Growth of the Osprey Pandion haliaetus
population
in the Orleans Forest 1984 - 2005
data collected by "les Naturalistes
Orleanais" 1985 - 1994, and by Rolf Wahl from 1995 unwards
graphs made by Ruud Kampf
no use without permission!
(E-mail: rowahl@rekel.nl)
2005 |
occupied
nests |
succesful |
nr of young |
nr of young per nest |
nr of young per succesful nest |
total young
produced |
Orleans forest |
20 |
12 |
30 |
1.5 |
2.5 |
221 |
Chambord |
7 |
5 |
11 |
1.6 |
2.2 |
48 |
|
Essonne |
1 |
1 |
3 |
3.0 |
3.0 |
3 |
|
grand total |
28 |
18 |
44 |
1.6 |
2.44 |
272 |
The nest in Esonne was a new "starters colony" in 2005,
| no use without permission! |
 |
|
The number
of breeding pairs is still growing, in 2005 with three "colonies" |
| no use without permission! |
 |
| |
The number of succesful nests ---
> nests with a fledged young birds |
| no use without permission! |
 |
| |
The number of young per year |
| no use without permission! |
 |
|
From 1985 to 2005
a total number of 272 young has fledged. |
| no use without permission! |
 |
| no use without permission! |
This fit of the number of occupied nests
shows that the population still grows with an exponential rate, partially because of the
influx of birds from the German population.
The
equation of the fitted model is:
Year_nests = exp(-314.228 +
0.15818*select(year,colony=1))
Since the P-value in the ANOVA table is less than 0.01, there is a statistically
significant relationship at a 99% confidence level.
lThe correlation coefficient equals 0.976366, indicating a relatively strong
relationship between the variables. The standard error of the estimate shows
the standard
|
| no use without permission! |
 |
|
The
breeding success is still good |
|
|
|
|
The spacial development of the population in the
Orleans forest from 1990
With many thanks to Rolf Wahl, specialist on Ospreys
in the Orleans Forest for the hospitality and company
When you find any information on Ospreys with colored
rings in France, please contact Rolf Wahl
(E-mail:rowahl@rekel.nl)
back to the Osprey index page
of Ruud Kampf
Home page Ruud en Kitty
Kampf
Email: ruud@rekel.nl
