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2. Migration distance and the effect of North Atlantic Oscillation on the spring arrival of birds in Central Europe
- Creator:
- Hubálek, Zdeněk and Čapek, Miroslav
- Type:
- article and TEXT
- Subject:
- climate, NAO, phenology, temperature, and weather
- Language:
- English
- Description:
- Mean annual first arrival dates (FAD) of 45 migratory bird species recorded in Moravia (Czech Republic, c. 49º N) in 109 spring seasons between 1881 and 2007 were correlated with the preceding winter (December to March) North Atlantic Oscillation (NAO) index. The arrival of birds occurred significantly earlier following high NAO winter index values (those result in spring warmer than normal in central Europe) in all short-distance migratory species with a European or North African winter range, whereas the arrival timing did not correlate significantly with the seasonal NAO index in long-distance migrants having sub-Saharan winter range. When the values of Pearson coefficient between NAO and FAD were correlated with the migration distance of all 45 bird species, the correlation was remarkable and significant (p<0.001): r = 0.848 for the distance to central locations of winter range, and r = 0.822 for the northern limits of the wintering area. The migration distance was thus responsible for 68–72 % of variation in the regression of birds’ arrival on NAO winter index in central Europe. The data are robust (this is the longest avian phenological record analyzed for correlation with NAO in Europe), and indicate different mechanisms that govern timing between short-distance and long-distance migrants in their departure from wintering areas.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
3. Spring migration of birds in relation to North Atlantic Oscillation
- Creator:
- Hubálek, Zdeněk
- Type:
- article and TEXT
- Subject:
- phenology, migration, weather, climate, temperature, and NAO
- Language:
- English
- Description:
- Long-term spring phenological instants of 57 migratory bird species, i.e. arrival in summer visitors and departure in winter visitors, were recorded in South Moravia (Czech Republic) from 1952 through 2001 and evaluated for annual correspondence with the North Atlantic Oscillation (NAO) weather system. The migration instants occurred significantly earlier following positive winter/spring NAO index values (causing periods warmer than normal in Europe) in a number of short-distance migrants with a European winter range (e.g., Alauda arvensis, Columba palumbus, Corvus frugilegus, Motacilla alba, Phoenicurus ochruros, Phylloscopus collybita, Serinus serinus, Sturnus vulgaris, Vanellus vanellus), whereas they did not correlate with NAO in most long-distance migrants having a sub-Saharan winter range (e.g., Acrocephalus spp., Anthus trivialis, Apus apus, Cuculus canorus, Delichon urbica, Ficedula albicollis, Hippolais icterina, Hirundo rustica, Jynx torquilla, Lanius collurio, Locustella spp., Muscicapa striata, Oriolus oriolus, Phylloscopus sibilatrix, Riparia riparia, Streptopelia turtur, Sylvia spp.). The winter/spring (especially February and March) NAO conditions thus affect the migration timing of short-distance migrants that winter in western or southern Europe, and could explain their earlier than normal arrival that had been observed in Europe since the 1980s.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
4. Weather factors affecting the male mate-locating tactics of the small copper butterfly (Lepidoptera: Lycaenidae)
- Creator:
- Ide, Jun-Ya
- Type:
- article, model:article, and TEXT
- Subject:
- Activity pattern, Lycaena phlaeas daimio, mate-locating tactics, patrolling, perching, thermoregulation, and weather
- Language:
- English
- Description:
- Males of the small copper butterfly, Lycaena phlaeas daimio, exhibit two mate-locating tactics: patrolling and perching. Field investigations were conducted to determine the biotic and abiotic factors affecting the mate-locating behaviour of male L. phlaeas. Patrolling was often observed when light intensity was high. Perching was performed throughout the day regardless of environmental conditions, but the chasing of passing insects increased at high light intensities. The activity patterns of the males were not affected by those of the females. The thoracic temperatures of patrolling males were lower than those of perching males under cool conditions, suggesting that patrolling males lose heat more easily. In contrast, perching males may more easily regulate their body temperature to a suitable level as they fly for shorter periods and can bask while waiting for mates. These results highlight several reasons (i.e., heat loss, energetic costs) why males patrol when weather conditions are favourable.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public