Guwahati: Butterflies in Arunachal Pradesh are far more selective about their "mud puddling" habits than previously understood, with a new study revealing that different species and families prefer specific substrates ranging from wet sand and stream puddles to animal dung and decaying matter.
Mud puddling is a behaviour seen mostly in male butterflies, where they gather on moist surfaces such as wet soil, riverbanks, animal dung, or decaying organic matter to absorb minerals and nutrients like sodium and amino acids that are essential for survival.
The research, conducted in the biodiversity-rich Talle Valley Wildlife Sanctuary in Arunachal Pradesh's Lower Subansiri district, documented mud puddling behaviour in 63 butterfly species across 11 different substrate types over a two-year period.
Published in the International Journal of Tropical Insect Science, the study by researchers Tajo Kamra and Sudhanya Ray Hajong from North-Eastern Hill University (NEHU), Shillong, highlights how butterflies actively choose nutrient-rich microhabitats rather than puddling randomly.
The researchers found that wet sand, rocks, stream puddles, and wild animal dung were the most preferred puddling sites, while bird droppings, wet soil, and decaying plant matter attracted comparatively fewer butterflies.
Among the species observed, Udara dilecta, Junonia iphita, Byasa polyeuctes, and Dodona adonira showed the highest frequency of substrate use.
The study also uncovered distinct family-level preferences. Butterflies from the Nymphalidae family emerged as the most diverse and adaptable puddlers, using a wide range of substrates, while Pieridae species showed a strong preference for stream puddles and wet sand. Riodinidae butterflies, meanwhile, were frequently seen on rocks and wild animal dung.
Seasonal shifts in puddling behaviour were another striking finding. During the monsoon and post-monsoon months, butterflies relied heavily on rainwater and stream puddles, while in winter many species shifted towards organic matter such as leaf decay and bird droppings.
The researchers noted that butterflies spent the longest time puddling on wet soil, rainwater puddles, and wild animal dung, suggesting these substrates may provide richer or more sustained nutrient sources.
According to the authors, the findings underline the ecological importance of preserving moisture-rich microhabitats and organic resource zones inside forest ecosystems.
"Understanding these substrate preferences is crucial for conservation efforts, as habitat modifications that reduce access to critical types of substrate may disproportionately affect butterfly populations," the study noted.
The researchers added that habitat degradation, seasonal water fluctuations, and changing rainfall patterns could alter the availability of preferred puddling sites, potentially impacting butterfly diversity and behaviour in fragile Himalayan ecosystems.
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