Ecological race nesting parasites

Ecological races or biological races , more rarely biological lines are groups (or evolutionary lines) of individuals of the nesting parasite , having connections with a specific educator species. They are usually distinguished when studying nesting parasitism. Gnezdovye parasites, such as cuckoos, which use several types of educators, to feed their chicks, are divided into different groups or lines associated with a particular type of educator. This specialization allows nested parasites to lay eggs, which in some cases can imitate the host eggs, which increases the chances that the egg tossed will not be recognized and thrown away by potential caregivers.

The exact mechanisms of evolution and maintenance of the ecological races of the common cuckoo are still the subject of ongoing research. However, in the common cuckoo , it is believed that the signs that determine the color of the eggs are linked to the floor and are found in the W chromosome , which is only present in the female. Males of cuckoos, which, like all males of birds, do not have a W chromosome, are capable of mating by females of any ecological race, and thus the unity of common cuckoos, as a single biological species. This is a different case than other nesting parasites, for example, such as cow corpses , where both males and females imprint their preferred host. What further leads to speciation, for example, as among widows , who, as suggested, have a more recent evolutionary origin than their masters.

Different approaches to the definition of the concept of “ecological race”

According to A. S. Mal'chevsky, the “genetic“ races ”of cuckoos are a group of females that differ in the color and coloring of the eggs that are laid” ^[1] . After giving this definition, Malczewski stresses that since, for example, “a biological race that lays blue eggs can <...> parasitize not only on the Redstart , but also on a whole number of other bird species that have the same egg color. Thus, the conjugate evolution of the nesting parasite with any one particular type of warbler in nature, apparently, does not happen " ^[1] . On the basis of the accepted definition, Malyky notes that the charmer, in contrast to the redstart coot, was able to raise cuckoos belonging to different biological "races" <...> with eggs <...> of "redstart" , "chaff" , "reed" and "ridge" types ^[2] .

A.D. Numerov points out that “the isolation of ecological races should be carried out according to the type of educator, since it is with him that the nest parasites establish a temporary connection through the mechanisms of imprinting.” Below, he stresses that “it is according to the“ owner ”, and not according to morphology, the selection of ecological races from parasitic invertebrates is accepted ^[3] .