As regular CFZ-watchers will know, for some time Corinna has been doing a column for Animals & Men and a regular segment on On The Track... particularly about out-of-place birds and rare vagrants. There seem to be more and more bird stories from all over the world hitting the news these days so, to make room for them all - and to give them all equal and worthy coverage - she has set up this new blog to cover all things feathery and Fortean.

Monday, 27 August 2018

There is not one kind of 'good sperm' -- it depends on other qualities in the male, bird study shows

Date: August 16, 2018
Source: Uppsala University

Summary: In a new study, researchers show that the same type of sperm is not always the best for all male birds. Depending on how attractive or dominant you are you might be more successful with longer or shorter sperm.

In a study published in Behavioral Ecology researchers from Uppsala University show that the same type of sperm is not always the best for all male birds. Depending on how attractive or dominant you are you might be more successful with longer or shorter sperm.

Getting a big family can be a difficult business in nature. If you are a male bird, you have to work hard to secure a territory where you will find food for your chicks and convince a lady that you are both good looking enough and also will be a good dad. But getting a mating partner is not the end of the story, you also need to fertilize her eggs, preferably all of them!

For this, you will need good sperm: sperm that is good at fertilizing eggs, but not only, it also has to be BETTER than the sperm of your potential rivals, that is other males your partner might be copulating with before laying all of her eggs. This happens often in nature, because females do not want to put all of their eggs in the same basket and it might be advantageous instead to have some genetic variation among your offspring.


No comments:

Post a comment