Lead poisoning affects which systems in birds?

Lead poisoning in birds primarily affects the nervous system and the digestive system. When birds ingest lead, it can cause severe neurological symptoms because lead is highly toxic to neural tissue. This toxicity can result in a range of symptoms including tremors, lack of coordination, and even seizures, as the central nervous system becomes impaired.

Additionally, the digestive system is impacted because lead can cause gastrointestinal disturbances. Birds that ingest lead may experience vomiting, diarrhea, and reduced appetite, which can lead to weight loss and malnutrition over time. The lead typically accumulates in the tissues, further worsening the condition as it disrupts multiple bodily functions.

Other systems mentioned in the incorrect options do not prominently factor in lead poisoning's primary pathways. The skeletal system might be affected indirectly if lead exposure leads to systemic health issues over time, but it is not a direct consequence of lead ingestion. Meanwhile, respiratory issues are not a hallmark of lead poisoning in birds, as it primarily targets the nervous and digestive systems. Plumage is also not directly influenced by lead exposure, although overall health impacts can indirectly affect feather quality.