Author: Matt Perry

Update for Friday, May 24, 2024

The process of feather growth in nestling Peregrine Falcon is a crucial part of their development, transforming them from helpless hatchlings into fledglings ready for flight. This process begins shortly after hatching and involves several stages, each critical for the young falcons’ survival and eventual independence. When Peregrine chicks hatch, they are covered in a layer of soft, white down feathers. These down feathers provide insulation, keeping the nestlings warm, but they are not suitable for flight. At this stage, the chicks are highly dependent on their parents for warmth, protection, and food. As the juvenile feathers grow, they gradually replace the initial down feathers. The sheath surrounding each new feather breaks down, allowing the feather to unfurl and take its full form. These juvenile feathers are darker and more structured than the down, providing better protection and laying the groundwork for future flight capabilities. By the time the nestlings are about five to six weeks old, they have developed a full set of juvenile feathers, including the critical flight feathers on their wings and tail. The flight feathers, which are stronger and more aerodynamically shaped, are essential for flying. These feathers are meticulously preened by the nestlings to ensure they are in optimal condition.  

The process of feather growth in nestling Peregrine Falcons is a meticulously timed and energy-intensive phase of their early life. From the initial insulating down to the development of robust juvenile feathers, each stage prepares the young falcons for the critical transition from nestbound chicks to adept aerial hunters. This transformation is essential for their survival and marks the beginning of their journey as one of the world’s most formidable avian predators.

Update for Thursday, May 23, 2024

Astrid became very upset today when she perceived workers up on the bank roof. She gave loud cackling calls for at least an hour. She hazed them; she got Ares involved, and she generally put on quite a show. During the breeding season, Peregrine Falcons exhibit highly territorial and aggressive behaviors; they haze intruders or other perceived threats near their nesting sites. These raptors are fiercely protective of their nests, particularly when they occupied by nestlings. Any encroachment by other birds, predators, or humans is met with swift and decisive action to safeguard their offspring.

Peregrine falcons use a combination of aerial maneuvers, vocalizations, and physical attacks to deter intruders. When a threat is detected, they will often launch into the air with rapid, powerful wingbeats, using their considerable speed and agility to confront the intruder. They may dive-bomb the threat in a series of aggressive swoops, coming very close or even making contact with their talons to scare it away. These hazing dives are both intimidating and effective, showcasing the falcon’s prowess as a top predator. In addition to physical hazing, peregrine falcons employ loud, piercing vocalizations to warn off intruders. Their sharp, repetitive cackle calls serve as an auditory deterrent, signaling to the intruder that they have entered a highly defended territory. These vocal displays also alert the mate and any fledglings of potential danger, ensuring that the entire family remains on high alert.

Update for Wednesday, May 22, 2024

Astrid and Ares fed their young an impressive 12 times between 11:00 PM Tuesday and 8:00 AM Wednesday. Anticipating a hot afternoon and the need to fast their nestlings for several hours, A&A worked diligently to provide their young with as much nutrition as possible, as early as possible. This behavior also highlights their significant nocturnal activity. Traditionally, Peregrines were not known for being active between dusk and dawn. However, urban nesting Peregrine Falcons exhibit fascinating nocturnal habits, showcasing their adaptability to city environments. While believed to be primarily diurnal hunters, these raptors have adjusted to the urban landscape’s unique conditions, allowing them to optimize their breeding success. The extended hours of artificial light and the abundance of prey in cities play significant roles in shaping their nighttime behaviors during the breeding season. Although primarily diurnal hunters, these raptors have adjusted to the unique conditions of urban landscapes to optimize their breeding success. The extended hours of artificial light and the abundance of prey in cities are crucial factors in shaping their nighttime behaviors during the breeding period.

Update for Tuesday, May 21, 2024

Overnight Astrid and Ares fed the young multiple times and they continued providing meals right until about 10:40 AM. Their plan was to pack them with as much nutrition as possible so it would be easier for them to fast during the hottest part of the day. During periods of extreme heat, breeding Peregrine Falcons may refrain from feeding their nestlings as a strategic response to prevent overheating and dehydration. Peregrine falcon chicks are highly susceptible to the effects of intense heat due to their limited ability to regulate their body temperature and their high metabolic rates. Feeding, particularly with protein-rich prey, generates additional metabolic heat, which can exacerbate the risk of overheating in young nestlings. By delaying feeding during the hottest parts of the day, adult peregrine falcons help to minimize the thermal stress on their chicks. Instead, they often prioritize shading the nestlings with their wings or positioning themselves to block direct sunlight. This behavior helps to keep the nest cooler and provides a more stable environment for the young birds. Feeding may be concentrated during the cooler morning and evening hours when the risk of overheating is lower, ensuring that the nestlings still receive adequate nutrition without the added stress of high temperatures.

Update for Monday, May 20, 2024

It was hot today, and that meant Astrid & Ares had to provide shade for the nestlings in the box. Sometimes we make light of the adults and their shading techniques and how ridiculous they sometimes appear, but it is a serious business. In hot conditions, raptor chicks face a significant risk of overheating in their nests, which can have dire consequences for their health and survival. Birds of prey, such as eagles, hawks, and falcons, typically nest in exposed areas like cliffs, tall trees, or open landscapes where they are more vulnerable to direct sunlight and high temperatures. Unlike adult birds, which can regulate their body temperature more effectively by panting or seeking shade, nestlings are less capable of managing extreme heat. Overheating can lead to dehydration, heat stress, and fatalities if the chicks are unable to cool down.

Parents of nesting raptors do their best to mitigate the risks by shading their young with their wings, or by corralling them to shadier parts of the nest. However, during prolonged heatwaves or extreme temperature spikes, these measures may not be sufficient. The limited ability of nestlings to thermoregulate, combined with their reliance on parental care, makes them particularly vulnerable. Overheating can impair their growth, weaken their immune systems, and reduce their chances of fledging successfully. Therefore, it is crucial for the parents to be ever vigilant, to monitor their offspring, and to be ready to do what it takes to protect them from the dangers of extreme heat.