Table 1.

Questions made to the participants from the online survey and resulting variables.

Question	Variable	Type of variable	Levels
How long have you lived in your building?	Months	Numerical	—
How long do you stay at home during daylight hours?	Hours	Categorical	More than 4 hours/Less than 4 hours
How many windows does your building have?	Windows	Numerical	—
Are there trees or vegetation that reflect on the windows of your building?	Reflection	Categorical	Yes/No
Are there trees or vegetation that provide food or nesting places for birds outside your building?	Natural_Attractor	Categorical	Yes/No
Do you have any artificial bird attractor outside your building? (feeders, nests, water fountains)	Artificial_Attractor	Categorical	Yes/No
Have you ever seen or heard a bird collide with the windows of your building?	Collision_Ever	Categorical	Yes/No
Have you seen or heard a bird collide with windows of your building in the past year?	Collision_Year	Categorical	Yes/No
How many bird collisions against your building windows do you remember until a year ago?	Collision_Number	Numerical	—
How many birds that collided on those occasions died?	Fatality_Number	Numerical	—
Which of these groups of birds collides most frequently with the windows of your building?	Group_Birds	Categorical	Raptor/Passerines/Pigeons/Hummingbirds//other bird species
What type of building do you live in?	Type_Building	Categorical	1 to 3 story-building/>3 story-building

The type of variable and the levels of each categorical variable are reported. The variables were included in the models or used in metric comparisons.