English: It is common for water fowl, such as these Mallards, to accept extra ducklings into their brood. But don't get sentimental over the adoptions. The behaviour is linked to a phenomenon known as the "dilution" effect. Among ducks, the extra offspring cost the parents very little extra effort. By hiding their own offspring among a larger brood, they decrease the chances of one of their own offspring being eaten. The adoptive chicks also benefit from this same dilution. Everyone wins.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.