At its Annual Meeting on 16 February 2020, the Illinois Ornithological Records Committee (IORC) made adjustments to the definitions of the status codes for species on the official Illinois State List of Birds. IORC also reviewed the status of each species on the state list and made updates as necessary, starting from a set of recommendations assembled by Keith McMullen.
The new definitions for the status codes are as follows. These codes are now uniformly based on the number of records.
- Regular: Species for which there are at least eight records in the past ten years. This includes species that are very local and those that cannot be located reliably anywhere in the state. Most species in this category are expected within the state annually.
- Casual: Species for which there are at least six records in the state and three to seven records in the past ten years.
- Accidental: Species for which there are either less than six records in the state or less than three records in the past ten years.
- Accidental (provisional): Forms with accepted records, all of which are sight records documented by no more than one observer.
- Extirpated: Species which were formerly Regular in Illinois but which have not been recorded in the state in the previous 50 years.
- Extinct: Species which have occurred in the state but no longer exist.
Species for which status category was changed include the following.
- Black-bellied Whistling-Duck: status changed to Regular from Casual.
- Gray Partridge: status changed to Accidental from Regular.
- Ruffed Grouse: status changed to Extirpated from Accidental.
- Ruff: status changed to Regular from Casual. This species will remain on the Review List.
- Purple Sandpiper: status changed to Casual from Regular. IORC now requests that sightings of this species from anywhere in Illinois be documented.
- Long-tailed Jaeger: status changed to Casual from Accidental.
- Little Gull: status changed to Regular from Casual. This species will remain on the Review List.
- Neotropic Cormorant: status changed to Regular from Casual. This species will remain on the Review List.
- Anhinga: status changed to Regular from Accidental. This species will remain on the Review List.
- Brown Pelican: status changed to Casual from Accidental.
- White Ibis: status changed to Regular from Casual. This species will remain on the Review List.
- Fork-tailed Flycatcher: status changed to Accidental from Casual.
- Common Raven: status changed to Accidental from Extirpated.
- Rock Wren: status changed to Accidental from Casual.
- Mountain Bluebird: status changed to Casual from Accidental.
- Townsend’s Solitaire: status changed to Regular from Casual. This species will remain on the Review List.
- Sprague’s Pipit: status changed to Accidental from Casual.
- Evening Grosbeak: status changed to Casual from Regular. This species is now on the Review List.
- Pine Grosbeak: status changed to Accidental from Casual.
- White-winged Crossbill: status changed to Casual from Regular. This species is now on the Review List.
- Bachman’s Sparrow: status changed to Extirpated from Accidental.
- Golden-crowned Sparrow: status changed to Casual from Accidental.