Missing egg

Tragedy has befallen our Yellow-eyed penguin colony: we lost a (likely) fertile egg and we believe it was stolen as this was the only nest directly accessible to visitors. Something similar happened last year as well and there is nothing we can do: the landowners tolerate 50,000 unsupervised visitors within close proximity of this penguin every year and visitors are here daily for 12 hours. The egg was there on Tuesday and on Friday it was gone (and no sign that it rolled out of the nest, the parents were experienced). Now the second egg is gone too - to a new home. We were not going to risk its life - the parents have the summer off. If only we could explain to them what happened and that they need to find somewhere safe to nest. 
What we want to know is how is this ok? Where is the due care from those in charge of our endangered birds?