VU
Sprague's Pipit Anthus spragueii



Justification

Justification of Red List category
This species qualifies as Vulnerable owing to a rapid ongoing population decline. However, the rate of decline in the U.S.A. is now not as severe as it formerly was and overall declines may be slowing.

Population justification
Partners in Flight (2019) estimate the global population to number 1.4 million mature individuals.

Trend justification
This species has undergone a large and statistically significant decrease. Over the past 51 years (1966-2017), data from the North American Breeding Bird Survey suggests an annual rate of decline of 3.2%, or 27.8% across a ten year period (Pardieck et al. 2018). However, when viewed across the most recent time period (2010-2017), declines are shown to have accelerated in recent years with annual declines measured at ~5.22% per year, or ~41% over ten years (Pardieck et al. 2018). The rate of past decline is therefore placed in the band 30-49%. However, recent data from the Audubon Christmas Bird Count (Meehan et al. 2018) and Partners in Flight's (2019) estimate of a 27 year half life for the species (22.6% decline over the next decade) suggest that the rate of decline may have slowed over the past few years; if this continues the species may warrant downlisting in the near future.

Distribution and population

Anthus spragueii breeds relatively commonly in grasslands of south-east Alberta, southern Saskatchewan, south-west Manitoba and occasionally southern British Columbia, Canada, and north and central Montana, North Dakota, and locally South Dakota, casually to north-west Minnesota, U.S.A. (Prescott 1997, Prescott and Davis 1998, Robbins and Dale 1999, Davis et al. 2020). It winters throughout much of the southern U.S.A, particularly Arizona and Louisiana, and northern Mexico to Guerrero and Veracruz (Prescott and Davis 1998, Davis et al. 2014). The population has declined considerably since 1966 (Prescott 1997, Prescott and Davis 1998, D. R. C. Prescott in litt. 1999, Pardieck et al. 2018), but the most significant declines probably occurred in the late 19th and early 20th centuries (Robbins and Dale 1999, Davis et al. 2020); declines in Canada are considered to outweigh those in the USA (Pardieck et al. 2018).

Ecology

The species inhabits well-drained short- and mixed-grass native prairies, usually in patches of at least 65 ha with low canopy cover and a low amount of woody vegetation (Environment Canada 2012, Muller et al. 2018, S. Davis in litt. 2020). Population density increases with pasture size (Davis 2004), especially with sparse to intermediate grass densities and intermediate grass heights, moderate litter depths, few shrubs and little woody vegetation (Dechant et al. 1999, Environment Canada 2012, Davis et al. 2020); pipit densities have been shown to be over 6 times higher in areas surrounded by at least 50% grassland (Environment Canada 2012). The species also breeds in planted grasslands in some parts of its range (Davis 2018), predominantly in those with similar vegetation characteristics to native grasslands. In particular, planted fields with a low amount of alfalfa and suitable vegetation height (20–30 cm) are likely suitable breeding sites (Fisher and Davis 2011a). On migration, the species also occurs in stubble and fallow fields. In winter, it occupies a wider variety of grasslands, including non-native, planted and anthropogenic grasslands (Muller et al. 2018). It arrives late April to mid-May on the breeding grounds, and late September to early November on the wintering grounds (Robbins and Dale 1999, Davis et al. 2020).

Threats

Conversion of prairie to seeded pasture, hayfields and cropland, and inappropriate grazing are responsible for habitat loss, degradation of remaining grassland, increased juvenile mortality and rapid declines in population (Fisher and Davis 2011b, Davis et al. 2020). Since the early 1800s, the prairies of North America have declined by ~79% and the negative effects of such conversion can spread into the surrounding grasslands, now considered the most endangered ecosystem in North America (Roch and Jaeger 2014, Davis et al. 2020). As a result, birds are potentially responding to edge to area ratio (Davis 2004); distance to crops/hay (Koper and Schmiegelow 2006); or the amount of grassland in the surrounding landscape (Davis et al. 2013); as much as to area per se. Additionally, linear anthropogenic changes are associated with lowered densities (roads [Sutter et al. 2000], gas wells, pipelines, and trails [Linnen et al. 2006, Ludlow et al. 2015]). The large-scale introduction of non-native plant species and their subsequent invasion of native prairie have reduced breeding densities and breeding success (Ludlow et al. 2015, Davis et al. 2016, Davis 2017, Davis et al. 2020). Grazing and burning can have positive or negative impacts on suitable habitat depending on moisture, soil-types, plant species, intensity and frequency (Davis et al. 2020). Nests may be destroyed by haying prior to the fledging period, though the species rarely nests in hayfields. Virtual cessation of burning in the breeding zone and intensive grazing in the wintering zone has led to encroachment by shrubs and trees (Davis et al. 2020), and the preferred short prairie grass in wintering areas such as Texas is not conserved (J. Grantham in litt. 2003). Brood-parasitism by Brown-headed Cowbirds Molothrus ater is comparatively low, but is highest in fragmented habitat (Davis et al. 2020). Climate change is projected to cause a major range shift northwards, with possibly detrimental effects on the species due to limited availability of suitable habitat in the shifted range (Nixon et al. 2016).

Conservation actions

Conservation Actions Underway
It is listed as Threatened in Canada (COSEWIC 1999). Most habitat is unprotected, but large areas are included in military reserves, national parks and on remaining provincial lands (Prescott and Davis 1998, Lipsey et al. 2015, R. Fisher and S. Davis in litt. 2016). These are relatively well protected against conversion to non-native cover. Agriculture censuses have provided some information on land-use trends, and breeding distribution and post-fledging movements are relatively well studied in Canada where monitoring programs and radio-tracking are underway (S. Jones in litt. 2003, Davis and Fisher 2009). This species forms part of many grassland conservation programmes in Canada (R. Fisher in litt. 2016), and receives some protection as part of the Migratory Bird Convention Act in Canada, which is part of the Migratory Bird Treaty with the U.S.A. (R. Fisher in litt. 2016). They are also incorporated in the Federal Provincial South of the Divide Action Plan for Multiple Species At Risk, and there is a recovery plan in place in Canada (see Environment Canada 2012, Environment and Climate Change Canada 2016)

Conservation Actions Proposed
Determine breeding distribution, centres of winter abundance, population size and decline rates. Monitor habitat conversion rates. Assess threats on wintering grounds. Protect large tracts of native grasslands (Dechant et al. 1999). The size of habitat required is disputed, with a minimum size of 65 ha suggested (S. Jones in litt. 2003, Davis 2004, Environment Canada 2012, Davis et al. 2020). Manage grasslands by removing invasive woody vegetation, and graze to maintain good to excellent range condition. A short burning rotation may be beneficial in more mesic areas or where growing conditions are good, but would have negative consequences in more arid locations/conditions and at sites with unproductive soils (S. Jones in litt. 2003, Davis et al. 2020). Manage livestock grazing and burning regimes to allow the grassland vegetation to reach a certain height and density, particularly on the wintering grounds (Muller et al. 2018). Potentially delay hayfield mowing until 15 July although this habitat is not thought to be of significant importance for breeding birds (McMaster et al. 2005, Davis 2018). Restore altered upland communities to a natural state (Dechant et al. 1999)

Identification

16 cm. Well-marked pipit. Heavily streaked mantle, streaked crown contrasting with pale facial area, whitish supercilium and pale buff ear-coverts. Underparts buffish with faint streaking on breast. Pale legs. Similar spp. American Pipit A. rubescens is less streaked (uniform grey above in spring), has dark legs, streaked flanks and closed-faced appearance. Voice Song given in arcing flight, call a loud tweep often given in pairs. A. rubescens gives high disyllabic chip-it or tsee-tseet call. Hints In breeding season, best located when singing. Forms flocks in winter.

Acknowledgements

Text account compilers
Everest, J., Hermes, C.

Contributors
Bird, J., Davis, S., Derhé, M., Fisher, R., Grantham, J., Harding, M., Jones, S.L., Panjabi, A., Pople, R., Prescott, D., Wege, D. & Westrip, J.R.S.


Recommended citation
BirdLife International (2024) Species factsheet: Sprague's Pipit Anthus spragueii. Downloaded from https://datazone.birdlife.org/species/factsheet/spragues-pipit-anthus-spragueii on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/12/2024.