Signs of Spring

  Our total rainfall to date is 101", approximately 40" above our normal yearly total!  The rainy season isn't over yet!  However, temperatures were a lot colder this week, and we got about an inch of new snow.  Despite the colder temperatures, signs of the approaching Spring are happening! 

American Robin - Turdus migratorius

This robin is all puffed up in his natural down jacket!  The trapped air between his feathers keeps him warm on snowy days!  Robins are one of the first birds to return to our neighborhood, from their winter habitat.  There were big flocks, of 20 to 40 birds, busily feeding on worms and grubs on the ground.  Apparently some flocks number in the hundreds, and even in the thousands!  I've never seen that many here, as there isn't enough food to sustain that many birds.

    Robber Fly - Laphria sacrator spp.                         Bumblebee - Bombus sp.                        

I revisited that blooming Manzanita and got these pictures of the insects that were feeding on the blossoms.  It turns out that there were Bumblebees there, along with a new kind of fly that I'd never noticed before, a Robber Fly!  

Robber Flies are true flies, and only have ONE pair of wings.  Most other insects, including bees, have two pairs of wings.  They are called "robbers" because of their notoriously aggressive predatory habits.  They will wait and ambush all kinds of insects, including Bumblebees!  Notice the difference in the position of the eyes on the head, as compared to the eyes of the Bumblebee.  Robber Flies are one of the first insects, besides Bumblebees, to show up in the Spring.  Probably all those yellow and black hairs keep them warm in these cool temperatures!  

The Bumblebees that you see out at this time of year are the females.  They are out foraging for nectar and pollen to start their colonies!  The colonies are made in tussocky grasses, small abandoned rodent burrows, or at the base of shrubs.  Once the queen picks a site, she forms a wax "honey pot" and fills it with regurgitated nectar (honey).  She then collects pollen, forms it into a ball, lays her eggs on it, and then covers the whole ball with wax!  She then "broods" her eggs, like a bird, for 4 days, until the eggs hatch into larvae!  Once hatched, the larvae feed on the pollen ball for 4-5 weeks, form a cocoon, pupate, and turn into adults!  A Bumblebee colony usually numbers about 50 in population.  At the end of the season, the queen lays unfertilized eggs, that turn into males, and lays a few special fertilized eggs that turn into new queens.  The males hang out for a few days in the colony, and then leave never to return.  These are the Bumblebees that you see spending the night in flowers!  The new queens leave the colony, mate with one or more male Bumblebees, then hibernate over the winter!

Hairy Woodpecker - Picoides villosus - and gall with grub
Wild Rose Bush with rose hips and galls

One morning I was thrilled to see this Hairy Woodpecker pecking away at the galls on this rosebush!  I'd never seen that before!!  Usually I've seen Hairy Woodpeckers foraging on the trunks of trees for insects!  After he (Male Hairy Woodpeckers have red feathers on their heads and females don't) flew away, I inspected the galls and found this open one with a grub inside! 

Galls come in a wide variety of shapes and sizes. Galls are formed by insect/mite feeding or egg-laying activity. Either mechanical damage or salivary secretions (introduced by insects and/or mites) initiate increased production of normal plant growth hormones. These plant hormones cause localized plant growth that can result in increases in cell size and/or cell number. The outcome is an abnormal plant structure called a gall.  Inside the gall, larvae feed on the gall, pupate and emerge out as adults, over a period of several months!  These larvae are what the Hairy Woodpecker was eating! 

Pocket Gopher - Thomomys bottae - surface tunnel and dirt mounds

Now, finally, the answers to the underground burrow questions!  

There are several local animals that live almost exclusively underground, such as Pocket Gophers and Moles.  They are usually not severely affected by heavy rains 
for several reasons.

 They usually dig their living quarters deeper than 1 meter underground, where the rain doesn't usually penetrate.  They usually make the entrance to their den on a slope, where rain doesn't pool up.  They usually plug the entrances when it's very rainy to keep the water out.  In some cases they even dig a separate sump, for excess water to sit in and drain!!  

I heard some frogs croaking this week before it got cold!  
It made me wonder where are all the reptiles and amphibians?  How do they survive the winter?
Check back next week for the answers!