Counting droppings

Who would guess that poo could tell us so much? Coupled with some simple observations of nest boxes or roosting pouches, over 100 people were able to reveal the presence or apparent absence of roosting birds using this simple method. Over 80 nest boxes were examined, with half of roosting birds being Blue Tits, and the next most frequently identified species being Great Tits (see graph below). However, around a quarter of nest boxes contained no droppings at all, indicating that birds might be picky about the boxes that they choose. Working out which factors influence nest box use for roosting could be a good focus for future research.

Only 24 survey participants looked for droppings in roosting pouches. However, these simple checks, coupled with some on-the-ground observations, revealed substantial differences compared with nest boxes. Over half of the roosting pouches examined were unused by roosting birds, while a third were occupied by Wrens – a much larger proportion than found in nest boxes (see graph below). Unlike nest boxes, no Blue Tits were identified, the only other species being a Dunnock.
 

Species that used nest boxes for roosting in the winter of 2010–11