Cold Day in the Canyon – Minor Raven Incident – Probable Intruders & Incubation Compromised Again

Utica Peregrine Falcon Update for April 7, 2018 –

Ares compells Astrid to let him have a turn on the eggs
Ares compells Astrid to let him have a turn on the eggs

It was a cold and windy morning with occasional snow flurries. Temperatures were in the mid-twenties and reached the freezing point by noon. After the great drama of last evening, Astrid settled down on her eggs at 8:00 PM. She remained incubating until Ares relieved her at 3:50 AM. In a few minutes she came back to take over, but he really balked at leaving, and so she let him stay. At 5:36, they switched again and Astrid was back on the eggs. By 6:00, Astrid was giving loud repetitive screech calls, very much like the begging calls that older nestling and fledglings produce. We think this meant that she was hungry and by the sound of her, really hungry. He didn’t have anything for her; he was edging up to her in an attempt to take over incubation. This was not what she wanted, but acquiesced and flew back into the canyon.  She made a few hunting forays in the canyon and came back after each one to perch on the State Building. Every time she went anywhere, he would make squeaking calls. They punctuated her every move. At 7:18, Ares began calling and he came off the eggs. Astrid was seen feeding on something on the ledge of the Hotel. It’s not clear if the prey was something she had caught for herself or if it was something Ares had stored. After Ares had satisfied himself regarding what she was doing, he returned to the box and sat back down on the eggs. He had only been gone for four minutes.

Astrid getting some rest while incubating
Astrid getting some rest while incubating
Two Ravens fly through the canyon
Two Ravens fly through the canyon
Ares on the State Building
Ares on the State Building

Of course Astrid had a right to be hungry today. Only yesterday she had laid the third egg and then had at least two long encounters with intruders. Surely she had expended a lot of energy. At 7:36, Astrid was done with her meal and was perched on the edge of the Hotel ledge, and looking surprisingly like a stuffed Penguin (as seen at a distance anyway). They switched at 7:47, and Astrid was back incubating the eggs. At 8:06, she became all worked up about something. It turned out to be Ares flying into the canyon with prey. He landed on the long perch, but in a few seconds she indicated that she wasn’t interested and so he flew off and presumably stored the food. After that, he was perched on the State Building. A dense snow squall affected the downtown canyon at around 9:30 and visibility became hampered for a little while. As the flurries started to taper off, Astrid let out a loud cackle alarm call. Two Ravens were flying through the canyon at just above rooftop levels. The Raven reacted immediately to the falcon calls and they gained altitude fast and picked up their pace. They soon disappeared into the north. During the incursion, Ares remained on State Building. He was monitoring and apparently not overly concerned. The falcons did a quick switch at 10:38, and Ares took over on the eggs. Astrid did some flying around; she was periodically launching out on forays and then returning to her perch on the State Building. Every time she moved, Ares would make his chirping calls. At 11:05, he got quite worked up. She was flying and had just landed again on the same building. He climbed off the eggs, swooped over and mated with her. Following that, Ares flew north and Astrid returned to the nest box and to incubation duty.

Astrid just finished a meal on the hotel ledge
Astrid just finished a meal on the hotel ledge
Eggs left alone for 33 minutes in early evening
Food transfer
Astrid returns to the box
Astrid returns to the box

At 12:40, Astrid began giving harsh screeching calls. Ares was just returning to the canyon and he had perched on the State Building. She came off the eggs and both falcons were in the air for a few minutes; after that he came back to the box and settled into incubating. She had landed on a high perch on the State Building. It was her turn to make periodic forays from the State Building. She was up and down for the next hour. At 3:22, he got off the eggs and flew into the canyon. She showed up at the box seconds later and got right on the eggs. Twenty minutes after that Ares brought food to the box. Astrid took it and flew over to the Hotel to feed on it. Ares wiped his bill on the long perch, flew off but then came back and was on the eggs by 3:42. At 4:53, Ares came off the eggs. Astrid came back to the box and resumed incubating one minute after. At 5:25, Ares brought prey to the nest. Astrid took it over to the Hotel, but didn’t feed on it for long. In a few minutes she was right back on the State Building. At 5:34, both were up and flying. They were gone for six minutes and then Ares returned to incubating the eggs. She was gone until 5:44, when she made a brief stop at the box. She had a short conversation with Ares and then left. Ares left the box screeching at 6:04. He flew up and took a high perch on the State Building and seemed to be standing vigil for his mate. The eggs were left uncovered. After an entire day of flawless and practically uninterrupted incubation, they had a great lapse. Astrid returned to the eggs at 6:37, which meant the eggs were alone in 32 degree weather for 33 minutes. Why is this happening? We don’t know for sure, but Astrid was likely dealing with intruders again. We can’t say conclusively that these eggs will not hatch due to these lapses in incubation, but we won’t be surprised if they don’t. Assuming flawless incubation takes place with yesterday’s egg and with the one we expect to be laid early tomorrow morning, we may still end up with some hatchlings in the nest his season. Astrid’s behavior seems consistent with a female Peregrine policing another pair of falcons on or near her territory.  It’s all speculative for now. Hopefully we will firm up details at a later time.

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