Sad Ending for Leucistic Hummer?

Over the past year or so, a beautiful little leucistic hummingbird has drawn quite a bit of attention at the UCSC Arboretum in Santa Cruz, California.  People have flocked to see this little beauty as it made the local news, birding sites and newspapers!  I had the unique opportunity to spend a couple of solitary hours with the bird on a gloomy, rainy morning at the arboretum.

October 2016 vs May 2017

Sadly however it appears to be on a downhill path based what I saw yesterday morning and is in a very much bedraggled state.  Once I had located the bird, I zoomed in with my telephoto lens and noticed distinct deformation to the beak. The overall appearance was not good with many feathers missing particularly on the back and wings which explained its lack of sustained or frequent flight.

As it rested, it exhibited labored breathing and I also wonder with the lack of plumage and the chilly, rainy morning yesterday, if it was also lacking sufficient insulation.

I am curious as to the cause of this drastic change in appearance although I am aware that leucistic hummingbirds are more prone to disease.

Audubon California posted an informative story last October entitled "Rare White Hummingbird Steals the Spotlight at California Garden". It details the rarity and excitement of the sighting, in addition to the challenges the bird may potentially face due to the lack of pigmentation, which it now clearly is exhibiting.  Very sad to see.

I subsequently contacted the Santa Cruz Bird Club and received this response:  We have known for some time that "Moby Dick" was not doing well.  I think everyone is surprised it has survived so long.  We don't have any avian disease doctor contacts, but ornithologists at UCSC are well aware of it's plight.  There was a good discussion a few months back about whether or not to intervene and the consensus was to "let nature take its course".