Orn. Anz. 41: 119-134

ARROYO, B. , GARCIA, J. T. & V. BRETAGNOLLE: Conservation of Montagu's Harrier Circus pygargus in agricultural areas.

Montagu's Harrier Circus pygargus is probably the most characteristic raptor of agri-cultural habitats, as it breeds nowadays mainly in cereal crops in western Europe. This habitat shift from the original grasslands implies that changes in this man-made envi-ronment are most likely to affect it. Montagu's Harrier reproduction is mainly depend-ant on food supply in natural conditions, so biodiversity decline in agricultural areas might affect harrier sustainability in the long term. Additionally, combine harvesters may kill harrier nestlings if unfledged at harvest time. In western Europe (which holds the stronghold of the breeding population, excluding Russia), an average of 60% of nestlings in agricultural areas could perish like that in the absence of conservation measures. There is therefore a need for developing sustainable and efficient conserva-tion plans. Such measures should include some directed to maintaining food supplies, as well as some directed to minimise impact of harvesting activities on harrier produc-tivity. We review current conservation techniques and resources used in France and Spain, and explore with simulation techniques ways of optimising conservation effort. Large scale agro-environmental measures should be implemented for maintaining food supplies. Protection of harrier nestlings from harvesting activity, in contrast, should be optimally implemented through a network of relatively small protected ar-eas. Promoting protection of natural vegetation areas, identifying and protecting the most productive and stable colonies in agricultural areas, and testing experimentally factors that are likely to attract and maintain harriers in protected areas should be prioritary in the short term.

Orn. Anz. 41: 87-92

BELTING, C. & R. M. KRÜGER: Population development and strategies for the protection of Montagu´s Harrier in Bavaria (Populationsentwicklung und Schutzstrategien für die Wiesenweihe Circus pygargus in Bayern).

The Montagu´s Harrier population in Germany is estimated at 250 breeding pairs. Approximately a third of them are located in Bavaria. The main population is found in "Mainfranken" with 70 pairs (in 2001). Besides some isolated pairs a smaller second population can be found in the "Nördlinger Ries" (6 pairs in 2001). The population in "Mainfranken" started with two pairs in 1994 and has grown continually since then. Except for a few pairs all of them breed in cornfields. From 1994-2001 164 out of 236 broods were successful. 539 young hatched. In Mainfranken, Montagu´s Harrier breeds in a region with open fields and only slightly elevated relief. Mainly cereals and sugar beets are cultivated in this region. These are low-precipitation areas, warm in summer and with fertile soil. The nests are protected against falling stalks by metal racks. Additionally the stalks are cut around the nest in a radius of one metre. The pulli are ringed.

In 2001 we started marking the young with coloured wing-tags on which we wrote consecutive numbers. If the pulli are not fully fledged when the grain harvest starts, the farmers are asked to leave a space of 50 x 50 metres with the nest in the centre. The crops are not reaped until all young are hatched. The "Naturschutzbehörde" (board for nature protection) compensates the farmers for extra time and the loss of crop. The compensation amount is usually 1278 Euro per hectare. The compensation agreement in the name of the Free State of Bavaria with the farmer is reached by the nest protectors.

Orn. Anz. 41: 143-158

CLARKE, R.: British Montagu's Harriers - what governs their numbers?

In Britain, the status of Montagu's Harrier Circus pygargus has remained tenuous over the past few decades, whilst the Marsh Harrier C. aeruginosus population has grown considerably. Is breeding effort of Montagu's Harrier in Britain governed by factors in breeding or wintering areas? Breeding attempts can go unnoticed in arable farmland, where harvesting is a threat and increased use of silage grass fields for nesting has made the species vulnerable to early cutting. However, despite close protection from farming operations, and a mean fledging rate in a core area for the species in Norfolk (2.19/started nest) comparable to those on mainland Europe, numbers show no sign of increase. The prey base is currently mainly avian in Britain; the Skylark Alauda arvensis is the most important prey. This is in contrast to the vole-rich diet in, for example, the Netherlands where protection has seen a sustained recovery in numbers. The principal vole in Britain, Microtus agrestis, is a surface-dwelling animal and therefore more vulnerable to agricultural practices than the continental, burrowing M. arvalis.

Montagu's Harrier specialises in locusts and large grasshoppers as prey on its win-tering grounds in both India and Africa. An individual harrier requires about 25 lo-custs per day. In the winter range, abundance of locusts and large grasshoppers is regulated by rainfall and vegetation growth. Over a period spanning 29 years, annual rainfall in the Western Sahel and numbers of Montagu's Harrier nests in Britain each following summer have shown positive correlation (rs = 0.38, n = 29, P < 0.025), providing strong circumstantial evidence that a link exists between drought and the weak breeding status of Montagu's Harrier in Britain. Do recent advances in locust control, including biological methods beginning to come on the market, add to threats to the winter prey base?

Orn. Anz. 41: 183-190

GARCÍA, J.T. & B. E. ARROYO: Population trends and conservation of Montagu's Harrier in Spain. In this paper we review the principal conservation problems for Montagu's Harrier in Spain and the actual knowledge of the current situation of the species. We also present some preliminary results of the Spanish national campaign for the study and conser-vation of Montagu's Harrier obtained from the two first study years (1999-2000). In Spain, the alteration of breeding and hunting habitats as well as the progressive intensification of agriculture seem to be the most important problems for the species. These problems, together with the lack of knowledge of the population trends at national level, could bring Montagu's Harriers into a dangerous situation at medium/long term.

We have found large year-to-year variations in breeding parameters (population density, productivity, and impact of harvesting). We also found large between-areas variations in these parameters. Different harrier populations seem to be spatially related, possibly throughout juvenile or adult dispersion. The harvesting phenology largely influences the probability of chick survival. We discuss the need for incorporating the spatial and temporal scales in our studies and to consider more efficient conservation actions than those that are actually used in Spain.

Orn. Anz. 41: 93-108

GÖTZ, S.: Brut- und Ernährungsbiologie der Wiesenweihe Circus pygargus in den Mainfränkischen Platten.

This study is about breeding biology and diet of Montagu's Harrier in Northern Bavaria. One pair of Montagu's Harrier was observed in one season (2000), pellets were collected and prey remains were included in the data of direct observation. 71% of the feeding was done by the male. The highest feeding rate was between 3 to 8 hours after sunrise, another peak was between 11 to 15 hours after sunrise; the female showed more activity in the morning. The number of food-passes on the ground or by flight was nearly equal, but the male had the tendency of passing it by flight, whereas the female preferred giving it to the young on the ground. The percentage of flight-passing increased during the whole period. Over 90% of the copulations took place after a food-pass. Nest building was done by the female, mainly in the breeding period (93% after food-pass) and nesting period (only 20% after food-pass). The diet consisted mainly of voles and birds, after hatching also of insects, whereas bird´s eggs, reptiles and amphibia made up only a small part. Before harvesting, diet contained more birds than voles, afterwards the amount of voles increased and the amount of birds decreased. The male preferred birds, even when voles were available after har-vesting while the female took mainly voles and insects. Foxes are of a great danger, especially after harvesting, whereas cats are easily chased away by the harriers.

Orn. Anz. 41: 201-206

HÖLKER, M.: Beiträge zur Ökologie der Wiesenweihe Circus pygargus in der Feldlandschaft der Hellwegbörde/Nordrhein-Westfalen (Contribution to the ecology of Montagu´s Harrier in the agraric landscape of the Hellwegbörde/North-Rhine West-phalia). Sorry, no abstract: Paper was received late and space was very limited.

Orn. Anz. 41: 167-174

KITOWSKI, I.: Present status and conservation problems of Montagu's Harrier Circus pygargus in Southeast Poland.

About 95-105 pairs of Montagu's Harrier Circus pygargus nested in the area of SE Poland in the 90ies, which constituted approximately 8% of their total population in Poland. 25-30 pairs nested in the Lublin Upland, 45-51 breeding pairs in the area of Polesie Lubelskie and 20-30 breeding pairs in the Leczna-Wlodawa Lake District. In the Masovian part of SE Poland and the southern agricultural part of the region (Tar-nogrod Plateau, Pobuze) 2-3 breeding pairs are known. The complex of calcareous marshes near Chelm (51°08' N, 23°37' E) played the pivotal role in the occurrence of Montagu's Harrier in SE Poland. In 1985-1988 there were 32-42 nesting pairs. In the following years this population decreased rapidly to a remaining 14-20 pairs.

The main conservation problems are created by a radical increase in the population of foxes Vulpes vulpes and some corvids which resulted in increased cases of preda-tion. Another real threat is the recession in the agriculture sector leading to loss of regularly mowed meadows and pastures which are foraging areas of Montagu's Harriers. Human infrastructure led to fragmentation of the hunting area of Harriers.

Orn. Anz. 41: 191-200

KITOWSKI, I.: Trends in parental care of Montagu's Harrier Circus pygargus during post-fledging period - case study from South East Poland.

The trend in post-fledging parental investment was studied in 14 families of Montagu's Harrier Circus pygargus with colour-marked juveniles. As the young grew older the parents spent less time with them, made fewer approaches towards them and fed them less frequently. The frequency of chasing away intruders by the adults and their ag-gressiveness towards them decreased as the young became more self-dependent. Col-lected data suggests that the major reduction of parental contribution took place at the beginning of the post-fledging period and that the juveniles are gradually introduced to independence. Recorded cases of adults diving at their young and refusing to provi-sion them with prey suggest the existence of parent-offspring tensions during the post-fledging dependency period.

Orn. Anz. 41: 159-166

KOKS, B. J. & E. G. VISSER: Montagu's Harriers Circus pygargus in the Netherlands: Does nest protection prevent extinction?

The Montagu's Harrier used to be a common breeding bird in the Netherlands. During the second half of the 20th century a massive decline took place due to the fact that natural habitats like peat-moors and heaths were destroyed, and another important breeding-habitat - the dunes - deteriorated. In the nineteen-fifty's only 250 pairs were left and at the end of the eighty's the species had become almost extinct in the Netherlands (Bijlsma et al. 2001). Due to set-aside-regulations of the EU, as part of the Common Agricultural Policy of reducing the amount of grains, thousands of hectares of arable land were laid fallow. Montagu's Harrier benefitted from this development, and from 1990 onward the Dutch population increased and between 26-45 pairs were found in the period 1990-2001 (Koks et al. 2001).

In this paper the population-development between 1975-2001 and the effect of nest-protection in crops are described, the general results of our diet-research in combina-tion with measurements to improve the quality of the arable land for the birds.

Orn. Anz. 41: 175-182

MRLÍK, V., HRUSKA, J., POPRACH, K., SUCHÝ, O., VESELÝ, J. & O. ZÁVALSKÝ: Breeding distribution, population size, dynamics, ecology and protection of Montagu's Harrier Circus pygargus in the Czech Republic.

Montagu's Harrier can be classified as a species regularly breeding in the Czech Re-public, with the actual population size of about 50 pairs, but the breeding population size shows considerable year-to-year fluctuation (min. 3-5 pairs). It is a raptor species with a stable population trend, yet a decline cannot be excluded. The species can be considered to be permanently threatened in the territory of the Czech Republic.

In recent years (1991-2001), most nests have been situated in agricultural landscapes (88 %), rarely in semi-natural habitats such as dry or wet grasslands, meadows and/or reeds in the vicinity of fish-ponds (n = 90). In the past 11 years (1991-2001) the pre-ferred altitude for nest sites was below 300 m (56 %). 20 % of the nests were situated at elevations of 301-400 m, and 24 % at 401-500 m (n = 50). In a single case, Montagu's Harrier nested successfully at an elevation of 610 m (in 1978). In the Czech Re-public, Montagu's Harrier is mainly a solitary breeder. Rarely, gregarious nesting of several breeding pairs was registered in some localities. In a rather small area, their nests were at least 15 m apart, and invariably the colony did not exceed 4 pairs. Our long-term estimate of the average breeding success is 1.5 young per commenced breeding (n = 151), or 2.9 young per successful nesting (n = 80, 1929-2001). In our experience, unsuccessful nests are more frequently due to natural losses (70 %) than to man-made ones (n = 54). Most of the natural losses include nests destroyed by terres-trial predators, and abandoned clutches. The man-made losses included destroyed eggs or young, one or both breeding partners killed (shot), and nests destroyed during harvest of field crops.

Protection of individual nests of these raptors needs, above all, co-operation with land owners (farmers, fish-pond managers). To prevent losses caused by terrestrial predators it is advisable to apply such repellents as carbolic acid or naphthalene to occupied nests. Further ways of protection are discussed.

Orn. Anz. 41: 135-142

RATTINGER, K.: Vorschläge für die Erarbeitung eines Bewertungsschlüssels für agrarisch geprägte Lebensräume der Wiesenweihe Circus pygargus.

Montagu's Harriers criteria for the choice of certain breeding places in farmland are not known for sure yet. Due to this fact investigations in a breeding area near Würzburg/Bavaria have been made. Results of a study on landscape and landuse in this breeding area and a comparison with results of some further publications show the necessity of using common criteria in future investigations for finding out landscape characteristics of breeding areas. Such investigations may lead to a development of a valuation key of farmland for improving suitable breeding areas. A catalogue of com-mon criteria is proposed finally. In addition some examples of characteristics of the analysed breeding area are shown in maps.

Orn. Anz. 41: 109-118

TÓTH, L.: Historical and recent distribution, population trends and protection strategies of Montagu's Harrier Circus pygargus in Hungary.

Montagu's Harrier was a regular but sporadic breeder in Hungary from the end of the 19th century. There are some traditional breeding areas such as the Hanság (West Hungary) and the wet meadows and swamps of the Kiskunság (the centre of the country). However, the population was never monitored in country level, thus we have no reliable data neither on the size and trends of the breeding populations nor on the breeding range of the species. During the 1930s the most considerable population bred in the Hanság where breeding of 20-25 pairs was registered. Presumably the population decreased to a minimum in the 1970s due to habitat destruction (extended wetlands were drained), hunting and the use of persistent pesticides as well as the use of poisoned eggs to decrease the number of Corvids. However, the numbers of Montagu's Harrier are on the increase at least during the last 25 years. Current population can be estimated at 250-300 pairs. Although breeding populations are rather localised the range of the species extends continuously. Pairs breed all over the country both in traditional habitats such as peatbogs, marshes and wet meadows as well as in grass-lands and in cereal crop lands. The population increase is characteristic in the eastern part of the country as the species has changed its nesting strategy and now occupies agricultural lands of the Great Plain for breeding. Shifting breeding area from the optimal habitat to cereal crop lands causes a considerable decline in reproductive output, because the second half of parental care coincides with the harvesting period when several broods are destroyed by mowing machinery. Owing to applied conservation measures - mainly on the Heves Plain - pairs breeding in agricultural lands are able to fledge almost all young.

Short notes also received:

J.-L. BOURRIOUX: Experiences with a program of wing-tagging adult Montagu´s Harriers. Orn. Anz. 41: 212-213

J. BÜHLMANN: Verbreitung, Bestandsentwicklung und Schutzstrategien der Wiesenweihe in der Estremadura (Spanien). Orn. Anz. 41: 215

J. C. CLARO: Perspectives for Conservation of Montagu's Harrier in Southern Portugal. Orn Anz. 41: 211

K. GABRIEL: Demands on expert´s opinions from the point of view of local and district authorities regarding interventions in habitats of Montagu`s Harrier. Orn. Anz. 41: 210

D. HOFFMANN: Wiesenweihe Circus pygargus in Schleswig-Holstein. Orn. Anz. 41: 209

J. KROGULEC: Distribution and population trend of Montagu´s Harrier Circus pygar-gus in Poland. Orn. Anz. 41: 212