The impact of climate change on long‐term population trends of birds in a central European country

Abstract

Numerous studies have shown that climate changes associated with increasing global temperature affect bird species. For instance, long-distance migrants are not able to respond adequately to rapid advances in spring phenology, and thus their populations decline due to lower breeding performance. Moreover, many species in the Northern Hemisphere have shifted their northern breeding range boundaries further north. However, studies focusing on bird populations at the scale of individual countries, which are responsible for creating environmental policies, are rather scarce. We hypothesized that bird species with different European latitudinal breeding distributions would have different long-term population trends in the Czech Republic, a small central European country, as a result of range dynamics caused by increasing spring temperature. In accordance with this prediction, the results of an analysis based on large-scale monitoring data (from 1982 to 2006) showed that species with more northern latitudinal distributions had more negative population trends in the Czech Republic. However, the strength of the relationship depended on the approach used for characterization of the species latitudinal distributions. When a phylogenetic regression was applied, the only significant explanatory variable was the latitudinal distribution expressed in categories defined by species range areas in different latitudinal bands. A more detailed analysis showed that southern and northern species groups have opposite population trajectories: the former increased and the latter declined throughout the study period. The effect of climate change remained significant when habitat association and the migratory strategy of each species were taken into account. However, it is difficult to determine whether climate change or habitat change is the more important driver of long-term trends in bird populations as the effects of both factors are dependent on interspecific variability in levels of species specialization.

Long‐term trends of heron and egret populations in Italy, and the effects of climate, human‐induced mortality, and habitat on population dynamics

“…Climatic variation, including ongoing climatic changes, is of utmost importance in determining demographic traits, population trends, and distribution of bird species (Bethke and Nudds 1995;review in Stenseth et al 2002;Böhning-Gaese and Lemoine 2004;Crick 2004;Saether et al 2004;Both et al 2006;Møller et al 2008;Reif et al 2008;Seavy et al 2008). Climate variation may influence bird populations both in their breeding and non-breeding areas, by affecting important demographic processes such as breeding success and survival (reviewed in Newton 1998;Lande et al 2003).…”

Changes in bird distribution in a Central European country between 1985–1989 and 2001–2003

“…Southern species that bred in the Czech Republic in both mapping periods extended their occupancy, corresponding with findings of an earlier study focused on annual changes in abundance of common birds in the Czech Republic (Reif et al 2008b). This result is consistent with the observations of climate change impact on bird species (Julliard et al 2004;Jiguet et al 2007;Bauer et al 2008).…”

“…Most of the species used for further analyses were already sorted into these categories in Reif et al (2006Reif et al ( , 2008b and Voříšek et al (2008). For the categorization of the remaining species, we used the following literature sources: Hudec (1983Hudec ( , 1994 and Hudec and Šťastný (2005) for the habitat requirements, anonymus (2008) for legal protection status and Hagemeijer and Blair (1997) for the breeding distribution in Europe.…”

“…Determination of particular groups defined by different breeding distributions in Europe followed the two-step assessment procedure described in Reif et al (2008b). First, we divided Europe into three large regions with respect to the location of the Czech Republic: the northern region had its southern boundary five geographical degrees north of the latitudinal midpoint of the Czech Republic, the southern region had its northern boundary five degrees south of the midpoint of the Czech Republic, and the central region laid between the northern and southern regions.…”

“…First, landscape changes, such as the loss of extensively cultivated farmland because of agricultural intensification or land abandonment followed by forest spread, should reduce the distribution of farmland birds and increase the distribution of forest species (Lenzen et al 2008;Reif et al 2008a;Orłowski and Ławniczak 2009). Second, the increase in the average annual temperature should have a positive effect on the distribution of south European species and a negative impact on the north European ones (Bauer et al 2008;Reif et al 2008b). Third, global warming, along with the degradation of wintering habitats, should lead to an increase in the distribution of resident species and to a decrease of migrants (Schaefer et al 2008).…”