The opening shot of Shaunak Sen’s documentary “All That Breathes” is very impressive.

It’s a slow pan across a vacant lot in New Delhi at nighttime, first a litter-filled corner, devoid of life. Then the evening residents come out. A dog here. A cat there. Something unidentifiable, but probably feral, lurking in the corner. The camera keeps panning, adjusting focus for any movement. Was that scurrying a rat? Probably. A truck passes in the background. Another rat. Or two? Or a dozen? Accompanied by the sound of squeaking, a group of rats appear. This is their land. The scene ends not with a hard cut, but with the lens flare from the headlights of an approaching car.

In a little under three minutes, Sen has encapsulated a vision of New Delhi in which modern life, particularly pollution and overpopulation, have placed new strain on the balance between humans and nature.

The 91-minute film deals with two brothers who really like birds.

Nadeem and Saud live in a working-class, predominantly Muslim neighborhood of New Delhi. They make money doing something involving soap dispensers, but their passion is their budding organization called Wildlife Rescue. Since 2003, the brothers have been collecting injured kites, birds of prey that seemingly float effortlessly over the city, occasionally coming down to landfills to consume waste. The air quality and air visibility in New Delhi are so bad that the birds literally smack into each other in the air. Nadeem and Saud, when they aren’t lobbying for donations and grants, tend to the kites, primarily in a cramped, dingy basement and a rooftop enclosure.

Nadeem and Saud’s pursuit is a noble one, inspired by their late mother, but as a character study, “All That Breathes” shows the toll that this all-consuming hobby has taken on them. Nadeem knows the impact they’re making on a micro level, but he yearns to see the world and to study abroad, taking what he’s learned global. Saud is more content to remain local, but he’s weighed down by the city’s out-of-whack ecosystem, with more hurt birds than they can handle.

Providing a tiny bit of levity is their new volunteer employee Salik. Salik brings a childlike enthusiasm and inquisitiveness. Would birds survive a nuclear attack on New Delhi? Is there actually enough water to cover the entire earth or is that just science fiction?

The long opening shot is just the first of many times that the camera is left to take in the intersection of natural and human-chaotic in the city. Wild hogs march in procession along a river. Oxen navigate the increasingly decrepit streets. Monkeys teeter precariously on the wires that connect stacked apartment complexes to modernity.

Viewers might notice that, while Saud and Nadeem look to the skies, “All That Breathes” is formally designed on a horizontal — panning to see what happens when all of nature comes together at street-level — rather than vertical. Even the closing credits are horizontal. Sen and Bernhard’s favorite type of shot is one where the thing you’re looking at gives way, through a rack focus, to something else, whether in the background or foreground, like the man-made bonfire that falls into a distant blur as we watch a snail, slowly inching forward. As with everything in the documentary, you can either appreciate such shots as lovely natural images wrought from a bustling urban space or as reflective of the persistence of flora and fauna in a moment of civilization running out of control.

In this tiny marvel of a documentary, it’s a little and a lot all at once.(SD-Agencies)