Buizerd Buteo buteo en Boommarter Martes martes in het Noord-Kennemerlands Duin: aanvullingen en herzieningen

In 2009, in the nest of a Buzzard in the dunes near Castricum a second egg was laid more than three weeks after the first egg. The first egg was thought to have been laid by the first-time female in this territory. During incubation, she was replaced by the female that used to breed in this territory for the past years; the latter probably produced the second egg. The chick from the second egg was raised successfully, but its sibling disappeared in the early chick stage. In 2010, for the first time in seven years this old female – a striking chocolate-brown Buzzard - failed to raise chicks, probably related to the poor food supply. In 2011, food supply was even worse. The old female was not recorded in her territory. Another female Buzzard took her place, but she also didn’t manage to raise chicks. In 2012, food supply was excellent. The old female reappeared in her territory, but was unable to regain her place. The new female Buzzard raised two chicks, for which she used a nest that had recently been used as a roost by a Pine Marten Martes martes. A Tawny Owl Strix aluco probably dispelled this Pine Marten from the nearby nest tree. In 2013, the new female Buzzard failed to raise chicks; food supply was very poor and a Pine Marten occupied a den in the nearby tree. In 2014, food supply was very good and the nearby nest tree was occupied by a Tawny Owl and not by a Pine Marten. Despite these promising conditions, the Buzzards in this territory left their nest in April for reasons unknown.