A vulnerable species
The Osprey has been eradicated!
Often sighted along French rivers and in ponds in the past, the osprey disappeared in the early 20th century. It is still present in Corsica, but only 4 pairs were present in 1974. Since then, with the protection status that has applied to birds of prey over the past 20 years as well as with the specific protection campaigns, the number of ospreys has slowly increased. Populations are also growing in many European countries.
The osprey’s demise resulted from its reputation as a fish thief and pond plunderer. It is the classification of the species as « harmful» within the framework of the May 7, 1883 Act, and the reward promised per killed bird, that resulted in their disappearance from mainland France. As is the case for all birds of prey, it was persecuted by fish farmers, fishermen, hunters and also egg collectors. In addition to the direct damage by shooting, entrapping and nest destruction, the contamination of the food chain by pesticides made matters worse. In view of the species’ low population density and its easy destruction (visible nesting grounds, slow flight), the nesting populations have completely disappeared in mainland France and neighboring countries: UK, Germany, Belgium, Italy, Switzerland. Caution is paramount as the threats are still very real.
While ospreys, like all living creatures, are exposed to natural threats, the main peril resides in human activities.
- Direct destructions: The persecutions (shooting, entrapping, nest destructions, egg collectors) have largely contributed to the osprey’s rarefaction and the disappearance of French nesting pairs. Although the number of direct destructions has significantly declined, they still occur.
- Disturbances: European ospreys are quite sensitive to human disturbances during their mating period (forestry, brazen photographers, tourism, navigation) because the persecutions that have victimized them for centuries have involved the individuals most fearful of humans. But while disturbed adults flee the nest, their eggs and offspring exposed to sunshine or cold temperatures are hunted by predators.
- Collision with man-made installations: collisions with power lines and the ensuing electrocutions are now one of the main causes of mortality.
- Pollution: pesticides and other pollutants jeopardize osprey reproduction.
- Abandoned fishing lines: this man-made threat is difficult to assess. The danger stems from fish that have broken the fishing line and that are easy prey. The lines can strangle and trap the birds who can be wounded by hooks or by swallowed lead sinkers.
- Available breeding sites are in short supply due to human presence.
Occasional egg-theft cases by such predators as corvids or seagulls have been observed. These cases occur when the adults do not defend their nest: either because they lack experience, or because human disturbances force them to abandon their nest. Martins living in wooded areas can also destroy osprey nests. Bad weather, rain and low temperatures can lead to failed nesting, particularly due to anthropic activities.
In North America, the osprey is regularly submitted to the thefts of the white-tailed eagle that it competes with for food (the white-tailed eagle can steal the osprey’s prey). The dead eagle owl and the raccoon can also be occasional predators. Currently in France, the sightings of white-tailed eagles and raccoons are rare, and, during reproduction periods, the dead eagle owl is not sighted near osprey sites.
The National Action Plan (2008 – 2012)
Within the framework of France’s international engagements, the Ministry of the Environment has decided to implement national action plans. The global objective of the plans is the improvement of knowledge so as to strengthen the conservation of threatened fauna and flora species. The choice of species is based on the following criteria: threatened natural heritage on the national scale and France’s heritage responsibilities.
The very limited populations of ospreys have required the monitoring and protection of nesting pairs, and an initial national restoration plan was entrusted to LPO from 1999 to 2004.
The assessment of the actions of this first national restoration plan revealed positive results and the need to pursue such efforts. A second national action plan was therefore implemented in March 2008, validated by the National Nature Protection Council (NNPC) (Comité National de Protection de la Nature (CNPN), where the technical responsibility was entrusted to LPO Mission Rapaces by the Ministry for Ecology, Energy, Sustainable Development and Land Use Planning. This national action plan covers 5 years, from 2008 to 2012. The focus of this second plan is the consolidation of current population groups and the support of natural recolonization of new sites so as to create a viable population at a national scale in the long term.
A website dedicated to this national action plan is available to all stakeholders. If you are interested, contact LPO Mission Rapaces.
Monitoring and Protection
In Corsica, the birds can be found on the western coast where they were moved in the 20th century. The north-west region of the island was never deserted and was the last shelter of the species in the 70s. No change within the breeding population has been observed since the 90s. Since the early 90s, the Corsican osprey population has increased slightly: 20 pairs reproduced in 1993 and 29 in 2009. We have also recorded that the average reproduction rate of nesting pairs in Corsica declined between 1977 and 1989. This decline is due to the increase in the number of pairs (Tariel & Thibault, 1996). The evolution is however somewhat chaotic, as demonstrated by the 1996-1997 demographic disaster. The high annual variability rate detected can be explained by the saturation of available sites and the intraspecific competition that this generates..
In continental France, the distribution area of the osprey population covers two main sites in the central regions of the country: Orléans forest (45), and Chambord forest (41). Other departments of the Centre region, such as Indre-et-Loir and Cher, are visited during reproduction periods. Isolated reproduction cases have been regularly observed over recent years. In Ile de France (Paris area), a pair nested in a protected site where it has reproduced more or less successfully since 2005. In Lorraine, a pair elected domicile in 2007 and has since 2009 encouraged its juveniles to take flight. In the Landes, birds are often sighted during migratory stopovers and sometimes during the nesting period. There are many sightings of ospreys throughout the territory during the migratory period.
Since 1995 in mainland France, the Natural History Museum in Paris has provided metal bands for chicks. These chicks can be also recognized via colored bands, for remote identification purposes. Some adults, fitted with metal but colorless bands, are sometimes captured to determine their point of origin.
Every year naturalists with binoculars identify many bands and also determine the identity of each bird. Band readings have also enabled the identification of migratory itineraries and wintering sites. See the articles on "Contrôle au Sénégal - Alauda 2006" (PDF 300 ko) and "Reprise au Senegal - Alauda 2006" (PDF 110 ko)
Data analysis has mainly enabled the identification of characteristics, such as the age at the time of the first reproduction period, pair formation, survival rate, and so on.
See the article "Dynamique de population - Alauda 2005" (PDF 400ko)
« In the Centre region, I began to study the osprey in 1995, supported by LPO Mission Rapaces and in partnership with ONF region Centre (National Forest Office), the CRBPO, Orléans Naturalists and the Pandion Group. This small dynamic group is composed of confirmed ornithologists who are dedicated to the species’ conservation. The group meets during breeding periods to prepare “special operations”, such as colored band readings, or to organize searches for potential nesting pairs. The study is based on the biology, ecology and expansion of the species. From the end of February to early August, the group is busy in the field with daily tours of the known sites of the Orléans forest. The objective is to collect useful data: the arrival dates of the birds, egg-laying, hatching, monitoring of the health of juveniles until they are fitted with bands at approximately 6 weeks after hatching, and on their first flight before departing for their wintering sites. Sightings are always remote (except for banding). In this context, « Admitted » means that the birds did not flee when observed. The distance can vary with individuals and according to the stage of their reproduction period. Generally, 250 to 300 meters are enough to observe them without disturbing them ».
Remember to read the bands!
During spring and fall migrations, many European ospreys fly over France and stop to rest in secure sites for more or less long periods of time. Several banding programs are underway in Europe. Band readings yield precious information on the birds’ point of origin as well as crucial data for the study of population dynamics. This is how we have learned that the population of the Orléans forest is composed of many ospreys from Germany.
In Germany, some 600 juveniles ospreys are fitted with bands every year. Pay close attention to the bands of these birds and always take note of the leg where you were able to read the code on a colored band. To make band reading easier, choose a perched bird while it enjoys fish.
German colored bands:
Artificial nesting platforms
The osprey’s nest is an imposing structure. Its construction and its location are crucial to successful nesting. Artificial nesting platforms are proposed to the birds to encourage them to colonize new environments and to form pairs.
Juveniles nesting for the first time often prefer old empty nests. Others, who do not find favorable nesting sites, postpone reproduction. The construction of artificial nesting platforms therefore encourages a part of the summering population to nest, and mainly juveniles who are inexperienced and often arrive too late to find available space. Furthermore, ospreys nest among other colonies as the presence of birds and nesting sites contribute to retaining passing birds. Ospreys are reluctant to colonize sites where there are no individuals of their species (intraspecific attraction). The presence of several nesting sites on a decoy site encourage the birds to populate them more readily. In the Orléans forest, the availability of artificial nesting platforms has contributed to retaining German ospreys and has had a positive impact on population dynamics.
To determine the optimal location of the nesting site that must satisfy the ecological requirements of the species, and to assess the quality of the environment, artificial sites are installed on the basis of an expert opinion.
Some environments can be home to osprey breeding populations. In order to assess the potential reception capacity of such sites and to examine their development requirements, specialists conduct expert assessments at the request of site managers. Based on the results of the expert assessment, site managers implement their recommendations to promote the installation of pairs: building artificial nesting platforms, preserving the right trees, limiting disturbances, and so on.
In France, ospreys visit many sites during their migratory period. This is however not the case during the reproduction period (May to July). Everywhere in France, on so-called favorable sites, monitoring is crucial to detect the possible presence of pioneer pairs.
A standard sighting form is used to report such findings.
Knowledge improvement is one of the priorities of the national action plan.
Research is more specifically focused on population dynamics, where parameters are examined on the basis of banding and field monitoring data. A summary of available knowledge has been published in Alauda.
More research is ongoing, managed by the Orléans Natural Science Museum and is focused on ecotoxicology and diets (see "Balbuzard info 20/21" and "Rapaces de France 2010")