Fun Facts About Blue Jays--the Caching Extraordinaire
- Just like bluebirds, Blue Jays have no blue pigments in their feathers. Instead, each feather barb has a thin layer of cells that absorb all wavelengths of color except blue. Only the blue wavelength is reflected and scattered, resulting in their blue appearance to our eyes.
- Blue Jays are often chastised for their known practice of eating eggs and nestlings of other birds. But extensive research has proven this to be a very rare occurrence, with only 1% of the study population showing any evidence of this behavior.
- Peanuts in the shell are a favorite among Blue Jays. Watch your feeder to see if you can observe them shaking peanuts to tell if the shell is full or empty.
- Jays will cache seeds and nuts to retrieve later, and make repeated trips to feeders to gather food and hide it in a safe spot.
- Blue Jays mainly select undamaged nuts to bury; research has shown that only 10% of the nuts they cache are not viable seeds.
- Blue Jays will bury seeds up to 2.5 miles from their original source, which is a record for any bird. This behavior has greatly helped with the range expansion of many oak species.
- The rapid northward dispersal of oaks after the ice age may have resulted from the northern transport of acorns by Jays.
- Due to Jay’s habit of burying acorns over a wide area, 11 species of oak trees have become dependent on Jays for the dispersal of their acorns.
- Research studies have recorded Blue Jays making over 1,000 trips per day when hiding food.
- In one research study, 50 Blue Jays were observed selecting and caching 150,000 acorns over a period of 28 days. Each bird cached a total of 3,000 acorns by selecting and hiding an average of 107 acorns per day.
- In another research study, Blue Jays were observed storing over 2,000 beach tree nuts in one month.
- A Blue Jay was observed packing over 100 sunflower seeds into it’s gullet during just one visit to a feeder.
- The Blue Jay is a talented mimic; its version of a Red-shoulder hawk’s call can fool even the most experienced birder.