**1. Introduction**

Birds reflect the quantities of xenobiotics in the environment and have been utilised as bioindicators to assess the extent of developing contamination present in any particular ecosystem. Due to the omnipresence of the environment in the modern world, heavy metals produced due to anthropogenic pressure persists in the environment Elemental poisoning in the environment has increased in recent years, raising concerns that have not only afflicted industrialised countries in Southern Asia but also India [1]. Heavy metal deposition in soils is caused by natural geological processes, whereas atmospheric deposition, flooding, and industrial discharge

are caused by anthropogenic sources. Higher-trophic level organisms absorb these elements from bacteria, macro-invertebrates, flora, and other abiotic elements, which are subsequently transferred to them [2]. Due to exposure parameters that are over acceptable limits, vital metals that would otherwise be necessary for the growth and development of the species throughout this process can instead become hazardous to the organism [3]. The contribution of heavy metal contamination to the terrestrial environment comes from several man-made sources, including urban activities, paint, manures, industrialisation, discharge from mines, biomedical and hazardous waste disposal, obnoxious use of fertilisers and pesticides, coal burning, vehicle exhausts, and open incineration [4]. Long-term accumulation of persistent toxicants in sediments exposes wildlife living in coastal environments to the effects of such toxicants, which can continue to occur for years [5]. Heavy metals, a significant ecotoxicological pollutant, have an impact on the diet, feeding habits, and evolutionary traits of several animals [6].

The first instance of using Aves as a biomonitor to assess environmental health was recorded in history in the 1960s [7]. Consumption of contaminated food is a significant method through which birds obtain metals [8]. Acute poisoning can cause adult birds to die [9], but chronic exposure to metals at low levels can continue to occur in birds with extended life spans [10]. Heavy metal toxicosis can cause physiological and genetic diseases, growth impairments, impaired development, reproductive issues, disease resistance, and population decrease [11, 12].

### **2. Background**

Diverse marine bird and animal species have recently perished from anthropogenic causes and rare diseases. One of the primary causes of such events is anthropogenic sources. Animals may exhibit endocrine physiological problems as a result of several man-made substances. Toxicants can be deadly to animals, including birds, and can mess with their endocrine systems. One of these toxicants is organochlorine since it can penetrate all topical layers. Endocrine disruptive substances, such as polychlorinated biphenyls (PCBs) and organochlorine pesticides, can accumulate in the tissues of wildlife over time. Due to exposure to excessive quantities of hazardous compounds from different pesticides, wildlife has suffered as a result of mass fatalities. The incapacity of open-sea creatures like Albatrosses and cetaceans to metabolise hazardous persistent pollutants has been linked to higher levels of organochlorines in these creatures [13]. As a result of their quick adaptation to climate changes, birds are regarded as pioneer indicators for changes connected to global warming.
