Nature Picture of Today image bank - the day in pictures

How do birds’ eggs get fertilized?

Submitted by Looduskalender EN on Sat, 09.04.2016 - 09:17

Photo Arne Ader

Translation  Liis

Kalakajakad mängivad

Mew gulls before mating


The mating of birds is an intricate process and it may quite often fail too.

The reasons can differ because birds must read each other’s wishes in the eyes or conclude them from behaviour. So a lack of understanding may occur between the sexes and in some cases a female who is irritated by the behaviour of her mate may even become aggressive. In some species the male tries to attain consent for the mating by bringing gifts but as we all have noticed, the birds don’t touch each other before the moments of actual copulation. This may in the opinion of scientists be the reason why birds must mate several times in order to fertilize one egg.

Web application for seeing pollen levels

Submitted by Looduskalender EN on Sat, 09.04.2016 - 08:55

Info from Estonian Environmental Research

Photos Arne Ader

Translation Liis


Hazel catkins


Flower pollen is an allergen that is present in ambient air and intrudes with breathed air into the bronchi, causing allergic problems for pollen-sensitive people, for instance asthma and hay fever. From spring to autumn, during the flowering period of trees and plants, the concentrations of different kinds of pollen are high in the atmosphere.

Pollen allergy most frequently shows as pollinosis, also called hay fever, the reactions of eyes, nose and bronchi to pollen. Symptoms of pollinosis are for instance reddening of eyes, itching and tear flow, runny nose and sneezing, a heavy whistling breathing and coughing characteristic of asthma. In Estonia about 10% of the population suffer from pollinosis.

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