Family Corvidae: Episode Four: Jays

Summary: In this final episode of Family Corvidae join Cheryl and Kiersten as they talk about what makes jays so interesting and learn about the five different jays found in Arizona.

 

For our hearing impaired listeners, a transcript of this podcast follows the show notes on Podbean.

 

Show Notes:

Ornithology by Frank B. Gill

 Https://corvidresearch.blog/catergory/jay-behavior/

 

Transcript

 

Host Voice: Welcome to The Feathered Desert a podcast all about desert bird feeding in the Southwest region of the United States. (Various bird calls play)

Corvidae Family Part Four: Jays

Kiersten: Intro – Welcome to the Feathered Desert, everyone!  This is part four of Family Corvidae, our final episode on this amazing bird family. In part four we are discussing Jays. This is my second favorite bird in the Corvidae family. My first is Ravens and I know Cheryl is extremely partial to crows.

 

Cheryl: Yes, I am!

 

Kiersten: If you have listened to the previous three parts you know that this bird family is celebrated for its complicated behaviors and problem-solving skills. Jays are no exception to this and the one attribute they are most well-known for is their spatial memory capacity.

 

            First question is, what exactly is spatial memory? Spatial memory is a form of memory responsible for the recording and recovery of information needed to plan a course to a location and to recall the location of an object or the occurrence of an event.

 

Cheryl: Something that humans need more of! (laughs)

 

Kiersten: Spatial memory is necessary for orientation in space. In layman’s terms, it means you can recall where you put your car keys or remember the route to the grocery store. Without this kind of memory, you just stumble through life coming across things randomly.

 

            The part of the brain that processes spatial memory is the hippocampus. The hippocampus of both mammals and birds are functionally identical, meaning they both process the same kind of information in the same way. Birds that rely heavily on seed-caching, like our Jays, have an enlarged hippocampus. Their enlarged hippocampus helps jays remember all the places they’ve hidden seeds for future use. In general, they have an 85% retrieval rate. The size of the hippocampus in jays was quite a surprise when scientists discovered it, but has led to a whole variety of questions about bird memory and social relationships.

           

Cheryl: Birds! The never-ending amazing facts! How I marvel at them!

Canada Jay

            We’re going to start off with the Canada Jay and I’m kinda excited because I didn’t know we had them in Arizona. My first experience with a Canada Jay was when I was up in Yellowstone National Park.

We are lucky to have five different jays in Arizona and we’re going to talk about one that is found in only a small portion of Northeast Arizona first, the Canada Jay. There are several subspecies of the Canada Jay that range across the northern North American continent. The one we will see most commonly in Arizona is a medium sized bird at approximately 11.5 inches with gray wings and tail, white chest, and pale gray underparts. The head is white with a gray stipe that circles the head from eye to eye. The beak and legs are both black. The Canada jay has no crest and a short, small beak. Juveniles are all gray. This jay is also known as the Gray Jay, Camp Robber, and Whiskey Jack.

I have a story to go with the Camp Robber!

They are found mainly in coniferous forests in Arizona. They eat insects, berries, seeds, carrion, bird eggs, and fungi. They forage in trees, shrubs, on the ground, and can catch insects on the wing.

            As we talked about before, this jay caches food but they have something that sets them apart from other jays. They have super sticky saliva! When they find food that they want to cache, such as seeds, they coat it in their sticky saliva and they deposit it on the sides of a tree trunk or the bottom of a tree branch. Once the saliva dries, it hardens around the food and keeps it safe for later use. The reason they place it on tree trunks is to keep it available when the snow covers the ground, especially in the northern regions where they are found. They are a non-migratory bird so they tough out the winter where ever they live. Placing their caches above the snow allows them to survive the winter and awards them the most northernly jay on the continent.

 

            When we were in Yellowstone we were cooking outside at the fire and had a run-in with Camp Robber! We were cooking chicken kabobs that you would cook over the campfire and these birds began to collect over our campsite. One swooped down and snagged a piece of un-cooked chicken off the cutting board! By the time we organized to get everything covered them took green pepper, potato, carrot, a few chips, and a roll! Talk about a Camp Robber!

 

Kiersten: Mexican Jay

            Next, we’re travelling down to the Southeastern corner of Arizona to talk about the Mexican Jay. Once again, there are several subspecies of this jay and their coloration can vary by population. The one found in Arizona ranges between 11-13 inches in length. The face, head, neck, back, wings, and tail are a bright sky-blue color while the throat, chest, and belly are white. They have no visible crest. The beak is long and wider at the head tapering down to the end. It is black, as are their legs. They prefer pine, oak, and juniper woodlands. They eat fruits, insects, seeds, carrion, bird eggs, and acorns. Acorns are especially coveted and are often cached for later use. They find about 85% of these cached acorns, but the ones they forget about are extremely important to the environment because those will grow into mighty oaks.

Mexican Jays are very family-oriented jays and can live in groups of 5-25 that often contain parents, siblings, and other relatives in the same territory or in an adjacent territory. They can live up to 20 years surrounded by family. With the warming temperatures brought on by Climate Change, Mexican Jays in Arizona now lay eggs 10 days earlier than they used to back in the 1970s.

 

Cheryl: Pinyon Jay

            Our next amazing jay is found throughout most of Arizona except the southwestern portion of the state. The Pinyon Jay is approximately 10.5 inches in length and is a lovely azure blue from head to tail. They have no visible crest. The beak and legs are both black. Clear leg feathers can be seen giving them the look of pants. The beak is thin but great for cracking open seeds. They prefer habitats with ponderosa pines, pinyon-junipers, and mixed forests of oak and pine. They eat nuts, pine seeds, grass seeds, berries, fruits, insects, and eggs. They forage in trees mostly but will go to ground for something worth their while, and have been seen searching for food in coniferous forests at elevation of 3,000 to 8,000 feet above sea level.

            Unlike other jays, the pinyon jay does not have feathers that cover their nostrils. This is because they probe deep into pitch-covered pinecones to extract the seeds and if they had feathers covering their nostrils, they would get goopy. It is also why this jay’s beak is so slender compared to other corvids. Breeding season in pinyon jays is closely correlated to the seeding time of the pinyon pine and when green pinecones appear it can trigger their breeding hormones. These birds can live in flocks up to 500 and they often stay in that flock their entire lives.

 

So those aren’t necessarily family groups?

 

Kiersten: Definitely! I’m sure there is some family but this is a big enough group you’ll find someone you’re not related to.

 

Cheryl: They have a strict dominance hierarchy that they abide by that is decided through observation alone, not direct interaction. For example, if Jay H sees Jay T, a dominant bird to Jay H, respect Jay F’s dominance, Jay H will also concede to Jay F’s dominance without having to physically interact with him.

 

That’s like mutual respect.

 

Kiersten: It is and it makes a whole lot of sense! If you are living in a group of 500 and are constantly jostling for position, you’d be fighting all the time and never get anything done. It’s so amazing!

 

Cheryl: We could learn something from birds there. They get more done than we do!

 

Kiersten: Steller’s Jay

            Our next jay is our most strikingly colored jay, in my opinion. The Steller’s Jay is approximately 11.5 inches in length with a black head, face, neck, and back and light blue underbelly and dark blue wings and tail that have black striping. This jay has a prominent black crest that they can raise or lower. In Arizona they are found in the eastern portion of the state with some residents in the northwestern areas,  as well. We are in the eastern half of their North American range and our populations often have thin, white stripes on the face above the eye and on the forehead. Like most of our other jays they prefer wooded forests as their chosen habitat. They eat nuts, seeds, acorns, small invertebrates, and bird eggs.

            The crest on the Steller’s jay is used to communicate with other jays. When the crest is raised to 90 degrees this can indicate an imminent attack, but if the crest is lowered flat the jay will most likely retreat. The length of the crest will vary by population and it is determined by the openness of the vegetation in their habitat and the effectiveness of the crests as social cues. There are several subspecies of this jay ranging somewhere between 15-17 different subspecies but all are found in the western portion of the US. They get their name from Georg Steller, the European naturalist who discovered the species in 1741.

           

Cheryl: Okay. I have a question. It has to do with subspecies. What exactly is that?

 

Kiersten: A subspecies is usually a population difference. Different regions will have slightly different versions of the species. It is most often determined by isolation. Coloration or size will differ in the entire population and scientists will determine whether they are considered a subspecies or not. They are all Steller’s Jays but with slight regional differences that are common enough in a population to make them a subspecies.

 

Cheryl: Thank you!

 

Woodhouse’s Scrub-Jay

            Our final Arizona jay is Woodhouse’s Scrub Jay. Their approximate length is 11.5 inches and they have a blue head with a thin, white eyebrow stripe and gray cheek patch. Their neck, wings, and tail are blue. The upper back is dark gray. The throat is white and the underparts are light gray. Beak and legs are black. They have no crest. They are found in the majority of Arizona with the exception of the southwestern corner. They are found only in the Southwestern region of the United States and Central Mexico. It prefers pinyon pines and juniper forests but can also be found in oak woodlands and mixed forests. They eat insects, grains, small lizards, frogs, fruits, and bird eggs.  They have been seen picking ticks off the backs of Mule Deer.

            The Woodhouse’s Scrub-Jay used to be lumped together with other species of scrub jays all called the Western Scrub Jay, but as time has gone by and populations of birds become more isolated scientists have broken the Western scrub jay into different species such as the California Scrub Jay and the Woodhouse’s Scrub Jay. When these birds ranged across the entire United States the Florida Scrub Jay was also included in this group and all were just called Scrub Jays. There is also the Island Scrub-Jay that lives only on the island of Santa Cruz off the coast of California. This particular jay is helping scientists replant trees that were burned from wildfires.

           

Kiersten: Replanting forests is actually one of the most important jobs that all jays across the continent have. When the birds cache their nuts and seeds, they don’t just cache any nuts and seeds, they must be just right, kind of like Goldie Locks. These birds look for the perfect nuts by shaking their heads after they’ve picked up the nut with their beaks. This motion helps them determine the weight of the nut. The weight of the nut can tell them exactly how many seeds are in the shell and whether it’s worth their effort to cache it. This also means these are healthy seeds that, if left buried, will grow into new trees, and as we mentioned before, jays have great memories but they always miss a few caches. I think that’s by design!

 

Cheryl: Yes!

 

Kiersten: Researchers on the Island of Santa Cruz have put the Island Scrub-Jay to work replanting the island’s lost trees by offering them acorns to cache. For a more in-depth look at this project check out our Groundbreaking Women of Ornithology Part 1.

 

We hope you’ve learned some new things from our Family Corvidae series. I know we both learned a lot as we researched and wrote each episode. This family of birds never stops amazing us!