History Of The Nest
An artificial cradle on a pole was erected in the late 1990’s after Ospreys attempted to nest on the mast of a moored boat. This nest has been occupied by Ospreys every year except 2014 when pelicans roosted on the Osprey cradle. During the 2014 nesting season the Ospreys did attempt to build another nest on the lighting tower within the Boyds Bay Holiday Park. But falling sticks posed a threat to park patrons. A drone was carefully used to check for eggs or chicks in the nest. When none were observed a crane was used to remove the nesting material and to install a cover to block the Ospreys’ access to the lights platform. The Ospreys subsequently returned to their original cradle and went on to successfully breed
The Sky Dance
As the days cool and the nights lengthen, an adult Osprey’s attention turns to family matters. In our part of the world this tends to be around April.
Early in the breeding season a magnificent courtship display occurs, often referred to as the “sky dance”. With legs dangling, males will hover up to 200 meters above the nest with a fish or a stick in his talons. He alternates intervals of hovering with slow, short swoops. This display can be sustained longer than 10 minutes while he repeatedly utters a screaming call (creee or cheeerk). He regularly descends in an undulating fashion to the nest.
At the Boyds Bay Bridge, if you are waiting for the traffic lights to change around April and you glance towards the river and up, you may be lucky enough to see the sky dance in progress.
Nest Building and Courtship
It is not a straightforward affair the selecting of a nest site. We have learnt that you can erect an artificial cradle in what to us seems a great location, but it can remain unused. Ospreys know best and the most successful artificial cradles are in places where Ospreys are known to have attempted to build a nest themselves.
This was certainly the case for the Boyds Bay Bridge nesting cradle.
The male Osprey is usually responsible for selecting the nesting site. Once chosen, he brings the majority of the nesting material in. He collects most of the sticks from the ground but some material is broken off from tree branches. The female osprey does the actual building, placing the material and shaping the nest into its final form.
During courting, the two birds spend time at the nest and feed each other. The male starts to bring the female all of her food. She may take this food to a perch to eat and then return to the nest with material to line it. The last two years I have been observing this behaviour at the Boyds Bay Bridge nest.
Incubation
Incubation begins when the first egg is laid. Subsequent eggs are laid one to three days apart; clutches have 2-4 eggs. The female usually takes on most of the responsibility of incubation, seldom leaving except to feed. The male at this time is supplying food for his partner. I have watched, on many occasions, the male bringing fish back to the nest for the brooding female.
Raising Chicks
After the incubation period, the eggs hatch, and the nestlings emerge!
The initial period of chick raising is a bit of a mysterious time for intrepid Osprey observers. The nest tends to be high and, while there is evidence of feeding activity taking place, not much can be seen from the ground. The Boyds Bay Bridge nest id no exception in this regard.
Early on the young ospreys are covered in down and are restricted to limited movements. They are utterly dependent on their parents for food and care.
As the chicks grow, observation from the ground becomes increasingly interesting as the young can be seen.
Fledging
Chicks develop rapidly. Initially their wings rest on the surface of the nest. As they approach fledging, their wings rest less and are increasingly held close to their sides like an adult osprey. To get to this point has required a lot of flapping which develops their muscles so that they can support their wings. Furthermore as they approach fledging they stand much more stably on the nest, and are flat-footed. This is an indication that their feet and talons have developed sufficiently for fishing and perching.
This was observed at the Boyds Bay Bridge nest in 2022 with one chick making it to fledging. Indeed, the chick was observed flapping his/her wings at the edge of the nest. Following departure from the nest this fledgling spent a lot of time sitting on the light poles that line the edge of Boyds Bay Bridge. It looked a precarious place to me for a young bird still learning to fly.
After a period of several weeks the young Osprey disappeared to who know here.