الفهرس 
Chapter I: Introduction and Aim of the WorkOnly 14 pages are availabe for public view
 |  | from | 224 |  |  |
| | | from | 224 | | |
Abstract
The thesis aims to: 1- Estimate morphometric measurements such as body weight and lengths of the head, bill, wing, tarsus and tail, 2- Evaluate the morphological changes of the ocular and histological tract and thyroid gland, 3- Measure the concentration of lead as a contaminated heavy metal in the tissues of the liver, kidneys and muscles, and samples of wing, tail, chest and back feathers for females and males in the laughing dove, the barn swallow and the house sparrow. The thesis consists of five chapters followed by an abstract in English and another in Arabic, as well as a list of references and recent research closely related to the subject of the study and contains many anatomical images, cross-sections, and diagrams showing the results obtained.
In chapter 1, there is an introduction to the subject of the study, explains the basic concepts of the systems of mating and the impact of environmental pollution on them, and the objectives of the thesis were also mentioned.
In chapter 2, previous researches were studied, which mentioned mating systems in birds and environmental factors affecting them, such as pollution with heavy metals, and the structure of the genitals and thyroid gland of both males and females of birds was also explained, and the ecology of the birds used in the study was explained.
In chapter 3, materials and methods are explained in terms of collecting samples, preparing them for histological examination, and determination of the concentration of lead in them.
Chapter 4 presents the results of the study in terms of morphological characteristics, morphometric measurements, anatomical and histological features of the male and female genital organs, the thyroid gland, and the concentration of lead in the tissues of each of the laughing dove, the barn swallow and the house sparrow.
Chapter 5 discusses the results of the study by comparing them with the results of previous studies and
clarifies the extent to which they agree or disagree.