Toxic air affects birds differently. Why?

Oscar nominated documentary, All That Breathes by Shaunak Sen, builds around the smog-shrouded skies of Delhi which humans, kites and many other living creatures share. The camera reflects on the lives of the two brothers who dedicate their life to saving and rehabilitating black kites.

However, what happens to the kites? Why do they fall from the sky? With Delhi and many other cities in India suffering from worsened air quality, the kites suffer as they try to live in an environment filled with particulates and toxic gasses.

How does air pollution affect birds? Does long term exposure have an effect on their nervous system, behaviour and reproduction? How do different types of birds deal with this?

Dr. Neha Afonso, Exotic Animal Veterinary Doctor from Goa explains how air pollution affects birds and why clean air is important for wildlife conservation.

Neha: We often talk about the impact of air pollution on humans but rarely do we think about how it affects birds. We share our cities with them and they are constantly being exposed to the pollution. Unlike humans, they don’t have many ways to protect themselves.

Birds are very vulnerable to air pollution. They have a very sensitive respiratory system. They have efficient gas exchange due to their unique respiratory systems helping support their high metabolic rates during flight. This means they are very vulnerable to contamination.

They can suffer from irritation to their respiratory system due to the particulates such as PM2.5, PM10 and nitrogen dioxide, sulphur dioxide. This can cause inflammation of the tissue and cause oxidative stress. If they are exposed to this for long periods of time, it can cause issues with their lungs, immune systems and cardiovascular system.

Long term exposure can cause issues with their reproduction. This could cause reduced breeding success and problems with their eggs and chicks.

Inscript: How toxic air impacts their nervous system?

N: Air pollution can cause issues to the neurological system of birds. Pollutants can cause inflammation and oxidative stress. The fine particulates and some toxic pollutants can cause issues. Lead is a heavy metal and is known to have neurotoxic effects.

Depending on the type of pollution and how much the birds are exposed to, they can suffer from issues with coordination, reflexes, awareness and behaviour.

I: Which birds are more susceptible to toxic air?

N: Depending on the type of bird, where they live, their age and how long they are exposed to the pollution, they can be affected differently. Small birds such as sparrows, finches and bulbuls can be very vulnerable to air pollution as they have high metabolic rates. Nestlings and young birds can be more vulnerable as their respiratory and immune systems aren’t fully developed.

Birds in urban areas such as pigeons, crows and mynas are constantly exposed to pollution. They are exposed to vehicles, construction dust and industrial pollution.

They are used to living around humans but this doesn’t mean they can cope with the conditions.

I: How polluted air transforms their behavioural pattern?

N:They may not show immediate signs of issues. They may become less active, have changes in feeding behaviours, spend more time resting and have less stamina.

This can cause subtle changes in their behaviour. They may spend more time resting due to stress on their bodies.

I: How do they cope?

N: Some birds may try to change their feeding and nesting areas. They may try to avoid areas with high pollution. They may also change their behaviours. Some species may move to greener areas with better air quality.

However, urban birds often rely on specific areas for their food, nesting and shelter. There may not be suitable areas for them to move to. They may just be moving away from one polluted area.

They aren’t immune to the pollution. Just because they are adapting doesn’t mean they won’t be affected in the long term.

I: Is there any reason to be worried?

N: Birds are crucial indicators for how healthy the environment is. Changes in behaviour, population and reproduction can tell us a lot.

After Diwali, several cities in India including Delhi, Dehradun, Bhubaneswar, Chennai and Mumbai saw a huge decline in air quality. Many northern cities in India had very high pollution levels.

The fire crackers contribute to the pollution with particulates and toxic gasses. Birds and wildlife are exposed to this pollution and often have no way to avoid it.

We often talk about the effects fire crackers have on our health but we need to think about the animals and birds breathing the same air. They are small, have high metabolisms and sensitive respiratory systems so prolonged exposure is concerning.

Most importantly, the pollution can cause long term issues. It can cause issues with their immune system, reproduction, lifespan and population. The effects can build up over time so it can be hard to notice until there is a significant amount of damage.

They can’t choose the air they breathe or the environment they live in. Their survival is linked to the quality of their habitats.

Clean air is important for wildlife conservation. We need to protect the air quality as it is important for biodiversity. When we think about clean air we need to remember we are not just fighting for ourselves but the many lives that rely on it.