if there is no sign of them under the tree-- even tiny immature fruit then one way or another theyve been taken possibly birds or squirrels?

Thank you, thats the thanks you get for feeding the birds!

my nut tree had half a dozen hazelnuts--- all gone I blame the squirrel!!

Some years pears just will not perform the right way. When you can get the flowers to white bud stage, try thinning them out with fine scissors, see if that helps. The tree may have let them go due to frost/cold or just overload, if on limited rootstock and too dry at the time of flowering and fruit set. I am going to try thinning at white bud stage on one of my trees next time round to try and improve fruit size and prevent overloading.