Monitoring Corncrake Crex Crex Numbers in European Russia: the First Stage

Home , Pes (river), Rybinsk Reservoir, Unzha

Ornis Hungarica 12-13: 135-141. 2003

Monitoring Corncrake Crex crex numbers in European Russia: the first stage

O. V. Sukhanova and A. L. Mischenko

Sukhanova, O. V. and Mischenko, A. L. 2003. Monitoring Corncrake Crex crex numbers in European Russia: the first stage. – Ornis Hung. 12-13: 135-141.

The Corncrake is a widespread and common species in Russia. Because agricultural conditions in Russia are unstable, it is important to establish the Corncrake's current population dynamics through studies in pilot areas. Two types of repeated censuses have been carried out: 1. In 1994, there were censuses on pilot plots in 4 regions. These regions had been censused between 6 and 18 years previously, but researchers had used a variety of methods. 2. From 1995 to 2000, regular nocturnal censuses were carried out, using standard methods in pilot areas in 5 'key territories' holding Corncrake concentrations. The census years experienced varying weather conditions, such as spring flood levels and differing hay mowing sequences. The data obtained show that in the 1980s and 1990s in European Russia there was no tendency for Corncrake numbers to reduce, something that had been noted from the 1950s to the 1970s. It is extremely important that the present monitoring scheme continues and that a network be established of model areas in Russia to moni- tor Corncrake numbers annually and to track the changes in agriculture technology.

O. V. Sukhanova and A. L. Mischenko, Russian Bird Conservation Union, Shosse Enthuziastov, 60, bld.1, Moscow 111123, Russia. E-mail: [email protected]

1. Introduction determine Corncrake numbers in the past and to establish a network of monitoring areas. For the future development of com- In the long history of ornithological sci- plex pro-active conservation measures for ence in Russia, very little attention has Corncrake, it is very important to know been paid to studying Corncrake. Its the history of Corncrake numbers and breeding range is large in Russia, and it dynamics, initially in 'key areas' holding was assumed to be common everywhere concentrations of breeding birds. The except in peripheral zones and to have a main aim of this paper is to assemble the favourable conservation status; conse- first results of monitoring Corncrake num- quently it was not regarded as deserving bers in several areas of European Russia. special monitoring of numbers or dynamics. Specific surveys of Corncrake num- 2. Study area and methods bers in European Russia in 1995-1996 (Mischenko & Sukhanova 1999) have allowed the determination of the present In 1994, censuses of calling male and recent population sizes. However, to Corncrakes were carried out during the assess trends accurately, it is necessary to breeding season in pilot areas in 4 regions 136 ORNIS HUNGARICA 12-13: 1-2 (2003) of European Russia. In all these areas, Indices for Monitoring data). The squares counts had been made previously in the of all surveyed areas are represented in 1970s or 1980s. In the Vologda Region, the tables below. censuses were carried out in the One of the main aims of this research Kharovskiy District (60°15`N, 40°10'E). was to determine Corncrake population In 1970-76, part of the surveyed area had trends in the pilot areas, and in order to consisted of small, partly boggy meadows make valid comparisons with earlier data, overgrown with bushes either in a mosaic we could not use unified methods, but had of fields or between 'islets' of forest and to use the earlier methods. In all pilot bushes. Another part of the area consisted areas, the census of calling males was car- of meliorated meadows. From 1975 into ried out during the breeding season. Using the 1980s, the total area of meadows data from repeated censuses, below we increased significantly after further melio- present the highest density figures ration, which grubbed out forest and bush obtained. 'islets', producing a marked reduction in In the Vologda Region we used 2 sur- field areas. vey methods: route and plots. We In the Kostroma Region, the study area employed both once-only and repeated is in the Manturovskiy District (58°10'N, surveys, but without keeping to the exact 41°20'E) and is bounded by the Unzha locality. During a route census, the birds River in the southeast and by woodland in were recorded in a strip equal to the mean the northwest. 81% of the square has ele- distance of discovery (average vations 40-50 m above the river level, 150 m+150 m=300 m). For censuses on 11% of which are flood meadows. In the plots, the points where calling males had Novgorod Region, the census was carried been recorded were mapped. Surveys took out near the township of Lyubytino place in early morning (0300-0900) or in (58°50'N, 35°25'E) on dry grass/herb late evening (2100-2300). The 1970-1976 meadows, most of which are on elevated and 1994 surveys were carried out from ground. In the Moscow Region, the cen- 10-30 June. In 1994, the following tech- sus was carried out in the Lotoshinskiy nique was employed on large meadow District (56°15'N, 35°50'E) on `meadows squares; three people, moving parallel to in the valleys of the rivers Bolshaya each other at 50-70 m intervals, would Sestra and Lama. Three areas possessed count Corncrakes at the same time. The mainly flood-plain meadows (Solotcha, total width of the survey strip was 300 m. Dedinovo and Klyaz'ma), one (Zavidovo) In the pilot area in the Kostroma had only dry meadows, but another Region in 1982-1985, Grabovsky (1993) (Ilmen) held both types. Solotcha was mapped calling males on large plots, censused several times per season, but for where constant routes were followed dur- comparisons only the maximum numbers ing the night and in daylight (during the are taken. In the other 4 pilot areas the seasonal peak of vocalization). From 13- censuses were conducted only once per 15 July 1994, the census used Grabovsky's season, in the same way every year. The mapping technique and counting methods, analysis of the counts data was carried out being repeated at night (2300-0400). In with the TRIM 3 software (Trends and the Novgorod Region in late May and O. V. Sukhanova and A. L. Mischenko 137 early June 1984, E. S. Ravkin carried out a 2. Klyaz'ma flood plain (Vladimir bird route census that included the Region, 55°58'N, 39°30'E). Corncrake. Each route in the census was 3. Dedinovo flood plain, the left-bank 6 km long. The surveys were made in area of the Oka River valley early morning and late evening according (Lukhovitsy District of Moscow to Y. S. Ravkin's methods (Ravkin 1967); Region, 55°10'N, 39°18'E). the results were extrapolated to produce 4. Zavidovo Reserve (Konakovo District numbers per km2, based on the mean dis- of Tver Region and Klin District of covery distances, by the formula: Moscow Region, 56°27N', 36°17'E). 40a +10b + 3c 5. Ilmen Lake Lowland. Surveyed area K = was located on the northwest bank of Nkm , the Ilmen Lake (Novgorod District of where the Novgorod Region, 58°23'N, K - the number of individuals per km2 31°02'E), 20 km southwest of the city a - the number of individuals discovered Novgorod. at a short distance from the observer (up to 25 m) 3. Results b - the number of individuals in the middle distance (25-100 m) c - the number of individuals at a far dis- 3.1 Analysis of literature tance (100-300 m). In 1994, from 5-8 June, we repeated The first step in the determination of the surveys using the same method. Corncrake past and present distribution In 1987, 1988 and 1994 plot censuses and abundance in European Russia was were carried out in the Lotoshinskiy the analysis of literature on this species. District of the Moscow Region. However, the specific data on Corncrake Furthermore in 1994, a route survey was numbers or population density are very made on a strip 500 m+500 m wide and fragmentary and are presented in but a 1.9 km long. These censuses were carried scattering of papers published after 1945. out at least 3 times per season (from late It is difficult to make comparisons, May to early July) in the early morning because the authors had used different sur- (0400-0800) and late evening (2100-2359) vey methods that were poorly described. hours. The sources from the late 19th century From 1995-2000, for the first time in to the early 20th century show that European Russia, we conducted repeated Corncrake was a common or abundant night censuses using standard methods species all over European Russia (except with pilot areas in 5 'key territories' (de at its northern range boundaries), being facto IBAs) holding Corncrake concentra- most abundant on flood meadows. Without tions: producing any quantitative data, the 1. Solotcha flood plain, the left-bank area authors often gave very picturesque of the Oka River valley (Ryazan descriptions of this species' great num- District of Ryazan Region, 54°48'N, bers. Therefore, Bogdanov (1871) noted, 39°47'E). 'the flood meadows of the Kama and Volga 138 ORNIS HUNGARICA 12-13: 1-2 (2003)

Tab. 1. The results of the repeated Corncrake censuses with the Intel apse in several years in four regions of European Russia. Regions 1970-1976 1982 1983 1984 1985 1987 1988 1994 km2 dens. km2 dens. km2 dens. km2 dens. km2 dens. km2 dens. km2 dens. km2 dens Vologda 3.4 3.8 5.8 3.8 Kostroma 36.0 0.8 36.0 1.5 (flood-plain) Kostroma (dry 5.4 3.1 5.4 2.6 5.4 1.5 5.4 2.4 meadows) Novgorod (dry 1.1 70.91.1 meadows) Moscow 3.7 2.4 3.3 3.6 3.9 3.3

Rivers are the real Corncrake kingdom. It common species of the Darwin Nature is also numerous in all large and small Reserve, noting that it inhabits not only river valleys of the Volga basin. It lives in meadows but also tall weed growth at the Ilovlya, Medveditsa, and Khoper River former village sites. In the other regions valleys in great numbers'. Zhitkov & of European Russia such as Perm Buturlin (1906) wrote that the air on the (Vorontsov 1949), Nizniy Novgorod meadows of the Simbirsk (now (Vorontsov 1967) and Leningrad Ul'yanovsk) Region was 'literally filled' (Malchevskiy & Pukinskiy 1983) no with Corncrake calls. marked decrease of the numbers was In the Moscow Region, the most pop- observed until the early 1960s. ulated and developed in Central Russia, From the 1950s in European Russia, a marked decrease of numbers was noted mechanized mowing became widespread, in the 1930s (Ptushenko & Inozemtsev the first dates of mowing becoming earli- 1968). Spangenberg & Oliger (1949) er. At the same time, extensive ploughing pointed out a decrease in Corncrake up and draining of meadows took place. numbers in the Darwin Nature Reserve These events had an adverse effect on the at Rybinsk Reservoir, already consider- Corncrake population. In the Moscow ing it as a rare species. According to Region, an abrupt decrease in numbers these authors, in 1946 Corncrake num- began from 1954-1955 (Ptushenko & bers on the meadows of the Reserve had Inozemtsev 1968). A severe decrease in reduced to only 1 male per 2-3 km, numbers in the Mary-El Republic whereas before the reservoir had been became noticeable from the early 1960s built this species had been abundant (Baldaev 1973), and in the Leningrad there (Isakov 1949). At the same time, Region and Mordovia from the late Nemtsev (1953) notes Corncrake as a 1960s or early 1970s (Malchevskiy &

Tab. 2. Dynamics of Corncrake numbers (calling males) in the pilot areas in 1995-2000.

S 1995 1996 1997 1998 1999 2000 Names km2 n density n density n density n density n density n density Solotcha 3.4 - - - - 42 12.4 50 14.7 91 26.8 81 23.8 Klyaz’ma 4.7 64 13.6 29 6.2 33 7.0 66 14.0 77 16.4 79 16.8 Ilmen Lake 6.6 21 3.2 - - - - 67 10.2 - - Zavidovo 21.1 99 4.7 - - 108 5.1 - - - - Dedinovo 16.7 156 9.3 233 13.9 140 8.4 - - - - O. V. Sukhanova and A. L. Mischenko 139

Pukinskiy 1983, Lugovoy 1975). A two- fields recently have become important fold decrease in numbers was noted on post-breeding habitats for Corncrakes. the flood plain of the Klyazma River dur- Visual observations and radio-tracking ing the period 1970-1982 (Izmailov & results have produced confirmatory data. Salnikov 1986). If we include the total optimum area of fields right up to the limits of the 3.2. The current agricultural crisis and Corncrake range in Russia, it is possible to its possible influence on Corncrake estimate the actual increase in the species' post-breeding habitat area. Towards the end of the 1980s, a deep and prolonged agricultural crisis began in 3.3. Results of the repeated censuses Russia, and still continues. Because of deficits in fuel and spare parts, mowing Results of censuses carried out at an inter- now begins later in the year. Ministry of val of between 6 to 18 years are represent- Agriculture statistics show that, in forest ed in Tab. 1. Data from the surveys in the zone regions, previously before 6 July Vologda Region from 1970-1976 are pre- each year up to 23% of areas of sowed and sented as the mean of the long-term natural herbs had been mowed (now, it is results. Pilot area censuses in 4 regions usually only 15-20%). Even in the drought have revealed that only the Novgorod year of 1999 in the most developed Region suffered a significant decrease in Moscow Region, this parameter has not numbers. At present, we cannot explain exceeded 38%. At the end of the 1980s this decrease in numbers; certainly there timing of mowing in the forest zone had were no landscape changes. Corncrake changed to peak in the first half of July, numbers in the other pilot areas were sta- which obviously had increased the mortal- ble, or had increased a little, but the ity rate of Corncrake chicks. In Russia, increases were within the limits of annual pastures with low livestock densities can fluctuations. hold successful Corncrake populations The results of repeated night censuses (Mischenko & Sukhanova 2000). As live- between 1995-2000 are represented in stock numbers began to decreased strong- Tab. 2. These censuses included years that ly (by 50% from the 1980s to 1998 experienced different weather conditions, [Agriculture in Russia 1998]), their pas- spring flood levels and hay mowing peri- tures became much more suitable for ods. However, we did not find an instant Corncrakes. correlation between Corncrake density As a whole, Russian production of pes- one year and the next and one or more of ticides (including herbicides and insecti- these factors. Possibly local soil humidity cides) reduced by a factor of 7.4 between is very important. For example, both 1997 1986 and 1995 (Agriculture in Russia and 1999 were very dry, but in 1999, the 1998). No generalized data are available spring flood level was appreciably higher. for more recent years, but it is known that The continual censuses during 1995-2000 pesticide production (and accordingly, its allow the possibility of a slight increase in use on fields) has decreased even more. numbers in the Solotcha and Klyaz'ma Consequently, cereal and fodder crop floodplains, allowing for annual number 140 ORNIS HUNGARICA 12-13: 1-2 (2003) fluctuations. In spite of the reduction in in agricultural technologies. It is essential Lyubytino, in the Ilmen Lake Lowland that the selection of monitoring areas (also located in the Novgorod Region), a throughout the Russian regions should be significant increase in numbers was both representative and differentiated. The recorded. goal is to identify those areas typical of Corncrake habitats that qualify as major 4. Discussion Important Bird Areas (IBAs). No significant changes have occurred on surveyed meadows in the Novgorod, Kostroma and The completed survey is the first step in Moscow regions since the censuses began. establishing Corncrake numbers in Russia. Acknowledgements. We are very grateful to Dr. Certainly, it would not be valid to reach Vladimir Butjev, Dr. Anton Mezhnev, Dr. categorical conclusions on long-term Sergei Fokin, Dr. Valery Nikolaev and Dr. Corncrake dynamics based on such limited Dmitry Shitikov, who participated in the data. However, it is evident that between repeated Corncrake censuses. In particular, we would like to express our appreciation to Dr. the 1980s and 1990s in European Russia, Arco J. van Strien for the valuable help with there was no decreasing trend in the TRIM analysis. In addition, we express sin- Corncrake numbers as noted in between cere gratitude to the RSPB for the financial the 1950s and 1970s. Probably we have support to these surveys. seen increases in Corncrake numbers and density over the whole of the centre of References European Russia.

The TRIM 3 analysis of the count data Agriculture in Russia. 1998. Statistical tabulation: from Tab. 2 shows a significant increase in 1998. Moscow. numbers in 1995-2000. The overall slope Baldaev, K. 1973. [The Corncrake]. – Okhota i okhotnichie khozyaistvo 7: 18-19. (In Russian). is 1.21, which implies a 20%, increase per Bogdanov, M. 1871. [Birds and mammals of the year during this period. However, we have black-soil belt of Volga Riverine areas of the insufficient data to confirm this. middle and lower Volga River valley]. Kazan. (In Russian). Due to the prolonged agricultural cri- Grabovsky, V. I. 1993. Spatial distribution and spac- sis, we have observed two different ing behavior of males in a Russian corncrake processes: the abatement of agricultural (Crex crex) population. – Gibier Faune Sauvage 10: 259-279. pressure on Corncrake habitats (positive Isakov, Y. A. 1949. [Short essay on the mammal and influence), and agricultural land abandon- bird fauna of the area between Mologa and ment, which results in encroachment of Sheksna Rivers before the reservoir formation]. – Trudy Darvinskogo zapovednika 1: 137-171. habitats by bushes and forests (negative (In Russian). influence). Without special monitoring, Izmailov, I. V. & G. M. Salnikov. 1986. [Bird populations of river flood plains]. pp. 46-60. In: Ptitsy we cannot predict the trend changes in Volzhsko-Okskogo mezhdurech'ya. Vladimir. (In Corncrake numbers. It is therefore Russian). extremely important to continue the moni- Lugovoy, A. E. 1975. [Birds of Mordovia]. Volgo- Viatskoye knizhnoye izdatel'stvo. Gor'kiy. (In toring process that has been established in Russian). Russia, by maintaining the network of Malchevskiy, A. S. & Y. B. Pukinskiy. 1983. [Birds model areas for monitoring Corncrake of Leningrad Region and adjacent territories. Vol. 1]. – Izdatel'stvo Leningradskogo numbers annually and by tracking changes Universiteta, Leningrad. (In Russian). O. V. Sukhanova and A. L. Mischenko 141

Mischenko, A. L. & O. V. Sukhanova. 1999. Ravkin, Y. S. 1967. [On bird survey methods in for- Corncrake Crex crex in European Russia: meth- est landscapes]. pp. 66-75. In: Priroda ochagov ods and results of a large-scale census. – kleschevogo entsephalita na Altae. – Nauka, Vogelwelt 120. Suppl: 323-327. Novosibirsk. (In Russian). Mischenko, A. L. & O. V. Sukhanova. 2000. [Results Spangenberg, E. P. & I. M. Oliger. 1949. of the two-year project 'Corncrake survey in [Ornithological studies in the Darwin Nature European Russia']. pp. 147-169. In: Mischenko, Reserve]. – Trudy Darvinskogo zapovednika 1: A. (Ed.). Korostel' v Evropeiskoj Rossii. – Sojuz 245-302. (In Russian). okhrany ptits Rossii, Moscow. (In Russian with Vorontsov, E. M. 1949. [Birds of the Kama-Ural area English summary). (Molotov Region)]. – Izdatel'stvo Gor'kovskogo Nemtsev, V. V. 1953. [Birds of the Rybinsk Reservoir Universiteta, Gor'kiy. (In Russian). shores.] pp. 122-170. In: [Rybinsk Reservoir. Vorontsov, E. M. 1967. [Birds of Gor'kiy Region]. Part 1.] Moscow. (In Russian). Volgo-Viatskoye knizhnoye izdatel'stvo. Gor'kiy. Ptushenko, E. S. & A. A. Inozemtsev. 1968. [Biology (In Russian). and economic value of the birds of Moscow Zhitkov, B. M. & S. A. Buturlin. 1906. [Data for avi- Region and adjacent territories]. – Izdatel'stvo fauna of Simbirsk Region]. – Zapiski Russkogo Moskovskogo Universiteta, Moscow. (In Geographicheskogo Obschestva 41: 1-275. (In Russian). Russian). 142 ORNIS HUNGARICA 12-13: 1-2 (2003)