Clark’s Nutcracker (Nucifraga columbiana)

Copyright © 2012 Corvid Corner. All rights reserved.

 

A member of the corvidae family, Clark’s Nutcracker is a lovely bird slightly smaller than the Spotted Nutcracker. It eats mostly seeds from the pine tree. And it has a pouch in the floor of it’s mouth in front of its tongue (a sublingual pouch — See below) which can hold up to 95 pinyon pine seeds (depending on the seed this number can vary from 50 to 150).

Sublingual pouch

 

To put this in perspective, 95 Pinyon pine seeds weigh up to 13% of the total weight of the bird!! How neat is that? They have a pouch in their mouth where they can store and carry almost 15% of their own weight! The Clark’s Nutcracker also has a “long, heavy, sharp bill… used for hacking open green, closed cones, many of which are covered with pitch. Nutcrackers can open the green cones of most of the pines. The bill is also used to thrust seeds into the substrate with strong japes of the head and neck. As their name implies, nutcrackers can open thick-hulled pine seeds by crushing them in their bills.”1 Most jays must wait for the cones to open naturally, but the Clark’s nutcracker (and the pinyon jay) are able to open the tightly closed green cones. Lucky for them, they don’t have to wait for a good seed.

In a year with a heavy cone crop a single nutcracker can cache between 22,000 and 33,000 seeds in over 7,000 individual cache sites (Vander Wall & Balda, 1977). Birds may place between one and 14 seeds per cache. Birds continue caching until the crop is depleted or snow covers the caching areas (Vander Wall & Balda, 1977). Possibly, birds curtail caching after snow remains on the ground because to cache in these conditions would reveal cache location by their foot prints left in the snow.2

Copyright © 2012 Corvid Corner. All rights reserved.

 

The Clark’s Nutcracker possesses a number of abilities and physical attributes that help them thrive. They have excellent spatial memory abilities which allow these clever corvids to “learn and generalize geometric rules about the placement of landmarks.” They use the landscape and even the sun (as a compass) to help them cache seeds. Their strong beaks help them crack open seeds, hence their name. Their long, pointed wings help them for strong flight to great distances. They can cache up to 22 km (a little over 13 and a half miles!). The Clark’s Nutcracker “can carry seeds 1,900 m up the side of the Peaks.”3 They use ‘bill-clicking’ which is the rapid opening and closing of the mandibles, to help determine if the seed is full as well as determine the thickness of the seed coat which saves time when seeds are abundant in the spring and summer.

Copyright © 2012 Corvid Corner. All rights reserved.

 

So intelligent are they, the Clark’s Nutcracker can discern between pinyon pine seeds that have nut meet and those that are empty just by observing the color of the shell. WOW! Corvids are so intelligent!

 

Sources:

  1. http://www.pigeon.psy.tufts.edu/asc/Balda/ []
  2. Balda, Russell P. and Kamil, Alan C. Linking Life Zones, Life History Traits, Ecology, and Spatial Cognition in Four Allopatric Southwestern Seed Caching Corvids []
  3. Balda and Kamil []

The Crow and the Pitcher more than fable?

The Crow and the Pitcher, originally uploaded by AnnaleeBlysse.

Scientists believe the fable of the crow and the pitcher might have been fairly accurate given the new research showing rooks using rocks to raise the level of water where a worm resided… to bring the worm up to their level.1

They are such incredibly intelligent birds. The other animal who showed fluid mechanics was the orangutan. I will bet corvids are just as smart if not smarter than many of the primates.

You can read more about the studies here.

  1. http://www.telegraph.co.uk/earth/wildlife/5983953/Aesops-fable-is-true-shows-crow-study.html []

Steller’s Jay eat deer!

Steller’s Jay, originally uploaded by pandatub.

I know that many of the corvids are scavengers, that they will eat whatever they can find and this is how they survive where other birds do not fare so well. However, having fed many eager steller’s jays peanuts it never occurred to me that they actually DO eat meat, if given the opportunity or if needed. But according to an article about a deer hunter by Carla Petersen1, some hunters hung a deer they had killed in their garage and,

“a Steller’s Jay latched onto the side of the carcass as if it were some kind of a giant suet feeder. That jay was sent packing but more jays were now posted on either side of the garage and weren’t shy about entering if no one was around. [One guy] added a little extra fencing on the doors, hoping to put an end to the intrusions, but the birds were persistent and willing to fly through fairly small gaps.

[Their] final solution was to put a slab of fat outside for the birds. The Steller’s Jays, with much posturing and discussion among themselves, have been feeding there for days, taking turns with the crows and ravens to fatten up for winter the easy way.”

I know the crows and Steller’s Jays I feed prefer peanuts over bread, raw beef, and bird seeds. So, maybe it is a matter of survival — eat whatever is available but if given some leeway, they will choose by taste.

  1. http://www.capitalcityweekly.com/stories/111010/out_733946466.shtml []