Interview with Bernard Joubert about the Short-toed Eagle in FranceDate of the interview: 24 January 2010 The Short-toed Eagle is a fascinating raptor with a very interesting biology. In this interview, Bernard Joubert talks about the current situation of the Short-toed Eagle in France.
Bernard Joubert: The official National Raptors Census Count for 2000-2002 states, using statistical analysis, an estimated 2600 pairs (2400-2900). Meanwhile, data gathered non officially through the reading of regional Avifauna writings and by consulting specialists working on the subject, has wielded other – and I think more accurate – number nl. 1818-2480 pairs. A sensible estimate would thus be about 2400 pairs. This represents appr. 40% of the western Europe’s total number. As to abundance, France takes second place after Spain. Markus Jais: How has the population developed during the last decades ?
Bernard Joubert: Considering the lack of previous precise census, we can list only a general trend. Near the end of the 19th century, the huge human presence in our country left but a small place for Short-toed Eagles. After the Great War, many people left for the bigger towns, leaving thus more room for the birds. This exodus continued until the beginning of the ‘70s, and even ‘80s in some areas of Massif central and the alpine foothills. Meanwhile, after the Second War, the impact of hunting has increased due to improved guns and more leisure time. The raptors were considered a nuisance. During the last 30 years, we witness an increasing population of Short-toed Eagles - a hard won result of a necessary conservation campaign. Recently, some attempts at breeding, successful or not, have been observed north to the Loire, in those regions from which the species had dissapeared. Markus Jais: Where are the most density populated areas in France ?
Bernard Joubert: Simplifying, the area of geographical distribution covers the southern half of France. But naturally, the birds are not evenly spread throughout these 250000 km². Most favoured are regions bordering the Mediterranean : southern Alps - Provence - Sud Languedoc-Roussillon - eastern Pyrénées, and also a large arc south-east of the Massif central. In other words: regions of medium mountains, warm and hilly.
As to population density, it is the region of the Massif central that has been more widely studied. Thus, the most remarkable densities can be found south of this Massif (Hérault), and in Lozère and the Gard (6-9 pairs to 11-12 pairs per 100 km²). In my department (county) - la Haute-Loire -, centre-eastern part of the Massif central, density varies from 8-11.5 pairs per 100 km² to some exceptional "hot-spots" of 1 pair per 2.3 to 4.3 km². It seems only natural to imagine that densities just as high, or even higher, exist in certain areas like the Provence hills and the southern fringe of the Alps. Markus Jais: How has the intensification of agriculture affected the Short-toed Eagle in France?
Bernard Joubert: Looking at the distribution zone in France, there are gaps. This coincides with intensive farming and foresting (Bassin aquitain). On the other hand, the most densely populated spots coincide with areas of lesser agricultural activity and/or extensive herding. The Short-toed Eagle likes patchwork habitats. Formerly, a small part of the species nested in the northern half of the country. Distribution limit has receded due to modern farming methods and development of one crop cultivation. There are no longer snakes. It should be noted that isolated population group about 50 pairs survives in the North, not surprisingly in a region with varied farming methods. Markus Jais: How many birds are electrocuted ?
Bernard Joubert: The most dangerous electric wires for Short-toed Eagles are those of the medium-voltage network. In this country, more than 140.000 km are not buried underground. An example : in one area of 230 km² in the South, a study has revealed the death of 21 birds in 9 years (1988-1996). That is 17% of all diurnal raptors killed this way. This area is rather special in that it’s almost without trees and thus, the only possible roosts are electricity poles.
Among the 60 cases of mortality noted since 1996, 25 were caused by the power network of which 9 were due to electrocution and 16 due to impact with the wires.
Short-toed Eagle, © Bernard Joubert
Bernard Joubert: No year goes by without its load of complaints about shooting. French hunters live up to their bad reputation.
Nevertheless, one has to admit that destruction by guns has decreased enormously during the last 40 years, following nature protection laws and a real effort to inform the public. Attitudes have changed but it is necessary to stay alert. Frequently hunters ask that certain raptors be taken from the list of protected species. Moreover, it is very difficult to judge and impose a fine on someone who has destroyed a raptor. Markus Jais: What other threats do exist for the species ?
Bernard Joubert: At the moment, a major danger is deterioration of habitat caused by changing agricultural methods and growing urban sprawl. Add to that, a considerable development of motorized sports (bike - quad) and other outdoor leisure activities (hiking etc.). Biotopes are becoming ludotops. This phenomenon becomes more and more widespread as the size of unspoiled places diminishes and the number of nature consumers augments. Moreover, logging provokes each year destruction of nests and broods. Markus Jais: Snakes are the most important food for Short-toed Eagle. How is the conservation status for snakes in France ?
Bernard Joubert: 12 different species of snakes can be found in France, of which 4 are vipers. Two of these have a very limited geographical distribution, and are probably not often caught. Officially, all species are fully protected by the law, with an exception for Vipera aspis and Vipera berus (no taking, no holding, no selling). This does not stop wilful destruction, however. But the main problem encountered by the snakes is the destruction or the modification of their habitat. No region harbours all of the species. The presence of Short-toed Eagles is related to abundance of prey, rather than to specific diversity of this prey.
Meandre de la taillide, © Bernard Joubert
Bernard Joubert: There is no simple answer possible to this question. Obviously, the Short-toed Eagles catch the prey that they can find, which means that is abundant ! But, from one region to another, this need not mean the same species. An example : in Haute-Loire, the Short-toed Eagle can be divided in two distinct population groups. One in the Loire valley, and one in that of the Allier. These are "twin" valleys, in that they are running almost parallel, and both are axed north-south. In the central part of the department, only 25 km separates them. Nevertheless, in the west (Allier), the main prey is Elaphe longissima and Vipera aspis, while in the east (Loire), it is Natrix natrix and Coluber viridiflavus. This phenomenon can be explained by the absence, or small numbers, of Elaphe longissima in the Loire valley and of Coluber viridiflavus in that of the Allier. Not that far from those two areas, in Lozère, the main prey is Elaphe longissima and Coluber viridiflavus, while going to the South-west it is Natrix natrix. It has to be stressed that capturing venomous snakes is not a problem for Short-toed Eagle. In certain departments, vipers account for 26% of their food intake. The impact that the Short-toed Eagles have on snake population is important. When in Europe, a pair raising one young successfully captures 700 to 800 snakes in 6 months time. Jean-Pierre Malafosse estimates that some 150.000 snakes are taken over 6 months by the 250 pairs nesting on 4.000 km² in the Cévennes. Markus Jais: What other animals do Short-toed Eagles prey on in France and how important is that prey for the eagles ?
Bernard Joubert: In France, snakes make up 71 to 96% of their diet.
Other prey are mostly lizards: Lacerta viridis, Lacerta lepida, Podarcis muralis, Anguis fragilis. In my area of observation, some pairs catch often Lacerta viridis because the species is abundant, as well as Anguis fragilis when the weather is bad.
Some 5% of prey are not reptiles. Among these, figure mammals such as Mustela nivalis, Mustela erminea, Erinaceus europaeus, Rodents. Less often, one may find batrachians (Bufo bufo) and, exceptionally, birds. Insects (Orthoptera, Mantis) are taken at times, especially by young birds before autumn migration. Markus Jais: Is it known (for example via ring recoveries or satellite telemetry) where french Short-toed Eagles spend the winter and which migration route they take ?
Bernard Joubert: A few birds have indeed been tracked by satellite telemetry, for the first time in 1995 by Meyburg. These data did confirm wintering sites that we knew existed. They made it possible to define the exact routes taken by the birds. France’s Short-toed Eagles go to Africa by way of the strait of Gibraltar. They go south following and keeping close to the maroccan Atlas, then they cross the Sahara. Finally, they arrive in the sahelian zone between the 20th and 14th parallel. Some continue into the sudanian zone until the 11th parallel. Their wintering area consists of a 1000 km large and 6000 km long strip between Senegambia and the lake Tana in Ethiopia. Birds coming from France probably winter in the West of Africa. They even go as far as the longitude of lake Chad. Contact with birds coming in from the East by way of Suez and Bad Al Mandab must take place near the 15° east meridian. Markus Jais: Are there any conservation programs for the species in France ?
Bernard Joubert: Short-toed Eagle is a fully protected species in France. Stability and number of population make a special conservation program unnecessary. I do hope that this will always be the case because ecological demands and specialization of the Short-toed Eagle would make this quite impossible to do. Jean-Pierre Malafosse and I have created a national wide surveillance network. One of its tasks is to detect possible lowering of numbers and to identify the causes. The network consists of some 40 people, of whom 10 very active members. LPO’s Raptor Mission helps us publish a newsletter. We’ve already organized two meetings. During the last one, Italian (Petretti) and Spanish (Yanez Vega) colleagues joined us. Markus Jais: How do you see the future of the Short-toed Eagle in France ?
Bernard Joubert: Immediate future: quite good. Distant future: bad.
French population numbers are rising. We are now 63 million, which means 26.250 French people for 1 pair of Short-toed Eagles! And we will be more. Politicians and economists applaud these rising numbers and present them as a victory. But in fact, it’s a sign of failure, a disaster for nature. Each day, we trample a bit further on the habitat of neighbouring species. But Short-toed Eagles need a lot of space to survive. I’m conscious that right now the situation is improving for the birds, but I know this cannot last for ever. Markus Jais: What was your most amazing experience with Short-toed Eagles ?
Bernard Joubert: Each year, I have this habit of paying a "polite visit" to the young in their nests. These visits take place when the parents are not there.
One day - while I had just approached the nest, and my face was about 50 cm from the young bird -, the female arrives at the nest without noticing me. She stays there for a few seconds, and then she turns her head in my direction. Instead of taking off in a hurry, she fixes me without any fear. More surprised than she, I spoke a few words to her (I use to speak to birds…). This magic moment probably was shorter than it seems to me. Without any hurry, she went to the edge of the nest and took off. She hovered over me during the time it took me to climb down the tree. Hardly on the ground, I noticed she had landed next to her young without paying any further attention to me. It has happened to me to climb a tree in company of a squirrel. Or to wait for a stag to leave before climbing down - but never before had I actually started talking to a lady snake eagle, 10 meters above ground! (my wife said I must see a psy…) Markus Jais: Bernard, thank you very much for the interview