The biologist/project leader posted something interesting today with regards to the failed eggs here from the past 2 years. They did indeed have the eggs tested - $1,000 an egg to test!!- and they were found to be high in contaminants! No comment as to whether or not this is the same pair from the past 2 years was included with the post.
Just a bit of a clarification, all wild peregrines in North America are sure to have some contaminants in their system - the spend their winters in Central/South America where pesticides/herbicides including DDT and DDE are regularly used on crops. Eggs are produced from the reserves of the female, so if the female has contaminants store in those reserves, they are passed along to the eggshell. Question is, and I can't tell from your post Carly, is if the contaminants in the eggshell samples have been shown to be related to eggshell thinning or with reduced viability of the eggs or whether they are present and unrelated to the eggs' viability.
If you find out more, let us know ...
Would I be correct to assume TPC - that in the event of a possible predator the egg is regarded as 'ours' and must not fall into enemy hands? Maybe that's what the parent at this site was doing, trying to gather the eggs to protect them from predatation?
They are hardwired to protect their young, regardless of age/stage. Intruder arrives, all young must be undercover. That simple.