The best replacement for grackle is starling.

The best alternatives to grackle are rated as following:
★★★★★  starling
★★★★  crow
★★★★  blackbird
★  cowbird
★  brewer's blackbird
★  drop noseband
★  flash noseband
★  purple martin
  boat-tailed grackle

Your alternative for grackle is not listed? Suggest!
Speaking about grackle, one probably shouldn't forget about pelham.

Other search terms related to grackle and their ratings are:
★★★★★ pelham
You have in mind a companion for grackle and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of grackle in all years. Click on graph for more.
grackle
starling
crow