Matrix population models are often applied to a variety of organisms possessing different life history traits, and fertility rates need to be estimated differently for them. Although there is a general method described for estimating fertility rates, there is a substantial variability in the ways fertility rates are estimated. The objective of this study was to evaluate the clarity in fertility parameters as well as the accuracy in methods used to obtain them. Then, the results were compared with the life history traits of the organisms. The study involved meta-analysis of published articles that constructed a matrix population model for organisms within the Kingdom Animalia. Literature was organized into different animal group categories including, invertebrates, fish, birds, reptiles, and large mammals. Within each category each individual study was categorized based on whether it included sufficient information about estimating fertility rates and if the methods used for parameters were correct. We especially focused on the time-scales of fertility rate compared with other vital rates in the model.
Results/Conclusions
Matrix population models are a useful tool for ecologists when trying to understand the dynamics of a particular population. They are commonly used in conservation biology. Our results suggest that at least twenty percent of matrix population models within each animal group are not clearly written, and as a result methods were not easily replicable. Among the remaining papers, organisms in smaller body mass size also tended to have a higher percentage of inaccuracies when defining and estimating fertility rates. This results mostly from the mismatch between the time scale of a population matrix and reproduction of organisms. The results suggest that there is a significant percentage of papers with mistakes when constructing matrix population models across different animal groups. We conclude that there is need to improve the method for estimating fertility rate in matrix population models especially for smaller organisms.