mscacco/sdpMig_v2: Optimal Migration Model sdpMig_v2

A package simulating optimal migration within a stochastic dynamic modeling framework, adapted from https://github.com/slisovski/sdpMig.

In this new model version, species parameters are all extracted from allometric relationships and therefore derivable from body mass. This makes the parameter definition easier and makes the model easily applicable to a wider range of species. The model predicts the optimal timing and route of migratory birds from their wintering grounds to their breeding grounds (spring migration), based on species-specific energetic and environmental parameters. The current version also allows for multiple combinations of wintering and breeding grounds. The model takes two site/environmental parameters: the "opening day" (day of the year at which a certain location/stopover can be visited by the migrating individuals) and a suitability layer (with values between 0 and 1, which affect the expected food intake/food at that site). The user therefore has to convert environmental information relevant for the species of interest to these two parameters, which affect the accessibility of each site along the route as well as the expected gain at each site.