Infact
80 / 100
True unknown

Urban birds use cigarette butts as nesting materials.

Infact verdict: True (80/100).

The claim that urban birds use cigarette butts as nesting materials is supported by multiple sources. Research indicates that birds like house finches and sparrows incorporate cigarette butts into their nests for insulation and to repel parasites due to the nicotine content. This behavior is an adaptation to urban environments, as noted by studies from St Andrews University and other research published on PMC. These sources provide a consensus that supports the claim, leading to a high factScore and confidenceScore.

July 04, 2026 Language: en 1 claim analyzed
How is this score determined? →

Individual claims

80
True Animal Behavior
Urban birds collect cigarette butts and use them as nesting materials in their nests.
Multiple sources, including a study from St Andrews University and research published on PMC, confirm that urban birds like house finches and sparrows use cigarette butts in their nests. The nicotine in the butts helps repel parasites, and the material provides insulation. This behavior is an adaptation to urban environments, supporting the claim's accuracy.
Fact Check Score None
Fact Check Weight 0
Web Consensus Score 90
Web Consensus Weight 50
Source Quality Score 85
Source Quality Weight 25
Llm Reasoning Score 80
Llm Reasoning Weight 25
Weighted Total 80
Evidence Summary 3 web sources confirm urban birds use cigarette butts for nesting.

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