We’ve all seen squirrels carrying acorns around in their mouths and burying them in the ground. This is a way to hoard food, and most squirrels use a strategy called scatter-hoarding. Instead of storing all of their excess food in one spot for easy access later, squirrels spread their food around in so many different caches that it is hard to believe they could find all of the spots again later. However, a squirrel has a choice to make when it comes across a food item – will it cache it and save it for later or will the squirrel eat it right there? Several factors play into this, such as quality, perishability, and scarcity. Mikel Delgado et al. studied how these different factors had an impact on the food-storing decisions of adult fox squirrels.
GPS has always seemed to me to be a kind of magic technology. The idea that a grid of satellites so far above my head that I cannot even see them can tell me exactly where I am and help give me directions where to go is pretty stupendous. And you do not even have to pay for the information! GPS is such a powerful technology that it is being applied to a great diversity of areas. One example is precision agriculture. For instance, if you are growing crops, they will often need water, pesticides and fertilizer. If you don’t give them enough they will have a reduced yield and if you give them too much you spend too much money and you might cause pollution. The image on the right  shows a crop that needs watering. But only the red areas are dry. So if that data is fed into a GIS databank and that is coupled to a GPS receiver on the irrigation system, the farmer will know precisely where to give water (or chemicals) so that the crop gets the right amount and there is minimal waste and runoff.
Whether it’s an older sibling taking the last piece of cake from their younger sibling or a dominant coyote shoving a subordinate out of the way so it can eat the food, nature has its hierarchies. Generally, the stronger individual is at the top of the food chain – for example, the older sibling or the dominant coyote. Getting to the resource first doesn’t matter if you can’t defend the resource, as can be seen very well in the example of coyotes. Even if the subordinate coyote discovers the food source, the dominant will still monopolize the food there.
Dominant or subordinate?
Recently, a study was done by scientists in Millville, Utah, to investigate the effects of social hierarchy on the foraging efficiency of an individual. Eight pairs of coyotes (one male and one female in each pair) were observed in order to determine the effects of a dominant and subordinate being paired in the hunt for food. Before scientists could observe the coyotes, though, they had to determine which of the coyotes was dominant and which was subordinate. Winner-loser trials were used to test dominance, by letting the pair have a single food source and see which of the coyotes was displaced from the food.