Comprehensive Report Species - Cistothorus platensis Page I of 19 NatureServe () EXPLORER • '•rr•K•;7",,v2' <-~~~ •••'F"'< •j • ':'•k• N :;}• <"• Seach bot. the Dat -Abou-U Cot Chana eCrite «<Previous I Next»> Cistothorusplatensis - (Latham, 1790) Google, Sedge Wren Search for Images on Google Spanish Common Names: Chivirin Sabanero, Chercan de las Vegas French Common Names: Troglodyte & bec court Other Common Names: Curruira-do-Campo Unique Identifier: ELEMENTGLOBAL.2.105322 Element Code: ABPBG10010 Informal Taxonomy: Animals, Vertebrates - Birds - Perching Birds Kingdom Phylum Class Order Family Genus Animalia Craniata Aves Passeriformes Troglodytidae Cistothorus Genus Size: B - Very small genus (2-5 species) Check this box to expand all report sections: Concept Reference 0 Concept Reference: American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, DC. 829 pp. Concept Reference Code: B98AOU01NAUS Name Used in Concept Reference: Cistothorusplatensis Taxonomic Comments: Formerly known as Short-billed Marsh-Wren. Composed of three groups: STELLARIS (Sedge Wren), PLATENSIS (Western Grass-Wren), and POLYGLOTTUS (Eastern Grass-Wren) (AOU 1998). Constitutes a superspecies with C. MERIDAE and C. APOLINARI (AOU 1998). Conservation Status 0 NatureServe Status Global Status: G5 Global Status Last Reviewed: 03Dec1996 Global Status Last Changed: 03Dec1996 Rounded Global Status: G5 - Secure Nation: United States National Status: N4B,N5N Nation: Canada National Status:N5B (09Aug2000) http://www.natureserve.org/explorer/servlet/NatureServe?searchName=Cistothorus+plat... 1/23/2008 Comprehensive Report Species - Cistothorus platensis Page 2 of 19 (SNRB), Ohio (S2), Oklahoma (S2N), Pennsylvania (S1B), South Carolina (SUB), South Dakota (S4B), Tennessee (S3N), Texas (S4), Vermont (S1B), Virginia (S1 B,S1S2N), West Virginia (S1B), Wisconsin (S4B) ECanada II(S5B)IAlberta (S2), Manitoba (S5B), New Brunswick (S1B), Ontario (S4B), Quebec (S2), Saskatchewan Other Statuses Committee on the Status of Endangered Wildlife in Canada (COSEWIC): Not at Risk (OlAprI993) IUCN Red List Category: LC - Least concern NatureServe Conservation Status Factors Global Short Term Trend Comments: Termination of the USDA Conservation Reserve Program and a return of enrolled land to cultivation are expected to cause a population decline of 26% in North Dakota (Johnson and IgI .1995). Data from North American Breeding Bird Survey (BBS) routes (Robbins et al..1986) indicate that populations across the U.S. showed no significant trends from 1966-89 (n = 282 routes), although more routes (P <.0.01) had decreasing populations (0.60) than increasing populations (0.38). In the eastern U.S., populations remained stable during the period 1966-89 (n = 224 routes), although a significantly (P < 0.01) greater proportion of routes had decreasing populations (0.60) than increasing (0.36). In the Northeast Region (U.S. Fish'and Wildlife Service Region 5), populations declined -1.47% annually from 1966-90 (P < 0.05, n = 31). Data were too few, however, to assess populations in any state in the northeastern U.S., except New York. The status of the wren as a breeding species in the northeastern U.S. is precarious. Breeding populations in all states are very sparse, sporadic, and local (or extirpated). Populations in all states have evidently undergone substantive declines during this century. Furthermore, the habitat base has deteriorated and continues to decline throughout the region. Populations in the northeastern U.S. may have waxed and waned over a 200-year period in response to changes wrought upon the landscape by humans. Prior to the arrival of Europeans, the East Coast was heavily forested and probably provided scant nesting habitat, although the bird likely bred in tidal marshes, sedge meadows along water courses, old beaver meadows, and sedgy areas of bogs and other wetlands throughout the region. In response to massive deforestation and the creation of fields and pasturelands during the late 1700s to mid-1800s, however, populations probably expanded over much of the region. It is notable that sedge wrens were scarcely known north of Massachusetts and southern New Hampshire until the end of 1800s, but thereafter were reported with some regularity in northern Vermont, New Hampshire, Maine, and Quebec (Forbush 1929, Bagg and Eliot 1937, Palmer 1949), an expansion that may have followed an increase in the availability of abandoned farmland in northern regions. Habitat gains were subsequently lost during this century due to drainage and filling of shallow wetland areas, loss of grassland communities to vegetative succession, and a shift from low-intensity agriculture, which required extensive~areas of fields to be left fallow for two to three years, to high-intensity agriculture, which keeps land in continuous cultivation. Such a pattern of colonization and retreat has been exhibited in Ontario (Cadman et al. 1987). Populations are thought to have expanded into the province following the clearance of forests for agriculture more than 150 years ago, and the current distribution of Ontario Breeding Bird Atlas records closely follows the distribution of abandoned farmlands. Breeding records are remarkably few from portions that are intensively cultivated and subject to clean-farming (Cadman et al. 1987). It is plausible that heavy mortality, of both migrating and overwintering birds, during the severe weather of 1940 reduced already diminished populations in the Northeast to such low levels that populations were never able to recover (Griscom 1949, Griscom and Snyder 1955, Bond 1967). Although Griscom (1949) refers mainly to weather conditions in the southern U.S., climatological events in New England during 1940 included widespread "heavy to killing" frosts in late August, two hurricanes in September, an extremely heavy snowstorm in November, and severe cold during the first week of December (Noyes 1941), events that could have killed many late-breeding and migrating wrens in the northeastern states. Global Protection Needs: The U.S. Fish and Wildlife Service's responsibility for reviewing wildlife habitat attributes of properties foreclosed by the Farmers Home Administration (U.S. Department of Agriculture) presents an opportunity to acquire and preserve grassland habitats in the northeastern states (Gibbs and Melvin 1992). Threats: Decline presumably has been due to loss and degradation of wetlands (Ehrlich et al. 1992), caused by suburbanization, intensive agricultural development, and natural succession. These factors and drought have resulted in declines in the northwestern part of the range (Jalava 1993). Loss of nesting habitat may be the major cause of declines in populations. About 4.75 million acres (1.92 million ha) of palustrine emergent wetlands, which include wet meadows important to nesting, were lost in the U.S. between the mid-1950s and mid-1970s (Tiner 1984). Preferred wetlands, such as sedge/grass meadows with moist or saturated soils, are the most easily http://www~natureserve.org/explorer/servlet/NatureServe?searchName=Cistothorus+plat... 1/23/2008 Comprehensive Report Species - Cistothorus platensis Page,3 of 19 drained and filled and are the wetland type most frequently destroyed by agriculture and urbanization (Tiner 1984). Substantial losses of grassland habitats in the northeast to urbanization and vegetative succession are evident. In just ten years (late 1960s-70s) along woodcock survey routes in all northeastern states combined, the availability of abandoned and active fields declined by 23- 25%, whereas the amount of land in young forest increased by 63% and that in urban/industrial uses increased by 33% (Dwyer et al. 1983). Clean-farming of wet fields (i.e., establishment of crop monocultures) was suggested as a primary cause of declines in the midwest region (Tate and Tate 1982). Aside from direct habitat loss, habitat disturbance such as late-summe" burning of tidewater marshes in Maryland and livestock grazing (Walkinshaw 1935, Lingle and Bedell 1989) are considered threats to nesting. Regional reductions of the water table due to extensive urbanization in the Northeast may prevent occurrence of water "ponding" in fields, which creates the preferred wet-meadow habitat, and, also may increase rates of vegetative succession. Wetland loss often leads to drying processes on adjacent upland habitats, and may ruin nesting habitats for wrens, which prefer to nest at moist upland margins of wetland patches. Severe weather conditions during winter could result in heavy mortality and influence population levels (Griscom 1949). Considerable mortality of migrant wrens has been observed at television towers throughout the eastern U.S. (Taylor et al. 1983). In the Argentine Pampas, overgrazing by cattle, soil compaction, and fires have eliminated tall grass habitats and have led to severe declines in populations (Bucher and Nores 1988). No information is available concerning the extent to which disease, parasites, predation, competition, or contaminants may limit populations. Distribution 0 U.S. States and Canadian Provinces fi , j;y°° AX .- it[ yr1"[ j --CN' http://www.natureserve.org/explorer/servlet/NatureServe?searchName=Cistothorus+plat... 1/23/2008 Comprehensive Report Species - Cistothorus platensis Page 4 of 19 State/Province Conservation Status SX: Presumed • : Extirpated SH! Possibly Extirpated I Critically S $ :Imperiled S2: Imperiled f-7 S3: Vulnerable S4: ApparentlySecure-