Is there a connection between weather at departure sites, onset of migration and timing of soaring-bird autumn migration in Israel?

Abstract

Aims Different aspects of soaring-bird migration are influenced by weather. However, the relationship between weather and the onset of soaring-bird migration, particularly in autumn, is not clear. Although long-term migration counts are often unavailable near the breeding areas of many soaring birds in the western Palaearctic, soaring-bird migration has been systematically monitored in Israel, a region where populations from large geographical areas converge. This study tests several fundamental hypotheses regarding the onset of migration and explores the connection between weather, migration onset and arrival at a distant site.Location Globally gridded meteorological data from the breeding areas in north-eastern Europe were used as predictive variables in relation to the arrival of soaring migrants in Israel. MethodsInverse modelling was used to study the temporal and spatial influence of weather on initiation of migration based on autumn soaring-bird migration counts in Israel. Numerous combinations of migration duration and temporal influence of meteorological variables (temperature, sea-level pressure and precipitable water) were tested with different models for meteorological sensitivity. ResultsThe day of arrival in Israel of white storks, honey buzzards, Levant sparrowhawks and lesser spotted eagles was significantly and strongly related to meteorological conditions in the breeding area days or even weeks before arrival in Israel. The cumulative number of days or cumulative value above or below a meteorological threshold performed significantly better than other models tested. Models provided reliable estimates of migration duration for each species. Main conclusionsThe meteorological triggers of migration at the breeding grounds differed between species and were related to deteriorating living conditions and deteriorating migratory flight conditions. Soaring birds are sensitive to meteorological triggers at the same period every year and their temporal response to weather appears to be constrained by their annual routine.

Environment, behavior and physiology: do birds use barometric pressure to predict storms?

“…Our data thus provide modest support for the hypothesis that animals can use changing barometric pressure to predict the onset of inclement weather. Several studies indicate that birds can detect changes in barometric pressure (Kreithen and Keeton, 1974;Lehner and Dennis, 1971), and may alter behavioral patterns as a result (especially during migration) (Blokpoel and Richardson, 1978;Maransky et al, 1997;Matthews and Rodewald, 2010;Panuccio et al, 2010;Pyle et al, 1993;Sapir et al, 2011;Shamoun-Baranes et al, 2006). However, this is the first study to experimentally test this idea.…”

“…However, homing requires a map and a compass [vision and magnetic detection (Kramer, 1953)], but not a barometer. Several other studies have hypothesized that the PTO detects barometric pressure (Paige, 1995;Shamoun-Baranes et al, 2006;von Bartheld and Giannessi, 2011), but none have tested it directly.…”

“…Studies from a variety of taxa indicate that animals use barometric pressure to time behavioral transitions. Frogs may call more when barometric pressure is low and rain is likely (Brooke et al, 2000;Oseen and Wassersug, 2002); fish move into salt marshes (possibly to forage) as barometric pressure declines (Crinall and Hindell, 2004); and bats and birds can sense changes in barometric pressure (Kreithen and Keeton, 1974;Lehner and Dennis, 1971;Paige, 1995), and may alter migratory behavior to avoid poor weather (Blokpoel and Richardson, 1978;Cryan and Brown, 2007;Maransky et al, 1997;Matthews and Rodewald, 2010;Panuccio et al, 2010;Pyle et al, 1993;Sapir et al, 2011;Shamoun-Baranes et al, 2006). The majority of studies, however, examine correlations among behavioral patterns and naturally varying barometric pressure.…”

Why are bird migration dates shifting? A review of weather and climate effects on avian migratory phenology

“…weather, food supplies) before choosing a well-balanced response. For example, autumn departure dates can show large differences from year to year related to weather, which suggests a fine tuning of endogenous rhythms according to the particular environmental conditions (see Shamoun-Baranes et al 2006). Furthermore, interannual climatic fluctuations could indirectly affect departure decisions of individuals due to food supplies (Fig.…”

Climate warming, ecological mismatch at arrival and population decline in migratory birds

“…In addition, temporal shifts in plant phenology generate cascading effects on organisms at higher trophic levels [2,8,31]. The progress of spring at a given date can thus be conveniently expressed by degree-days (DD; the sum of mean daily temperatures above a given threshold from a biologically meaningful start date till the date of interest) indices, which summarize the thermal conditions affecting phenology ( [27][28][29]; see also electronic supplementary material), although, to the best of our knowledge, this approach has never been applied in the studies of avian phenology [32].…”