first class
second class
third class
fourth class
fifth class
Class #6 - Clark's Nutcrackers, Memory and Whitebark Pines with Teresa Lorenz & Eireann Pederson
February 29, 2016
Watch and listen to the entire class on this video
Clark's nutcracker in Mazama eating suet, by Mary Kiesau |
Clark's nutcrackers are named after William Clark of the
Lewis and Clark expedition. Clark's nutcrackers are social animals that straddle
two worlds. In one world they are similar to other corvids in that they eat a
diverse variety of foods but in the other world they are specialists who
primarily dine on large pine seeds. They are partial migratory birds, meaning
that specific groups migrate to different areas but there still may be Clark's nutcrackers in your backyard year around however they are unlikely to be the
same Clark's year around.
They are gray-bodied birds with black and white wings and
tails. The juveniles have a light gray face and a pink mouth. It is impossible
to tell male and female apart based on coloration but it may be possible to do
so by observing their behavior. Clark's nutcrackers look similar to northern
shrikes, and gray jays.
By Michael Sulis, https://commons.wikimedia.org/w/index.php?curid=31796706 |
Pine trees produce variable seed amounts each year. Some years
there is a bumper crop and Clark's nutcrackers will have plenty of seeds to go
around but other years seeds are scare and they rely more on other varieties of
food. Clark's have been known to eat salamanders, eggs, small birds and frogs.
But their primary food besides pine seeds is insects.
--------
Whitebark pine (Pinus albicaulis) was discovered by George Englemann in 1863. They are the only stone pine (tight closed cone) tree in the Americas. They
have large seeds with a high fat content. They rely on animals such as Clark's nutcrackers
to distribute them. However Clark's nutcrackers in the Pacific Northwest often prefer to cache seeds
in trees rather than in suitable areas for white bark pine to grow, because they need to be able to find them in the winter when snow levels are high.
Whitebark pine are the 11th longest living tree species on the planet. The oldest whitebark pine was 1,270 years old and nearly a foot in diameter.
Whitebark pine are high elevation trees (6000-7000ft) and can
be identified by their five needles. Whitebark pine's habitat range, not so coincidentally, overlaps with the range of Clark's nutcrackers.
Whitebark pine cone (Wikimedia) |
Whitebark pine take 20-30 years to reach cone bearing age.
They then must mature to 60-80 years of age before they produce a large cone
crop. It takes two years for a cone to reach maturity, and a whitebark pine
will take 3-5 years between cone cycles. So, it's a slowly regenerating tree.
Whitebark pine are Clark's nutcrackers preferred food. While
Clark's nutcrackers are able to adapt to different food sources, whitebark
pines are not as adaptable. Whitebark pines are early colonizers after
disturbance, and the fire suppression of the west has allowed other trees such
as lodgepole pine and other shade tolerant species to easily out-compete them. Whitebark pine also face threats from blister rust (fungal disease that was introduced from Europe), mountain pine beetles, and
climate change.
Whitebark pine was proposed to be listed under the
Environmental Species Act (ESA) multiple times. However due to the decrease in
the mountain pine beetle population, the whitebark pine was removed from the
proposed listing on 12-24-15. Whitebark pine is currently listed as endangered
in Canada.