Effects of urbanisation and pollution on the heterophil/lymphocyte ratio in birds from Brazilian Cerrado.

Stressing agents can cause morphophysiological and behavioural changes in several animals, including birds, which are good study models for environmental biomonitoring. The heterophil/lymphocyte ratio (H/L) is an efficient indicator of chronic stresses in birds. In this study, we aimed to compare the H/L ratio of birds between the areas with different levels of urbanisation, anthropogenic noise and carbon monoxide (CO) emission rates.

Effects of urban proximity and the occurrence of erythroplastids in Antilophia galeata.

Air pollution can generate changes in the morphology, physiology, and behavior of several animals, including birds, which, when responding to such environmental changes, can be used as biomonitors. Quantitative and qualitative analyses of erythrocyte nuclear anomalies comprise a useful tool for biomonitoring, with anucleated erythrocytes, called erythroplastids, being particularly significant. The objectives of the present study were to quantify the presence of erythroplastids in Antilophia galeata and relate their presence to distance from the nearest urban environment.

Effect of urbanization on the micronucleus frequency in birds from forest fragments.

The urbanization contributes to environment contamination, mainly by the increased vehicle traffic. This intense traffic releases in the air chemical compounds with mutagenic properties that can affect the entire ecosystem. The birds for the flight accumulate air, absorbing gases or particles.

Dominant frequency of songs in tropical bird species is higher in sites with high noise pollution.

The structure and organization of acoustic signals arise through evolutionary processes and adaptive pressures on each species. During learning, natural or anthropogenic factors, such as high noise levels in urban areas, pose challenges to acoustic communication in birds. Many species adjust their acoustic signals to higher noise levels by increasing the frequency of vocalizations.

Micronucleus as biomarker of genotoxicity in birds from Brazilian Cerrado.

Birds are considered efficient bioindicators, by their behavioral characteristics, diversified diet, and use of several vegetation layers, including in contaminated environments. The accumulation of contaminants can harm the reproductive process and survival of species, in addition to causing severe metabolic disorders. Air pollution can also affect the birds' health.