Data Zone
Justification of Red List category
Based on data sources that cover most of the species’ range, a reduction exceeding 20% in three generations is estimated. This species is therefore assessed as Near Threatened. It remains abundant and widely distributed, but the drivers of the decline are uncertain and require investigation.
Population justification
This species is widespread and very commonly observed. The global population is estimated to number 2,300,000 mature individuals (Partners in Flight 2023).
Trend justification
A reduction of 22.0% (-26.9 to -18.0%) within three generations was estimated in the Avian Conservation Assessment Database December 2023 update (Partners in Flight 2023) based on modelled Breeding Bird Survey data. This species is abundant and commonly observed and this trend is considered well-supported. The above rate of decline is supported by an analysis of eBird trend data which estimated a three-generation reduction of 18.3% (-22.8 to -14.3%) (Fink et al. 2023).
Data from the North American Breeding Bird Survey and Christmas Bird Count indicate declines of c.19% and c.13% respectively in the three-generation period 2008-2021, with no indication the rate is slowing (Meehan et al. 2022, Ziolkowski Jr. et al. 2022). The Central American Waterbird Census found a moderate decrease (-16%) over the period 2012–2020 during the winter period in southern Mexico and Central America (van Dort et al. 2023). Although low, numbers wintering at Tomales Bay in California are declining and are thought to reflect population decreases elsewhere in the west (Warnock et al. 2021).
A recent analysis of migration count data at stopover locations throughout North America (Smith et al. 2023) also indicates declines, though only covers part of the population. A reduction of 37.0% was estimated over three generations, albeit within a wide confidence band of -63.8% to -1.1%.
Overall, based on data sources that cover most of the species’ range, a reduction exceeding 20% in three generations is estimated. Uncertainty over the future rate of decline means that a value for the future three generations is not determined.
Migratory in the north of its range where breeds from Alaska, south through Canada and the northern tier of states, United States of America, wintering south throughout Central America, Colombia, and Venezuela, and along west coast of South America to Peru and Chile; southern populations resident (Jackson and Jackson 2020). However, there is increasing evidence the species is at least an occasional breeder in Central America and Colombia (van Dort 2019, Castro-Vargas et al. 2021, Sequeda-Zuleta et al. 2021).
Charadrius vociferus inhabits a wide range of open areas, including grasslands, mudflats, agricultural fields and shorelines. They are adaptable and can thrive in human-altered landscapes such as golf courses, parks, gravel roads and urban areas. Breeding sites need to be almost bare, usually with a clear view and are often on gravelly substrate. However many breed in agricultural fields: almost all observations in a study estimating the size of the breeding population in the Eastern Rainwater Basin in Nebraska came from agricultural fields, with a preference for fields that were planted with soybeans the previous year (Jorgensen et al. 2009).
It is currently uncertain what is causing the recorded reduction and there is an urgent need to elucidate the drivers and their relative impacts. Habitat modification and human disturbance are potential threats, however the species is attracted to many human environments and can thrive in altered landscapes. Additionally, while historically hunted, the species is protected by law and there is no evidence this remains a significant threat (Jackson and Jackson 2020). The high use of potentially risky agricultural habitats for breeding by a large proportion of the population in the north of the range warrants investigation (Jorgensen et al. 2009): there is the potential that this represents a sink habitat, with disturbance and nest loss from agricultural operations, exposure to potentially harmful chemicals (Fisk 1976) and reduced food resource (Fair 1995) which may result in lowered reproduction and survival. Direct mortality from pesticide application has been recorded (Fisk 1976). Disease may be an additional factor (Jackson and Jackson 2020).
Conservation Actions Underway
No targeted actions known, however protected by the U.S. Migratory Bird Treaty Act.
Conservation Actions Proposed
Continue to monitor population trends. Investigate threats. Protect and manage key habitat.
Text account compilers
Vine, J.
Contributors
Smith, P. A.
Recommended citation
BirdLife International (2024) Species factsheet: Killdeer Charadrius vociferus. Downloaded from
https://datazone.birdlife.org/species/factsheet/killdeer-charadrius-vociferus on 12/12/2024.
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 12/12/2024.