|Scientific Name:||Ammodramus henslowii|
|Species Authority:||(Audubon, 1829)|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Reviewer(s):||Symes, A. & Butchart, S.|
|Contributor(s):||Rosenberg, K. & Wells, J.|
|Facilitator/Compiler(s):||Harding, M., Isherwood, I., Khwaja, N., Wege, D.|
This species has declined significantly over the last three decades owing to the loss and degradation of its grassland habitats. Although recent population trends are unclear, it is precautionarily listed as Near Threatened as a result of suspected moderately rapid population declines. Nevertheless, further information on the apparently positive trends observed since the establishment of the Conservation Reserve Programme may in due course lead to its reclassification as Least Concern.
|Previously published Red List assessments:||
|Range Description:||Ammodramus henslowii breeds in the eastern U.S.A., from Minnesota (primarily in the south-east) east to southern Ontario and New York, and extending south-west to north-east Oklahoma, and south-east to north-western Kentucky and West Virginia. Isolated breeding populations also exist in north-east Virginia and north-east North Carolina. It is extirpated or a rare breeder in the north-east U.S. states, from Vermont south to Delaware. It winters in coastal states from south-east North Carolina south to Florida (except for the southern tip) and west to eastern Texas (AOU 1983, Sibley and Monroe 1990). It was once common in unploughed, periodically burnt tall-grass prairie, which originally stretched from Illinois west to Kansas and Nebraska (Rising 1996), but these populations have declined over the last three decades, with the greatest declines being in the northern and eastern portions of the range (AOU 1983). Southern populations, however, have tended to increase (Rising 1996), apparently in association with the creation of undisturbed grassland habitat by the Conservation Reserve Program, and the current population is estimated to be 79,000 individuals (Rich et al. 2003).|
Native:Canada; United States
|Continuing decline in area of occupancy (AOO):||Unknown|
|Extreme fluctuations in area of occupancy (AOO):||No|
|Estimated extent of occurrence (EOO) - km2:||652000|
|Continuing decline in extent of occurrence (EOO):||Unknown|
|Extreme fluctuations in extent of occurrence (EOO):||No|
|Continuing decline in number of locations:||Unknown|
|Extreme fluctuations in the number of locations:||No|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Rich et al. (2003).
Trend Justification: This species has undergone a large and statistically significant decrease over the last 40 years in North America (-96.3% decline over 40 years, equating to a -56.1% decline per decade; data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007). However, analysis by the US Fish and Wildlife Service indicated that the population has now stabilised and may even have begun to increase. Therefore, recent declines are estimated to fall within the band 20-30%.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||During the breeding season, the species is typically found in grassland with tall and dense grass, dead trees and thick leaf-litter. On their wintering grounds, though, birds prefer recently burned areas, with low densities of litter and near-ground vegetation. They are often associated with longleaf pine Pinus palustris savanna at this time, but also occur in saline soil barrens (Holimon et al. 2008). Mowed fields are generally avoided, as are fields with a lot of woody vegetation (Rising 1996, Holimon et al. 2008).|
|Continuing decline in area, extent and/or quality of habitat:||Unknown|
|Generation Length (years):||3.9|
|Movement patterns:||Full Migrant|
|Major Threat(s):||Wetland draining and destruction of grassland habitat through fire suppression, conversion to agriculture or pine plantations and earlier and more frequent cutting of hayfields (Rising 1996, Federal Register 1998, Pruitt 1996) all represent threats, and in combination they have caused population declines.|
Conservation Actions Underway
The species is monitored within the North American Breeding Bird Survey and Christmas Bird Count. It is listed as an Endangered species in Canada, and within its U.S. breeding range is considered Endangered in seven states, Threatened in five, and of Special Concern in four. Some grassland conservation activities will be undertaken as part of the national Partners in Flight bird conservation efforts. The Conservation Reserves Programme, while not specifically intended to benefit this species, has provided a large area of undisturbed grassland habitat, and Henslow's Sparrow has colonised these fields in many areas. Creation of large areas of undisturbed grasslands through this programme appears to have been responsible for recent reversal of long-term population declines. Conservation Actions Proposed
Continue to monitor population trends and determine its responses to grassland management regimes.
|Citation:||BirdLife International. 2012. Ammodramus henslowii. The IUCN Red List of Threatened Species 2012: e.T22721138A39919475. . Downloaded on 27 November 2015.|
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