[Yahya (OP)]

I think that is the reason why birds are the happiest creatures on earth , they are confident as well , they are not aware of possible famine , death , sickness , and off course poverty!! are animals happier than humans ?

[RD]

... birds are the happiest creatures on earth ...

Bird-singing ≠ bird-happiness ... https://www.wired.com/2014/03/birds-sing-morning/   

[SquarishTriangle]

Why wouldn't they be aware of those things? The would still experience illness, hunger and shortage of resources (food, water, shelter, nesting materials). They would still potentially see deaths that occur around them, and experience the loss of family members/mates. They wouldn't have previously experienced death for themselves, but then, what living animal has?

[cheryl j]

I've often wondered about this. There has been some research with apes and chimps and what appears to be mourning like activities after the loss of a member of the group or off spring. I read one anecdotal account of a researcher herself who lost a child and was away on leave. When she returned explained she was away because her baby died, Washoe signed "cry". Maybe too much is being read into this account, I don't know. http://www.lifebuzz.com/chimpanzee-communicates/

On a personal note, I was struck by how oddly my two cats reacted when my border collie died. It was mid winter, and the ground was too frozen to bury him  right away, so we placed him the basement for a day or two, and then later transferred him to the barn. But while he was in the basement, the cats would go down there, and sit and just look at him. They didn't poke or try to play with him, they just sat looking. After we moved him, one cat would wake us up at 2 in the morning howling like it was in distress. That was the only time she ever did that - maybe a coincidence, but it was quite weird.

[Yahya (OP)]

Why wouldn't they be aware of those things? The would still experience illness, hunger and shortage of resources (food, water, shelter, nesting materials). They would still potentially see deaths that occur around them, and experience the loss of family members/mates. They wouldn't have previously experienced death for themselves, but then, what living animal has?

it is the level of awareness, birds experiences disasters but they have low level of awareness , they may see deaths around them , but it will never be like what humans feel. even adult humans are less happy than  childern
it is about high level of awareness , responsibilities and life complexion  animals do not have these . they experience  pain but never affect  them psychologically the way it affects humans.

[evan_au]

[quoteYahya ] (animals) experience  pain but never affect  them psychologically the way it affects humans[/quote]
I have heard anecdotes about elephants pausing at the skull of their previous matriarch.
Elephants are reputed to have good memories.
Perhaps the loss of their matriarch does affect them emotionally?

[Yahya (OP)]

 Hi Evan, glad to see your great replies again 
what I think about animal's feelings is that it is instant and momentary, if there is a problem they feel sadness , fear and pain but they do not have a past , only what they learn , for instance for a cat it learns that a dog is a danger but if there are not dogs it is happy , they do not have conclusions , something like their owner might bring a dog to the house, I think animals aware of death as something only caused by predators or accidents, if they are away of predators accidents then they live eternity ,they aren't aware of aging nor sickness, I always asked a question : what makes someone happy? I had a very simple answer: if he had all he wants. you may feel sad even if you have everything according to another person , but you think you do not have everything you want , animals have everything they want at least a " rich animal".birds are an exception they have the most protective weapon which is flying, low possibility of both predators and accidents , birds also do not feel angry like predators , they do not have problems with others .