Climate change effect on birds

This is really tragic. This is an excerpt from an article entitled, "Dutch study sheds light on climate change's threat to birds":

PARIS (AFP) - Environmental scientists in the Netherlands say they have found evidence that climate change can decimate migrating bird species by affecting the date when their main food supply becomes abundant.

A small long-distance migrating bird called the pied flycatcher (Ficedula hypoleuca) spends the northern hemisphere winter in West Africa, returning to northern Europe in the spring to breed.

Dutch researchers have been following the species for decades, using nestboxes in forests, observations of their arrival and departure and monitoring availability of their staple food, which is caterpillars.

They have found that the earlier arrival of warm weather causes the caterpillars to emerge sooner -- and as a result, the flycatchers may arrive too late to properly feed their young. The birds breed, but without having an adequate food supply for the nestlings.

This just breaks my heart. The thought of little birds starving because their parents can't find enough food to feed them is beyond horrible. Dear God, what have we done?