How can we augment the few that remain? Using stable population dynamics to aid reintroduction planning of an iteroparous species

Restoration of depleted populations is an important method in biological conservation. Reintroduction strategies frequently aim to restore stable, increasing, self-sustaining populations. Knowledge of asymptotic system dynamics may provide advantage in selecting reintroduction strategies. We introduce interactive software that is designed to identify strategies for release of females that are immediately aligned with stable population dynamics from species represented by 2-, 3-, 4-, and 5-stage life history strategies. The software allows managers to input a matrix of interest, the desired number of breeding females, and the desired management timeline, and calls upon stable population theory to give release strategies that are in concert with both stable population status and the management goals. We demonstrate how the software can aid in assessing various strategies ahead of a hypothetical restoration. For the purpose of demonstration of the tool only, we use published vital rates of an ungulate species, but remark that the selection of species for demonstration is not central to the use of this tool. Adaption of this tool to real-life restorations of any 2-, 3-, 4-, or 5-stage iteroparous species may aid in understanding how to minimize undesirable recovery complications that may naturally arise from transient population dynamics. The software is freely available at: https//cwhl.vet.cornell.edu/tools/stapopd.

Estimation of total fertility rate and birth averted due to contraception: regression approach

Fertility plays an important role in any demographic transition and total fertility rate (TFR) is one of the basic measurements of fertility. Absences of complete and reliable data, a large number of indirect techniques have been developed to estimate the demographic parameters with incomplete data. Some of these techniques are based on utilizing the data from stable population theory while others are based on the regression technique in which the parameters are estimated through regression equations between the dependent variable which is the TFR and the independent variables which is the socio economic well as demographic variables. The first method is based on the relationship between the Total fertility rate (TFR) and contraceptive prevalence rate for all women. By using this modified estimate of TFR, demographic analysis can easily calculate the birth averted for different regions as well as states also. In fact, provide reasonable estimates of births averted due to contraceptive use by national populations. The variables are CPR that about 51.2 percent variation in TFR can be explained by the first regression approach. The second is based on the relationship between total fertility rate (TFR) and Additive combination of CPR and proportion of currently married females having open birth interval. Using new predictor variable, the improved model explained about 55percent of the variation in TFR. The findings reveal that the values of TFR calculated by the present method are quite close to the observed values of the TFR without involving much computational complexities at different background characteristics. Estimates of births averted and the percent change in births in the absence of contraception, based on the two methods, are fairly consistent.