often bojko can't work his fields because birds are brooding in them.ean bison and deer also invade his wheat fields. >> they inflict great damage. animals destroy up to 90% of the crops not protected by an electric fence, by eating them or trampling on them. with such a fence, which must be checked every day, the damage is only half as great. mateusz szymura loves to discover new places to show his tour groups. the primeval forest has been around for some 12,000 years -- since the end of the last glacial period. >> this is a place where you can hear the silence -- the silence of being away from civilization. this forest is unique in the world. it's my second home. >> and each year 100,000 tourists pay it a visit. they're drawn by bialowieza's natural beauty and biodiversity. >> and we end on those beautiful images. until we meet again from myself and the entire global team bye bye and have a good week! captioned by the national captioning institute --www.ncicap.org--