Autumn is a great time to catch the migratory birds at the RSPB nature reserve on Radipole Lake in Weymouth. The half term holidays is a good time to visit with the children. Details of the RSPB nature reserve in Weymouth can be found here.
The nature reserve is a short walk from Weymouth station. On the journey out and back you will probably need to change at Bournemouth. However there are direct trains before 9 am and sometimes there are direct trains during the day at weekends.
The map below shows the nature reserve and Weymouth station.
There are opportunities to buy food and drink near the station, along the seafront and in the town centre in Weymouth.