Richmond Falcon Cam

Nest Failed; Remaining Eggs to be Collected for Testing

With the expected hatch date for the first egg well behind us, it is certain that this year’s clutch has, unfortunately, failed.  Yesterday afternoon (May 1) at approximately 1:20 pm the female was observed consuming the yolk from one of the eggs, which was revealed to be cracked when she stood up from incubating.  The undeveloped embryo was removed shortly after by the male.  (See below for photos of the egg eating.) Consumption of a broken egg is not uncommon in peregrine falcons: damaged eggs are no longer treated as an egg by a parent, whose instinct is to eat them.

Egg failure in peregrine falcons can be due to several reasons.  The birds’ reproductive potential decreases as they age past their reproductive peak.  The banded male of the pair was hatched in 2000; he is 16 years old.  We cannot confirm the age of the female because she is unbanded, but she has been recognizable as the same individual since at least 2006 or 2007 via available photographs; as such, she is likely at least 10 years old.  According to the US Geological Survey, the maximum lifespan documented for a banded falcon in the wild is 19 years and 9 months.

We do not know the extent to which declining reproductive vigor may have been responsible for this year’s loss of the nest.  Generally speaking, not all peregrine falcon eggs are hatched in all years.  Reasons for hatching failure include egg infertility, death of embryos, and breakage and removal of eggs.  Since 2003, the Richmond falcons have only hatched all of their eggs on 4 occasions; in 2013 they lost all 5 of their eggs in their first of 2 nesting attempts that year.  Including this year’s nest loss, the pair has produced 61 eggs since 2003, of which 33 (46%) have hatched; of these, 30 chicks survived to flight age.

We plan on accessing the nest box on May 3 (weather permitting) in order to collect the remaining three non-viable eggs.  These will be analyzed for potential contaminants.  Although it is late in the season, there is a possibility that the pair will re-nest at this or at another site in the greater downtown Richmond area; collecting the eggs increases the probability of this happening.  Re-nesting typically takes place within 2-3 weeks of nest failure.

Snapshot 1 (5-2-2016 3-24 PM) Snapshot 2 (5-2-2016 3-25 PM) Snapshot 4 (5-2-2016 3-27 PM) Snapshot 5 (5-2-2016 3-29 PM)Snapshot 3 (5-2-2016 3-26 PM)
  • May 2nd, 2016