Global climate change promotes the expansion of rural and synanthropic bird species: The case of Zhytomyr region (Ukraine)
Authors: Tkachuk R. , Nykytiuk Y. , Komorna О. , Zymaroieva A. 
Published: July 2024

The article reveals which ecological groups of birds in Zhytomyr region are most vulnerable to global climate change and which birds will benefit from warming in the next 70 years. The following data networks were used as predictors of bird ecological niche: climatic biogeographic variables, soil properties and indicators of landscape cover types. The results of the ENFA analysis were used to derive ecological niche margins for bird species, which were subjected to three principal component analyses to estimate marginality along bioclimatic, edaphic, and landscape variables. The bird species habitat preference index was estimated using the Maxent procedure. The assessment was made on the basis of both current predictors and projected climate variables. It was found that the climatic conditions of the Zhytomyr region are close to the European average. The average annual temperature in Zhytomyr region is 2.1 °C higher than the European average. Furthermore, the average value of monthly temperature ranges, isothermality, annual temperature range and seasonality in Zhytomyr region do not differ significantly from the European average. The maximum temperature of the warmest month in Zhytomyr region is 1.4 °C higher than the European average, while the minimum temperature of the coldest month is 1.7 °C higher. The temperature of the wettest quarter is 4.6 °C above the European average, while the temperature of the driest quarter is 2.3 °C below. The temperatures of the warmest and coldest quarters in Zhytomyr region are slightly higher than the European average (1.8 and 1.6 °C, respectively). The annual precipitation in Zhytomyr region exceeds the European norm by 20 mm. Zhytomyr region exhibits a distinctive pattern of precipitation, with a significantly higher amount of precipitation for the wettest and warmest quarters than the European average. The climate change forecast for the next 70 years indicates that the average annual temperature in Europe can be expected to increase by 4.1°C. For Zhytomyr region, the average annual temperature is likely to increase by 4.4 °C. Furthermore, other temperature indicators are also expected to increase. The contrast of thermal conditions throughout the year will decrease in the future. Precipitation in Europe will increase by 60.3 mm per year on average. In Zhytomyr region, precipitation will increase by 87.2 mm per year compared to the current state. Based on the estimates of the marginality of the birds' ecological niche, principal component analyses of climatic, edaphic and landscape projections were conducted. The principal component analysis of the climatic projection of the ecological niche identified three principal components with eigenvalues exceeding one. Principal component 1 was characterised by a high correlation with temperature bioclimatic variables, which allowed us to interpret this principal component as the position of the species optimum in the thermal gradient. Principal component 2 exhibited a high correlation with bioclimatic variables indicative of precipitation, thereby enabling this principal component to be meaningfully interpreted as the position of the species optimum in the precipitation gradient. Principal component 3 exhibited high correlation coefficients with bioclimatic variables indicative of rainfall variability, thereby enabling this principal component to be interpreted as the position of the species optimum in the rainfall variability gradient. The principal component analysis of the variation of the marginality parameters of the projection of bird ecological niches onto the matrix of diversity of landscape cover types allowed us to extract three principal components with eigenvalues greater than one. Principal component 1 was meaningfully interpreted as the position of the species in the habitat gradient from open spaces (grassland, sparse shrubs, cropland, bare) to forest. This component can also be denoted as the ratio of campophilic/dendrophilic bird species. Principal component 2 denotes the ratio of open space bird species (water, wetland) to birds that prefer built, cropland and trees. This allows us to interpret this principal component as the ratio of wetland (moisture-loving campophilic)/rural bird species. Principal component 3 is positively correlated with the trend of preference for built and water (urbanised areas are usually associated with water bodies) and negatively correlated with trees, shrubs, bare and wetland. This principal component can be interpreted as the position of the species optimum in the urban/rural bird species gradient. It is anticipated that an increase in campophilic bird species compared to dendrophilic species will be the predominant trend in the next 70 years as a response to global climate change. Moisture-loving campophilic species will be outcompeted by rurally-dependent species, and rurally-dependent species will be outcompeted by urban species.