I Have based the documentay on the following theory of the investigators Angel Corral Arroyo and Pedro Conde de Caso.

"In the animal kingdom, the least the brain capacity of the young is, the more they tend to reproduce the conducts learnt from their parents. So, the less brain capacity there is, the less will the organism evolve. However, behaviour is aquired and not genetic. There can exist certain type of benhaviour which is not learnt and that is wrongly called instinctive or inbred . Therefore, these conducts are only an answer to smell and auditive instincts, which means that if these sense are not stimulate, there aren't any actions or conducts.
For this reason, animals of a population have loyal and rigid conducts, as what is expected. Because of this major reason, two populations that are isolated from its own species will have their conducts gradually growing apart, as its slow and inexorable evolution creates divergence. The thing is that this happens at an imperceptible rate which leads us to consider the conducts as inbred.
This is why when we change the context or the habitat of the animals they are extinguished as their conducts are too rigid to adapt quickly to new circumstances. So when we destroy an ecosystem or artificially change eating habits of an animal population and thereafter take away their food supply (ie.: a rubbish dump), these individuals perish because food in the dump is their livelihood. That's why mankind evolves at an excessive rate, meaning therefore that the adult young do not look to much like their parents. Due to this, cultures exist."


Pedro Conde:

"For about ten years aproximately, we have been studying in the province of Zamora, the repercussions of environmental changes over animal behaviour, especially birds. Zamora, and more specifically the region of Sayago, by characterized by it's extreme climate, thatis, very hot summers and very cold winters. Add to this, the fact that there is a noticeable depopulation and a great variety of flora, and the result is a great variety and quantity of birdlife. The reason for which we decided to study in depth some bird species, is the fact for about a decade or so, an important change of behaviour in some of the species was noticed, as well as changes in migration habits in birds like the White Stork and above all the influential progression in the downfall of some species such as the Black Stork, the Imperial Eagle, etc. Faced with the alarming and continuous progression of birds in danger of extinction, we think that a natural alternative is to study whether birds accept other species as their own young, and also to analysewhat climate changes can influence if eggs and other young are rejected or not. The idea parted from the study of parasital birds, such as the Cuckoo and the Great Spotted Cuckoo, two species which are quite common thoughout this area and whose behaviour is different. The Cuckoo doesnÇt accept the presence of his ñstepbrothersî in the nest and consecuently, when it is born it gets rid of the eggs of the female that whoÇll care for it. On the other hand, the Great Spotted Cuckoo , lives together with the young parasital species, the Magpie. These are two diferent ways to parasitize. As a hypothesis, we asked ourselves the following question: Will other bird species of this environment, that are not used to being parasitized, be able to accept egg an young of different species in their own nest? According to studies made by scientists, on parasital species, the Cuckoo and the Viduinos have demonstrated that the adopted parents are able to distinguish the colour and the form of the young parasites. This is the reason for which the young, whether their own or adopted, have the same features, as in the case with Viduinos and Strildidos. Due to lack of research in this respect, with our esperiments we are able to verify the hypothesis and confirm the fact that birds accept without any problems whatsoever other different species, as long as we base in mind certain conditions that we expose in our work. To confirm with greater clearance the purpose of our work, we have studied two different species as regards to their size, colour of feathers an windpipe, , facts that are relevantly significant in such experiment. It's the case with the Great Grey Shrike (lanius excubitor) and the Magpie: both were residents and parasites at one time."


More information:

Angel Corral Arroyo
C/ Núñez de Balboa n’22,3’C
ZAMORA (Spain)
Phone: +34.(9)80.523021

Pedro Conde de Caso
Phone:+34.(9)39.480055