Saturday began with observations of two aerial dogfights between Ospreys and Bald Eagles. This is the season when Ospreys capture fish and bring them to their nests to feed both mates and chicks. As Ospreys are the better fishers, Eagles often try the easy route of stealing a catch, either in the air or from an unguarded nest. Although Ospreys sometimes lose the contest, they always put up a vigorous defence.
As observations of dogfights started the day, it seemed opportune to wander past osprey nests to watch for dogfights, to see if chicks are now poking their heads up, or just to enjoy this magnificent bird. The day brought many scenes along with three more dogfights, only one of which was close enough for decent pictures.
A male Osprey lands at its nest as a female looks on. There is no apparent sign of a chick.
Finally there was a nest where a chick’s head poked up as it looked at mommy.
A curious aspect of watching an osprey nest is the occasional sighting of a bird that has been banded. This band (insert) seems to say top: BAND, middle: 12, bottom: U8 USA. A few years ago, I wondered if a photographed band was worth reporting. Alas, the system seems to have been designed to record only the complete band of dead or captured birds, not the partial band of a bird in the wild.
There is something grand about the sight of an osprey landing on its nest.
This adult Bald Eagle passed overhead without bothering an Osprey.
Finally, one dogfight took place close enough for a satisfactory picture. The fight was between a juvenile Bald Eagle (in its second year) and an experienced eagle-fighting female Osprey. I have seen her many times before and she is at least six years old and probably much more. In the end, the inexperienced thief was driven off and the victor returned to her nest.
A male Common Yellowthroat has managed to catch a bug to eat.
Swallow’s saga
Tree Swallows often nest in the cavities that Northern Flickers have carved in the pilings of docks.
A person commits an offence if the person … possesses, takes, injures, molests or destroys a bird or its egg. BC Wildlife Act.
But in mid-June, one of those pilings had rotted at the waterline. It then broke in two, and its upper portion began to cant dangerously. The broken portion was only stopped mid-descent by the stirrup that loosely held it to the dock.
However, the Lake was going down. It wouldn’t be long before the dock and its stirrup would drop below the broken piece causing the piling top to fall into the water and drift off. This would be bad on two counts:
• a broken piling floating among boat traffic poses a danger;
• the piling’s active nest of Tree Swallows would be destroyed.
Clearly, the broken piling had to be removed before it fell into the water. But, how was this to be done in the light of an active bird’s nest? Moving the nest and disturbing those birds would violate the wildlife act. And if it were moved, would the swallows accept the new location and continue incubating their eggs? Even if the swallows were to accept the new location, would the eggs have survived the double whammy of the break of the piling, and its subsequent move?
This was tricky. Three pictures tell the story.
A piling had rotted at the waterline, and two-and-a-half weeks ago, a storm had caused it to break. The portion above the waterline tipped but was held precariously by the stirrup loosely adhering it to the dock. As the water level was dropping, this momentary reprieve would soon end causing the piling to fall into the Lake and to drown the nest. A swallow can be seen looking out of the cavity.
A couple of days after the break, the top of the piling was cut off well below the cavity but above the waterline. It was then set on the dock at about the same sloping angle, and loosely attached to the adjacent piling with a collar which allowed it move down as the water level dropped. During the hour and a half it took to do all this, the Tree Swallows agitatedly flew in circles around the operation. However, the following morning, when this picture was taken, the swallows had accepted the new location and were again tending the nest. This part was a success, but did the eggs survived the break and the move? There was nothing to do but wait.
Two-and-a-half weeks went by. Even though the adults continued to occupy the cavity, there was no way to know if the eggs had actually survived. We would have to wait to see if chicks poked their heads out — or that was the thinking until unexpectedly the swallows offered early irrefutable evidence that at least one chick was doing well: a faecal sac. The picture shows the female flying towards the cavity while the male removes the poop from one of the chicks. It will be fun to see chicks when they emerge, but, for now, everything is looking good.
In the time that has passed since the piling broke, the Lake level has, indeed, dropped. Had nothing been done, the piling would have fallen, drifted off, and drowned the nest. Maybe the offence of briefly molesting these nesting birds can be forgiven.