looduskalender.ee

 

We have written quite often about the mating periods of our mammals and birds, and also published videos. In fact it is necessary in order to understand the etiology of mammals  and to understand the motives of their activities.

 

When the seal mothers have brought their little pups, already with eyes open, into the world (just in case one more reminder that their weight at birth is between 10 and 12 kilos), they are fed on  the extremely rich mother’s milk that also is the source of most of the antibodies that the pups need for life. The suckling lasts a little less than 3 weeks (17 -19 days). During this period the pups gain 30 – 40 kilos in weight. The bigger pups in camera view are such, and loudly call for food that is not offered them any longer.

 

The seal pups now exchange the white ”baby fur”, lanungo, for proper fur – the larger are busy with scrubbing against rocks and their appearance turns darker day by day. As individuals the little world citizens are quite different: some go into the water already in their baby fur, others will not have anything to do with sea water although already showing ”moustaches and beard”. Be that as it may, but within a month or two from the birth they must cope on their own, and that includes knowing how to fish – until then they can manage with the accumulated reserves in the body.

 

The female seals that have had pups are in heat four weeks or a month after giving birth. As the camera image shows a great many large seal bulls with dark coats  saunter about on the shore, rolling around on the beach like barrels, when necessary scaring away smaller males. In the video the mating of the seals may seem brutal but nature dictates that the most viable offspring will be from large and powerful males. No matter then that the weight difference may be twice the female’s weight – the weight of large bulls reaches up to 300 kilos.

 

The gestation period of the females lasts 11 months, after the fertilization the first 5 months will be an embryological diapause.

 

 

In the centre of the image we see a weaned seal pup whose fur already starts to go flecked but who in daytime still begs loudly for food. It may be the same individual that we wrote about on February 18th when we got the web camera in working order: LINK