Compare the.... mongoose

Woe ! If only this had been about meerkats, for then we would have meerkats that compare the market, validating almost a decade of advertising : https://en.wikipedia.org/wiki/Compare_the_Meerkat

Dr. Kern said: "We began by using detailed natural observations collected over many months to show that individuals who perform lots of sentinel duty also receive lots of grooming and are well-positioned in the group's social network. But, to prove a causal link, we needed to nail a tricky field experiment."

Professor Radford added: "Over three-hour periods when groups were foraging, we simulated extra sentinel behaviour by a subordinate group member using playbacks of its surveillance calls—vocalisations given to announce it is performing this duty. At the sleeping burrow that evening, we monitored all grooming events, especially those received by the individual who had had their sentinel contribution upregulated."

The researchers found some striking results. On days when an individual was perceived to conduct more sentinel duty, it received more evening grooming from groupmates than on control days (when its foraging calls had been played back during the preceding foraging session). Moreover, the individual who had had its sentinel contribution upregulated received more grooming than a control subordinate in the group.

Market trade was once considered the domain of humans but the exchange of goods and services is now widely recognised in other animals. What the new research shows is that mongooses have sufficient cognitive ability to quantify earlier acts of cooperation and to provide suitable levels of delayed rewards.
https://phys.org/news/2018-05-mongooses-reward-friends.html