Bluebird house, skunk cabbage, etc.

Today starts the spring session of Green Rangers. (It doesn't look like spring with snow still covering the ground, but we know that spring is arriving!)  We welcomed new students and returning students.  An "ice-breaker" activity helped us to learn a little more about each other.

After bundling up, we went outside to the Eastman Conservation Area.  We had learned that skunk cabbages are in bloom now (see last post - yes! a sign of spring) and that they are thermogenic (create heat).  They melt the snow above them, and the temp inside the "hooded" part of the flower (the spathe) is warmer than the outside air.  So we set out to find some and hit upon a bonanza of them in the wetland beside Newman's playing fields.  We put the wired sensor of an indoor/outdoor inside one and left it there while we continued on the trail.

 


At the field area of Eastman there is a bluebird house.  Our instructor told us that she had spotted a male bluebird last weekend in an open area (under power lines) along the trail from Farley Pond to Needham's Town Forest, and she told us that bluebirds will start nesting soon (yes! - another spring happening).  So, we proceeded to clean out the bluebird house to prepare for the season.  We found remnants of acorns and a pile of old nesting materials.  The acorns make us think that a rodent - chipmunk? field mouse? - used the house at some time.  The house had other inhabitants at some point - wasps!  The cluster of wasps' paper cells were attached to the ceiling of the house.  We scraped out the house and left it clean. 

Along the trail we found many deer tracks (and places where they had peed!).  Earlier in the day, our instructor had walked the trail and saw an otter in Eastman Pond!!!!  She thinks that it stopped to feed there for a while as it traveled overland, exploring. 

Back at the skunk cabbage, we were puzzled to find that the inside temperature was only a few degrees warmer.  Hmmm...

Inside the Science Center we had hot chocolate and got a few updates from our instructor:

• Our letter to the editor about the 40th anniversary of the Endangered Species Act was in the Needham Times last week!
• The population of right whales has increased to about 500 because of more births in recent years. (It was around 300 in the 1990s.)  Yay!!
• The Migratory Bird Act, that protects birds migrating through different states, is 100 years old this year.  It has a cool Needham connection: " In 1908 Charles H. Hudson, a farmer in Needham Heights, wrote to his Congressional representative, John Wingate Weeks, imploring him to sponsor 'a national law put on all kinds of birds in every State in the country, as the gunners are shooting our birds that Nature put here...'" (from Mass Audobon magazine).  Five years later, this law was passed - the Weeks/McLean Act, also known as the Migratory Bird Act. 

Vernal Pools in the Town Forest

It's the middle of March now, so we took a field trip to Needham's Town Forest to look for vernal pools.  Very soon, these pools will be visited by breeding amphibians - frogs, toads, salamanders.  A "vernal pool"  is a small pond that forms in woods in the spring from melting snow and spring rains.  These are good places for amphibians to breed because they dry up or shrink a lot in summer, so fish usually cannot live in them, and fish love to eat amphibian eggs!  The eggs hatch and then the tadpoles grow and develop into their adult forms before the pool dries up. 

The earliest arrivals to vernal pools around here are yellow-spotted salamanders and wood frogs.  They are expected between the middle of March and the end of the month.  The first warm, rainy night in this breeding season is a good time to look for salamanders and wood frogs heading to the pools.  They lay jelly-like eggs that stick together in egg masses in the water..  During breeding season, you can often locate a vernal pool by listening for what sounds like ducks quacking, but you don't see any ducks - those are wood frogs calling!

We drove to the Robinwood Ave. entrance to Town Forest.  The first thing we noticed in the forest was a rushing stream near the entrance.  We explored along it and crossed it on a log.  There was a lot of long, bright green algae growing on the rocks.  It streamed out like green hair in the stream's flow.  Then we followed a trail toward a small pond where our instructor had found wood frog eggs in past years.  On the way there, our instructor pulled out a deer's skeletal leg that she found in this spot 2 days ago and had hidden.  It was cool to check it out.  We wondered how the deer had died, but didn't find any clues on the leg.  The leg might have gotten separated from the rest of the deer's bones by a dog finding it and carrying it away to chew on and play with.

At the pond we checked out the edge, but the middle was still iced over and we decided that there would be no amphibian eggs there yet.  We sat on a log and had a snack of popcorn while our instructor showed us pictures of spotted salamander and wood frogs, and talked about vernal pools.

Then we followed the trail to a much smaller vernal pool.  We found a large slug in there.  It looked like it had drowned.  This pool was shallow enough to see to the bottom very well.  We also found an "oak apple gall" and learned how a small wasp had laid an egg on an oak leaf.  The egg hatched and the tiny larva started eating and the leaf then grew a rounded growth over this irritation.  This growth is a gall, and the larva developed in it.  When it developed into an adult, it then chewed a hole in the gall to get out.

Next, we followed a trail to an unusual and cool place in this forest.  You'll have a ask a Green Ranger about it!  The trail went up and down over rocky hills and we crossed a wooden bridge over a stream.  We arrived at our destination, and after checking out all of the interesting things there, we had hot chocolate with marshmallows!  We followed a stream downhill and explored the wetland that formed below.  Skunk cabbage was blooming.  It is a very early wetland bloomer with a thin, rod-like flower inside a mottled purplish "hood" (spathe).  It has a slightly stinky smell and is very unusual because it can create its own heat (thermogenesis).  The smell and, probably the heat as well, attract early pollinators - flies and beetles. (see picture of skunk cabbage below.) We also found a red-backed salamander and a red eft (land-living part of the newt's life cycle) under a log! Then we had to hurry back to get to the Science Center for pick-up time.