasonality of [Cdcivoru cauducutu] and Bearded Tachuri grazing, fire, and other disturbances on grassland [Polystictus pectoralis]) move to older grass- conservation areas should mimic natural pro- lands, whereas birds that prefer sparser cover cesses as closely as possible. This is important (e.g., Coal-crested Finch [Charitospiza eucos- for many of the plants and that occur in ma] and Campo Miner [Geobates poecilopte- these unique habitats. In North America, for ex- rus]) shift to newly burned sites. Large or con- ample, intensive grazing by native herbivores nected areas are needed to provide both types of such as prairie dogs (Cynomys spp.), bison (Bi- habitats; small reserves protected from fire turn son bison), and pronghom (Antilocapra ameri- to scrub, whereas annually burned ranches sup- cana) was one of the major ecological forces port few species (Parker and Willis 1997). that shaped and maintained shortgrass prairies It is especially important that small individual (Vickery et al. in press). Fires, ignited both nat- sites (< 500 ha) not be managed for the greatest urally and by Native Americans, were primarily diversity of grassland bird species. Management INTRODUCTION-Vickery et al. 13

TABLE 3. PRELIMINARY LIST OF OBLIGATE GRASSLAND BIRDS OF SOUTH AMERICA

Famllv

Rheas Rheidae Lesser Rhea Rhea pennata Red-winged rufescen.s Rhynchotos maculicollis Darwins’ Nothura darwinii Nothura maculosa Lesser Nothura Nothura minor Dwarf Tinamou Taoniscus nanus Waterfowl Andean Goose Chloephaga melanoptera Ruddy-headed Goose Chloephaga rubidiceps Hawks Accipitridae Swainsons’ Hawk Buteo swainsoni Falcons Falconidae Carunculated Caracara Phalcoboenus carunculatus Mountain Caracara Phalcoboenus megalopterus White-throated Caracara Phalcoboenus albogularis Striated Caracara Phalcoboenus austrctlis Aplomado Falcon Falco ,femoralis Stone curlews Burhinidae Double-striped Thick-knee Burhinus bi.striatus Plovers, lapwings Charadriidae Southern chilensis Andean Lapwing Vanellus resplendens Rufous-chested Plover Charadrius modestus Tawny-throated Dotterel Eudromias rujicollis Diademed Sandpiper-Plover Phegornis mitchellii Seedsnipes Thinocoridae Rufous-bellied Attagis gayi White-bellied Seedsnipe Attagis malouinus Grey-breasted Seedsnipe orbignyianus Shorebirds Scolopacidae Upland Sandpiper Bartramia longicauda Eskimo Curlew Numenius borealis Buff-breasted Sandpiper Tryngites subru$collis Gallinago paraguuiae Puna Snipe Gallinago andina Giant Snipe Gallinago undulutu Andean Snipe Gallinugo jamesoni Doves Columbidae Blue-eyed Ground-Dove Columbina cyanopis Black-winged Ground-Dove Metriopelia melanoptera Golden-spotted Ground-Dove Metriopeliu aymara Owls Strigidae Burrowing Owl Athene cunicularia Short-eared Owl Asio flammeus Goatsuckers Caprimulgidae Least Nighthawk Chordeiles pusillus Lesser Nighthawk Chordeiles acutipennis Band-winged Caprimulgus longirostris White-tailed Nightjar Caprimulgus cayennensis White-winged Nightjar Caprimulgus candicans Spot-tailed Nightjar Caprimulgus maculicaudus 14 STUDIES IN AVIAN BIOLOGY NO. 19

TABLE 3. CONTINUED

Hummingbirds Trochilidae White-tailed Polytmus guainumbi Polytmus milleri Ecuadorian Hillstar Oreotrockilus ckimborazo Andean Hillstar Oreotrockilus estella White-sided Hillstar Oreotrockilus leucopleurus Black-breasted Hillstar Oreotrockilus melanogaster Olivaceous Thornbill Ckalcostigma olivaceum Blue-mantled Thornbill Ckalcostigma stanleyi Bronze-tailed Thornbill Ckalcostigma keteropogon Rainbow-bearded Thornbill Ckalcostigma kerrani Bearded Helmetcrest Oxypogon guerinii Hooded Augastes lumackellus Augastes scutatus Horned Sungem Heliactin cornuta Ovenbirds Furnariidae Campo Miner Geobates poecilopterus Common Miner cunicularia Puna Miner Geositta punensis Dark-winged Miner Geositta saxicolina Creamy-rumped Miner Geositta isabellina Short-billed Miner Geositta antarctica Rufous-banded Miner Geositta rujipennis Slender-billed Miner Geositta tenuirostris Cipo Canastero Astkenes luizae Austral Canastero Astkenes antkoides Junin Canastero Astkenes virgata Scribble-tailed Canastero Astkenes maculicauda Straight-billed Reedhaunter Limnomis rectirostris Tapaculos Rhinocryptidae Varzea Tapaculo Scytalopus iraiensis Tyrant flycatchers Tyrannidae Sharp-tailed Grass-Tyrant Culicivora caudacuta Bearded Tachuri Polystictus pectoralis Cock-tailed Tyrant Alectrurus tricolor Fork-tailed Flycatcher Tyrannus savana Larks Alaudidae Eremopkila alpestris Wrens Troglodytidae Sedge Wren Cistotkorus platensis Merida Wren Cistotkorus meridae Pipits Motacillidae Correndera Pipit Antkus correndera South Georgia Pipit Antkus antarcticus Short-billed Pipit Antkus furcatus Hellmayrs’ Pipit Antkus kellmayri Paramo Pipit Antkus bogotensis Yellowish Pipit Antkus lutescens Chaco Pipit Antkus ckacoensis Ochre-breasted Pipit Antkus nattereri Emberizids Emberizidae Grasshopper Sparrow Ammodramas savannarum Grassland Sparrow Ammodramus kumeralis Black-masked Finch Corypkaspiza melanotis Plumbeous Sierra-Finch Pkrygilus unicolor Red-backed Sierra-Finch Pkrygilus dorsalis White-throated Sierra-Finch Pkrygilus erytkronotos INTRODUCTION-Vickev et al. 15

TABLE 3. CONTINUED

Family Canary-winged Finch Melanodera melanodera White-winged Diuca-Finch Diuca speculifera Short-tailed Finch Idiospar brachyurus Puna Yellow-Finch Sicalis lutea Bright-rumped Yellow-Finch Sicalis uropygialis Greater Yellow-Finch Sicalis auriventris PatagonianYellow-Finch Sicalis lebruni GrasslandYellow-Finch Sicalis luteola Wedge-tailed Grass-Finch herbicola Duida Grass-Finch Emberizoides duidae Lesser Grass-Finch Emberizoides ypiranganus Great Pampa-Finch Embemagra platensis PlumbeousSeedeater Sporophila plumbea Capped Seedeater Sporophila bouvreuil Ruddy-breastedSeedeater Sporophila minuta Tawny-bellied Seedeater Sporophila hypoxantha Dark-throated Seedeater Sporophila ruficollis Marsh Seedeater Sporophila palustris Rufous-rnmped Seedeater Sporophila hypochroma Chestnut Seedeater Sporophila cinnamonea Narosky’s Seedeater Sporophila zelichi Black-bellied Seedeater Sporophila melanogaster caerulescens Cardinals and allies Cardinalidae Dickcissel Spiza americana Meadowlarks, blackbirds Icteridae Bobolink Dolichonyx oryzivorus Saffron-cowled Blackbird Agelaius flaws White-browed Blackbird Sturnella superciliaris Peruvian Meadowlark Sturnella bellicosa Red-breastedBlackbird Sturnella militaris Pampas Meadowlark Sturnella dejilippii’ Long-tailed Meadowlark Stumella loyca Eastern Meadowlark Sturnella magna Yellow-rnmued Marshbird Pseudoleistes puirahuro

No~P: This hst wa( derived primarily from the following SOU~CW Hayman et al. 1986, Ridgely and Tudor 1989; Stotr et al. 1996; and R. S. Rid&y, per.% comm.

for enhanced alpha diversity is neither necessary possible to address the complete range of habitat nor practical and is likely to be counterproduc- needs required by different species, including tive to regional conservation goals (Vickery et rare and , and to minimize al. in press). It is important to recognize that the risks of stochastic catastrophic events. In certain sites are usually best suited to manage- Florida, extensive research on and management ment for a particular subset of grassland birds. of the endangered Florida Grasshopper Sparrow Sedge meadows, for example, are better suited have been site specific but have not yet incor- to management for Sedge Wrens and Le Conte’s porated landscape planning or conservation ac- Sparrows than to a full range of grassland spe- tion. Despite intensive site management, popu- cies (Herkert et al. 1993, Sample and Mossman lations of this endemic sparrow are declining, in 1997, Vickery et al. in press). part because of the absence of a broader geo- graphic framework (Shriver and Vickery 1999). REGIONAL CONSERVATION PLANNING Regional grassland habitat and bird manage- To be effective, grassland habitat conservation ment plans are developing in many parts of planning and action must be conducted within a North America and are becoming established in large regional context. Although conservation parts of South America. These broad initiatives action and management usually take place on a provide the best opportunities for grassland bird local scale at specific sites, cooperative manage- and ecosystem conservation. ment on a landscape or regional level makes it Partners in Flight, an international effort to 16 STUDIES IN AVIAN BIOLOGY NO. 19

TABLE 4. PRELIMARYLIST OF FACULTATIVEGRASSLAND BIRDS OF SOUTH AMERICA

Rheas Rheidae Rhea americana Tinamous Tinamidae Small-billed Tinamou parvirostris ornata Nothoprocta pentlandii Curve-billed Tinamou Nothoprocta curvirostris Elegant Crested-Tinamou elegans Quebracho Crested-Tinamou Eudromia formosa pentlandii Tinamotis ingoufi Herons Ardeidae Whistling Heron Syrigmu sibilutrix Cattle Egret Buhulcus ibis Ibis Plumbeous Ibis caerulescens Buff-necked Ibis Theristicus caudatus Black-faced Ibis Theristicus melanopis Storks Wood Stork Mycteria americana Maguari Stork Ciconia maguari Jabiru Jahiru mycteria New World vultures Cathartidae Black Vulture Coragyps stratus Turkey Vulture Cathartes aura Lesser Yellow-headed Vulture Cathartes burrovianus Andean Condor Vultur gryphus Waterfowl Anatidae Upland Goose Chloephaga picta Ashy-headed Goose Chloephqa poliocephala Hawks Accipitridae Pearl Kite Campsonyx swainsonii White-tailed Kite Elanus leucurus Long-winged Harrier Circus buffoni Northern Harrier Circus cyaneus Cinereus Harrier Circus cinereus Savanna Hawk Buteogallus meriodionalis Harriss’ Hawk Parabuteo unicinctus Black-chested Buzzard-Eagle Geranoaetus melanoleucus Crowned Eagle Harpyhaliaetus coronatus White-tailed Hawk Buteo albicaudatus Variable Hawk Buteo polyosoma Falcons Falconidae Crested Caracara Caracara plancus Yellow-headed Caracara Milvago chimachima Chimango Caracara Milvago chimango Spot-winged Falconet Spiziapteryx circumcinctus Seriemas Red-legged Seriema Cariama cristata Black-legged Seriema Chunga burmeisteri Stone curlews Burhinidae Peruvian Thick-knee Burhinus supercilaris Seedsnipes Thinocoridae Least Seedsnipe Thinocorus rumicivorus INTRODUCTION-Vickery et al. 17

TABLE 4. CONTINUED

Shorebirds Scolopacidae Hudsonian Godwit Limosa haemastica Bairds’ Sandpiper Calidris bairdii Fuegian Snipe Gallinago stricklandii Doves Columbidae Picazuro Pigeon Columba picazuro Spot-winged Pigeon Columba maculosa Eared Dove Zenaida auriculata Common Ground-Dove Columbina passerina Plain-breasted Ground-Dove Columbina minuta Ruddy Ground-Dove Columbina talpacoti Buckleys’ Ground-Dove Columbina buckleyi Picui Ground-Dove Columbina picui Bare-faced Ground-Dove Metriopelia ciciliae Morenos’ Ground-Dove Metriopelia morenoi Long-tailed Ground-Dove Uropelia campestris Scaly Dove Scardafella squammata Parrots Psittacidae Burrowing Parakeet Cyanoliseus patagonus Monk Parakeet Myiopsitta monachus Green-rumped Parrotlet Forpus passerinus Cuckoos Cuculidae Striped Cuckoo Tapera naevia Smooth-billed Ani Crotophaga ani Groove-billed Ani Crotophaga sulcirostris Barn Owls Tytonidae Barn Owl Tyto alba Owls Strigidae Striped Owl Rhinopgnx clamator Goatsuckers Caprimulgidae Nacunda Nighthawk Podager nacunda Scrub Nightjar Caprimulgus anthonyi Scissor-tailed Nightjar Hydropsalis brasiliana Trochilidae Fiery-throated Panterpe insignis Green-tailed Goldenthroat Polytmus theresiae Woodpeckers Picidae Andean Flicker Colaptes rupicola Campo Flicker Colaptes campestris Ovenbirds Furnariidae Straight-billed Earthcreeper Upucerthia rufcauda Rock Earthcreeper Upucerthia andaecola Scale-throated Earthcreeper Upucerthia dumetaria Bar-winged Cinclodes Cincloides fuscus Long-tailed Cinclodes Cincloides pabsti Dark-bellied Cinclodes Cincloides patagonicus White-winged Cinclodes Cincloides atacamensis Rufous Hornero Fumarius rufus Pale-breasted Spinetail Synallaxis albescens Lesser Canastero Asthenes pyrrholeuca Cordilleran Canastero Asthenes modesta Streak-throated Canastero Asthenes humilis Streak-backed Canastero Asthenes wyatti Puna Canastero Asthenes sclateri Many-striped Canastero Asthenes jlammulata Hudsons’ Canastero Asthenes hudsoni Firewood-gatherer Anumbius annumbi 18 STUDIES IN AVIAN BIOLOGY NO. 19

TABLE 4. CONTINUED

Tapaculos Rhinocryptidae Collared Crescent-chest Melanopareia torquata Tyrant flycatchers Tyrannidae Plain-crested Elaenia cristata Rufous-crowned Elaenia Elaenia ru$ceps Lesser Elaenia Elaenia chiriquensis Grey-backed Tachuri Polystictus superciliaris Rufous-sided Pygmy-Tyrant Euscarthmus rufomarginatus Grey Monjita cinerea Black-crowned Monjita Xolmis coronata White-rumped Monjita Xolmis velata White Monjita Xolmis irupero Rusty-backed Monjita Xolmis rubetra Black-and-white Monjita Heteroxolmis dominicana Chocolate-vented Tyrant Neoxolmis ru$ventris Black-billed Shrike-Tyrant Agriornis montana White-tailed Shrike-Tyrant Agriornis andicola Great Shrike-Tyrant Agriornis livida Grey-bellied Shrike-Tyrant Agriornis microptera Lesser Shrike-Tyrant Agriomis marina Spot-billed Ground-Tyrant Muscisaxicola maculirostris Dark-faced Ground-Tyrant Muscisaxicola macloviana Cinnamon-bellied Ground-Tyrant Muscisaxicola capistrata Rufous-naped Ground-Tyrant Muscisaxicola rufivertex Puna Ground-Tyrant Muscisaxicola juninensis White-browed Ground-Tyrant Muscisaxicola albilora Plain-capped Ground-Tyrant Muscisaxicola alpina Cinereous Ground-Tyrant Muscisaxicola cinerea White-fronted Ground-Tyrant Muscisaxicola albifrons Ochre-naped Ground-Tyrant Muscisaxicola Jlavinucha Black-fronted Ground-Tyrant Muscisaxicola frontalis Austral Negrito Lessonia rufa Spectacled Tyrant Hymenops perspicillatus Strange-tailed Tyrant Alectrurus risora Streamer-tailed Tyrant Gubernetes yetapa Cattle Tyrant Machetornis rixosus Crows, jays Corvidae White-necked Raven Corvus cryptoleucus Emberizids Emberizidae Rufous-collared Sparrow Zonotrichia capensis Yellow-browed Sparrow Ammodramus aurifrons Coal-crested Finch Charitospiza eucosma Many-colored Chaco-Finch Saltatricula multicolor Ash-breasted Sierra-Finch plebejus Carbonated Sierra-Finch Phrygilus carbonarius Yellow-bridled Finch Melanodera xanthogramma Long-tailed Reed-Finch Donacospiza albifrons Black-and-rufous Warbling-Finch Poospiza nigrorufa Stripe-tailed Yellow-Finch Sicalis citrina Pale-throated Serra-Finch longicauda Blue-black Grassquit Volatinia jacarina Grey Seedeater Sporophila intermedia Sporophila corvina Caqueta Seedeater Sporophila murallae Wing-barred Seedeater Sporophila americana Rusty-collared Seedeater Sporophila collaris Lessons’ Seedeater Sporophila bouvronides Lined Seedeater Sporophila lineola Black-and-white Seedeater Sporophila luctuosa INTRODUCTION-Vickery et al. 19

TABLE 4. CONTINUED

Family

Yellow-bellied Seedeater Sporophila nigricollis Double-collared Seedeater Sporophila caerulescens White-bellied Seedeater Sporophila leucoptera Chestnut-bellied Seedeater Sporophila castaneiventris Chestnut-throated Seedeater Sporophila telasco Large-billed Seed-Finch Oryzoborus crassirostris Great-billed Seed-Finch Oryzoborus maximiliana Lesser Seed-Finch Oryzoborus angolensis Band-tailed Seedeater Catamenia analis Plain-colored Seedeater Catamenia inornata Yellow-faced Grassquit Tiaris olivacea Black-faced Grassquit Tiaris bicolor Meadowlarks, blackbirds Icteridae Red-winged Blackbird Agelaius phoeniceus Yellow-hooded Blackbird Age&us icterocephalus Brown-and-yellow Marshbird Pseudoleistes virescens Chopi Blackbird Gnorimopsar chopi Bay-winged Cowbird Molothrus badius Molothrus rufoaxillaris Shiny Cowbird Molothrus bonariensis Bronzed Cowbird Molothrus aeneus

Note: Thk list WBS derwed primarily from the following sourcc~: Heyman et itl. 1986: Rldgely and Tudor 1989: Smtr et ill. 1996, and R. s. Rldgely, pers. comm.

protect and enhance North American bird pop- the Northeast Grassland Bird Working Group fa- ulations, is organized at state, regional, national, cilitates communication, inventory, and planning and international levels and provides an excel- across a 13-state region from Maine to Virginia. lent, flexible structure for facilitating regional In 1997 this group was involved in a seven-state conservation efforts (Finch and Stangel 1992). inventory of grassland birds, emphasizing re- For example, a Northeast Grassland Bird Work- gionally rare species such as Upland Sandpiper ing Group functions within the rubric of the and Henslows’ Sparrow (Shriver et al. 1997). Northeast Working Group. As a specialist group, Because Partners in Flight has been instrumental

TABLE 5. ESTIMATED HABITAT LOSSTO GRASSLAND ECOSYSTEMS IN THE UNITED STATES SINCE EUROPEAN SET- TLEMENT

Estimated ECOSyStW IOSF (%) Reterence

Critically endangered ecosystems (> 98% habitat loss)” Tallgrass prairie east of Missouri River > 99 Noss et al. 1995 Sedge meadows, Wisconsin > 99 Reuter 1986 Black belt prairie, Alabama and Mississippi > 99 Noss et al. 1995 Sandplain grassland, Long Island, NY 99.9 Niering 1992 Native prairie, Willamette Valley, OR 99.5 Ingersoll and Wilson 1991 Palouse prairie, Montana, Idaho, Oregon, and Washington 99.9 Noss et al. 1995 California grasslands, all types 99 Kreissman 199 1 Ungrazed sagebrush steppe, Intermountain West > 99 West 1995 Endangered ecosystems (SO-98% habitat loss) Tallgrass prairie, all types combined 90 Madson 1990 Grassland shrubsteppe, Washington and Oregon > 90 Noss et al. 1995 Shortgrass prairie, Montana SO-90 Chadde 1992 Shortgrass prairie, North Dakota 90 Madson 1989 Coastal heathland, s. New England and Long Island, NY > 90 Noss et al. 1995 Sandplain grassland, New England > 90 Noss et al. 1995 Palmetto dry prairie, Florida 81 Shriver and Vickery 1999 a Clasrificatmn of cr&zdly endangered and endangered ecory~temr adapted from Noss et al. 1995. 20 STUDIES IN AVIAN BIOLOGY NO. 19 in bringing together multiple agencies, more gered species legislation in Canada, complemen- than 30 collaborators and dozens of volunteers tary provincial and federal legislation to desig- contributed to the grassland inventory, which nate species is being developed, with an empha- censused nearly 1,100 sites (Shriver et al. 1997). sis on rewarding stewardship rather than punish- More importantly, organizations and agencies in ing offenders. Efforts have centered around each of these states have become invested in the changing adverse government policy and work- results of this regional effort. In New York, ma- ing with agriculture to find “Best Management jor breeding habitat for grassland birds has been Practices” for conserving remaining native prai- included in the states’ registry of important bird rie and other grassland habitats. For example, areas and has also received legislative protection the recent abolition of grain-shipping subsidies (Wells 1998). based on the number of hectares under cultiva- In the midwestern United States, a multistate tion has removed one incentive to plow native plan for grassland has devel- prairie. oped a broad outline of the regions’ conservation Most farmland in Canada is privately owned, priorities (Herkert et al. 1996). Within the re- and conservation funding is limited. Identifying gion, more detailed state plans have been de- options that make it worthwhile for landowners veloped. In Wisconsin, for example, Sample and to maintain native prairie or use bird-friendly Mossman (1997) have produced a plan that de- cropping methods has thus proven to be the most scribes goals and organizing principles of grass- effective and economical approach to conserv- land bird management, including a detailed dis- ing grassland habitats. Among such options are cussion of overall management philosophy; they subsidy-based programs such as Agriculture also identify management priorities for both ’ Permanent Cover Program (PCP). In- grassland birds and their habitats within this stituted in 1989, the PCP has converted 450,000 broad geographic area. The plan supplies de- ha in poor soil classes to grass cover for 10 or tailed habitat management guidelines and man- more years. The payment to landowners covers agement recommendations based on individual some of the cost of seeding, and the landowner species ’ responses to specific management prac- may use the land for haying or grazing so long tices and identifies specific landscapes, sites, and as it is not broken. A recent study showed that properties worthy of special management atten- many grassland obligates use PCP sites (Mc- tion. This type of specific targeting of conser- Master and Davis 1998). vation activities will undoubtedly result in on- In Brazil, high-priority areas for biodiversity the-ground management that is likely to benefit conservation in the Cerrado were identified in a grassland birds in the target area. 1998 workshop in which more than 200 scien- In Canada, conservation of prairie grassland tists participated. The workshop was part of the habitat and birds has been gaining momentum Brazilian governments’ biome-level biodiversity through the actions of many organizations since program to establish biodiversity priorities in the 1990. The scope of these partnerships and inter- country. Important criteria for designating sites actions has grown, culminating in the formation included species richness, number of endemic of provincial implementation groups for the species, presence of rare and/or endangered spe- Prairie Conservation Action Plan (PCAP) and cies, and sites of unique communities or key ar- the formation of provincial (Manitoba) and re- eas for migratory species. Eighty-seven priority gional Partners in Flight-Canada groups. PIF- areas were identified, 20 of which were recom- Canada sets general priorities based on trends mended for reserve status because of their im- and geographic responsibility (based on propor- portance for birds (Silva 1998a). Priorities for tion of range) as set forth by Dunn 1997. conservation action for each of these areas were In most cases, Canadian prairie fragments in then determined by cross-referencing biodiver- national and provincial parks, federal govern- sity data with data on human encroachment and ment bird sanctuaries, national wildlife areas land-cover changes (Cavalcanti 1999b). (NWAs), military bases, Prairie Farm Rehabili- In addition to creating new reserves in the tation Administration (PFRA) holdings, and fed- Cerrado, new strategies must be adopted as soon eral and provincial crown grazing lands are se- as possible to minimize the impact of human cure. Examples of large blocks include Grass- activities on the biota of this region (Silva lands National Park, Saskatchewan (90,000 ha); 1998b). The most pressing need is to provide the Last Mountain Lake NWA, Saskatchewan agricultural technology to help landowners in- (15,000 ha); and Canadian Forces Base Suffield, crease productivity of lands already under cul- Alberta (270,000 ha). Large holdings include tivation. It is hoped that this will reduce the PFRA pastures (75 million ha) and Saskatche- pressure on lands covered by natural vegetation. wan crown grazing lands (2.9 million ha). Macedo (1994) has suggested that by increasing Because there is presently no federal endan- productivity on lands already used for agricul- INTRODUCTION-Vickev er al. 21

ture in the Cerrado region, it would be possible use of pesticides in Argentina that has killed to produce 100 millions tons of food annually, many Swainsons’ Hawks (Krapovickas and de or enough to feed 250 million people. The sec- Perez 1997) clearly demonstrate the need for ex- ond strategy is to establish legal mechanisms panded international grassland bird research and that would preclude the destruction of the bio- conservation. logical resources of the Cerrado; as an example, Changing agricultural practices in Argentina new agriculture projects in areas covered by nat- have profoundly reduced the amount of native ural vegetation could be banned until their im- grassland in that country, and the loss is seri- pacts on fauna and flora were rigorously as- ously affecting populations of endemic grass- sessed. land birds such as the Pampas Meadowlark (Tu- baro and Gabelli 1999). This habitat change is HEMISPHERIC CONSERVATION PLANNING likely to affect populations of nearctic breeders Since most grassland birds migrate between as well and may be particularly significant for breeding and wintering areas, it is necessary to long-distance migrants such as Swainsons’ understand the habitat requirements and conser- Hawk, Eskimo Curlew, Upland Sandpiper, Buff- vation needs in both these areas. In South Amer- breasted Sandpiper (Tryngites subrufcollis), and ica, some grassland species breeding in Tierra Bobolink, all of which winter in Argentina (Ol- de1 Fuego and Patagonia winter in the southern rog 1984). Similar agricultural changes else- Pampas. This is the case for Upland Goose where in Central and South America will un- (Chloephaga picta), Ashy-headed Goose (C. po- doubtedly have consequences for both neotrop- liocephala), and the endangered continental race ical and nearctic grassland breeders. of Ruddy-headed Goose (C. rubidiceps). Other The Western Hemisphere Shorebird Reserve grassland species, such as seedeaters and some Network (WHSRN), an international conserva- tyrant flycatchers, breed in the Pampas but win- tion network focused specifically on shorebirds ter in northern Argentina, , and Brazil (Bildstein et al. 1991) may provide an excellent (Ridgely and Tudor 1989, Chesser 1994). model for international grassland bird conser- Although some species of North American vation efforts. WHSRN has successfully collab- grassland birds are long-distance neotropical mi- orated with more than 120 other agencies, in- grants, most species migrate relatively short dis- cluding the North American Waterfowl Manage- tances and winter primarily in the southern Unit- ment Plan and Partners in Flight, on intemation- ed States and northern Mexico. This provides al wetland and shorebird conservation issues and conservation opportunities for species wintering has helped protect more than 3.6 million ha of in North America and Mexico but also under- habitat in 7 countries (J. Corven, pers. comm.). scores the need for coordinated research and For example, joint efforts by the For- conservation efforts across international borders est Service, Canadian Wildlife Service, and (Hagan and Johnston 1992, Wilson and Sader WHSRN have helped protect critical wintering 1993, Vickery et al. in press). habitat for Semipalmated Sandpipers (Calidris The habitat requirements of many species pusilla) in Suriname (J. Corven, pers. comm.). wintering in Central and South America are Recognizing the rapid decline of many South poorly understood. Recently there have been en- American grassland birds, especially Sporophila couraging research and educational efforts in seedeaters, Silva (1999) has suggested a system grassland habitats in Mexico (e.g., Colorado of reserves across South America that would Bird Observatory 1996, Manzano-Fischer et al. protect a large majority of grassland endemics. 1999) and other parts of Central and South Such planning, critical for the protection of en- America. For example, the Canadian Wildlife demic neotropical species, could be coupled Services’ newly developed Latin American Pro- with efforts to protect nearctic migrants such as gram is working to train local avian biologists Swainsons’ Hawks and Dickcissels, and thus to and build local capacity to study and protect mi- develop a comprehensive system for grassland gratory and resident birds (Hyslop 1996). The bird protection throughout the Western Hemi- U.S. Fish and Wildlife Service is undertaking sphere. Although international efforts, initiated similar collaborative efforts. Additionally, pri- largely by the American Bird Conservancy, in vate nonprofit conservation organizations such Argentina in 1995 stopped or minimized inci- as The Nature Conservancy and BirdLife Inter- dental Swainsons’ Hawk mortality that resulted national have also developed international bird from insecticide use on agricultural fields, the conservation programs. There are few efforts, absence of an established international network however, directed exclusively toward grassland meant that emergency measures were required bird and habitat protection. Widespread efforts (Anonymous 1996, Krapovickas and de Perez by farmers in Venezuela to reduce Dickcissel 1997). It is hoped that an established interna- crop damage (Basili and Temple 1999) and the tional grassland bird network would anticipate 22 STUDIES IN AVIAN BIOLOGY NO. 19

such a major crisis and thus minimize the need GRASSLAND RESTORATION for such emergency actions. We hope that pub- Because loss of native grassland habitat has lication of this volume will facilitate such a net- been so extensive and has occurred over such a work. broad region, habitat restoration has become in- SEEKINGCOMMON GROUND creasingly important for many regions and may be critical for the persistence of some rare and The effective management of grassland land- endangered species. For example, a recent land- scapes will require the involvement of a diverse scape analysis in Florida demonstrated that only group of natural resource professionals, includ- 19% of the original prairie remains and that the ing range managers, game and nongame biolo- configuration of remaining prairie is insufficient gists, soil conservationists, agronomists, farm- to maintain and enhance populations of the U.S. ers, and ranchers (Vickery et al. in press). In federally endangered Florida Grasshopper Spar- many areas, grassland management has histori- row (Shriver and Vickery 1999). The best option cally emphasized soil conservation. To increase for the long-term viability of this rare ap- the likelihood of successfully conserving grass- pears to be major habitat restoration (Shriver and land habitat, it will be important to combine the Vickery 1999). Although similar landscape anal- goals of avian habitat conservation with those of yses have not been undertaken in South Amer- soil conservation and agriculture. Because the ica, the sharp decline in Pampas Meadowlark ecological and habitat requirements of many en- populations in Argentina (Tubaro and Gabelli dangered grassland species in South America are 1999) and the rapid destruction of grassland poorly understood, it will be most difficult to habitat in the Cerrado of central Brazil (Caval- achieve these disparate goals in South America. canti 1999a) both suggest that some form of Although habitat loss is the main cause of grass- habitat restoration may be critical for the long- land bird declines in South America (Bucher and term survival of endemic grassland birds in Nores 1988, Cavalcanti 1988), more subtle fac- South America. At least in the Pampas, habitat tors such as competitive interactions, nest para- restoration should be possible to achieve in a sitism, social facilitation, and failure to colonize relatively short time if land is left undisturbed new patches are probably also involved. These (Leon and Oesterheld 1982, Leon et al. 1984). factors are probably stronger when populations In North America, several grassland species are small and fragmented. have adapted to agricultural fields (Graber and The North American Waterfowl Management Graber 1963, Knopf 1994) or to other artificial Plan (NAWMP), through Ducks Unlimited Can- habitats such as airports and reclaimed surface adas’ Prairie Care program, has established graz- mines (Melvin 1994, Jones and Vickery 1997). ing systems on about 132,000 ha in the grass- Because few native prairie or grassland rem- land portion of Canadas’ three prairie provinces nants remain in most of midwestem and north- (Alberta, Manitoba, and Saskatchewan). Provin- eastern North America, effective grassland bird cial agricultural extension services helped pro- conservation will require the protection and en- ducers revamp grazing systems on many addi- hancement of artificial grassland habitats. Re- tional hectares. Because these systems make claimed surface mines in West Virginia, Penn- grazing more economically viable, they keep the sylvania, Ohio, and Indiana provide important land under grass cover. Initial studies show that habitat for Henslows’ Sparrow and other grass- a greater variety of bird species, including many land birds, and airfields in northeastern North grassland obligates, use these sites than use con- America support some of the largest New En- tinuous-grazing (i.e., season-long) sites (Dale gland populations of several regionally threat- and McKeating 1996) and that avian productiv- ened species, notably Upland Sandpiper and ity is about the same as it was before the grazing Grasshopper Sparrow (Jones and Vickery 1997). systems were instituted (Prescott et al. 1998). Protection and enhancement of these non-native The initial demonstration farms and agreements habitats that serve as refugia for many grassland with cattle ranchers required a substantial input, birds will be critical. Where feasible, however, but as the economic benefits became clear and efforts to restore native habitats should be a neighboring cattle ranchers saw the results, the long-term objective. conservation management was voluntarily adopted on many more farms and ranches. FUTURE RESEARCH NAWMP has proven to be a good partner in grassland bird conservation. The Canadian From a hemispheric perspective, the most Wildlife Service initiated nongame evaluations pressing needs are additional research and relat- of NAWMP in 1989 and was joined in this by ed conservation in Central and South America, provincial partners in 1993 (Dale and Mc- where loss of habitat and population declines are Keating 1996). becoming more acute. The number of endemic INTRODUCTION-Vi&~ er al. 23

species and families in the Neotropics, and the servation actions need to be taken. Unfortunate- fact that this area provides habitat for wintering ly, funds for basic ornithological inventory and nearctic breeders, makes this the highest hemi- taxonomic studies in Central and South America spheric priority for conservation research and are scarce and, when available, are directed at action. As in North America, a better under- studies on forests rather than grasslands or other standing of the ecological effects of fire and open habitats. Any international conservation grazing on South American obligate grassland project directed at Latin American grasslands birds and their habitats should be a high priority must include support for both long-term studies (Collar et al. 1992). on threatened bird populations and basic biolog- Grassland bird conservation programs in the ical inventory and taxonomic studies. United States and elsewhere in the Western Hemisphere need to address both breeding and ACKNOWLEDGMENTS wintering ecology (Vickery et al. in press). Al- We especially thank B. Dale and R. S. Ridgely for though the wintering ecology of most grassland their knowledge and insights of Canadian and South birds is poorly known, there continues to be lit- American grassland birds, respectively, and for their valuable contributions to this manuscript. We also tle research on the wintering habitat require- thank R. A. Askins, R. Cannings, J. L. Dunn, l? W. ments of many grassland bird species, as the Dunwiddie, A. L. Jones, J. E. Pierson, J. T Rotenberry, paucity of papers on wintering ecology in this and W. G. Shriver for helpful comments on earlier book clearly demonstrates (3, versus 23 for the drafts of the manuscript. Many people shared their in- breeding season). It is unclear whether habitat sights regarding lists for North and South American loss and degradation on the wintering grounds grassland birds, and we express our deepest gratitude are primarily responsible for the population de- to them: C. Bock, S. Davis, E. Dunn, J. L. Dunn, R. clines reported for many species. Winter survi- Fraga, I? Handford, L. Igl, E Knopf, M. Koenen, C. vorship may be critically important in the long- Norment, J. Pierson, E Rabufetti, J. C. Reboreda, R. term declines of some grassland species (Herkert S. Ridgely, G. Shriver, and D. Stotz. We thank V. May- nard for meticulous map preparation. We are grateful and Knopf 1998, Vickery et al. in press). to the following institutions for their support: Center Additionally, although there has been substan- for Biological Conservation, Massachusetts Audubon tial research on some arctic-nesting birds, nota- Society and the Switzer Foundation (Vickery); Insti- bly waterfowl (e.g., Snow Goose [Chen caeru- tuto de Biologia y Medicina Experimental CONICET Zescerts]; Ganter et al. 1996) and shorebirds (Tubaro); Conselo National de Desenvolvimento Cien- (Charadriidae and Scolopacidae; e.g., Whitfield tifico e Tecnol6gico (CNPq), Brazil (Silva); U.S. Geo- and Brade 1991), there has been little research logical Survey, Biological Resources Division (Peter- on other grassland species, especially passerines, john); Illinois Endangered Species Protection Board (Herkert); and Departamento de Zoologia, Universi- that breed at high latitudes or altitudes. In par- dade de Brasilia, CNPq, and Conservation Internation- ticular, there is essentially no research on the al, Inc. (Cavalcanti). winter ecology of these species on temperate grasslands, although initial efforts are underway LITERATURE CITED (E. Dunn, pers. comm.). Winter habitat use, pop- AMERICAN ORNITHOLOGISTS’ UNION. 1998. Check-list ulation dynamics, and survivorship of species of North American birds. 7th ed. American Orni- such as Smiths’ Longspur and the rosy-finches thologists’ Union, Washington, D.C. (Leucosticte spp.) are largely unknown and mer- ANDERSON, D. L. 1977. Las causas de la invasidn de it careful study. chaiiar en el tiea medanosa de pastizales e isletas Unlike in North America, most species of de chaiiar. Pp. 11-13 in Limitaci6n en la producci6n grassland birds in Central and South America ganadera de San Luis debido a las leiiosas invasoras are still poorly known, and information regard- [no editor]. Gobierno de la Provincia de San Luis. 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