Tag Archives: Jays

You need to know more about jay spit

Look, I’m a reasonable person.  I know what you’re thinking.

“Literally never has it occurred to me I might know too little about jay spit.”

But here’s the thing: it’s actually super interesting and you really can’t understand Canada jays without knowing about their saliva.  It would be like trying to understand the internet without cat videos-you just can’t do it.  So trust me when I tell you this is the information you didn’t know you needed.

DSC_0164

In the early 1960’s Walter Brock was examining Canada jay corpses when he discovered that they have massive salivary glands on par with the ones found in woodpeckers.1 Such generously sized glands are found in no other songbird.  Furthermore, like the woodpeckers, it’s not just that Canada jays make a lot of saliva, but they make a lot of sticky saliva.  At the time this discovery was made, it was already known that the enlarged glands of woodpeckers served to allow for a foraging tactic called “tongue probing” where, like anteaters, the birds use their long sticky tongues to extract food from narrow crevices.  Although Canada jays don’t have especially long tongues, the ability to tongue probe seemed the most parsimonious explanation for this strange adaptation, and Brock suggested that this strategy may actually be the key to the jays’ winter survival.  A study a few years later examining their foraging behavior revealed that they don’t feed in this manner, however.  They feed more or less the same way the other corvids do.2  It seems instead, that it’s what they do with the food after that’s different.

DSC_0440

Rather than using their copious amounts of weird, sticky spit for acquiring food, it’s used for depositing it.  If you watch a jay closely after it’s got a bit of food you’ll notice it seems to have missed Emily Post’s memo about chewing with your mouth closed. Over the course of a few seconds you’ll see the food peek out from the bill as the bird moves it around inside its mouth.

DSC_0366

This jay picked up this bit of food about 60sec before this photo was taken.  Now it’s working it around with its tongue, coating it in sticky saliva.

Once sufficiently spit coated, the bird will deposit the food blob (called a bolus) onto the foliage or trunk of a tree.  No matter the material or angle, once the spit dries the food is safely secured come hell or high-water.  Because these caches are pretty small there’s little fear that many will be found.  More importantly, by stashing food high in the trees instead of burying them into the ground like many other cache-dependent corvids do, Canada jays can thrive in areas that receive much heavier snowfall, allowing them the title of the most northern residing jay in North America.

Here’s where it all really comes together though.  If you’ve seen me write about Canada jays before you’ll have noticed that it’s almost inevitable that I’ll use the phrase “Cute little faces” at some point to describe them.  But have you ever wondered why? Why do they have such cute little faces?  While jays do feed more or less in the same way as other corvids the one exception is that they don’t hammer at objects.  If you’re ever given a crow or a Steller’s an unshelled peanut you’ll know exactly the motion I mean. Without the need the hammer objects, or dig holes for burying food, Canada jays don’t need the heavy bills their cousins do.2  Instead they have the blunt little bill that helps give them their characteristic baby-faced look.  So not only is their spit responsible for their ability to tough it out in some of the harshest winter environments this continent offers, but it also means they get to look super cute while doing it.

So like I said, you don’t really know Canada jays until you know a thing or two about their spit.

DSC_1042

Literature cited

  1.  Brock WJ. (1961). Salivary glands in the gray jay (Perisoreus). The Auk 78: 355-365
  2. Dow DD. (1965). The role of saliva i food storage by the gray jay.  The Auk 82: 139-154

14 Comments

Filed under Birding, Canada jays, Corvid trivia, Diet, Field work, Jay behavior, Science

15 of the prettiest corvids from around the world

When most Americans think of corvids, the color palette that probably comes to mind is black, grey, blue, white and iridescent.  Together, these colors have certainly assembled a handsome collection of birds, but there’s an awful lot more pigments in the corvid family than that.  Even among those colors, some of the more topical corvids exploit them in dazzling ways.  Unlike American or New Caledonian crows though, these birds have not gotten their fair share of the corvid limelight and it’s time we change that.  The following is a sample of just some of the corvid diversity more folks should know about.  If you really want to have a little extra fun, ignore the scientific names and see if there are any birds you would group together in the same genus (reminder: Family>Genus>Species).  Then you can go back and look at the first part of the scientific name to see if you were right!

These photos were primarily sourced from some of the generous and talented photographers that can be found on Flickr.  Please click on their names to see more of their great work.

1. Common green magpie (Cissa chinensis).  Found in parts of India, China and Indonesia.  A flocking corvid often found low in the canopy where they can be very difficult to spot among the vegetation.  According to the International  Union on the Conservation of Nature (IUCN) their populations are considers stable and of least concern.

2. Taiwan Magpie (Urocissa caerulea).  Endemic to Taiwan, these are flocking corvids that feed mostly from tree canopies.  Their populations are stable.

magpie

Photo c/o Dave Irving

3. Lidth’s jay (Garrulus lidthi).  The only jay endemic to Japanese islands of Amami-oshima and Tokunoshima.  In the fall they can gather in groups as large as 100 birds where they feed mainly on acorns.  Habitat loss and predation have this bird listed as declining and vulnerable.

5637063965_f97ed950d3_z

Photo c/o Mark Curley

4. Unicolor jay (Aphelocoma unicolor).  Ranges intermittently from western Mexico to El Salvador and may have as many as 5 subspecies! They are considered of least concern, though populations are declining.

16443583870_bccb15d51e_z

Photo c/o Maynor Ovando

5. Green jay (Cyanocorax yncas). These jays can be found from southern Texas throughout central America and as far south as Peru.  Although they are a solitary breeder, they are very social in the non-breeding season.  Populations are increasing and they are considered of least concern.

5403740048_329060fb75_z

Photo c/o Wade Strickland

6. Spotted nutcracker (Nucifraga caryocatactes).  Native across Europe and Asia, theses birds are monogamous and generally hang out only with their mate.  Like the unicolor jay they are considered of least concern but trends point towards decline.

eurasian-nutcracker

Photo c/o Dave Irving 

7. Ceylon magpie (aka Sri Lanka blue magpie; Urocissa ornata).  Another Sri Lankan endemic.  These birds can be seen in pairs or small flocks where they noisy work the tree canopy.  They are considered vulnerable and declining.

shr-lank-blue-magpie

Photo c/o Dave Irving 

8. Black-throated magpie jay (Calocitta colliei).  This bird is limited to northwest Mexico where it can be found in open woodlands chatting loudly and waiving their tails.  They are common and populations are stable.

black-throated-magpie-jay

Photo c/o Ahmed Eldaly

9. Turquoise jay (Cyanolyca turcosa).  Can be found in the humid forests of Ecuador, north Peru, and south Columbia.  Overall this species is poorly documented.  Right now it is considered a least concern species but it’s possible that’s due to lack of data.

untitled

Photo c/o Dave Irving

10. Rufous treepie (Dendrocitta vagabunda).  Found across India and southeast Asia.  These birds are generally wary of people but have been known to enter houses to look for geckos.  Would love to find one in my house!  Populations are stable and they are considered least concern.

11.  Gold-billed magpie (Urocissa flavirostris).  Endemic to Taiwan, these birds keep their tails erect when on the ground, possibly to prevent the feathers from being damaged. Populations are stable and they are considered of least concern.

12. Bornean green magpie (Cissa jefferyi).  Found only in Indonesia and Malaysia, these birds look (and act) similarly to the common green magpie.  Relatively little is known about this species as they are hard to access high in the mountain forests.  It’s listed as of least concern.

neat

13. Eurasian jay (Garrulus glandarius) Found throughout Europe, Asia and Northern Africa.  This bird is common to most birders outside of North and South America.  Although these birds remain with their mates for extended periods they do not keep much contact throughout most of the year. Eurasian jays are in no danger of global population decline.

16285055912_facafd2544_z

Photo c/o Simon Forster

14. Azure-winged magpie (Cyanopica cyana).  Native across Asia and as far north as Mongolia and southern Siberia*. They form small family parties during the breeding season but amass into large groups during the nonbreeding season.  Populations are increasing and they are of least concern.

3316801943_fe8ba71c61_z

Photo c/o Crotach

15. Finally we have, literally, the beautiful jay (Cyanolyca pulchra). Found only in the Andes of Columbia and north Ecuador.  They can be found alone or in pairs but are not believed to interact in large social groups.  Little known about reproduction, social behavior or predators.  Populations are declining and near threatened.

beautiful-jay

Photo c/o Andrew Spencer

Did you pick out a favorite bird?  Let me know in the comments and I’ll try to dedicate a post to it!

Literature cited

*A previous version of this post incorrectly stated that the Azure-winged magpie spread as far west as Spain and Portugal.  Although this was true at the time the reference guide used to write the post was written, since 2002 these western birds have been splint into their own species called the Iberian magpie1.

1Fok KW, Wade CM, Parkin DT (2002). “Inferring the phylogeny of disjunct populations of the azure-winged magpie Cyanopica cyanus from mitochondrial control region sequences.”. Proc. Roy. Soc. B Biol. Sci. 269 (1501): 1671–1678.doi:10.1098/rspb.2002.2057.

All other species descriptions were based on: Madge, S. and Burn, H. 1999.  Crows and jays.  Princeton, New Jersey: Princeton University Press 1999.

 

 

9 Comments

Filed under Birding, Diversity