Habitat type, food resources, noise and light pollution explain the species composition, abundance and stability of a winter bird assemblage in an urban environment

Table 1 List of environmental variables, their codes and descriptive statistics

Variable	Code	Mean ± SD	Range	Unit	Data source
Area of buildings	BUILDINGS	20094 ± 20408	0–93230	m²	(WODGiK 2009)
Area of roads and railway tracks	ROADS	13113 ± 9708	0–34164	m²	(UMK 2012)
Distance to landfill sites	LANDFILLS	8048 ± 4035	1426–16015	m	(MIIP 2015)
Distance to water	WATERS	384 ± 353	21–1541	m	(WODGiK 2009)
Area of forest and natural woodlands	FORESTS	18595 ± 40090	0–233443	m²	(UMK 2012)
Area of urban greenery	GREENERY	139164 ± 82816	0–234123	m²	(UMK 2012)
Area of open spaces	OPENAREAS	76371 ± 83812	0–240806	m²	(UMK 2012)
Emission of pollutants	POLLUTION	3.39 ± 0.89	2–5	class (μg/m³)	(MIIP 2015)
Nocturnal noise emission	NOISE	1.96 ± 0.86	1–4.03	class (dB)	(MIIP 2015)
Light pollution	LIGHT	6.38 ± 1.29	3–8	class (W/cm²×sr)	(MBM 2015)
Sources of food	FOODSOURCES	13.4 ± 14.1	0–72	items	this study