When migrating, animals like the great white pelican have to walk the fine line between saving time and saving energy. (Image Credit: Ray in Manila, CC BY 2.0, Image Cropped).
Landscape-dependent time versus energy optimisations in pelicans migrating through a large ecological barrier (2019) Efrat et al., Functional Ecology, https://dx.doi.org/10.1111/1365-2435.13426
We have all seen the amazing scenes in nature documentaries of the great seasonal migrations undertaken by many different species on this planet. By migrating between two different habitats, migrating animals are thought to maximize both how many resources they have access to, and to minimize their exposure to harsh environmental conditions.
Despite these benefits gained by migrating animals, there are risks associated with these seasonal, long-distance travel events. Migrating animals, like the great white pelican (Pelecanus onocrotalus), have to decide what is better: traveling for a shorter distance or using less energy by taking a less strenuous – but longer – path. Today’s authors tracked the great white pelican during its seasonal migration over the Sahara to study how these birds made decisions about their travel.
Animals depend on consumable energy to live, and that energy can come from a variety of places. If the energy that animals get from their food varies in quality depending on where the animals get their food, what does this mean for birds like the Eastern Phoebe (Sayornis phoebe) that consumes both terrestrial and aquatic food? (Image Credit: Andrew Cannizzaro, CC BY 2.0).
Aquatic and terrestrial resources are not nutritionally reciprocal for consumers (2019) Twining et al., Functional Ecology, https://dx.doi.org/10.1111/1365-2435.13401
In the natural world, ecological subsidies, or the influx of sustenance from one habitat type to another, connect a variety of environments. While research has been conducted on this topic in the past, most of it has dealt with the quantity of energy moving between habitats, but not the quality of the resource itself.
When one habitat (such as an aquatic habitat) is rich in a specific resource that is hard to find in other habitats, subsidies of these resources play a unique role by providing animals and plants with food or energy that they could otherwise not get. The authors of today’s paper wanted to investigate if subsidies from aquatic habitats and terrestrial habitats contain the same amount of that hard to find, valuable resource: highly unsaturated omega-3 fatty acids (HUFAs). Read more