Justification This species is listed as Vulnerable because new analysis suggests that it has a small and severely fragmented range, and the area of suitable habitat is declining. Urban development is the main cause of this decline.

Family/Sub-family Emberizidae

Species name author (Gmelin, 1788)

Taxonomic source(s) AOU checklist (1998 + supplements)

Taxonomic note Ammodramus caudacutus (Sibley and Monroe 1990, 1993) has been split into A. caudacutus and A. nelsoni following AOU (1998).

Identification 13.5 cm. Well-marked and long-billed sparrow. Colourful orange, black and grey head pattern, grey crown and nape, and white streaks on back. Similar spp. Told from close relative Nelson's Sharp-tailed Sparrow A. nelsoni by its orange malar (brighter than breast), poorly defined white belly and the distinct black streaking on the breast and flanks. Voice Much softer song than A. nelsoni lacking distinctive final note of that species.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

250,000

decreasing

69,500 km²

No

Range & population Ammodramus caudacutus is confined to a narrow Atlantic coastal strip of the USA from Maine south to North Carolina, with a southward shift in winter as far as Florida and north to Maryland⁸. It is abundant in saltmarshes in the core of its range and was estimated to number c.250,000 individuals^3,6, however, based on crude recent density estimate the true figure more likely falls within a band of 50,000-100,000 individuals, probably at the lower end⁷. Its highly fragmented range is approximately c.20,000 km², within which it occupies an area of less than 2,000 km² of appropriate habitat^3,4.

Ecology: Ammodramus caudacutus is found in tidal coastal marshes where there is dense cordgrass, blackgrass or saltmeadow grass. Nesting takes place from mid May through to early August and males sing persistently during this time. Nests are placed 6-15 cm above the ground and usually 3-5 greenish white to greenish blue eggs, speckled with reddish brown, are laid. They are not territorial and are not usually found in mixed species flocks⁵.

Threats Localised populations have suffered throughout its range from the severe and ongoing loss, degradation and fragmentation of marshes owing to urban development^1,2,4. Further threats include chemical spills and other pollutants, invasive species (particularly Phragmites, which makes the habitat completely unsuitable) and sea level rise. The amount by which sea level will rise owing to climate change remains uncertain but Spartina patens dominated marsh (high marsh) may disappear or be greatly reduced in size as the large amount of development along the coast means that there is limited scope for marshes to migrate inland⁴. To date the species has not been recorded nesting outside of high marsh habitats; the implications of sea-level rise and loss of high marsh habitats are therefore extremely serious.

Conservation measures underway A current project is attempting to develop population estimates for sites in Connecticut. Using survey data from throughout the species's range this project will estimate the total population size⁴. Research into threats to the species, especially the impacts of climate change and sea-level rise is ongoing⁷. The species occurs within a number of protected areas supporting coastal habitat.

Conservation measures proposed Develop population and trend estimates for the whole species's range. Assess how the population could be monitored⁴. Assess the species's status in light of rising sea levels and the threat that they pose to Spartina patens habitat³. Manage habitats appropriately for this species, e.g. control Phragmites.

References 1. Greenlaw and Rising (1994) 2. Sibley (1996). 3. P. Comins in litt.(2003). 4. C. Elphick in litt. (2003). 5. Rising (1996). 6. Rich et al. (2003). 7. C. Elphick in litt. (2007). 8. Greenlaw and Woolfenden (2007).

Further web sources of information

Auduton WatchList

Text account compilers Phil Benstead (BirdLife International), Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International), Andrew O'Brien (BirdLife International), David Wege (BirdLife International)

Contributors Greg Butcher (National Audubon Society), Patrick Comins (Connecticut Audubon Society), Chris Elphick (University of Connecticut), Ken Rosenberg (Cornell Laboratory of Ornithology), Jeff Wells (Partners in Flight)

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Ammodramus caudacutus. Downloaded from http://www.birdlife.org on 10/2/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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