FJ7 Reproductive Ecology and Evolution

Date: April 8, 2021
Observation Period: 8:00 a.m. - 11:00 a.m. (3 hours)
Location: Lone Rock Point, Burlington, VT
Weather: 60 degrees F, Partly Sunny, Wind-3 mph NNW
Habitat: Forested cliff ledges overlooking Lake Champlain.

As a volunteer for the Audubon Vermont Peregrine Falcon Recovery Project, I monitor PEFA behavior at the Lone Rock Point site from March until July with the hope that successful nesting activity will occur. In 2018 two chicks successfully fledged. Although PEFAs were observed in 2019 and 2020, no nesting activity took place. During my recent visit on March 18, only one PEFA was observed. However, this now appears to be a promising year because during this field observation I observed a PEFA pair nesting near the same location as the 2018 pair. PEFAs become sexually mature at one to three years of age, remain paired from year to year and return to the same nesting site each year.
Upon arrival I heard the periodic wailing call of a Peregrine Falcon that is used to communicate with its mate as a sign of hunger or to locate its mate. One PEFA was perched on a snag. Five different perching spots were noted in their territory. During the courtship and nesting season, male PEFAs bring food to the female. At approximately 8:20 a.m. the male PEFA flew in and a mid-air exchange of prey took place. The female PEFA then perched on a branch to feed. No further vocalization was heard.
Both the male and female create several depressions in the substrate called scrapes, but the female chooses which of these nest sites to occupy. No additional nesting material is used. The scrape here is on a cliff ledge with surrounding vegetation. Two eggs were observed in the scrape. The period for egg laying lasts approximately one week so it's possible that more eggs were laid before incubation started. The female PEFA was on the scrape from 8:37 a.m. until 8:48 a.m. exhibiting egg-laying behavior such as lowering her body, turning frequently to face the opposite direction in a reclined position and laying down. She was there again from 10:43 a.m.-10:45 a.m. An updated visit on 4-13-2021 confirmed one PEFA incubating and one PEFA perched on a snag.
I also observed an Eastern Phoebe in this area perched in two different trees near the edge of the cliff opposite the PEFA location. The male was robustly singing to establish its territory, and displaying its taxing, high energy ability to attract a mate. The nesting habitat requirements for the Eastern Phoebe is different from the Peregrine Falcon in that the female Eastern Phoebe collects nesting material to build the nest from mud, moss, leaves, grass stems and animal hair, all readily available here. Eastern Phoebes breed in wooded areas particularly near water sources and use the eaves of buildings, overhanging decks, bridges or culverts to build nests. Before these sites were available, their original nest sites were on bare rock outcrops where some still do occasionally nest. Perhaps these Eastern Phoebes are “old school” and nest here on rock outcrops. It appears to be a prime location because I've seen the males in past years staking out this territory early in the season, and its stated that they return to the same site in successive years. The habitat may have less human disturbance than would be found around some buildings or bridges and ample food resources, particularly insects, are available.
I wonder what risk the PEFA poses to the Eastern Phoebe? I don't know. It is reported that PEFAs consume approximately 450 different North American species. However, it is also noted that PEFAs generally hunt away from the nesting area (eyrie). It would appear that this area has food resources for the PEFA that is more desirable and more easily available than the Eastern Phoebe.

Species List:
2 Wood Duck
1 Common Merganser
3 Mallard
1 Eastern Phoebe
2 Peregrine Falcon

https://www.rockpointvt.org/post/peregrine-falcons-at-rock-point
https://birdsoftheworld.org/bow/species/perfal/cur/introduction?login
https://www.liquisearch.com/peregrine_falcon/ecology_and_behavior/reproduction
https://www.nwf.org/Educational-Resources/Wildlife-Guide/Birds/Peregrine-Falcon

Mini Activity Sound Map

https://drive.google.com/file/d/1t_6E8YvEAUPRmR7ETCIq_-uHkYxYN7Iz/view?usp=sharing

Publicado el abril 25, 2021 10:48 TARDE por sdz456