July 28, 2025
Waste Management’s Unseen Heroes
- For decades, crows served as nature’s unpaid waste workers in cities across Bangladesh.
- They played a critical role in scavenging food scraps and organic waste from open bins and streets.
- Without them, organic waste now rots longer, attracting flies, rats, and disease.
The crows’ decline is now raising alarms among environmentalists, city planners, and ecologists alike. The connection? Climate change. And its consequences ripple far beyond birdsong.
Climate Change: The Silent Killer
“This is a textbook example of an ecological collapse. Crows were once seen as dirty. Ironically, their absence is making our environment filthier,”
Dr Rezaul Karim, ornithologist and conservation adviser
Rising temperatures, habitat loss, toxic waste, and air pollution are the main drivers of the crow’s decline.
- Rising Temperatures: Heatwaves disrupt breeding cycles and reduce chick survival.
- Habitat Loss: Urban expansion and tree-cutting reduce nesting areas.
- Toxic Waste: Formalin-laced food, pesticides, and industrial waste poison birds indirectly through scavenging.
- Air Pollution: Increased levels of airborne pollutants impair respiratory health in birds, especially in Dhaka, where PM2.5 levels regularly exceed WHO guidelines.
The crow is a keystone species in urban Bangladesh. Its decline has triggered a cascade of imbalances:
| Rise in Rat Population | Increased Mosquito Breeding | Dog-Human Conflict | Rise in Zoonotic Diseases |
| Increased pesticide use, harming biodiversity and soil health. | Greater contact with rodents and dogs increases the risk of disease transmission to humans. | Street dogs are turning to garbage for food, increasing their presence and often leading to more human–animal conflict. | Unmanaged organic waste and greater contact with rodents and dogs increase the risk of disease transmission to humans. |
Climate change is disrupting not only birds’ life cycles but the entire urban food web. “Extreme weather events like storms and sudden rain now destroy many nests before the eggs hatch,”
Dr Mahzabin Akter, an ecologist with IUCN Bangladesh
Human decisions have hastened the decline. In some areas, local authorities reportedly used poisoning or nest destruction near hospitals and airports to curb crow activity—moves that now appear tragically short-sighted. Urban development rarely includes planning for biodiversity. Cement replaces soil, and ornamental plants replace fruit-bearing or native trees, leaving fewer food sources for birds. What Can Be Done?
- Plant Native Trees: Neem, mango, and banyan trees provide nesting areas and food.
- Ban Open Waste Dumps: Shift to sealed bins and composting methods.
- Regulate Harmful Chemicals: Control formalin, pesticides, and toxic food waste.
- Raise Public Awareness: Educate citizens about the ecological role of urban wildlife.
- Integrate Biodiversity into Urban Planning: Make space for nature in the city.
The disappearing crows are more than just an ecological footnote—they are a warning. Climate change does not just melt ice caps or flood coastlines. It disturbs the balance in our neighbourhoods, our streets, our daily routines. As Bangladesh steps into a hotter, more unpredictable future, we must decide: will our cities continue to push nature away, or will we make space for the very species that have helped us survive? In the eerie silence of crow-less mornings, the answer grows urgent.
