Author: Matt Perry

Update for Wednesday, May 29, 2024

Early this morning, Ares brought prey to the nest but Astrid did not meet him there. He went ahead and took it inside the box and started a feeding. Richae immediately stole the food from him and brought it to the back of the box where she started feeding on it. Made a couple of tries to recover it failing each time, but the third time he succeeded. He went to the lip of the box and began feeding out the meal. The chicks had not been fed yet that morning and so they were very right in his face, raucously begging. To his credits, Ares continued and was doing a great job. Astrid arrived and made an attempt to take over on the feeding, but she couldn’t get by youngsters. She then somewhat reluctantly stood back and allowed Ares to continue. After a minute, she made a mad dash into the fray and took over from her mate.

Male Peregrine Falcons exhibit a strong instinct to feed their nestlings, a behavior that underscores their crucial role in the family unit. During the breeding season, males are primarily responsible for hunting and providing food for their mates and chicks. They excel in capturing a variety of prey, which they bring back to the nest site. Despite this essential contribution, males often face a unique challenge: their mates, the female Peregrine Falcons, are typically more dominant at the nest and may not always allow them to feed the chicks directly. This dominance stems from the females’ larger size and assertive nature, which ensure they maintain control over the feeding process to monitor and ration food distribution among the hungry nestlings.

Even with these limitations, male Peregrines show persistent efforts to contribute to the feeding of their offspring. They deliver prey to a designated spot near the nest or directly to the female, who then takes over the task of tearing the prey into manageable pieces for the nestlings. This indirect method of provisioning highlights the cooperative nature of falcon parenting, where the male’s role in hunting is indispensable, even if he doesn’t always get to feed the chicks himself. The male’s consistent hunting efforts ensure a steady supply of food, which is crucial for the rapid growth and development of the young falcons.

Update for Tuesday, May 28, 2024

Peregrine Falcon nests can be very loud places especially when the young inside are over three weeks of age. Their squealing begging calls are ear piercing and it’s amazing that parent falcons can stand being in the nest with them. As it happens, nestling Peregrine Falcons exhibit a range of vocalizations that are crucial for their development and survival. Primarily, these sounds communicate their needs to parents and facilitate interactions with siblings. The most prominent vocalization is the begging call, a high-pitched, insistent “cheep”, “chip-chip”, or squeal that intensifies when a parent arrives with food. The frequency and intensity of these calls are directly related to the nestlings’ hunger levels, with louder and more persistent calls indicating a greater need for food.

As they grow, nestling Peregrines produce a variety of other vocalizations, including softer, more conversational sounds used during interactions with siblings. These sounds help establish social bonds and hierarchies within the nest. Additionally, as nestlings practice flapping their wings and other pre-flight behaviors, their vocalizations can include excited chirps, squeals, and wails, signaling their readiness for the next stages of development. These varied vocalizations are essential for ensuring that their needs are met and for maintaining the social structure of the brood, ultimately preparing them for independence.

Update for Monday, May 27, 2024

Almost every year, we face challenges in distinguishing male from female nestlings in the Utica nest. It’s quite common for us to mistakenly give a female a male name or vice versa. Fortunately, the birds never seem to mind or get offended by our mix-ups. One reliable method for differentiating between the sexes is through measurements, as there is a notable size difference between adult males and females. Female peregrine falcons are generally larger and heavier than males, a trait known as reverse sexual dimorphism. However, this size difference is not as pronounced in nestlings, making it challenging to assess with the naked eye. Detailed measurements of the nestlings’ tarsus (leg bone), beak, and overall weight can provide clues, but these often require careful handling and precise tools, which can be stressful for the birds.

If the Utica birds were subject to banding, then they would be measured and weighed, but since they are not, and it would not be safe to do so at their nest box, we can only make educated guesses regarding their measurements and weights. The complicating factor with gauging the size of our birds is the wide-angle lenses on our nest cameras. They always show a distorted view of the size of the birds and their legs. Generally, whichever bird is closer to the middle of the camera frame looks the largest. It is typically only when the nestlings start emerging from the box and going to the verandas or the cross perch that we get a true idea of their size. This is when we can see them with our roof cameras, which do not distort. This year, it seems particularly hard for us to determine gender via visual inspection. We are still reasonably sure that we have one definite female and one definite male, but the jury is still out, and we may not know for sure until fledging is upon us in a couple of weeks.

Update for Sunday, May 26, 2024

As the days progress, and as the nestling develop, they began to act more like young Peregrines and less like defenseless chicks. Interactions between sibling Peregrine Falcons in the nest are a blend of competition and cooperation, crucial for their development and survival. From hatching, these young birds engage in behaviors reflecting their struggle for resources and family dynamics. Competition for food is a prominent interaction; when a parent brings prey, the nestlings beg vigorously, displaying animated movements and loud calls. Dominant and assertive chicks often secure more food, creating a pecking order within the nest. This hierarchy helps more dominate chicks get the lion’s share of food, although lower ranked chicks rarely suffer from malnutrition since Peregrine parents often provide an overabundance of prey. Beyond food competition, sibling interactions significantly influence the physical and social development of young falcons. As they grow, they engage in play-fighting, including mock attacks, pecking, stealing food from each other, and grappling, which are essential for honing hunting and defensive skills. These activities develop their strength, coordination, and agility, vital for survival once they leave the nest. Additionally, cooperative behaviors such as wing-flapping practice and preening strengthen social bonds and prepare the young falcons for collaborative hunting and survival in the wild. These interactions equip the young birds with the necessary skills and social acumen to thrive as independent predators.

Update for Saturday, May 25, 2024

Ares does very well providing food for his family. Indeed, he spends much of the day and sometimes a good deal of the night hunting. Adult male peregrine falcons have adapted remarkably well to urban environments, achieving high hunting success rates thanks to the abundance of prey and suitable high perches like tall buildings and bridges. These structures mimic the natural cliffs that Peregrines use for nesting and hunting, allowing them to perform their signature stoops, diving at speeds exceeding 200 miles per hour to strike prey with great force. Cities provide a steady food source, with large populations of Pigeons, Starlings, and other birds that thrive on human refuse, making them prime targets for Peregrines. Of course, Ares also can exploit a wide range of prey species that live at the nearby Utica Marsh and other areas along the Mohawk river floodplain.

Studies indicate that urban Peregrine Falcons can achieve hunting success rates as high as 50-70% during certain times of the year. This efficiency is bolstered by the predictable presence of prey and the falcons’ unparalleled speed and agility. Urban prey birds, often less experienced with avian predators, are more vulnerable to attacks. The success of Peregrine Falcons in urban areas underscores their adaptability and resilience, highlighting their ability to coexist and thrive in human-dominated landscapes.