Prevalence of hantavirus antibody showed seasonal and multiyear patterns that suggested a delayed density-dependent relationship between prevalence and population density.
Indeed, Smith et al. [ 23] and Ergon et al. [ 21] suggested that a delayed density-dependent effect in the timing of the onset of breeding was sufficient to generate population cycles in the field vole Microtus agrestis in the UK.
Since the chance of infection was lower in the increase phase than the decline/low phase, we suggest that the effect was not so much a result of delayed density dependence but of having a large reservoir of infection in the population.
The most significant a posteriori evidence when analyzing delivery delay densities of messages generated by MN3 and SN4 is that we were correct in postulating the statistical independence between the positions of the two trams at a random time, which the model derivation is explicitly based on.
Similarly, increasing the degree of fragmentation of optimal habitat available to the prey was accompanied with a shift in the delayed density dependence, from strongly negative to gradually becoming less negative.
By contrast, the coefficients of direct density dependence were approximately equal in all populations, regardless of the degree of specialization in the predator (Table 2, Fig. 1a) Increasing the degree of fragmentation of optimal habitat available to the prey (Fig. 2), caused a shift in the delayed density dependence, b2, from being strongly negative to gradually becoming less negative.
The effects of predation versus no predation had an even stronger effect on the delayed density dependence of the simulated prey populations.
Because of the inclusion of red fox numbers, we did not include a delayed AR term (i.e. X t-2 ), as inclusion of both delayed density dependence and predator abundance can be seen as redundant [ 37].
Recently, Liu et al. [37] focused on a general -species discrete competitive Lotka-Volterra system with delayed density dependence and delayed interspecific competition which takes the following form: (1.2).
And he pointed out that delayed density dependence can arise in natural populations as a result of interactions with other members of the community such as natural enemies, or because high population density may adversely affect the fecundity of the next generation.
