Understandably, people would assume Jo Durt and Kids on Grass live in their igloo year-round, but they don’t. An igloo, nest box, or other substrate resembles an office or job site. Their business is making more Peregrines. They only use it as long as needed and generally split it as soon as their work is done.
During the winter, the male Peregrine falcons are responsible for holding the territory, which means they are usually around, although not necessarily on their towers or nest areas. In contrast, the females embark on sometimes remarkable journeys, often traveling far and wide on a migration. This can result in them being unseen for months. If you see a falcon at the BOIS tower during winter, it is most likely he.
Some females, like V, stay close to home and frequently visit their nest area. This is why it was so evident when she disappeared on camera this winter that something had changed. Jo Durt & Kids and Grass are seen much less frequently on camera after the chicks have fledged in the late summer.
Here is a detailed timeline of events at the BOIS tower this winter featuring noteworthy photos from the last memory card. It commences on January 29th with a winter appearance from Jo Durt on camera at the tower, and ends up to the disappearance of all three adults. It contains the last known photos of Jo Durt and Kids on Grass.
1/29/24 Jo makes a winter visit to the tower
2/12/24 Barn owl visits
2/16/24 Jo appears
2/18/24 Jo appears with large prey; duck. She feeds for almost an hour.
2/19/24 – 2/21-24 Jo spends most of her day at the tower
02/24/24 Owl visits and spends time in the igloo
2/24/24 Jo shows up the morning of the owl visit
2/27/24 Last day Jo is seen
2/27/24 Last photo of Jo Durt
3/1/24 Jo’s mate Kids on Grass BE/68 visits briefly
3/02/24 Owl visit
3/11/24 – 3/12/24 Kids on Grass stays at the tower most of the day for two days
3/17/24 Kid on Grass appears to be defending the tower. Multiple short visits, defensive postures, several flights across the deck, and appears to be vocalizing
3/18/24 34/BH makes her first appearance on camera
3/19/24 Kids on Grass appears to be bringing her food the next day
3/20/24 Copulation, 34/BH and Kids on Grass
3/20/24 Prey deliveries and bonding between the new mates
3/23/24 Pair bonding continues
3/25/24 Last sighting of new female 34/BH
3/25/24 Last sighting of BE/68, Kids on Grass
4/08/24 Owl returns
4/11/24 Crows raid the nest
That’s it. The end of an era, as told by the Little Egg Camera at Bonnet Island. Even when photographing every movement at the nest 24/7, we have many unanswered questions. So much is up for interpretation, speculation, and debate. Here are a couple of things that stand out.
The Owl
We occasionally see owls at the tower, especially on winter nights. They have always been Great Horned Owls. This is the first Barn Owl and the first photographed spending time inside the igloo. This owl is responsible for the pellets I recovered from the igloo.
Owls are a known source of avian flu, and chicken farms are going to great lengths to keep hawks and owls away from their buildings. They are believed to be introducing the disease to some facilities.
It seems much more likely that a falcon would become infected by eating sick prey than by an owl infecting its nesting structure, but it is still worth noting and watching for.
The Duck
Peregrine falcons are often called “Duck Hawks” because they can take these huge prey items. In reality, it is really the females who are strong enough to handle such a large meal. The cameras show that most of the diet at the tower is pigeon and dove, with some shorebirds mixed in. Ducks are rare.
Avian flu is known to be concentrated in ducks, and there was a significant die-off on Barnegat Bay this winter. Sadly, an ill, infected duck is most likely to be caught by a Peregrine.
The timeline regarding the duck is that Jo arrived with a duck, gorged herself, spent three days at the tower, and then vanished eight days later.
The Speed of the New Bond
The speed with which Kids on Grass began full courtship with 34/BH is interesting, as seen on camera. She appears, and the next day, he brings her food, and the day after, they are copulating. The courtship usually moves more slowly. Kids on Grass was most likely already in nesting mode when Jo Durt disappeared. The instincts triggered the hormones, and there was no turning back. The clock was ticking, and they certainly didn’t waste any time. It’s also possible they had been bonding for longer in the region, and she just wasn’t picked up on camera until later in the courtship.
When we run these cards through our software to extract all the prey items, it will be interesting to look at their diet in relation to their collective disappearances.