Adults return and incubate eggsThe year got off to a good start when the pair of Ospreys that produced a chick in 2001 returned. The male 03(97) arrived back at the nest site on 23 March and was joined by the female ten days later on 2nd April. They spent most of the month together, improving the nest and frequently mating. Late in the month eggs were laid and incubation began. A very large team of volunteers joined project staff in round-the clock monitoring of the nest site and recording the comings and goings. The actual nest site remained confidential. |
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Above is the breeding female, having a break from incubation with 03(1997) just visible sitting on the eggs. |
During incubation the male did all the fishing, bringing an average of two fish per day to the nest. The female carried out nearly all the incubation, with the male taking over briefly while she fed in a nearby tree. The notes made by volunteers were analysed and compiled into an interesting report by Jody Ettema, a Dutch student who was working as a long-term volunteer with the project.> How much time did each of the pair spend incubating? How many fish did the male catch and bring in? The answers to these questions , and other interesting facts are on a separate webpage - please click here |
The nest fails
In early June, subtle changes of behaviour began to occur, though the female was still protecting the bottom of the nest against the frequent rain. Then on 5 June the female was seen tearing small pieces of fish and apparently presenting them to the chick or chicks in the bottom of the nest, convincing us that an egg or eggs had hatched.However, the weather was atrocious - five days of continuous heavy rain and unusually low temperatures. As early as 7 June there were no obvious signs of young being fed. By 9 June the adult female left the nest for longer periods than usual and the male did not replace her, leaving the nest unoccupied for an extended period. Sporadic and half-hearted bouts of incubation by both male and female continued until June 14 and by 17 the pair were absent from the nest vicinity for lengthy periods.
Osprey chicks are born weak, wet and relatively helpless. In Scotland heavy rain for as little as 2 to 3 days can lead to the death of the recently hatched young, even of very experienced adults. In such circumstances any dead young are quickly removed from the nest and the male and female often continue to incubate any failed eggs for up to two weeks.
In a statement to the press , Project Officer Helen Dixon, said:
Over the last few weeks both birds had been seen sharing incubation and last week we were confident that at least one egg had hatched. Since the recent heavy rain, the behaviour of the parent birds has changed. We are continually monitoring them and the nest for any sign that there may be a chick or chicks but we are not optimistic.
The timing could not have been worse as some of the roughest weather conditions coincided with the first few days when the chicks would have been at their most vulnerable.
Stephen Bolt, Anglian Water's Head of Environmental Standards, said:
We are still encouraged by the fact that for a second year running the same pair of Ospreys came back to nest. In nature you cannot expect every breeding attempt to be successful and this year's probable failure will not jeopardise the long-term aim of establishing a breeding colony of Ospreys in central England. We have also seen more adult Ospreys visit the reservoir this year than ever before, which does bode well for the future. As more males set up territories around the reservoir we can expect to see more nests being built.
03(97) and his female remained in the vicinity of the nest for some weeks with the male continuing to bring fish for the female. They maintained the used nest and there was also some frustration building in nearby suitable trees. Later the female was recorded briefly in the company of two of the non-breeding males but she kept on returning to her own territory.
By 3 September both 03(97) and the unringed female appeared to set out on migration.
An after-thought : the unringed female
As it turned out, the unringed female was not seen again. When she had first appeared in 2000 we had assumed that she was a young un-paired female and this view was maintained throughout the successful breeding in 2001. With the benfeit of hindsight another theory began to gain ground: perhaps she was an old female who called in at Rutland after an unsuccessful breeding attempt in Scotland in 2000. Her behaviour during incubation seemed to be that of an experienced bird but advanced age might be consistent with her having produced just one healthy chick in 2001 and perhaps only one very weak chick in 2002.