Steller’s Jay at Crater Lake in Oregon

Copyright © 2012 Corvid Corner. All rights reserved.
  What a beautiful little bird! According to the Crater Lake Institute, four of the six birds mostly like to be seen at Crater Lake in Oregon are corvids: Ravens, Gray Jays, Stellers' Jays, and Clark's Nutcrackers (see yesterday's post about this clever little corvid!) Maybe we can nickname it Corvid Lake =). ((http://www.craterlakeinstitute.com/planning-visit/faqs/birds-crater-lake.htm))

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 []