What color might bat rub marks appear when stained?

Bat rub marks often appear yellow to brownish black when stained due to the oils, fats, and proteins present in bat guano (feces) and urine. These substances can react with environmental factors, leading to discoloration that results in the yellow to brownish black hues noted in rub marks. This coloration can be particularly pronounced when bats frequently come into contact with surfaces, leaving behind a residue that can darken over time. Understanding this helps in identifying bat activity in an area, especially in wildlife management and conservation contexts. Recognizing the color and characteristics of rub marks is crucial for wildlife professionals and trappers working to mitigate human-wildlife conflicts or monitor bat populations effectively.