Blue Jays: Are they REALLY Blue?
Blue Jays Interesting Facts
Technically “no.” The Blue Jay‘s blue plumage details are a result of structural as opposed to pigmented coloration. In fact, the pigment in Blue Jay feathers is melanin, which is brown.
The illusion of blue is caused by its pattern of keratin which reinforces blue wavelengths of light while cancelling out red and yellow wavelengths.
The varying shades of blue are a result of the different shapes and sizes of air pockets that reflect the light differently.
If you crush the feather of a Blue Jay, you will find that the blue coloration disappears.
Blue Jays have a reputation for destroying the eggs and nestlings of smaller birds.
According to a study on Blue Jay feeding habits led by the Cornell Lab or Ornithology, evidence of eggs or nestlings were only found in the stomach contents of about 1% of Blue Jays.
The Blue Jays are able to mimic sounds from their environments, including human speech.
These intelligent birds appear to be using their mimicking abilities both as protective measures as well as manipulative devises.
For example, they may drive other birds away from bird feeders or nests by imitating the calls of hawks. They have also been observed mimicking the hawk’s call near feeding birds; and as those fled, the Blue Jays swooped down and stole the food left by the other birds.
(Scroll down for a video of a juvenile Blue Jay rendering the calls of a Red-tailed Hawk.)
Blue Jays – the Tool Makers:
The University of Massachusetts researched the behavior of Blue Jays kept at their lab and found that these smart birds were able to make and use tools to reach food items that would otherwise be unattainable.
One Blue Jay used pieces of newspaper at the bottom of the cage to collect food pellets that were just out of its reach.
The researchers provided a plastic bag tie, paper clip, straw grass and feather to eight different Blue Jays and found that 6 out of these 8 Blue Jays were again able to select and use a tool to retrieve out-of-reach food pellets.
Food Storage:
Blue Jays collect nuts and store them for later retrieval. They can carry up to 5 acorns at a time; 3 acorns can be stored in the gular pouch (“throat sac”), 1 in the mouth and 1 in the bill.
As these birds hide nuts in the ground, they inadvertently contribute to the dispersal of trees, as these nuts germinate in the ground and grow into new trees.
Blue Jays are Bold!
They will form groups and attack birds much larger than themselves, including birds of prey – such as owls and hawks – that enter their territories.
Migratory or Not?
To this date, Blue Jay migration remains a mystery. In a meta-analysis of over 8,000 recaptured Blue Jays in banding stations in the Atlantic Flyway, Paul A. Stewart – an expert ornithologist – found no defining factors which determined which jays migrate south and which remain in their nesting area. Some birds migrate, while others in the same areas don’t.
Even amongst birds that migrated in the past, some chose to remain in their breeding territory one year and then migrated again the next.
Those birds that do migrate form large flocks that may include thousands. In some areas along the East Coast, these “blue clouds” of birds are a well-known phenomenon.
Blue Jays’ Place in Society:
- The Blue Jay is the provincial bird of Prince Edward Island.
- Many sport teams adopted Blue Jays as mascots, such as the Toronto Blue Jays, Bluefield Blue Jays, Johns Hopkins University’s Blue Jays and the Westminster Blue Jays.
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