The human fibula is quite a tricky bone. On first glance your specimen does not look like the perfect stereotypical human fibula, but it is possible. The morphological range of the human fibula due to anatomical variety, usage and pathology is considerable. I don think a final judgement can be made based on only pictures. You will probably need physical reference material. I suggest you look at the anatomy of the bone itself and the inside of the bone, like the nature of the cortical bone. This may help in determining or excluding a human origin, because human bone tissue is different and compared to animals our skeleton is somewhat flimsy.  ;-)