• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	A2bc+3bc+4bc

Red List history

Year	Category	Criteria
2020	Vulnerable	A2bc+3bc+4bc
2017	Vulnerable	A2bc+3bc+4bc
2016	Near Threatened	A2bc+3bc+4bc
2012	Near Threatened	A2bc+3bc+4bc
2008	Near Threatened	A2b,c; A3b,c; A4b,c
2004	Near Threatened
2000	Lower Risk/Least Concern
1994	Lower Risk/Least Concern
1988	Lower Risk/Least Concern

Migratory status	full migrant	Forest dependency	does not normally occur in forest
Land-mass type	continent	Average mass	20 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	1,150,000 km2	medium
Extent of Occurrence (non-breeding)	1,880,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	3100000 mature individuals	medium	estimated	2019
Population trend	decreasing	medium	estimated	2014-2024
Rate of change over the past 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Generation length	2.68 years	-	-	-

Population justification: Partners in Flight (2019) currently estimate the population to number 3.1 million mature individuals.

Trend justification: This species has undergone a large decline, measured at ~85% between 1970 and 2014 by Partners in Flight (Rosenberg et al. 2016), whom currently estimate the species to be declining at a rate of 4.38% per year, or 36.1% across a ten year period (Partners in Flight 2019). The Breeding Bird Survey also note a ~88.8% decrease since 1966 (Sauer et al. 2016) and estimate current annual declines of ~3.22% between 2010-2017 (Pardieck et al. 2018). Whilst only equable to a 27.9% decline across a ten year period, the Christmas Bird Count however suggest that the rate of decline may be higher (Meehan et al. 2018) and as such, in agreement with the Partners in Flight (2019) estimate, the rate of population decline is placed in the band, 30-49%. Declines are most pronounced in Canada where the species is estimated to have declined by more than 95% between 1970-2017, with short-term population declines reaching 52.9% per decade between 2007-2017 at rate of ~7.2% per year, peaking in Alberta at ~11.8% per year (COSEWIC 2019, Smith et al. 2019).

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Canada	extant	native		yes
Mexico	extant	native			yes
USA	extant	native		yes	yes	yes

Country/Territory	IBA Name
Mexico	Complejo de Humedales del Noroeste de Chihuahua
Mexico	Cuchillas de la Zarca
Mexico	Janos - Nuevo Casas Grandes
Mexico	Laguna de Bustillos
Mexico	Laguna de Mexicanos
Mexico	Santiaguillo
USA	Medicine Lake National Wildlife Refuge
USA	North Valley Grasslands
USA	San Rafael Grasslands
USA	Westby Prairie-Wetland Complex
USA	Wichita Mountains National Wildlife Refuge

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Grassland	Temperate	major	non-breeding
Grassland	Temperate	major	breeding
Shrubland	Temperate	suitable	non-breeding
Shrubland	Temperate	suitable	breeding
Altitude	1000 - 2500 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Agro-industry farming	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Livestock farming & ranching - Scale Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Human intrusions & disturbance	Work & other activities	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		No decline		Low Impact: 4
		Stresses Species disturbance
Invasive and other problematic species, genes & diseases	Problematic native species/diseases	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Reduced reproductive success, Species mortality
Pollution	Agricultural & forestry effluents - Type Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation, Ecosystem conversion
Transportation & service corridors	Utility & service lines	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Species mortality

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Recommended citation
BirdLife International (2024) Species factsheet: Chestnut-collared Longspur Calcarius ornatus. Downloaded from https://datazone.birdlife.org/species/factsheet/chestnut-collared-longspur-calcarius-ornatus on 22/11/2024.
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 22/11/2024.