Alternatives to census, monitor and evaluate synanthropic rodent populations

It is a mistake to try to assess the success or progress of a rodent control campaign based on the number of animals killed. It is imperative to know how to estimate and monitor commensal rodent populations. The only way to know the population density is to carry out adequate sampling. This initial estimate will allow sizing the

impact of control strategies, given that it manifests an initial reference number. There is a lot of literature that talks about methods for evaluating a population of rodents, the most

RODENT POPULATION ASSESSMENT METHODS simple and easy to apply are indirect detection methods and should be used when the problem being

want to resolve is not of great importance or the area is limited, in these cases we can apply Harold Gunderson's criteria where the population in Low, Medium and High infestations is estimated. This also requires the operator's experience, which is not always the same from one technician to another. Direct detection methods such as food consumption, Lincoln index, Petersen method.

PROPOSAL FOR THE INSPECTION, MONITORING AND EVALUATION OF INTEGRATED RODENTS CONTROL INSPECTION When carrying out the initial inspection we must detect the predisposing factors for the establishment of rodents as a pest. Once detected, if the rodent problem is not serious, we can begin with the location of the points to place the bait boxes. If there is evidence that rodent infestation is significant, I recommend the Joule and Cámeron method or the elimination of trapped animals. It is a simple and practical method that only requires experience in trapping rodents and Day 1st 2nd 3rd

No. Animals

their habits. Joule and Cameron maintain that 80% of the animal population is trapped in the first two nights and 90% in three nights. This method has particularly given me very good results, it is easy to apply and without having to carry out complicated formulas and trapping methods. This method consists of placing 100 traps to capture live animals in the form of a net, in 10 rows of 10 stations and placing them at intervals of 10 meters. You can also use hit or dead capture traps, personally I like it better as it simplifies the task of eliminating rodents. H 2A, 1J 5A, 1J 1A

INFESTATION INDICES The infestation indices by synanthropic rodents were proposed by Larry Perdomo after observations and establishment of carrying capacity (K), Economic Injury Level (NDE), action threshold (UA) and tolerance thresholds in Integrated Rodent Control campaigns during periods of 5 to 10 years of monitoring and evaluation. The action threshold (UA) can be set to 10 which is an infestation indexM –

light ion since after this number of rodents you begin to observe scattered feces, some gnawing and urine stains, based on the moderate infestation levels and species present, the action program is directed to:

• Protection and sanitation of facilities.
• Burrow detection.
• Use of rodenticides.
• Reevaluation of the action program.

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• Placing traps before dark.
• Check the traps within 4 hours of sunrise.
• Animals captured alive or dead are removed and the traps are replaced with the

purpose of trapping animals with diurnal habits. Before nightfall, the traps are checked and the trapped specimens are collected, replacing the traps. The operation is repeated during the three nights of trapping.

CONSUMPTION CENSUS The consumption census through the feeding stations is a technique for evaluating the rodent population that can be used to estimate the minimum number of rodents existing in a given area. The use of non-poisoned baits is required but after having evaluated the situation in the initial inspection we can place rodenticide baits according to the area to be treated, which may be baits, paraffin or fresh baits. The important thing in these cases is that the bait chosen is palatable and attractive to the rodent. In the case of farms and primary production properties, the bait must exceed the amount of protein offered in the feed to the animals. It is important to take into account the monitoring of the feeding stations and their location. Bobby Corrigan, researcher at Purdue University, USA, recommends that the feeding stations should be placed on a tile approximately 3cm thick. The idea behind this is that the rodent, when searching for food, raises its head to detect odors and with the feeding station raised at this height, the search for food within the station becomes more attractive to the rodent. This situation was put into practice giving favorable results since in places where it was necessary to wait up to a week for consumption of the feeding stations to be recorded, consumption was recorded the day after their installation. The bait placed in the stations must be weighed and placed in a quantity greater than what the rodent consumes daily (30gr.) Once all the stations have been monitored according to the action program, the quantity consumed will be divided by 30 and a rough estimate of the minimum number of rodents existing at the beginning of the control campaign will be obtained. We will obtain relative values ​​which over time will be absolute since the food consumption of a population or population dynamics is being evaluated. We can then set the infestation rates according to Table 1 and validate the information by calculating the trapping index, Faculty of Veterinary Medicine, Havana Cuba 2005. The calculation of the trapping index will be carried out with the following formula: Trapping index = Total rodents captured X 100 / Total traps placed. The intensity will be estimated with the following scale:

In Conclusion, when an Integrated Rodent Control campaign is carried out and we have already established the infection rate, the carrying capacity (K), the action threshold (UA), economic damage level (NDE) and the tolerance threshold, we can measure and evaluate the success of the rodent control campaign as follows:

1. Measure the census of the consumption of the bait boxes. Suppose that in the measurement of the population of a given area by the Joule Cameron method it gave us that the area is Moderately Infested (11 - 50) trapping in the three nights a total of 10 specimens that are 90% of the population of the determined area, applying a simple rule of three we obtain 100% of the population (11) and for the second phase which would be the control chemical in the feed boxes we should have a minimum consumption of 120g assuming that the remaining rodent ate for 3 days in the feed boxes and taking into consideration the immigrant population.

2. Calculation of the trapping index. Continuing with the previous example, we have that the census of consumption in the bait boxes gives us a total of 650g in consumption, which would be 22 rodents that swarmed during the period of monitoring and the infestation would be in the moderate infestation index. To validate this information, we use the calculation of the trapping index, which should give us between 2 to 5%, which would be a moderate intensity that validates the index of trapping. moderate infestation obtained in the consumption census. This calculation is particularly recommended every 3 months to validate the information obtained with the consumption census and also serves as a means to guarantee the effectiveness of an application company and to measure the success of a rodent control campaign.