Plains and Mesa Grassland This is the most extensive grassland in the state (Dick-Peddie 1993), this habitat type comprises two distinct regions: the Eastern Plains and Great Basin grasslands. The Eastern Plains start along the Texas border and run west to the bajadas of the Sangre de Cristo Mountains in the north, the Sandia and Manzano mountain ranges in central New Mexico and the Sacramento Mountains in the south, excluding the Pecos Valley below Roswell. Great Basin grasslands, or Mesa Shortgrass areas, are found in the northwest quadrant of the state and the Rio Grande valley. These include the Plains of San Agustin and mix with Plains grassland over a large area of northwestern and north-central New Mexico (Brown 1994). In climax condition, these grasslands are composed almost entirely of grasses. The few shrubs and forbs constitute less than 10% of the vegetation. The transition area from grassland to grassland-scrubland ecotone is often subtle and extensive. Blue grama (Bouteloua gracilis) is the most common component of these grasslands in New Mexico. It codominates with buffalo grass (Buchloe dactyloides) in the northeast and east-central plains and with western wheatgrass (Agropyron smithii) or galleta (Hilaria jamesii) on northern mesas. On fine-textured soils in the north, indian ricegrass (Oryzopsis hymenoides), New Mexico feathergrass (Stipa neomexicana), and needle and thread (Stipa comata) may be important components/codominants. Other areas may be dominated by threeawns (Aristida spp.) or side-oats grama (Bouteloua curtipendula). Tobosa (Hilaria mutica) swales occur within this type of grassland. These are dominated by Hilaria spp. and, in some areas, alkali sacaton (Sporobolus airoides). Galleta and indian ricegrass are the primary grasses in the northwest. Shrubs often occur where the soil is calcareous. Shrubs that may occur scattered through eastern shortgrass communities are soapweed yucca (Yucca glauca) and fringed sage (Artemisia frigida). Winterfat (Ceratoides lanata) and bigelow sage (Artemisia bigelovii) can be found in western areas. Broom snakeweed (Gutierrezia sarothrae) increases in overgrazed areas in eastern grassland as do clumps of low-growing honey mesquite (Prosopis glandulosa) and chollas (Opuntia spp.). Rabbitbrush (Chrysothamnus spp.) and sagebrush (Artemisia spp.) replace broom snakeweed in the disclimax communities caused by overgrazing in Great Basin Grasslands. Livestock grazing in the early part of the century resulted in extensive and rapid succession of these grasslands toward shrubland. Great Basin grasslands tend to be more arid than Plains Grasslands and mix with Great Basin desert shrub at lower elevations. In the past, high temperatures and summer winds contributed to lightning-set grass fires where grasses from prior growing seasons provided ample fuel. A natural succession to climax grass-forb associations followed. As a result of grazing in most areas, less residual grass is available for fuel, and the incidence of fire is less frequent. Natural successions are now usually arrested and replaced by fire disclimax associations of shrubs. In healthy grasslands, fire will suppress mesquite and other shrubs. Areas with little grass initially, sometimes as a result of overgrazing, lack sufficient fuel to carry a fire. Fire is often prescribed in eastern New Mexico, mostly in swales. Fire is being reintroduced into the Middle Rio Grande valley at Sevilleta National Wildlife Refuge and the Kiowa National Grasslands in eastern New Mexico (Mike Means pers. comm.). Ford (1999) resummarizes several studies on grasses and response to fire, which have been used to promote fire suppression in shortgrass prairies. Upon reanalysis, Ford concludes that "Most of the literature ... reviewed was primarily interested in the use of fire as a tool to increase the forage value of the grassland vegetation. Perception and the value of fire in shortgrass steppe may have been colored by a desire for rapid recovery or for increases in grassland productivity to benefit domestic livestock." Ford continues, "the use of fire in shortgrass steppe need not be perceived in a negative light. Regardless of fire type, buffalograss and blue grama response to fire was predominantly neutral or positive, and it depended largely on precipitation and possibly season of fire." Ford and McPherson (1996) state that "there is general agreement that fire is necessary (though usually not sufficient) to control the abundance of woody plants and maintain most grasslands". However, there is some disagreement about the succession of shrubs in healthy non-burned grasslands. Bahre (1991 in Ford and McPherson 1996) concluded through the use of historical accounts that "fire size and frequency have diminished greatly in desert grasslands since the 1880's". In a summary of grassland fire studies, Ford and McPherson (1996) state that many macroarthropod herbivores increase after fire, as do soil-dwelling microarthropods. Other reports effects of fire include increased habitat heterogeneity. "Fires ... affect [bird] population levels indirectly by altering habitat structure, abundance of competing species, and food levels (Bock and Bock 1990;Dickson 1981; Rotenberry et al. 1995 in Ford and McPherson 1995). In shrub-grass complexes, bird diversity and abundance are enhanced if shrub cover and nesting sites are interspersed with open grassy areas maintained by fire (Baldwin 1968; Kramp et al. 1983; Pulliam and Mills 1977 in Ford and McPherson 1995) ... Many bird species that inhabit grasslands have been documented to increase habitat use in shrublands or grasslands after fire." They include American Kestrel, Scaled Quail, Mourning Dove, Greater Roadrunner, Eastern Kingbird, Western Kingbird, Loggerhead Shrike, Horned Lark, Sprague’s Pipit, Lark Bunting, Savannah Sparrow, Baird’s Sparrow and Western Meadowlark. "Far fewer bird species are reported to be negatively affected by fire. These species are generally closely associated with shrubby habitat, and [are] more abundant in unburned areas (Ford and McPherson 1995)." "Summer fires can stimulate seed yields of native grasses more than fires in winter or early spring (Biswell and Lemon 1943; Paton et al. 1988). ... In general, plant species in semi-arid grasslands are more strongly influenced by fire season and frequency than fire behavior (intensity, percent of area burned, fuel consumption)(Steuter and McPherson 1995) (Ford and McPherson 1995)". "Plant growing season and fire season, along with other biotic and abiotic environmental variables, including grazing and rainfall, are important factors in determining the response of plants to disturbance by fire. (Ford 1999)" Shrubby habitat (usually mesquite in the east) is now extensive due to grazing that generally took place in the last century. A combination of overutilization, changes in fire frequency, and poor soils has contributed to the current abundance of shrub habitat. It should be noted that shrub encroachment dynamics in northeast New Mexico, north of the mesquite range, may differ from areas south of the Canadian Escarpment (Dick-Peddie 1993). There is clearly a dynamic balance between the distribution and abundance of grass and shrub conditions in eastern New Mexico. Grass conditions are suitable for Grasshopper Sparrow and other grass-preferring birds. Shrub conditions are more suitable for Cassin=s Sparrow and Loggerhead Shrike. Urban Urban areas exist within this habitat and are considered to be a subhabitat. This section is being developed and will appear in a later version of this Bird Conservation Plan. The vast majority of eastern plains lands are privately owned. Some areas near Clayton, comprising the Kiowa National Grasslands, are managed by the U.S. Forest Service. Three National Wildlife Refuges are in this habitat: Grulla (near Portales), Las Vegas and Maxwell. Of the privately owned lands, most are ranches rather than agricultural lands. A high proportion of agricultural lands exist around Clovis/Portales, the Tucumcari Basin to the Texas border, along the Texas border near Clayton, and the Estancia Valley. Many portions of western grasslands are managed by the Bureau of Land Management: the majority of the Plains of San Agustin and grasslands further north, including the Bisti/De-na-zin Wilderness areas. Chaco Canyon National Monument, managed by the National Park Service includes small areas of this habitat, as does Sevilleta National Wildlife Refuge. A large area of former grassland has been converted to agriculture at the Navajo Agricultural Products area south of Farmington. Other portions are privately owned. Physiographic Areas covered: Colorado Plateau and Pecos and Staked Plains Associated priority species from Appendices B and C: Table 1. Plains and Mesa Grassland Priority Species Highest Priority Priority High Responsibility Ferruginous Hawk Prairie Falcon Mountain Plover Long-billed Curlew Scissor-tailed Flycatcher Bendire's Thrasher Lark Bunting Dickcissel Loggerhead Shrike Grasshopper Sparrow Scaled Quail Burrowing Owl Common Nighthawk Say's Phoebe Cassin's Kingbird Chihuahuan Raven Cassin's Sparrow Additional Representative Species: Vesper Sparrow, Western Meadowlark Bird Habitat Requirements, Population and/or Habitat Objectives: (in taxonomic order) Ferruginous Hawk (Stravers and Garber 1998) Associated Species: Scaled Quail, Mountain Plover, Mourning Dove, Common Nighthawk, Ladder-backed Woodpecker, Say=s Phoebe, Loggerhead Shrike, Bendire=s Thrasher, Vesper Sparrow, Western Meadowlark, needs close proximity to high quality grasslands or irrigated agricultural lands in NM landscapes with moderate coverage of cropland and hayland used for nesting and foraging (Leary et al. 1998) prefers forest edge or mature, isolated, flat-topped junipers, with thick support branches for nests in NM. in NW New Mexico, often nests on rock spires in eastern New Mexico, often uses old homestead trees, may nest on ground (D. Svingen pers.comm.) highly sensitive to human disturbance prey mainly small to medium-sized mammals in NM Distribution: Found breeding in the northern two-thirds of the state: north from Clovis west to Claunch; in the Rio Grande Valley, south to San Antonio and from the Plains of San Agustin to Quemado. Nesting in isolated areas further south is possible. Population and/or Habitat Objectives: in the West, T = 6.6%, p = 0.01, N = 92, RA=0.25 (Sauer et al. 1997) maintain known populations, especially the high density area of the Estancia Valley increase the known pairs in the state by 20% in 10 years. As of 1998, 73 known pairs; 11 additional suspected pairs (NMPIF) in juniper savanna, maintain open grassland between trees without a shrub layer, especially on the edges of pure grasslands. Keep small isolated junipers in grasslands. prevent conversion of large areas of native prairie to monotypic stands of grass or other types of agriculture (Bechard and Schmutz 1995) when converting tree communities to grassland, provide nest sites by leaving individual trees, a mosaic of stands of trees, or a thin scattering of trees (Olendorff 1993) maintain a minimum 820ft (250m) buffer zone around nesting sites (White and Thurow 1985) between March 15 - July 15 (Bechard and Schmutz 1995) Prairie Falcon (Steenhof 1998) Associated Species: Long-billed Curlew, Western Kingbird, Horned Lark, Grasshopper Sparrow, Eastern Meadowlark, Western Meadowlark open grasslands and shrub-grasslands most common nest sites are ledges or cavities in cliffs or bluffs availability of appropriate nest sites can be highly limiting ground squirrels are important breeding food source; Horned Larks and meadowlarks in non-breeding season have become habituated to low-level flying ( Harmata et al. 1978 in Steenhof 1997) Distribution: Found in appropriate habitat, especially in areas near cliffs, statewide. Population and/or Habitat Objectives: in the West, T = -2.7%, p = 0.11, N = 97, RA = 0.12 (Sauer et al. 1997) keep population at estimated level in 1975 of 293-406 pairs (Platt 1975) limit human activity to a minimum of 410ft (125m) from known nests (Holthuijzen et. al. 1990 in Steenhof 1998); preferably 0.62mi (1km) (Suter and Joness 1981 in Steenhof 1998) reduce or eliminate overgrazing in areas within 4mi (7km) and up to 24mi (38km) ( Steenhof 1998) of known nesting sites. The associated sheet erosion and lower plant cover limits food for ground squirrels (Platt 1974). Mountain Plover (Knopf 1996) Associated Species: Burrowing Owl ( if burrows), Horned Lark, Vesper Sparrow requires substantial amount of bare ground cover can be extremely short some shrubs or junipers are tolerated some denser or lusher grasses necessary for young cattle grazing effects may be too uniform for this species there is not (or is no longer) a tight relationship between plovers and prairie dog towns is loosely colonial Distribution: Found in the northern half of the state, especially from Las Vegas and Mosquero north, occasionally at Santo Domingo Pueblo, perhaps regularly west of Taos, and sporadically in the Plains of San Agustin west to Quemado and north to the Farmington area. Population and/or Habitat Objectives: In the U.S., T = -2.7%, p = 0.02, N = 33, RA = 0.31 (Sauer et al. 1997) maintain known populations in the northeastern plains, north and west of Tres Piedras, on Santo Domingo Pueblo and in the De-Na-Zin Wilderness maintain areas where bare ground exists with a small shrub component in known breeding areas maintain prairie dog towns in areas where they exist; associated habitat created may be appropriate for breeding Mountain Plover in agricultural areas, reduce late spring planting of fallow fields or discourage nesting in fields slated for late spring planting (Knopf 1997) Long-billed Curlew (WY PIF) Associated Species: American Kestrel, Prairie Falcon, Scaled Quail, Western Kingbird, Lark Bunting, Vesper Sparrow, Say=s Phoebe, Western Meadowlark short- or mid-grass prairie, mid-grass grasslands, sagebrush grasslands late succession grasslands 4-12 in (10-31cm) high Nesting generally in sites with grass <3. 9in (10 cm) tall. However, grasses are taller in the immediate vicinity (within 20 ft or 6m) of nest sites. Grass within 50 ft (15m) was significantly shorter overall than random vegetation heights in Utah. (Paton and Dalton 1994) some taller shrubs (~ 5%) for protection and shade for young avoids areas with excessive bare ground (Cochran and Anderson 1987 in Paton and Dalton 1994) flat to Amoderate@ topography 5ac (2ha) needed per breeding pair; nests can be as little as 750ft (229m) apart abundant invertebrate prey sensitive to habitat fragmentation some grazing prior to breeding may be beneficial; in Utah, Curlews initiated nesting from mid-April to mid-May (Paton and Dalton 1994); may occure earlier in New Mexico (NMPIF) Distribution: Breeds primarily in the grasslands from White Lakes and Rowe Mesa east and north following the uplands defined basically by the Canadian Escarpment. Has occasionally nested in the northwest as far south as the Plains of San Agustin. Population and/or Habitat Objectives: in Region 2, T = -1.1%, p = 0.77, N = 20, RA = 1.01 (Sauer et al. 1997) maintain continued presence in the Northeastern quadrant of the state moderate grazing just prior to nest initiation in areas of known nesting may be beneficial. Patchy, late summer grassland burning may be beneficial to the following season’s breeding (NM PIF) Scissor-tailed Flycatcher (Regosin 1998) Associated Species: Ladder-backed Woodpecker, Say's Phoebe, Loggerhead Shrike, Cassin's Sparrow, Eastern Meadowlark uses savannas, with occasional trees, shrubs, and brush patches, but also towns, agricultural areas, and landscaped areas such as golf courses density decreases with increased presence of grama-buffalo grass associations needs sufficient number of perches (trees, shrubs, fences, wires) ranging from just above ground to 32ft (10m) in height nests in isolated trees or shrubs, often honey mesquite: average distance of 45ft (13.8m) to next nearest shrub, 15.4 ft (4.7m) in height, and 225 yd; (172m;) in volume; shrubs had less vertical cover from 0-9.8ft (0-3m) and more from 9.8-19.7ft (3-6m) (Nolte and Fulbright 1996 in Regosin 1998) needs wide shrubs as nest placement can average 6.2ft (1.9m) from main stem Distribution: Found in the southeastern quadrant of the state; from Clovis/Portales and the Texas border south and west to Fort Sumner and the Pecos Valley Population and/or Habitat Objectives: In Region 2, T = 0.2%, p = 0.77, N = 209, RA = 17.64 (Sauer et al. 1997) maintain current populations in the Carlsbad, Lovington, Clovis-Portales, and Tatum areas reverse recent observed declines in southeastern New Mexico populations (S. West pers. comm.) create or maintain suitable habitat in 100ac (40ha) patches with at least 50% grass cover and at least 10% shrubs or trees, some reaching up to 30ft (9m) (possibly through regular burn cycles) within the southeastern quadrant of the state create or maintain at least five hundred 100ac (40ha) blocks described above Assumption: The above habitat blocks will be enough to maintain Scissor-tailed Flycatcher populations in New Mexico. Bendire's Thrasher (England and Laudenslayer 1993) Associated Species: Scaled Quail, Mourning Dove, Common Nighthawk, Loggerhead Shrike, Horned Lark, Lark Sparrow, Black-throated Sparrow, Western Meadowlark relatively open grassland with scattered shrubs or trees, may use fringes of dense vegetation areas such as riparian woodland or desert washes large shrubs of one or more of the following species are usually present: cholla, junipers or sagebrush may breed in relatively open, degraded grasslands with moderate to dense shrubs avoids cholla in the south but uses it in the north nest placed in semi-dense shrubs, cacti or trees typically 2.3 - 4.9 ft (0.7 - 1.5m) above the ground but can be as high as 2ft (6.5m) Distribution: Found in areas from Corona north and west to Santa Fe and Cuba, occasionally in the middle Rio Grande Valley from Los Lunas to the Jemez mountains and from the Plains of San Agustin south to the Mexico border. Population and/or Habitat Objectives: in NM, T = -7.1%, p = 0.19, N = 14, RA = 0.80 (Sauer et. al. 1997) stabilize, then reverse current BBS trend in New Mexico maintain continued presence at known nesting areas, especially in northern McKinley and southern San Juan counties, and in Hidalgo and Grant counties maintain large shrubs from 3 - 6ft (0.9 - 1.8m) high in grassier habitats Cassin=s Sparrow (NM PIF) Associated Species: Scaled Quail, Mourning Dove, Western Kingbird, Scissor-tailed Flycatcher, Loggerhead Shrike, Lark Sparrow, Western Meadowlark prefer shrubs from 1.5 - 6 ft (4.9 - 19.7m) 65% - 30% (or less) shrub cover no more than 10% trees among shrubs needs 80% of non-shrub area covered in grasses or forbs mid-grasses preferred; some short grass, though not preferred, is acceptable if suitable patch is inhospitable, then size of patch must be at least 2 ac (0.8ha) territory size is relatively small at 1-2 ac (0.4-0.8ha) productivity tied to rainfall, if no rainfall then few, if any, young Distribution: Found in the eastern and southern portions of the state, north to Mogollon Rim, Albuquerque area, and Las Vegas to Clayton. Rarely occurs in the northwestern quadrant of the state. Population and/or Habitat Objectives: in NM, T = 0.3%, p = 0.81, N = 36, RA = 26.68, in the Pecos and Staked Plains, T = -1.7%, p = 0.21, N = 29, RA = 29.97 (Sauer et al. 1997) maintain 5ac (2ha) blocks of dense grama spp. within a 40ac (16ha) block of mixed grass and shrubs with 30-60% shrub cover and of the remaining area 80% grass cover maintain 250 blocks of suitable breeding habitat as described above, per 10,000ac (4049ha) block of contiguous grassland Assumption: the above block habitats will sustain Cassin's Sparrow populations Vesper Sparrow (Yanishevsky and Petring-Rupp 1997) Associated Species: Mountain Plover, Mourning Dove, Common Raven, Horned Lark, Eastern Meadowlark, Western Meadowlark dry grasslands above 6000 feet, also in open shrublands and occasionally open pinyon-juniper woodland needs sparse shrub brush for perches requires low percentage of grass cover and corresponding high percentage of bare ground less than 40% shrub canopy cover is required in sagebrush areas territory size averages around 5ac (2ha) nests on ground at base of grass tussocks or forbs; no apparent need for shrub canopy concealment will not recolonize a grassland until three years after burning frequent cowbird host Distribution: Found from the Plains of San Agustin north in the west and from Torrance county to Harding County north in the east Population and/or Habitat Objectives: in NM, T = -4.6%, p = 0.21, N = 19, RA = 7.59 (Sauer et al. 1997) maintain less than 40% canopy cover from shrubs and trees in dry grasslands and juniper savanna above approx. 6000ft (1829m) maintain blocks of 5ac (2ha) with low grass cover and bare ground where appropriate reduce grazing during nesting season between May 21-August 10 (Nelson 1993) to prevent nest destruction and increased parasitism (USFS 1994) Lark Bunting (Yanishevsky and Petring-Rupp 1997) Associated Species: Long-billed Curlew, Cassin=s Sparrow, Grasshopper Sparrow, Western Meadowlark primarily found in shortgrass grasslands occasionally in sagebrush shrublands, weedy agricultural areas, and other shrubby grassland areas on the Pawnee Grasslands in CO, preferred habitat had high (>70%) grass cover and only 10-16% bare ground preferred grass was 5.2in (13.4cm) tall and relatively dense (32.2 plants/0.1 m5) 5-15% of vegetative canopy cover was taller than average surrounding areas less than 15% bare ground considered optimal with corresponding 60-90% grass cover, will not use if >60% bare ground (Finch et al. 1987 in Yanishevsky and Petring-Rupp 1997) territory size is only 1.2-2ac (0.5-.75ha) however, Finch et al. (1987) consider patch size to be much larger due to the species social nature nests on ground and needs 10-30% cover (shrubs and midgrasses) for nest shading and protection from solar radiation, which may be critical (Pleszcynska and Hansell 1980 in Yanishevsky and Petring-Rupp 1997) in NM, may breed only in higher rainfall years (NM PIF) main diet is grasshoppers breeding beginsin late May. 21 days from egg-laying to fledging (Baicich and Harrison 1997) Distribution: Nearly no breeding activity in dry years. Wet years may produce breeding from Tucumcari west along I-40 to Clines Corners and north in grassland areas of the northeast. Breeding has also been documented in San Juan County in recent years. Population and/or Habitat Objectives: in Region 2, T = -8.1, p = 0.09, N = 19, RA = 1.62 (Sauer et al. 1997) in wet years, maintain 10-13 singing males per 100 ac (40ha) (Weins 1971 in Yanishevsky and Petring- Rupp 1997) in dry years, it is possible that no birds will breed in the state high quality grasslands with <16% bare ground and dense grass cover maintained at 65-75%; average grass height should be kept at least 5in (12.8cm) high with 5-15% higher grasses or shrubs during breeding Dickcissel (Yanishevsky and Petring-Rupp 1997) Associated Species: Eastern Kingbird, Western Meadowlark prefers nesting in areas of dense forb cover in alfalfa and sweet clover fields, but also uses cropland, grassland (especially tallgrass), and unused, weedy fields in early successional stages density of males, and increase in polygany positively correlate with amount and density of vegetation song perches are critical: forbs or shrubs that rise an average of 19.3 in (49cm) above the average height of surrounding vegetation nests are generally 3.28ft (1m) or less above the ground cowbird parasitism is a large factor in population decline, parasitism decreases with increased male density reproduction appears to suffer with heavy grazing in shortgrass, but appears stable with moderate grazing in tallgrass This species is an opportunistic nester. While New Mexico does not serve as a core nesting area, it may serve as a secondary breeding area during drought elsewhere in the Midwestern U.S. (NM PIF) Distribution: Breeds locally, although possibly not annually, from Fort Sumner and Clovis/Portales area north to Maxwell NWR. Population and/or Habitat Objectives: in Region 2, T = 0.6%, p = 0.31, N = 173, RA = 17.05; in the U.S., T = -1.6%, p = 0.00, N = 783, RA = 16.29 (Sauer et al. 1997) maintain current known nesting populations near Fort Sumner, Clovis and Maxwell NWR maintain habitat: early successional weedy fields, mid-grass prairie and shrubby shortgrass reduce grazing in mid to shortgrass areas delay haying until after breeding season (beginning of August) maintain early successional, weedy fields and perches rising above average height of vegetation Western Meadowlark (Lanyon 1994) Associated Species: Prairie Falcon, Long-billed Curlew, Loggerhead Shrike, Cassin=s Sparrow, Vesper Sparrow, Grasshopper Sparrow found in native grasslands, semi-desert and sagebrush shrublands, open woodlands, weedy borders of cropland, roadsides, and moist lowlands prefers good grass and litter cover along with some shrub cover occupies drier upland sites where its range overlaps with Eastern Meadowlark layered herbaceous cover necessary for nest concealment adults show high fidelity to home territories averaging between 3-15ac (1.2 -6ha) Distribution: generally found statewide, though a less common breeder from the Plains of San Agustin south and in the southern Rio Grande Valley Population and/or Habitat Objectives: in NM, T = -0.8%, p = 0.22, N = 52, RA = 35.03 (Sauer et al. 1997) maintain grasslands with a high degree of litter cover and little to moderate amount of shrub cover blocks of 5-15ac (2-6ha) of appropriate habitat should be maintained Overall Habitat Strategies: Over time and a large landscape managers should address the following issues: Grass Canopy Cover: Even in healthy grasslands, 100% grass canopy coverage does not occur. Managers should try to achieve a 50-65% grass canopy cover on an overall basis. Bare ground should be kept to a minimum. Canopy cover is important for grass-utilizing species and a lack of adequate cover will cause species to abandon an area. Bare ground is important for such birds as Horned Lark, which should not be the dominant bird, although it is an important component of most grassland bird assemblages. Avoid seeding of exotic grasses and cultivation of habitat where possible (Janes 1985) Grass Height: Managers should work toward maintenance of grass heights averaging 4-8 in (10-20cm) or more. Depending on soil conditions, grazing regimes, and other factors, this is not possible in every area. However, an average can be maintained over an entire landscape. In areas that are slightly more mesic, i.e. drainages in grassland areas, swales, etc., grasses should be maintained at an average of 1ft (30cm). Fire: Fire should be prescribed during early spring or late summer, as a tool to reduce shrub and litter cover. It appears to be beneficial to many grassland species (Ford and McPherson 1996), excepting those needing denser, taller grasses, such as Dickcissel. ATiming of prescribed burns should be a major consideration to resource managers concerned with declining [bird] populations that breed in the southern Great Plains. ... Birds in general, are most vulnerable to fire during nesting and fledging periods. Fires can be devastating to ground-nesting birds because they destroy existing nests, remove protective cover and eliminate insect food resources (Daubenmire 1968 in Ford and McPherson 1995) that may be associated with ground litter and vegetation (Ford and McPherson 1995).@ Shrub encroachment: True grasslands contain few shrubs. Healthy grasslands generally allow minimal shrub encroachment. Encroachment is an indication that a grassland is not maintaining its integrity. Some shrub cover is a part of grasslands, but generally at considerably lower densities than found in most grasslands today. Managers should work towards maintaining no more than 10-20% shrubs in the overall landscape. While shrub habitat is used by many birds, the xerification of grasslands over the last century and a half has caused an increase in the abundance of birds utilizing shrubs. This has occurred at the expense of those species which require pure or primarily grass habitats. Grazing: The use of rest-rotation methods or the Savory method, appears to be a more effective method for maintaining grassland integrity, and the health of the herd, than many historic methods of grazing, particularly those that allow cattle to graze one area throughout the year. "In short-grass types, grazing results in a dramatic increase in percent of bare ground and reduces food, shade, and nest site availability (Finch et al. 1987 in Yanishevsky and Petring-Rupp 1997)." Prairie dog control: Prairie dogs currently inhabit a small percentage of their historic range. Burrowing Owls largely depend on burrows created by prairie dogs. They can also be an important food source for raptors such as Golden Eagles, Ferruginous Hawks, and in New Mexico, Bald Eagles. Managers should refrain from controlling prairie dog populations whenever possible. Research and monitoring needs: 1. Determine Ferruginous Hawk production levels necessary to sustain population. Survey for additional pairs, especially in the northeastern quadrant of the state. 2. Survey for nesting populations of Mountain Plover in the Plains of San Agustin and the northwestern quadrant of the state, especially the De-Na-Zin Wilderness. Determine method to discourage Mountain Plover nesting in fallow fields that are slated for late spring planting. 3. Determine population status of breeding Long-billed Curlews. 4. Determine shrub encroachment dynamics in northeastern New Mexico grasslands north of the Canadian Escarpment. 5. Manipulative field-based experimental research to determine the underlying mechanisms of fire in grasslands, including response to drought and fire. 6. Manipulative field-based experimental research to determine effects of grazing and fire on vegetation and bird populations. Additional species for which monitoring is recommended: Scaled Quail Burrowing Owl Common Nighthawk Cassin's Kingbird Vesper Sparrow Western Meadowlark Table 2. Plains and Mesa Grasslands Priority Species: Habitat Factors Species Vegetation Composition/ Structure Abiotic Factors Landscape Factors Special Factors FEHA juniper savanna for nesting, open grassland for foraging; nests in isolated, flat-topped junipers     can do well if nests are adjacent to agricultural areas PRFA open and shrubby grasslands nests on cliffs breeders need cliffs in close proximity to grasslands ground-squirrels important food source in breeding season; birds important during non-breeding MOUP very short grasslands, some shrubs substantial bare ground required   small shrubs needed for shelter of young LBCU ~5% shrubs in 4-12in high late succession grasslands   flat to moderately hilly; minimum patch 5ac per pair sensitive to habitat fragmention STFL grassland savanna with shrubs and trees for perches reaching heights up to 30ft     density decreases with increased grama-buffalo grass BETH grassland with some dense shrubs averaging 2 - 5ft     may be found in areas of degraded grasslands CASP mid-level grasses with shrubs or trees; no more than 65% shrub cover, no more than 10% trees, both from 0.2-0.6ft in height; 80% of non-shrub area must be covered by grasses or forbs   occupies areas no smaller than 1ac, often no smaller than 2ac   VESP dry grasslands, shrublands or pinyon-juniper; requires only 40% ground cover and high percentage of bare ground found breeding above 6000 ft will occupy territories as small as 5ac frequent cowbird host LARB prefers grass averaging 5 in. with 5-15% grass taller; some shrubs or very dense mid-grasses critical <15% bare ground preferred; >60% bare ground is not used. solar radiation protection critical patch size deemed to be much larger than 1.2-1.9ac terr. size highly social in behavior; often nests in NM only in years with high rainfall DICK areas of tall,dense grass or forbs; needs to have a few perches rising an average of 19.3 in above average height of surrounding vegetation     heavy grazing in short grass has detrimental effect ; moderate grazing in tall grass may be beneficial WEME grasslands with good grass and litter cover; some shrub cover occupies drier areas than Eastern Meadowlark in areas of sympatry moist lowlands, agricultural fields are acceptable