Abstract
Abstract Rattus norvegicus occurs in Singapore, with several other commensal rodent species. This preliminary study examined populations and a possible control method in urban and semi-urban areas. Commensal rats are generally undesirable, and a possible role for R. norvegicus in spreading any introduced plague is a particular worry. Populations were examined by catch, mark, release (CMR) and by removal (regression) methods. Species and numbers indicated by removal were—R. norvegicus (57.4, 31.9 and 48.5/ha in different trials), R. exulans (37.2/ha) and Mus musculus (8.3/ha). There were indications that these figures were very considerable underestimates; a Lincoln Index, using recovered dead rats (after poisoning in a CMR Plot) as the second sample, estimated R. norvegicus at 985/ha (i.e. in a ca 0.6 ha plot—618 ± 694); the recovery of only three out of 32 marked rats, and the presence of many dead but uncollected rats, even though more than the number estimated by removal was picked up in the plot (58) ...
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
