CC BY
40
Чаун М.Г. 1958. Состав и динамика местных популяций мухоловки-пеструшки в искусственных гнездовьях // Привлечение полезных птиц-дуплогнездников в лесах Латвийской ССР. Рига: 73-99.
Berndt R., Sternberg Н. 1966. Der Drutort der einjährigen weiblichen Trauerschnäpper (Ficedula hypoleuca) in seiner Lage zum Geburtsort///. Ornithol. 197: 292-309.
Berndt R., Sternberg H. 1968. Terms, studies and experiments on the problem of bird dispersion// Ibis 110: 256-269.
Berndt R., Sternberg H. 1969. Alters- und Geschlechtsunterschiede in der Dispersion des Trauerschnäppers (Ficedula hypoleuca) Ц J. Ornithol. 110: 22-26.
Haartman L. 1949. Der Trauerschnäpper. 1. Ortstreue und Rassenbildung // Acta zool. fennica 56: 1-104.
Haartman L. 1960. The Ortstreue of the Pied Flycatcher // Proc. 12th Intern. Ornithol. Cong. Helsinki, 1: 266-273.
Ю СЯ
ISSN 0869-4362
Русский орнитологический журнал 1998, Экспресс-выпуск 56: 12-15
The population of the slender-billed curlew Numenius tenuirostris becomes steady. Monitoring researches are necessary
Dimitar N. Nankinov
Institute of Zoology, Bulgarian Academy of Sciences, boul. Tzar Osvoboditel, 1,
P.O.Box 445, 1000, Sofia, Bulgaria
Received 12 December 1998
Нанкинов Д.Н. 1998. Популяция тонкоклювого кроншнепа Numenius tenuirostris стабилизируется. Необходим тщательный мониторинг // Рус. орнитол. журн. Экспресс-вып. 56: 12-15.
Несмотря на широко распространённое мнение, что тонкоклювый кроншнеп Numenius tenuirostris исключительно редок, он регулярно встречается в Болгарии, причём в последние годы его встречи заметно участились. Его стали отмечать как на Западном и Северном побережьях Чёрного моря, так и в других районах. Это свидетельствует о том, что его популяция стабилизируется. Благоприятное влияние на этот процесс оказывает уменьшение загрязнённости мест обитания вида, запущенность полей и пастбищ и снижение активности охотников как следствие экономического кризиса в ряде восточноевропейских стран. В будущем возможны колебания численности этого вида, но в целом популяция тонкоклювого кроншнепа продолжает увеличиваться.
Институт зоологии, Болгарская Академия наук, бульвар Царя Освободителя, 1, п/я 445, София, 1000, Болгария
I know that such title will provoke surprise and bewilderment in some naturalists, dilettantes and professional ornithologists, as the word is about one of the rarest and most mysterious bird on the Earth, considered as "undoubtedly dying species" or even as "completely extinct species" (Козлова 1962; Иванов 1976). There are mentioned lower and lower figures for its number in the literature: 1000 individuals (Сорокин 1984), 800 (Флинт 1978), 100-400 (Gretton 1991), 300 (Винокуров 1982), 50-300 (Baccetti, Zenatello 1996), 50-270 (Stroud 1997), 50-200 (L'Homme et l'oiseaux 1995, 1: 10), less than 100 (Dutch Birding 1988, 10: 145), several dozens of pairs (Кистяковский 1980) and so on.
However my observations in Bulgaria and the collected information about the past and the present state of the slender-billed curlew make me think in a different way. I have been occupied seriously with its observation in the last two decades. I have recorded it many times. I published several scientific works (Nankinov 1989, 1991, 1994a,b, 1996, 1997; Nankinov, Minchev - in press, Nankinov et al. — in press) and great number of popular articles. I may assert that for the preservation of the slender-billed cirlew as a species on the Earth the territory of Bulgaria is very important. My country is situated between the supposed Westsiberian nesting places and the most distant Maroccan winterings, and so the bird visits it regularly.
During the period 1989-1996 there are 88 announcements (495 individuals altogether) about meetings of the slender-billed curlew in Bulgaria. From them only for the last six years (1991-1996) these meetings are 48 (55%) and the number of the recorded curlews is 143 (29%): 1991 — 21 birds, 1992 — 13, 1993 — 37, 1995 — 2, 1996 — 71 birds. I must emphasise that only in 1993 a purposeful searching of the slender-billed curlew together with a mass inquiry were accomplished. Because of the lack of money during the next year there were no such observations or they were insufficient. However the irregular recordings strikes the fact that the number of the species in Bulgaria increases, especially in 1996. If the researches in the last years were of large dimensions and were in different parts of the country, the recorded slender-billed curlews would have been several times more. The flocks which we observed in spring of 1996 on the Lake Atanasovsko (Nankinov et al., in press) shows that the migration of slender-billed curlews is in stages and the concentrations on places favourable for feeding and resting on their route are of different individuals. For example, between 11 and 19 April the composition of the flock changed as follow: 11, 12 and 13 Apil — 3 adults and 1 young bird; 14, 15, 16 and 17 Apil — 6 adults and 2 young; 18 and 19 April — 7 adults and 2 young birds.
In confirmation of our thoughts that the population of the slender-billed curlew becomes steady and there are the first steps for increasing of its number are more frequent records of the species along North and West coasts of the Black Sea and on other places: Southern Ukraine — 2 sighting records in September 1993 (Adam Gretton, pers. comm.), Southwestern Ukraine, river Sarata, 29 September 1996 — 2 birds (Nankinov 1997), the Black Sea Nature Reserve, 2 August 1995 — 2 curlews, 4 August 1996 — 1 + 1 (Ardamatskaya 1996, 1997), Ukrainian part of the Danube delta, 18 August 1994 — 1 bird, 17 September and 16 October 1996 — 1 + 1 birds in the Romanian part of the Danube delta: "Janosh Kish several times recorded small flocks" (Zhmud 1997a).
We can add the announcement of Eugeniusz Novak: "... about several dozens of wintering Slender-billed Curlews in Iran" (Zhmud 1997b). I am sure that during the last years on the Balkans and other places along the migratory route of the species there are several more records of slender-billed curlews, which are for the moment not published. There are two suggestions for the supposed nesting places of the slender-billed curlew: 1) vast marshes of Westsiberian taiga and 2) forestry marshes, situated amidst of a hilly landscape. It is possible the species to breed on both places, but there can be surprises, and the nestings can be several, isolated on great distances from each other. The nestings can be most easily found with satellite following of birds with transmitters fixed on their bodies. It is glad that Japanese Telegraph and Telephone Corporation and Bird Life International already work on this problem ("Birding World", 1996, 9, 4: 121-122). In this respect the collaborators of the Bulgarian Ornithological Centre can help as they know best when and where the catchment of splender-billed curlews and the attachment of the transmitters are possible.
I hope that in the next years all nesting places of the slender-billed curlews will be found and we will try to estimate its real number. I suppose that its number is not under critical minimum, the minimum vital populations is not reached. Therefore the species increases its number and the chances for its survival are good.
Now the stabilisation of the population of the slender-billed curlew is stimulated by several factors, but as if three of them are most important:
1) Decreasing pollution (and degradation) of some habitats with harmful for the species substances (poisons, radioactive and industrial wastes and so on) in the supposed nesting places in Russia and Kazakhstan, as well as along its migratory route, especially in Eastern European countries: Bulgaria, ex-Yugoslavia, Romania, Ukraine and others.
2) The unkempt agriculture and stock-breeding in Eastern Europe. Vast areas in regions with previously intensive agriculture and also some pastures are uncultivated for years. During migrations birds found there security and plenty of fresh food: insects and their larvae, worms, bulbs, green grass.
3) The decreasing activity of hunters in the same countries and nearly ceased shot of waders in some countries, for example, in Bulgaria in the last hunting season.
The mentioned factors are closely connected with economic crisis, which engrossed during the last decade.
The population of the slender-billed curlew becomes steady. Its number cased its decreasing. The records of the species become more frequent on the migratory route. In the next decades occasional variations in the breeding success are possible, but as a whole the population slowly but surely will increase its number. The monitoring researches will prove this. Bulgaria is a country where such long monitoring researches of the slender-billed curlew can be realised by estimating its number in different stations of the region. The results of these investigations will provide a possibility for an exact registration of the annual variations in the species number and also for timely respond against the danger and for the establishing of efficient measures for protection.
Many thanks to my students Avetlan Kirilov, Konstantin Popov, Nikolai Minchev,
Nikolai Dimitrov, Toni Tonev and Anton Dimov, who helped me in my exploration of the
lakes Atanasovsko and Pomoriisko.
Литература
Ardamatskaya T.B. 1996. Record of the Slender-billed Curlew in the Black Sea Nature Reserve, Ukraine, in 1995 // Inform. Materials of the Working Group on Waders 9: 34.
Ardamatskaya T.B. 1997. The Slender-billed Curlew, Numenius tenuirostris, in the Black Sea Nature Reserve in 1996 // Inform. Materials of the Working Group on Waders 10: 39-40.
Baccetti N., Zenatello M. 1996. И chiurlottello Numenius tenuirostris: И piano d'azione per la sua conservazione e le piorita per il future // Proceedings from research to action plans, Bologna, Italia, 15-17.03.1996: 177-180.
Gretton A. 1991. Conservation of the Slender-billed Curlew // J СВР Monogr. 6: 1-159.
Nankinov D. 1989. The status of waders in Bulgaria // Waders Study Group Bull. 56: 16-25.
Nankinov D. 1991. Sightings of Slender-billed Curlew Numenius tenuirostris (Vieillot, 1817) in the Balkan countries// Waders Study Group Bull. 62: 24-32.
Nankinov D. 1994a. Bulgaria is of great importance for the conservation of Slender-billed Curlew Numenius tenuirostris// J. Ornithol. 135: 223.
Nankinov D. 1994b. Analysis of the situation of Numenius tenuirostris in Bulgaria // Preparation d'un plan de sauvetage pour Numenius tenuirostris. Belgique. 2, 17: 1-5.
Nankinov D. 1996. The contribution of the Bulgarian Ornithological Centre to the investigation of the globally endangered bird species///. Bulg. Acad. Sci. 3: 61-65.
Nankinov D. 1997. Record of Slender-billed Curlew, Numenius tenuirostris, in the south-western Ukraine // Inform. Materials of the Working Group on Waders 10: 40-41.
Stroud D. 1997. Proposal for international action plan and specialist network for globally threatened waders // Wader Study Group Bull. 82: 34-37.
Zhmud M.E. 1997a. Records of Slender-billed Curlew, Numenius tenuirostris, in the Ukrainian part of the Danube delta // Inform. Materials of the Working Group on Waders 10: 41-42.
Zhmud M.E. 1997b. The annual conference of the Wader Study Group in Kasterle, Belgium. 8-11 November 19% // Inform. Materials of the Working Group on Waders 10: 49-51.
Винокуров A.A. 1987. Редкие птицы мира. M.: 1-207.
Иванов А.И. 1976. Каталог птиц СССР. Л.: 1-276.
Кистяковский А.Б. 1980. Сохранился ли еще тонкоклювый кроншнеп? // Новое в изучении биологии и распространения куликов. М.: 62-63.
Козлова Е.В. 1962. Ржанкообразные: подотряд кулики. М.; Л.: 1-433.
Сорокин А. 1984. Тонкоклювый кроншнеп Numenius tenuirostris // Красная книга СССР. М., 1: 153.
Флинт В.Е. 1978. Птицы // Красная книга СССР. М.: 87-149.
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