A Péczely-féle makroszinoptikus helyzetek hatása az erdei szalonka (Scolopax rusticola L.) tavaszi vonulására Magyarországon
Authors: Bende Attila , Faragó Sándor , László Richárd 
Published: July 2024

The effect of Péczely’s macrosynoptic situations on the spring migration of Woodcock (Scolopax rusticola L.) in Hungary. In the framework of the Hungarian Woodcock Bag Monitoring, we analysed the spatial and temporal patterns of the migration of Woodcock (n = 23,539) collected in Hungary between 2010 and 2019. We assumed that weather anomalies had a significant influence on the spring migration of the species, and to confirm this, we examined the dynamics of spring migration at national and finer scales, with a county distribution. For the latter, we used spring migration data from the south-western (Somogy County) and north-eastern (Borsod-Abaúj-Zemplén County) regions of the country. The analysis was based on the start and end dates of the main migration period, which are the sampling days related to the 25% and 75% thresholds of the cumulative sampling rates of the migrating populations. We found that in years without extreme weather conditions during the main migration period an average of 10 days was needed for at least 50% of the birds to pass through. We found no difference in the number of sampling days between the first half (25%–50%) and the second half (50%–75%) of the main migration period in normal years (p = 0.7194; t = 2.3) or in years with anomaly (p = 0.9500; t = 4.3). The former averaged 8 days (SD = 1.50) and the latter 12 days (SD = 1.89) on average across the country. Between the western and eastern regions of Hungary, min. 3 days; max. 10 days in years with no weather extremities (BENDE, 2021), which fitted well with the migration performance reported in the literature, considering rest periods as well. Between 2010 and 2019, migration in the Western Hungarian counties started earlier in all cases (with 3-10 days difference), but the variation in the spatial and temporal pattern of migration was significantly influenced by weather factors in addition to geographical reasons. To confirm this, we used the distribution of PÉCZELY'S macrosynoptic situations recorded in the week before and after the migration peak. Our results show that in years without weather extremities, the migration period is characterised by neutral (80.0%) macrosynoptic conditions. Unfavourable (9.5%) and favourable (10.5%) conditions are much less frequent. In years with weather anomalies (2013, 2016, 2018), unfavourable macrosynoptic situations (81.3%) determined the characteristics of the spring migration. The overall percentage of macrosynoptic situations with neutral conditions was only 17.2% in these years. The impact of weather anomalies on the timing of spring woodcock migration was clearly demonstrated: macrosynoptic conditions with stormy winds and heavy snowfall can result in a delay, up to one week compared to normal years, but regional differences were confirmed in every year regardless of weather conditions (p = 0.4042 t = 2.1). Our findings are consistent with the finding that long-distance migratory species may typically travel towards their nesting areas under weather conditions which are either neutral or result in atmospheric physical conditions which negatively affect migration (BULTE et al., 2014; KRANSTAUBER et al., 2015).