Image Credit: Alina Fisher, Image Cropped, CC BY 4.0
Optimizing release strategies: a stepping-stone approach to reintroduction (2019) Lloyd et al., Animal Conservation, 22.
Restoring endangered species through breeding the species in captivity has become common practice over the last century, and has led to the successful recovery of many species. But the process is complicated, as there are always dangers inherent in releasing species that have become used to captivity back into the wild.
This week’s researchers wanted to test a new approach: rather than releasing species directly back into an area where they have disappeared from, they wanted to first release individuals into an already-occupied habitat patch, where predators and prey were present but the species had a high survival probability. This would be a stepping stone before a second release, intended to restore a population in a new area.
Species like this red-crowned crane perform yearly migrations, but how do they weigh up the costs and benefits? (Image Credit: Alistair Rae, CC BY-SA 2.0, Image Cropped)
Where the wild birds go: explaining the differences in migratory destinations across terrestrial bird species (2018) Somveille, Manica & Rodrigues. Ecography, 42, p. 225-236.
Migratory birds make up a huge chunk of the world’s bird life, yet there are still a lot of gaps in our knowledge concerning why they migrate to the areas they do. There’s a variety of potential benefits to migration, from remaining within a comfortable temperature range or a preferred habitat, to gaining access to areas that have a surplus in resources, to escaping competition with resident species. However, migration also results in increased mortality due to the amount of energy it takes. This week’s study tried to analyse the drivers of migration, and what trade-offs were made between migration’s potential benefits and costs.