Flick SMART multi-catch rodent station and bait station data sets: Council of the city of Sydney, October 2019 to July 2020

Shortly after the enactment of preventative measures aimed at limiting the spread of COVID-19, local governments and public health authorities around the world reported an increased sighting of rats. We combined multi-catch rodent station data, rodent bait stations data, and rodent-related residents’ complaints data to explore the effects that social distancing and lockdown measures might have had on the rodent population within the City of Sydney, Australia. We found that rodent captures, activity, and rodent related residents’ complaints increased during the COVID-19 related lockdown period, followed by a steep decline post-lockdown. We found no changes in the geographical distribution of any of our indices of rodent abundance. We hypothesize that lockdown measures resulted in an increase in rodent activity driven by a reduction in human-derived food resources. This might have increased the mortality rate triggering a population crash. There is a high chance that the surviving individuals might be rodenticide resistant. It is possible that the onset of COVID-19 might have disrupted commensal rodent populations, with profound implications for the future management of these species. Here we make available multi-catch rodent station data and rodent bait stations data. We do not include rodent-related residents’ complaints data due to potential identifier data that could be seen as a breach of private information sharing.

Methods
These data sets comprise:

Flick SMART Multi-Catch rodent station data set, obtained from 20 to 60 multi-catch rodent stations deployed across the council from October 2019 to July 2020. Deployment was non-random and guided by strategic pest management priority zoning. These stations were baited with barbeque grease and commercially available rodent attractants. The Council receives monthly reports from Flick Anticimex Pty Ltd that contained the number of traps active, their location in latitude and longitude coordinates, and the number of captures per day per each trap.

Rodent bait stations (PROTECTA EVO Ambush and PROTECTA LP, Bell Laboratories, Inc.) data set, obtained from 940 stations deployed across the council of the city of Sydney from September 2019 to August 2020. Deployment was non-random and guided by strategic pest management priority zoning. These stations were baited with commercial poisoned baits (Bromadiolone: Contrac Blox and Contrac Soft Bait; Brodifacoum: Ditrac Blox; Difethialone: Generation Block and Rodilon Soft Block; Flocoumafen: Storm Secure Block and Storm Soft Bait). Baits were randomly rotated at each station, to prevent rodents from developing an aversion to any bait. Each station was checked regularly (mean: 10.56 Days ± SE: 0.06) and scored according to the rodent activity i.e. low: no bait consumed and no visual signs; or high: bait consumed and visual signs present. Following strategic pest management, a bait station with consistent low activity scores was relocated. The location for all bait stations was recorded in UTM coordinates to facilitate spatial analyses.