What are the eating habits of bumblebees

News from science: Why big bumblebees are picky and how masks make us face-blind

The more nectar, the bigger the bumblebee

If bees have discovered a plant with high-sugar nectar while searching for food, they memorize its position on the return flight. Bumblebees, which also belong to the bees, proceed in a particularly sophisticated way, as British researchers have now discovered in experiments (“Current Biology”).

Little bumblebees, which only fly short distances and can carry little nectar, use any plant as long as it carries only a little nectar. Large bumblebees, on the other hand, invest more effort in foraging for food and are therefore more picky. You only remember those plants as a source of food that have a particularly high amount of nectar. The experiments were carried out in greenhouses, where the bumblebees were offered nectar in the form of sugar solutions.

Masks make us face-blind

Did you recently run into your best friend who you barely recognized behind the mask? No need to worry, because wearing a mask fundamentally affects our ability to recognize faces. Researchers have now found this in a study of almost 500 women and men ("Scientific Reports").

Recognizing a face is a complex process in which numerous features of a human face are processed at the same time. If someone wears a mask, this process is reduced in a similar way to a person who suffers from facial blindness - also known as prosopagnosia. According to the scientists, research still needs to be done on the social consequences of this phenomenon.

How man colonized the Caribbean

It is the largest study to date with ancient human DNA from America: Researchers compared the genomes of 263 people who lived in the Caribbean and Venezuela 400 to 3100 years ago ("Nature").

The analyzes showed that different groups from Central and South America had colonized the Caribbean in two large waves of migration. Once 6000 years ago and another time between 2500 and 3000 years ago. Interestingly, according to the study, only a few tens of thousands of people were living in the Caribbean when the Europeans arrived, rather than a million or more as Columbus had reported.

Milk could reduce the risk of allergies

If the mother drinks a relatively large amount of cow's milk while breastfeeding, her child has a lower risk of developing a food allergy. This was the finding of researchers who had asked more than 500 Swedish women about their eating habits and the frequency of allergies in their children at the age of one (“Nutrients”).

One explanation for this could be that cow's milk contains substances that stimulate the maturation of the child's immune system. However, drinking cow's milk is not a general remedy for food allergies, according to the researchers. These often also have genetic causes.

New blue whale population discovered

Blue whales are not only the largest animals that have ever lived on our planet, they also sing particularly deep songs that are easy to recognize. Each population has its own song that it repeats over and over again. This has now made it possible for researchers to locate a still unknown blue whale population in the western Indian Ocean ("Endangered Species Research"). The stocks have been recovering around the world for several decades.

When the dog and its owner develop diabetes

Human and pet health sometimes go hand in hand, as a Swedish study shows. Researchers observed 208,980 dog owners and 123,566 cat owners for several years.

The surprising finding: Owners of dogs suffering from diabetes had an increased risk of developing diabetes themselves - and vice versa. No such connection could be found in cats («BMJ»). If a dog falls ill with diabetes, this could serve as an early warning sign of an illness in its owner, write the researchers.