Inventories

Since the family left, we've been getting ourselves into routine.  Things have changed, and it's definitely not the same old grind.  Inventories are the new focus of our days.  This is the gross part of our nesting season, where we dig up nests that have hatched or are really old.  We count up the contents, sorting into four categories: egg shells (greater than 50%), unhatched eggs, dead hatchlings & live hatchlings.  This give us a lot of information.

First, the shells + the unhatched eggs = the total clutch size.  For a relocated nest, where we counted the eggs going in, we can compare the calculated clutch size with the actual and determine the percent error caused by the 50% egg shell rule (there are often fragments of shells that may not add up to the whole).  That percent error can be applied across our in situ (non-relocated) nests in future calculations.  The two primary calculation we use are hatch success, and emergence success.

Hatch success is the percentage of eggs that actually hatched, calculated from the shells (50% or greater), over the total eggs (shells + undeveloped eggs).  Emergence success is the just about the same, but we subtract any dead or live hatchlings from the number hatched (shells), before dividing by the total.  These numbers give us an indicator of problems with the nests, whether they be infertility, blocked nests where hatchlings couldn't emerge, root inundation, washover, predation, etc.

The actual inventory process involves removing the screen, post and stakes protecting the nest, digging up the nest, sorting its contents into the four categories, and recording the data in our book.  Any live hatchlings are taken to the sea and encouraged to swim off - though most are unable to do so, due to deformity or injury.  Dead hatchlings and the remaining eggs and shells are taken and buried on the backside of the dune.  This returns vital nutrients to the beach environment, and prevents us from finding the contents later and mistaking them as something new.

The nest contents can be pretty nasty.  Often the undeveloped eggs are open.  Inside them can be a cottage cheese like material of an undeveloped egg, a partially developed hatchling, or a hot pink bacteria you know as Salmonella.    The nest cavities often smell like the rot of dead things or feces, with a vinegar smell as well.  The flies and gnats seem to like all the decompositions and hang out during the excavation, often biting.  If gloves aren't worn, the smell persists on the hands for several washings.  Still, the data is invaluable, and of course, sometimes the nest include stragglers, which to rescue, makes all the trouble forgotten.

Today I did 6 excavations.  I also had 1 nest and 3 false crawls.  Nesting has definitely fallen off, but emergences are on the rise.  Now, on the 5th day after an emergence occurs, we must inventory the nest.  We also inventory any nest that has reached 70 days incubation without an emergence.  Today we had 5 emergences, which means 5 days form now, we'll have to do 5 inventories.  It's a lot of smelly work.  Though it is nice to take data cards out of the book and white nest markers off the beach - less nests to check each day.  Also, getting a feel on just how many little turtles are running out to the sea is a joy.