Nest Failure
It is with regret that we report that the falcon nest at Riverfront Plaza has failed. When we checked the Falcon Cam this morning, Wed June 26, we noted that the nest box appeared empty. We suspected that the chicks had died and were removed by the parents, since at this early age the chicks are not yet mobile enough to leave the box on their own. We accessed the ledge later in the morning and confirmed that the box was indeed empty. As expected, both parents reacted aggressively towards us. We searched the ledge and found the body of the smaller of the two chicks in its western section, near the remains of various avian prey items. We conducted a search of the perimeter of the building at street level, as well as of the roof of the parking deck across the street, but were unable to locate the body of the second nestling. The high temperatures and heat index yesterday may be implicated in the death of the chicks, perhaps in conjunction with other factors. We will arrange to have a necropsy performed on the chick to see whether a more definitive cause of death can be identified.
In monitoring the Falcon Cam yesterday afternoon we noted that the smaller of the two chicks was missing the majority of the feathers from the top of its head. Sibling aggression on the part of the older, larger chick is one possible cause. This can sometimes occur among raptors in situations where there is a substantial disparity in the body size of the chicks, especially if there is competition for food resources. Unfortunately we do not have information on the frequency with which the parents fed the chicks over the past few days, and whether both chicks were being fed consistently. Yesterday afternoon the adult female spent considerable time shading the smaller chick. The chick appeared somewhat weak and wobbly, falling over several times as it attempted to stand.
This has not turned out to be a good year for this peregrine falcon pair – we hope for a better outcome next year.