Look for 2 adults on the nest. The adult pair will show pair bonding behaviors such as vocalizations, aerial sky dances, and the male feeding the female fish. You may see the pair copulating, which typically begins 14 days before laying eggs.
Females will lay 1 - 4 eggs at a rate of one egg every 1 - 2 days. After laying, incubation starts. Look for adults taking turns sitting low in the nest incubating eggs. The incubation period can last 35 - 43 days.
Chicks hatch ~39 days after incubation begins. Look for adults bringing food to the nest and making "head bows" into the center. Chicks typically can't be seen until they are 2 - 3 weeks old, so feeding behavior is the only way to know chicks are there.
Around 4 weeks after hatching, look for the heads of chicks to show over the rim of the nest, particularly when adults bring food to the nest. Other times they lie flat and are harder to see. Count the number of chicks in the nest before they learn to fly
Chicks begin flying around 7 - 8 weeks old, and are still fed by the adults. Count the number of chicks who have successfully fledged the nest and are observed flying.
Chick Last Observed
4 - 10 weeks after fledging, chicks begin leaving the nest area to migrate south, once they have learned to fly and feed themselves. Record the date that the last chick left the nest.
Look for signs of nest failure like adult abandonment, adults no longer incubating eggs or feeding young.
Since the previous entry, the two osprey who seemed to vacate the nest, have very slowly, first separately and then together, returned to it from about noon through the evening. I saw two mating attempts on 7/2. On 7/5 the male was seen adding small branches to the nest. While that was happening, the female sat on the post just outside the nest box and chirped loudly for as long as I saw him bring and arrange the twigs. I have not seen that activity since then. The two osprey in the field remain either on the ground in what they have established as their territory, or on the
crossbars. I do not know. whether the osprey in the nest remain there overnight.
In the days since the nest has been empty the two osprey who occupied it have spent most of their time on the ground on the western edge of the marsh. Occasionally one or both have suddenly appeared standing on the edge of the nest, continually looking around or picking at their feathers. They appear restless and uncomfortable. They have never sat anywhere on the nest. After a short time they fly and either return to the same grassy territory, or a few times have sat in the grass near the cross bar post of the two birds who consistently tried to take over the nest. Despite the fact that the nest is now empty most of the time, those birds remain on the cross bar post or on the marooned floating dock and have made no attempts to occupy the empty nest.
On 6/15 the nest failed. An observation at 6:30 AM indicated that the nest was empty and the adults were gone. It is assumed that the birds
who consistently challenged the osprey in the nest, finally succeeded. That day one of the birds from the nest was spotted in the grass around noon, but the second one was not seen for the rest of the day. That night there was an air battle between the one osprey and the two on the cross bar post, but all three birds were active the next day. The next day both of the nest birds were perched on the side of the box, but never sat or stood in the nest again. On Friday 6/17i Bill Stuemfig inspected the nest, and confirmed that it was completely empty - no remains of the chicks. Today the two adults birds sat together on the grass on a distant part of the marsh, and spent a great deal of time flying together. The last they were seen was when they flew across the tree line beside the GSP, perhaps in search of a new safer nesting site. I will keep this nesting diary open for a while in case anything further develops.
The osprey nest pair have continued cooperating to seemingly feed two chicks, although neither my partner nor I have had a view available to see them. The parents take turns staying with the nest, obtaining food, feeding the chicks and are generally excellent parents. There have been three attempts at
nest take overs by the two homeless osprey, who have established their new territory south
of the nest towards that edge of the marsh. The male osprey was able to easily deter the birds
as they approach, and they have remained in their territory in the time that the chicks seem to have hatched.
It appears that yesterday, 6/8/22 a chick hatched, due to the behavior of the parent birds during the morning and further in the afternoon.
There was a flurry of activity to rearrange the nest with scooping out of the center and fish being brought into the nest by the male for the female. In the afternoon the female appeared to be bending down with gentle motions with her beak. I cannot see directly down into the nest, but someone who can will try to see if chicks
are in the nest later today. And today it did
appear that a second chick had hatched, given
increased feeding behavior by the female. The
male is standing on a post abutting the nest box, clearly on the lookout for intruders. None
have appeared so far.
The male and female continue to share time incubating the eggs. They function extremely well together.
The two outlier osprey seem to have taken up residence on the crossbar post across the marsh. They eat their fish there, they roost there side by side, and also have launched three takeover attempts of my nest since since my last entry. However, they come one at a time, and continue to be rebuffed by the male in the nest. After the last attempt where one of them flew very low almost right into the nesting female, with the male sitting on the marsh facing the nest, he the female stood up to defend herself. The male on. the grass was in the air and flying at the intruder so fast that the nestless male was taken by surprise, and easily chased away. The female remained standing, and the male returned to the nest, stood beside
her, and actually touched her beak with his as if to reassure her that he had taken care of her.
The female bird continues to incubate the eggs, rolling them from time to time. The male is always close by. For the last three days two osprey (sometimes only one) roost on the cross bar post across the marsh almost directly behind the nest. They have not
flown toward the nest, but are on the cross bars for the entire day - at least one if not both. The osprey in the nest do not exhibit any signs of distress during the day.
Since the 5/06 entry until 5/15 each day continued the same routine as the 5/6 entry. This pair work well together. On 5/15 around 8 AM an osprey
was spotted flying towards the nest being monitored. The male osprey, who was in the nest with the female spotted the oncoming bird and flew directly towards it. They seemed to make contact for a moment, and then the oncoming bird turned away and flew across the marsh to the west. The chase continued until the bird from the nest had herded the other osprey to the western most bank of land. He then turned back towards the nest I'm monitoring. Rather than landing in it, he stopped short of it by about 20 feet, landing on the ground facing
the nest and stayed on that spot for the rest of the day. The female remained in the nest during
the latter part of the afternoon, when the male
came to the nest and took her place.
The next morning the male osprey was sitting
in his previous spot on the grass, when an osprey came flying towards the nest from the west. Since the osprey from the nest sitting on the ground was facing west, he spotted him approaching. The Osprey in flight kept coming, but the nest bird did not let him get close. He flew towards the oncoming bird and chased him
back towards a western strip of land. Then he
returned to his position on the ground. He has
sat in either that spot or another a little further out where he can see the nest but is facing north. The bird from the west has not returned
since his last attempt, at least during the times I have been monitoring the nest. The female has sat on the nest for much longer periods of time than she had been. On the very windy days, she lies flat and stretched out. I assume she is incubating some eggs, but these birds never leave the central nest area open to view.
Since the last entry, this pair has settled into a routine of taking turns sitting in the nest and sitting on the nearby small roost, flying in the area, and bringing fish back to eat on the roost or take into the nest. This morning the female was sitting in the nest when the male flew into the nest and stood beside her, as if ready to take over for her. She did not acknowledge. his presence. After about five minutes, he gently pecked her beak. She looked around and saw him there, immediately stood very high in the nest. He slid in under her belly as she moved forward and flew. Quite a coordinated move! As a pair, these two osprey seem compatible and to understand and accept their roles!
The male osprey sat on the nest most of this morning. The female returned around noon and stood beside the male for a while before he stood up and flew off. She then took over and has been sitting there for these last few hours. The male has spent most of his time on the ground close by the nest.
Since the last entry, he female has spent more and more time on the nest and the male has spent short periods of time in the surrounding area either sitting on the marsh close to the nesting platform or out over the water. Today for the first time the female sat on the nest for the first half of the day, and around 1 PM the male flew into the nest with her bringing a fish!
She stood up, stretched her wings, an flew off
to the roosting post close by. The male dragged
the half eaten fish over to another spot and proceeded to claw at the center of the nest. Then he sat on the center of the nest and remains there until now, about 5 PM. The female returned earlier, but has been roosting on one of the crossbars beside the nest.
Until yesterday,4/25, the routine previously described continued. Yesterday the behaviors changed. The male and female appeared to be functioning separately. They chose posts that were opposite each other to perch on throughout the day; one would leave the other
alone in the nest consistently, one of them would bring his/her fish to the roosting post
and the other was either in the nest or off somewhere on the marsh. At one point the female sat in the nest for a short period of time
as if she were incubating eggs, but that only
happened once. Today the behavior was similar until this afternoon, when the female began bringing nesting material and arranging it in the nest. The next time I saw her she had begun sitting again, as if incubating eggs. The male
flew to the nest, would stay for a short while, and leave. The wind began to increase later in the afternoon, the sky darkened, and it seemed
as if a storm was approaching. The male flew
but the female stayed on the nest, I don't know
how long she remained, but clearly, it was a change in behavior.
Up until today the days since the last entry have been routine. The osprey do everything together now - nest building, sharing a fish usually caught by the male, sitting together on the marsh, flying off together, etc. There were
four more unsuccessful attempts by the male to
mate that I have observed - he slides off her back each time. Today the female was in the
nest alone for the first time in a while during the times I have been observing, and two osprey came flying low out of the south towards the nest, one behind the other. The first one flew low over the female osprey in the nest, and the second one landed on her back and tried to mate with her. She cooperated. He was there for what seemed like only seconds and flew off. She stood alone in the nest, and eventually the male osprey who she has bonded with returned. I could not tell whether the osprey who tried to mate was the one she seems to have bonded with. I will just add that the two osprey without a nest have remained as a pair on the western edge of the marsh, bringing the fish that are caught back to the same general area to eat, and sitting for periods of time in the grass. I do not see an attempt to create a nesting area in the grass with additional material placed on top of it. I do not know whether the male who tried to mate with the female in "my" nest was the male across the marsh.
For the past three days there have been no more
attempts by the two osprey without a nest to take over the nest already occupied. It appears that they have chosen to "nest' permanently on the far west bank of the marsh, consistently return to that spot with fish. Yesterday I had them in my scope, and they
were mating. As they eat their catch of fish on the ground at their nesting sight, they are constantly mildly harassed by four or five gulls.
The two birds in my nest are constantly together now whether in the nest or on the marsh. They are engaging in nest building, with the male
bringing materials to add to the nest. Yesterday the male brought a fish to the female, and as she began eating it, he attempted to mate with her and tried to mount her. However, he kept sliding off her back. She quickly realized what was happening, stopped eating, and arched her back to a more level position by bending her neck and head down towards the nest. The male made four more attempts, and she remained completely still throughout. He still kept sliding backwards and onto the nest. On
his fourth attempt, she curved her neck and head to the left, and pecked at the upper part of his left leg, seemingly in frustration at his
lack of skill at mating! He immediately flew away, and she followed! But wherever they go, they are together now during the times I have observed them.
Today was the first day there was no attempt by the outlying osprey to take over the nest already occupied by a pair. However it is clear that the
two who challenged the occupants do not have
a nest, and thus their attempts to overtake one.
They huddle together on a bank of the western
edge of the marsh, flying off from time to time,
but always returning to the ground in the same location.
Another challenge to the nesting osprey was made by a single osprey and chased away by the male nesting bird. He was positioned outside
the nest on the ground in the previous location.
At the same time a red fox appeared, and the
nesting male osprey dive bombed him once he
had chased away the bird challenging him for the nest. The female remained in the nest throughout.
Yesterday and today were days of the pair of osprey spending some time together in the nest, sometimes separated with one in the nest and one fishing for a meal, and sometimes both away from the nest. They did not make a mating attempt during times I was observing them, which is not say it didn't happen. Then, later in the afternoon, a lone osprey came flying
in fast from the west, and directly flew into one of the osprey in the nest. Both of the nesting
ospreys flew at the intruder and a fast and furious chase began in the sky above the nest.
At one point, with the nest empty, the interloper
dropped down into the nest, standing up tall
in the center of it. He was immediately crashed
into by one of the other birds, and flew up into
the sky, but not off into the sunset. At this point a fourth bird joined the sky battle. This
went on for about another ten to fifteen minutes, when two of the birds flew off, and one of the two original birds inhabiting the nest returned. I could not find the other bird with my scope, and she was absent almost until sunset.
I continued to look for her in my scope, and shortly after the other bird returned to the nest, I noticed the fourth bird who had joined the sky
battle, sitting on a crossbar post far across the
marsh. I'm sure of its ID because it was larger than the three osprey. It was a juvenile bald
eagle! This fight and flight episode was followed by another one around 8:30 this morning, but two osprey flew at the two in the nest, and was followed by about a 20 minute
chase in the air. At one point a male osprey had
pinned the other male into the bank along the bay. It was low tide. When the two intruders finally flew off, the male osprey returned to the nest. Again, I could not locate the female. After
a couple of hours she returned, and the routine of the previous day was resumed.
The two osprey spent little time on t he nest together today. At one point the female was eating a fish on a part of the marsh that is somewhat distant from the nest. But the. male
was spotted in the same area about fifty yards
behind her sitting in the grass, as if keeping close watch on her. At other times one would be in the nest without the other. Later in t he
afternoon they both appeared in the nest and
he mounted her. She stood still, but after about a minute he flew off, and she stayed in the nest for a short while and then flew off. Neither has returned to the nest yet, about three hours later.
Since Sunday 4/3/22 the two osprey have been
behaving as a "couple". They are on the nest together, fly off together, and are together when
a fish is brought to the nest for a meal. Only one eats at a time. The female has been encouraging mating, but I have not seen it happen. Also, altlhough I obviously could have
missed the mating attempts, she continues to
try to encourage the male by standing in front
of him and flapping her wings, standing in front
of him and shaking her body, just standing in
front of him and looking over her shoulder towards him. He stands there for a while, and
then flies off for a while! I was gone most of the
day, but I will say she was in the nest alone late
this afternoon, and for the first time I saw her sitting calmly. There is not any nest building
going on with the exception of a large bare branch the female brought to the nest on Sunday. She laid it along one edge of the nest,
but by today (Wednesday) it has fallen under the
nest between the crossbars on the post.
This is my first year of reporting on this nest, but I
have been observing it unofficially since 2011.
It has been occupied by osprey who each year until 2018 have successfully raised. 2-3 chicks.
Since 2018 once the osprey have mated and either are sitting on the eggs or have hatched
nestlings, the nest has been attacked by two
osprey who either destroy the eggs or kill the chicks. The male occupant of the nest always puts up a valiant defense, while the female tries
to protect the chicks or the eggs. This year the
post used as a roost by the two intruding osprey is being removed in the hope that the pattern will be disrupted. The osprey who occupy the nest are not the same pair each year, but the
aggressors appear to be the same.
Yesterday, March31, at 8:15 AM a male osprey
flew to the roost near the nest and proceeded to
eat the fish he had been carrying. He then flew
to another post across the marsh, and stayed
there for about an hour. Then he flew across
the marsh and out of sight. He has not yet returned.