Friday, August 06, 2010

Water comes and goes in a wetland in California

Putting out traps for an insect study at Mugu can be a challenge if the area is inundated with the tides. One site this year I will only set sticky traps while the other sites I set drop traps (85% water, 14 +% ethanol, a couple of squeezes of Dawn dish soap). Diptera is the group that is found in most abundance. Hemitera in some places is second, but Hymenoptera is usually the second most abundant insect Family with Chalcids, Halictidae sometimes Apidae making the second group very challenging to identify. I have been looking at the insects of Mugu since 2001 and somehow I collect something that stumps and surprises me - which is wonderful!

Every time I walk out in the marsh I feel great peace. The birds, like this little Plover which was running around the clumps of algae in the collecting pools, mostly try to ignore me if I am not too close. As the algae dies and dries it turns white. All of the little horn snails, Cerithidea, and the crabs make clicking noises in the mud. The soft breezes and the distant waves are sweet.

As the water evaporates in low tide, the smallest particles at the top of the mud bank dry faster then the heavier sediment, and start shrink and crack. The water in the mud below is exposed to the air and starts to dry too puling away and cracking along the same lines. There are fungal rings that grow as the water recedes - though not in this picture - like the flower rings in vernal or ephemeral pools.

When I walk in these area I sink sometimes up to my knees. But the little birds, like the plover above, leave tracks on top. But if you look at the bottom picture, a stilt left its footprints and its middle long toe continued to crack beyond the impression. For just a second, when I saw the tracks, 'reptile' jumped to my mind... until I looked closer.... Mugu does not have reptiles THAT big....

No comments: