Polar Bears - Data, Pictures and Videos

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A scientific analysis on the mating mechanics of polar bears:

"In conclusion, we modelled the mating system of polar bears to identify circumstances leading to a component Allee effect of reduced female mating success. The model is intentionally simple, predicting mating success from male and female densities using only four parameters, with predictions insensitive to two of them. It incorporates, however, key biological mechanisms of the mating system and performs equally as well as more complex models in explaining the observed pairing data. To evaluate the generality of the model, it would be desirable to assess whether the model performs equally in other polar bear populations. Our model could next be coupled with a population dynamics model to explore whether and how a component Allee effect translates into a demographic Allee effect, and aid the development of optimal sex-specific harvesting strategies. Female mating success, as discussed here, is just one component of female reproductive success, which is further influenced by the rate of successful pregnancies as well as cub mortality. Furthermore, demographic stochasticity could lead to random fluctuations in the population sex ratio, and thus affect the number of males and females available for mating, particularly at low population sizes (Legendre et al. 1999; Stephens et al. 1999; Møller & Legendre 2001; Engen et al. 2003; Sæther et al. 2004). Such fluctuations would then, in turn, affect female mating success. This interaction merits further exploration."


Modelling the mating system of polar bears: a mechanistic approach to the Allee effect Reply