zebra finch death

Question
Hi- I have owned zebra finches since 1993- my last one just died- she was over 8 years old.

I think she died because of pneumonia- I cracked the door open to my deck, and the temp. Dropped dramatically during the day- the cage was next to it for the benefit of the sun.  

At any rate, I came home tonight at 8 p.m. And she was on the bottom of the cage by 11 p.m.  She was beeping when I got home-- her name was Beeper- and I had given her new food and water.  When I took her from her cage, it aPpeared that she had a bloody mass coming from her tail area.  I am wondering if she was egg-bound,or just died of old age.

It's so sad to see a long line of birds be gone :(

I'd love to know what you think!  

Thank you so much.

Answer
It could be because the temperature dropped suddenly. I doubt she was egg bound since in my experience 8 year old birds aren't fertile anymore. Unfortunately, due to her age I can't give you a for-sure answer but it sounds like the temperature drop, combined with her age, was the cause of her death