LC
Dickcissel Spiza americana



Justification

Justification of Red List Category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Trend justification
This species has had stable population trends over the last 40 years in North America (data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007).

Distribution and population

This species breeds mainly in central USA, and winters nomadically from west Mexico to northern South America (Ecuador and Columbia east to French Guiana).

Ecology

It is found in open and semi-open areas, especially overgrown weedy fields and tallgrass prairie. It forms huge flocks in the winter, and up to 10-30% of the global population may occur in a single roost.

Threats

The species is heavily persecuted in its wintering grounds in Venezuela, where roosts are poisoned with toxic agrochemicals, including organophosphates which are applied by crop-duster planes. The concentrations of birds at these roosts means that the species is particularly susceptible to such threats. However, on its breeding grounds the species is tolerant of agricultural activities, and has the ability to move in response to drought.

Acknowledgements

Text account compilers
Ekstrom, J., Butchart, S., Harding, M., Fisher, S.


Recommended citation
BirdLife International (2019) Species factsheet: Spiza americana. Downloaded from http://www.birdlife.org on 25/06/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 25/06/2019.