Breeding in Manton Bay in 2008

29th March

30th March

At 10:30 next morning, a second Osprey appeared in the bay. 08 began displaying vociferously - hovering high over the second bird, dangling his legs and giving the distinctive high-pitched display call. Clearly the second bird was a female, but surely it was too early for it to be 5N? Frustratingly, neither bird landed, and a few minutes later both drifted off west.

In the photo on the right you can just make out 08 (top left) as he displays to the female.

Half an hour later, the two birds returned to the bay. This time the female hovered over the nest, dangling her legs. In doing so she revealed a green colour ring on her right leg - amazingly, it had to be 5N!

Sure enough, a few minutes later the female landed on one of the perches in the bay, enabling us to confirm her identity. Yes, it was 5N!

Her return was a week earlier than 2007.

3rd April

Spurred into activity by the arrival of his mate, 08 began to make numerous forays around the bay to collect sticks with which to build up the nest. Sometimes he would snatch sticks from trees, but more often than not he chose ones lying on the ground.

Whilst some of the sticks measured no more than a few inches in length, others were much longer, which made landing all the more tricky.

Once at the nest, 08 often spent several minutes manoeuvring his chosen stick into position, thereby creating a remarkably solid structure.

5N did not leave all the nest-building to 08. She made several flights to a nearby field to collect turf and grass with which to line the nest.

8th April

08 and 5N continued to add sticks and clumps of turf to the nest at an amazing rate. If you compare the photo on the right with those from 3rd April, it is possible to see how much the huge structure had grown in a week.

Aside from nest-building, numerous copulation attemopts were recorded - suggesting incubation may not have been too long away.

22nd April

At 7am on 22nd April, 5N was observed sitting low in the nest for the first time. It seemed that, three weeks after the birds' arrival, the long 35-40 day incubation period had begun. Females usually undertake three-quarters of incubation and so we expected 5N to spend much of the next five to six weeks sitting very low in the nest as she incubated (what we hoped was) a clutch of three eggs.

Males take over incubation duties whenever their mate requires a break, but their primary role is to catch fish. Over the proceeding days strong easterly winds had made fishing very difficult for the birds and 08 had spent prolonged periods away from the nest as he attempted to make a catch. We hoped the weather would improve...

During one such absence, 5N was forced to single- handedly defend the nest against a particularly aggressive intruder; 32(05). The young male (photographed on left) fledged from the Site B nest in 2005 (meaning he is 5N's younger brother) and returned to Rutland for the first time in 2007. At just three years of age, 32 (in photo on left) had yet to establish a territory of his own, and he made frequent intrusions at the Manton Bay nest after returning on 19th April. When 08 was present these intrusions did not pose much of a problem, but when 08 was away fishing 5N was often forced to leave the nest and eggs unattended while she chased away the persistent male.

It was not just 32(05) who was seen on the Lyndon reserve in early April. 5R(04) - also 5N's brother - began taking sticks to an artificial nest on the south side of Lax Hill after returning on 11th April. The platform is almost a kilometre from the Manton Bay nest and 08 and 5N largely ignored 5R as he attempted to build up the nest.

Unfortunately for the young male, strong easterly winds made nest building on the bare platform very difficult. Without the aid of a solid base, every time he placed a stick on the platform it would blow off, making building any kind of a structure almost impossible.

Seeing how 5R was struggling, we decided to give him a helping hand. We replaced the rotten base of the platform with a stronger plywood disc and built a new nest on top. We hoped that this would give 5R a firmer base on which to build up the structure.

25th April

When 08 was absent from the nest on Tuesday morning (22nd April), we suspected that he was merely having difficulty fishing. Strong easterly winds were disturbing the surface of the water, making catching fish difficult even for a hunter as adept as an Osprey. However, when 08 still had not returned by mid-afternoon we started to worry. Had he had an accident whilst fishing, perhaps becoming entangled in fishing line? By 5pm the alarm bells were really ringing. Clearly very hungry, 5N was beginning to food-beg vociferously, but not wanting to leave the nest and eggs unattended she had no choice but to continue to incubate. The photo on the left shows 5N alarm calling during one of 32's intrusions.

Then just when we were planning to send out a search party, 08 reappeared. He landed on the nest and copulated with 5N as if nothing had happened! 5N's food-begging became even more vociferous, but when 08 eventually left the nest to go fishing, his efforts were curtailed when he was forced to repeatedly chase away 32(05); the young male who had been intruding at the nest for most of the day.

08 roosted beside the nest all night but by first light, thick fog made watching the nest almost impossible. When the fog finally cleared at 8:30am, 08 was nowhere to be seen. Good we thought - he must be away fishing. However by lunchtime he was still absent - this was obviously more than a fishing trip. A phone call to Roy Dennis and quick consultation with the Osprey 'Bible' Poole, suggested that, although 08's absence was very hard to explain, it was possible that he had found a new female, and was building a nest elsewhere. It sounded far-fetched but there seemed no other explanation for his sudden change in behaviour. Meanwhile, 32 was continuing to prove a nuisance, intruding at regular intervals, and sometimes forcing 5N to leave the nest unattended.

Searches of surrounding farmland next morning came up with nothing, and 5N remained alone at the nest. We wondered how long she would be able to continue to incubate without feeding?

By mid-afternoon there was still no sign of 08, but the experience of the past few days suggested that there was still a chance he would return in early evening. Sure enough, at 5:15 an Osprey appeared from the east carrying a large trout. He took the fish straight to the nest - yes, it was 08! Within a matter of seconds 5N had taken the fish from her errant mate and 08 settled down to incubate. Eventually 5N returned to the nest with the fish, handed it over to her mate and he took it to a nearby perch where he remained throughout the night. It seemed, that at last, some degree of normality had returned!

Following 08's wayward behaviour normality returned to Manton Bay. Having returned to the nest with a fish, 08 resumed typical behaviour - sharing incubation duties with 5N and providing a regular supply of fish. The photo on the left shows 08 attempting to lift a huge trout out of the water.

We remained at a loss to explain his strange behaviour. There are examples of polygamy among the Osprey populations in the United States. In his book, Alan Poole describes how he found three instances of a male attempting to breed simultaneously with two different females, in the 1980s. So perhaps 08 had indeed attempted something similar?

1st May

5R continued to build up the artificial nest on the south side of Lax Hill, and by now 32(05) had taken up residence on an artificial nest close to Heron hide.

It seemed that with 08 back in the bay, 32 (right) had decided that he was best to invest all his energy in establishing a territory of his own. And perhaps finding a mate.

Shortly after lunch time on 1st May, 5R began displaying spectacularly above Lax Hill. We suspected that he had seen a female and, sure enough, a few minutes later a second bird dropped onto the nest. A quick look through a telescope revealed a dark breastband; it was definitely a female.

Eventually it was possible to see that although the female was not colour-ringed, she did have a metal ring on her right leg, suggesting she was probably a Scottish bird. For the next few hours she remained on the nest, and spurred into action, 5R brought numerous clumps of hay to line it. He also attempted to copulate with the female at regular intervals.

After an hour or so the female began food-begging and eventually 5R left the nest in search of a meal. Sensing his opportunity 32, who had been watching intently from his nest a few hundred metres away, began displaying, attempting to entice the new arrival towards his territory by dangling a newly caught fish in his talons. Sure enough, the female followed!

Although initially reluctant to hand over his catch, 32 finally passed the fish to the female and she remained with him for another hour or so. Like 5R, the presence of the female prompted 32 to begin nest-building furiously. He made numerous short flights to collect sticks and turf and made several ungainly attempts to copulate. Eventually though, the female grew tired of 32's advances, and returned to 5R!

The female remained with 5R for much of Friday morning, but when he failed to respond to her constant food-begging, she flew off north and did not return for the rest of the day. A chance missed perhaps?

9th May

As we suspected the female did not return, leaving 5R and 32 to continue their territorial dispute alone. It was a battle that 5R seemed to be winning - on Wednesday evening he repeatedly chased 32, attempting to oust the young male from his Heron Bay nest. The photo on the right shows one such chase.

Over the past few years we have monitored the behaviour of the non-breeding males closely, and there is no doubt that hierarchies do exist. Before finally breeding in 2007, 08 was always dominant among the non-breeding males, and it now seemed that 5R was exerting dominance over younger 32.

13th May

It was now three weeks since 5N had laid, meaning the birds were over half way through the incubation period. On 13th May at least three different Ospreys intruded at the nest, forcing 08 and 5N to give chase on a number of occasions. In Scotland there have been several examples of eggs being broken during aggressive intrusions by non-breeding birds, but thankfully the three intruders - 5R, 32 and another bird - did nothing more than circle over the nest. The photo on the right shows 32 and 5R during one such intrusion.

19th May

Although young Ospreys usually do not breed until they are at least three years old, most return to their natal site for the first time as two year olds. In 2007 30(05), a female who fledged from the Site B nest in 2005, returned to the reservoir in mid-May and was then present until early September. We had hoped that she would return early in 2008 and perhaps even breed - as her sister, 5N, did in spring 2007. However by early May she still had not returned and we suspected the worst...perhaps she had died?

But then, some great news! At lunchtime on 18th May, 5R was joined by a female. And yes, it was 30!

26th May

It was now day 34 of incubation, and excitement was growing. We knew that the clearest indication of hatching would be when the female offered fish down into the nest cup for the first time. With this in mind, all eyes were firmly fixed on the nest every time 08 arrived back with a fish. Not that fishing was proving particularly easy for 08. Strong winds and heavy rain combined to make spotting fish very difficult in the days leading up to expected hatching. Wind and rain not only disturbs the surface of the water, but it also churns up sediment from the reservoir bed, making the water much less transparent, and fish far more difficult to catch.

3rd June

With hatching apparently imminent, expectations were high. We hoped that the first egg might hatch on Thursday 29th May, and by the weekend at the latest. Thursday and Friday passed with no obvious change in the adults behaviour, but on Saturday morning, the female became very restless on the nest. Maybe a chick was hatching? 08 spent much of the morning fishing; perhaps spurred into action by what he had seen in the nest. The female continued to stand up on the nest at regular intervals, and then shortly after lunch time the male arrived back with a fish. Was this to be the magic moment? After eating the head, 08 flew to the nest. Everyone in the hide collectively held their breath, hoping 5N would remain on the nest and offer fish down into the nest cup. After a few moments though she flew off with the fish and the male settled back down on the nest. Never mind we thought, maybe the chick was not yet out of it's shell? A few hours later 08 went fishing again. Surely this would be the moment? After half an hour he returned to the nest with a small perch. He quickly consumed the head before flying to the nest. Once again though, the female flew off with the fish. Despite several more fishing trips 08 failed to catch any more fish that evening, and when the birds continued to change-over at regular intervals, we came to the conclusion that if a chick had hatched, it must have died soon afterwards.

Throughout Sunday 1st June the birds continued to incubate; but this was not overly surprising since Osprey eggs usually hatch two days apart. Maybe a second egg would hatch on Monday?

Sure enough, on Monday morning the nightwatchmen reported that the female was very restless shortly before 6am. She continued in much the same vain for much of the morning and 08 eventually arrived back at the nest with a large trout. Once again though, the female did not offer any fish into the nest. Although she continued to sit very high in the nest for much of the afternoon, a posture more typical of a brooding bird than an incubating one, 08 did not bring any more fish to the nest, not helped by heavy rain. Without the aid of a camera looking into the nest, we could only speculate as to what had happened, but the behaviour of the adults suggested that on both occasions a chick may have died soon after hatching.

18th June

It was now 58 days since 5N had laid the first egg, but both birds were continuing to sit tight. 08, in particular, showed no signs of giving up - flying straight to the nest whenever 5N left it unattended. 5N appeared the more restless of the two, but continued to sit low for long periods. Now almost three weeks after expected hatching date, we could only assume that the birds were incubating a failed egg.

29th June

70 days after she laying the first egg, it became clear that 5N had finally given up on incubation. Despite this she was rarely absent from the nest, and 08 continued to provide a regular supply of fish - helping to maintain the pair bond. 08 continued to 'incubate' at regular intervals for the next week - but eventually he too gave up.

17th July

By mid-late summer, non-breeding Ospreys are less tied to their territory and will often visit near-neighbours. As July progressed this resulted in a series of spectacular squabbles in Manton Bay. First, on Monday 14th July, 08, 5N and 5R (who continued to hold territory on the artificial nest on the south side of Lax Hill) were joined in the bay by three other birds; 09(98), 32(05) and an unringed female. This latter bird, probably a youngster from Scotland, arrived the day before and created quite a stir among the unattached males. The six birds spent several minutes circling together over the nest, providing an unforgettable experience for onlookers in Waderscrape hide.

Then on Tuesday morning, came an even more exciting few minutes. Shortly after 9am, 08 flew off east, presumably in search of fish. He was followed a few moments later by his mate, and for an hour or so there were no Ospreys in view - instead visitors to Waderscrape hide were entertained by a pair of Water Rails with their tiny week-old chicks - their second brood of the summer.

For the next ten minutes the two females became embroiled in aerial combat - DE's attempts to land on the nest thwarted by a series of spectacular stoops from 5N. 5R meanwhile had retreated to another nearby perch and was watching on with interest. Finally 08 appeared with a newly-caught trout . Rather than chasing the intruders though, he merely settled on the fallen poplar close to the nest and tucked into his meal!

7th August

08 and 5N continued to spend most of their time in Manton Bay, usually perched close to the nest. 08 generally caught two large trout (see photo on right) each day - normally eating the head before presenting the remainder to 5N.

18th August

Intruding Ospreys continued to make frequent visits to the nest during August. On 12th August three year-old Rutland female, 30(05), attempted to land on the nest (see photo on right). Amazingly 5N made no attempt to drive her away, and 08, not sure quite how to react, brought a clump of nest-lining to the nest! After five minutes though 30 took off again, and was followed away from the nest by 08 and 5N.

Many Scottish females leave their nest in early August to begin the long migration to West Africa. In autumn 2008 Roy Dennis had satellite radios on three adult females as they flew south. One, Beatrice, left her nest in Morayshire on 10th August and, after spending several days in northern England where she was held up by bad weather, she reached southern Lincolnshire on 15th August. After roosting in a wood to the north of Bourne, she changed course and headed directly towards Rutland Water next morning. The volunteers watching the Manton Bay nest were alerted, and sure enough, shortly after 1pm she landed on the nest! Although 08 and 5N were absent when the intruder first arrived, 5N had obviously seen her drop-in and soon returned to chase her off. The two birds headed south, followed by 08.

Satellite transmission showed that Beatrice then caught a fish at Eyebrook reservoir and roosted nearby. Then next morning John Wright found her eating a fish close to the reservoir (see photo on right). Around midday she circled high, still grasping the partially-eaten fish, and headed south. Two hours later she was passing Bedford, and by evening she had reached Surrey.