Human activities and landscape features interact to closely define the distribution and dispersal of an urban commensal

Abstract

The rock pigeon, Columba livia, is a cosmopolitan human commensal, domesticated thousands of years ago. However, the human‐mediated factors governing its distribution and dispersal are not well understood. In this study, we performed (a) hierarchical distance sampling on ~400 island‐wide point transects, (b) a population genomic inquiry based on ~7,000 SNPs from almost 150 individuals, and (c) landscape genomic analyses on the basis of extensive ecological and socio‐economic databases to characterize the distribution and dispersal patterns of rock pigeons across Singapore. Our distance sampling results indicated that the volume of intentional “mercy feeding” and availability of high‐rise buildings are the most reliable predictors of high pigeon densities in Singapore. Genomic analyses demonstrated that rock pigeons in Singapore form a single population possibly derived from rapid expansion from a genetically homogenous group of founder individuals. In specific, rock pigeons in Singapore lack sex‐biased dispersal and are clustered with a genetic patch size of ~3 km. Landscape genomic analyses of great precision pointed to the presence of dense trees as agents of resistance to dispersal, whereas a high road density reduces this resistance. By pinpointing a range of ecological and socio‐economic variables determining the distribution and dispersal of pigeons, our study provides urban planners with the tools for optimal management of this human commensal, such as a curtailment of the practice of mercy feeding and modifications to the urban landscape to reduce pigeon density and to lower the likelihood of repopulation by dispersal.

Mus musculus populations in Western Australia lack VKORC1 mutations conferring resistance to first generation anticoagulant rodenticides: Implications for conservation and biosecurity

“…As M. m. domesticus was probably introduced in Australia by European settlers in the late 18 th Century, the absence of mutations in the exons of VKORC1 might because they were absent from these founder animals [35,36]. The mitochondrial D-loop data supports this, as the low haplotype diversity indicates rapid expansion from a small founding population [37]. ARs were invented in the 1940s, and the first evidence of resistance in rodents dates to 1958 [18].…”

ResDisMapper: An r package for fine‐scale mapping of resistance to dispersal

“…Our ResDisMapper results on the pigeons in Singapore indicate high resistance to dispersal in central and western Singapore, which mainly comprise nonfavourable habitats for the rock pigeons such as dense trees and industrial zones. Compared to the mapping of resistance to dispersal in the original study (Tang et al, ) using DResD , the resistance mapping from ResDisMapper is more congruent with the landscape patterns in Singapore (Figure and Figure S4). Congruence between mapped resistance and landscape pattern is found regardless of whether resistance was calculated using sample pairs of individuals within 5, 10, 15, 20, 25 or 30 km (Figure S4).…”

“…This effect is best corrected by including only those sampled pairs within the typical range of dispersal. According to a previous spatial autocorrelation analysis, the typical range of dispersal for pigeons in Singapore was estimated to be within 10 km (Tang et al, ). Accordingly, the resistance map derived using only sampled pairs within 10 km should be the most relevant for illustrating the resistance to dispersal of pigeons in Singapore, and indeed, we found that this map was most congruent with what we expected from the landscape pattern (Figure ).…”

“…Top: urban landscape of Singapore. For detailed landscape categorization, please refer to Tang et al (). Blue circles are sampling sites.…”

Feral pigeon populations: their gene pool and links with local domestic breeds

“…While a number of the above-mentioned 73 studies on domestic breeds actually included one group of feral pigeons in their analyses (e.g. 74 Stringham et al 2012;Biala et al 2015), only two studies were specifically focused on feral 75 pigeons, with the aim of clarifying the pattern of genetic differentiation within and between urban 76 areas (Jacob et al 2015;Tang et al 2018). To our knowledge, no study has systematically 77 investigated the degree of influence of different domestic breeds on the genetic composition of feral 78 populations.…”