So there you have it, my “most used” colors for particular types of wildlife.
Something else to consider when deciding what you may need, will you be drawing single subjects or do you want to include backgrounds? If you plan to add even a slight hint of ground or partial background you’ll need to encorporate the colors of that bird or animal’s enviornment. Beyond dirt or grass will there be flowers? If there are leaves will they be springtime buds of light greens, deep greens of summer or beautiful crimson, golden and brown autumn leaves? Try to think about what you plan to draw and list out the colors you think you will need.
I sincerely hope this has given you a little help in deciding what you may or may not need for drawing wildlife.