A university entrance qualification is required to enter tertiary training. Seventh Form biology and maths with statistics are necessary subjects. Chemistry, geography and English are also useful. There are no other specific entry requirements for ecologists. Any experience in practical, 'hands-on' work, such as basic gardening, may also be useful.
Experience working in the outdoors is useful.
Some skills are gained on the job. Ecology is a huge field and you're always learning. So much of this job is about experience with lots of different things and if you stop gaining experience, you stop learning.