Tuesday, October 16, 2012

Sorting Acorns by Floating and Sinking

It turns out that floating acorns is a very quick way of selecting the good from the bad. The bad acorns float and the good acorns sink. In fact after floating them I found that the majority of the remaining acorns very unfortunately floated and failed the float/sink test. So how effective is this test anyway? I decided to dissect a number of good and bad acorns to see really how effective this test is. Results are shown in the following photos.
Evidently all the floaters were bad. 

The sinkers were evidently in generally very good condition. However a number of the sinkers still had larvae exit holes so this test is not 100%.

At some point the larvae should stop emerging so at that point we should be able to determine that all remaining acorns are clean. I can't store the nuts in a plastic bag if there are any larvae remaining.

The number of remaining acorns was sufficiently low to count them and 370 acorns are left. That is a loss of  71% of the nuts or a survival rate of 29% and I don't think it is over yet and more losses are expected.

Acorn Update

Red oak acorns need to be stored in a cool place for a month or so before planting. so I stored the acorns in a plastic bag in the beer fridge cooler.
Larva found of  Acorn Weevil
Much to my dismay, I found many larvae at the bottom of the fridge which tweaked my curiousity. It turns out that even though the acorns were selected many were still contaminated by eggs and the emerging larvae of the Acorn Weevil [Curculio glandium.] Apparently the larvae fall to the bottom of the bag and then chew their way through the plastic thus ending up at the bottom of the fridge. In nature they fall to the ground and then bury into the earth. I found that many of the acorns had the typical exit holes. So I will have to sort the good from the bad acorns one more time.   

Monday, October 08, 2012

A Friendly Thrush

Last week while clearing some trail and making lots of chainsaw noise I was surprised to see this thrush hopping around nearby among the leaves gleaning the forest floor for bugs and seeds. It seemed quite unperturbed by my ruckus, which for a thrush should be quite unusual. I am having a challenge trying to identify if this is a hermit thrush, or wood thrush which are the more common thrushes in the area. Anybody know? I am even thinking it might be a grey cheeked thrush. 
Not enough spots for a Wood Thrush