Looking at first glance like something much larger, this tiny cage is designed to protect seeds from hungry mammals, while permitting easy access for insects and other invertebrates.
It is one of 7000 identical structures recently deployed around the world for a 24-hour experiment to test a key Darwinian theory – that species interact with each other more as location moves towards the equator.
The experiment was conducted by a team of researchers led by Anna Hargreaves of McGill University in Quebec, Canada.
The results, at least for invertebrates, confirmed the hypothesis. Seed consumption increased 2.6% for every 10 degrees of latitude. All up, consumption increased 17% between Alaska and the equator.
The study is published in the journal Science Advances.