Justification of Red List Category
This species has a small and declining population within a restricted range. Landscape conversion for agriculture is causing rapid declines in the area of suitable habitat, with inevitable impacts on population size. However, recent surveys have found higher densities than previously thought within breeding areas. It currently qualifies as Vulnerable, although future increases in the rate of decline could result in uplisting to Endangered.
The population is estimated to number over 28,000 individuals, based on recent estimates from studies in Argentina and Uruguay, the only known breeding areas.
Repeat surveys have used different methodologies, so accurate trends cannot be estimated. However, the Extent of Occurrence is thought to have declined by 30% owing to habitat conversion between 1992 and 1999, suggesting that populations could be declining at a moderately rapid to rapid rate.
Sturnella defilippii was formerly common and widespread in east-central Argentina and Uruguay (Cotinga 1995, Azpiroz 2005), but always rare in south Brazil (four winter records from Paraná, Santa Catarina, and Rio Grande do Sul). Since 1900, its range has decreased by 90%, with most of this decline occurring between 1900 and 1950 (Tubaro et al. 1994, Tubaro and Gabelli 1999). In 1992-1993, the extent of occurrence in Argentina was estimated at 8,000 km2, the area of occupancy at 150 km2 and the population at c.7,500 birds (Tubaro and Gabelli 1999), whilst in Uruguay the breeding population was estimated at 78-90 pairs in the Arerunguá area (Azpiroz 2005). In 2004, a detailed study estimated the extent of occurrence in Argentina at 4,810 km2, and hence a range contraction of 30% within 10 years, although more intensive sampling revealed higher densities than previously estimated, with an area of occupancy of 512 km2 and a minimum population size of 28,000 individuals (Gabelli et al. 2004). These are concentrated in south-west Buenos Aires and adjacent La Pampa, with records in Entre Ríos, San Luis, Córdoba and Corrientes (Tubaro and Gabelli 1999, R. Fraga in litt. 2012).
It inhabits natural grasslands (vegetation height of 29-45 cm), including land abandoned for 5-15 (or more) years (Tubaro et al. 1994). Some birds breed and winter in planted pastures and cultivated fields with a similar vegetation structure (Tubaro and Gabelli 1999). However, a study in Buenos Aires province found that 90% of reproductive groups were present in natural grasslands with high vegetation cover (Fernandez et al. 2004). It can coexist with cattle, but apparently avoids planted pasture, as well as areas where grazing is more intensive and vegetation height is consequently lower (Tubaro and Gabelli 1999). Breeding occurs between mid-October and November, and 3-4 eggs are laid (Azpiroz 2005). The diet includes seeds, insects and shoots. There is some northwards movement in winter, but it is primarily resident (Tubaro and Gabelli 1999).
Rapid and widespread conversion to cattle-ranching, arable and plantation agriculture are primarily responsible for long-term declines. It is now restricted to areas least suitable for agriculture, although the rate of grassland conversion within occupied areas continues to outstrip the rate of grassland regeneration by three to one (Gabelli et al. 2004). Other factors may interact with habitat loss, including high rates of nest predation (Cozzani et al. 2004), although recent studies in Uruguay suggest that this may have only a limited effect (A. Azpiroz in litt. 2007). Trampling by cattle (Gabelli et al. 2004), and brood parasitism by Shiny Cowbird Molothrus bonariensis (Cozzani et al. 2004, Gabelli et al. 2004) could also influence productivity, although parasitism appears to be rare (Cozzani et al. 2004, A. Azpiroz in litt. 2007). Maintenance of moderate grazing regimes appears to favour the species (Zalba et al. 2008). Competition with Long-tailed Meadowlark S. loyca and White-browed Blackbird Leistes superciliaris could negatively influence this species (Tubaro and Gabelli 1999), although studies have found no evidence that presence of either species affects site selection (Gabelli et al. 2004). Capture for trade is not currently extensive (Tubaro and Gabelli 1999), but in 1988 over 100 birds were seen in local markets (Bertonatti and Tubaro 1993).
Conservation Actions Underway
It is protected under Brazilian and Uruguayan law and from trapping in Argentina. Studies have clarified its distribution , numbers and habitat requirements (Tubaro et al. 1994, Tubaro and Gabelli 1999, Fernandez et al. 2004, Gabelli et al. 2004, Azpiroz 2005). In northern Uruguay, educational visits to schools were carried out in association with surveying in 2003 (Azpiroz 2005).
21 cm. Striking icterid. Male upperparts and most underparts black, edged brown. Bright red supraloral stripe, throat and breast. Cream eyebrow. Black underwing-coverts. Female much browner and more streaked, with pinky-red centre to belly and buffy throat. Similar spp. Long-tailed Meadowlark S. loyca has pale underwing-coverts, longer tail, and browner coloration. White-browed Blackbird Leistes superciliaris has much shorter bill. Voice Short, buzzy series of high-pitched notes. Dull, raspy jzeet call.
Text account compilers
Gilroy, J., Harding, M., Pople, R., Sharpe, C J, Khwaja, N.
Fraga, R., Azpiroz, A.
BirdLife International (2018) Species factsheet: Leistes defilippii. Downloaded from http://www.birdlife.org on 21/09/2018. Recommended citation for factsheets for more than one species: BirdLife International (2018) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 21/09/2018.