1. Introduction
Makkah is located in a narrow valley at a height of 277 m
above sea level (Figure 1a). The resident population in 2012 was
roughly 7.47 million representing 26% of the total Saudi Arabian
population[1]. Visitors to Makkah can reach more than 7 million
every year. Makkah is characterized by the existence of a large
number of free-living pigeon flocks in many sites of the city. In
general, wild free-living birds (e.g. pigeons) are regarded as visible
indicators of diverse and healthy environments. Yet, from a public