Dorset County Council Natural Environment Manager Dr Phil Sterling said:
“This is an excellent outcome, with two young birds fledging the nest last Thursday.
“It is a remarkable event for Dorset, with this being only the second record of successful breeding in the past 50 years, and is all the more notable given the works going on nearby.
“When the RSPB first let us know about the nesting pair, we all thought these birds would be very sensitive to human disturbance.
“The relief road project team put in place a 50 metre exclusion zone and our monitoring programme quickly revealed that the birds had become accustomed to most of the construction works apart from those creating the greatest noise and vibration.
“In the end, we had to make relatively minor modifications to the working methods to make doubly sure that we did not disturb them.
“The workforce was briefed about the birds and everyone on site did their bit to ensure these birds were protected while nesting.
“We have now been able to remove the works exclusion zone and there are no further restrictions on working methods.
“We have continually monitored the nest and the information we have collected will add to our knowledge of these remarkable birds.”