We’ve noticed that when we take *our* dogs out they always poo nearby our house. We can estimate using Google maps that their **poo radius** is about 300 feet. Are other dogs the same?

We don’t know, yet. But the observation prompts an interesting idea…

Dog poos are not transported by the gods, nor dropped by the birds, nor, generally, left by trekkers traveling miles from home.

They are left behind by our neighbors. Can we be more precise than that?

** Which** neighbors?

It’s a pretty obvious idea when you think about it, and we all probably *implicitly* do come to the obvious conclusion: the neighbors *nearby*. But perhaps if we could come up with a quantitative spin on this we could make that intuition more concrete, and perhaps, more useful.

**Consider the ‘probability of poo’ distribution function**. The probability is low at distances close to zero (people generally won’t let their pups poo right at the foot of their steps, for example, but someone *else’s* steps, that’s another matter!) – and then the probability increases with distance, reaching a maximum at some point, and then decreasing as you get farther and farther from home.

There’s probably a right way to do this – collect data from a team of “dog-poo reporters” in order to establish the shape of the distribution function, P(p|d) (the probability of a poo (p) at a distance (d) from home). Then use that prior distribution and a little Bayesian statistics to ask: *given the occurrence of an orphan poo at location y, what’s the probability that the poo-coward lives distance x away? *

(There must be additional variables, too – poo behavior near a single family home will be different from near a condo, behavior near a front door will be different from a back door, a poo-friendly surface will facilitate poo, winter walks will be shorter than summer walks, etc, etc.)

This might take a lot of work.

But let’s take the easy way out. Imagine that there’s a single poo radius for all dogs (something we admit we have not established) and that the radius is 300 feet (something that might also vary – perhaps *FrouFrou* goes right away, while hefty *Gorgon* needs to walk a while to stir things up).

If we can make that simplification, then we can come up with this:

An interesting visualization of something that’s not usually made explicit, isn’t it?

*It suggests that we can identify the pool of candidate poo-cowards by simply mapping the position of the orphan-poo. *

The five locations identified in the map are recurring poo-hotspots at the southern end of the South Loop:

- Mary Jones Richardson Park
- The 1401 S. State Impact Zone
- Coliseum Park DPFA
- Poo Alley
- Wabash, South of 16th

Each of these sites, some of which are ongoing areas of poo crisis, others that ebb and flow, is created by someone, or several someones, who can be located within a specific geographic pool of residents of the South Loop.

Take MRJ Park, **#1** – that site can be assigned to residents of the northern end of the Dearborn Park II development.

Site **#2** – *ha!* 1401 S. State.

And Poo Alley, Site **#4** – that one can be assigned to Dearborn Tower (1530 S. State), with residents of Burnham Station and Dearborn Mews perhaps also contributing.

This suggests that it could be possible to use a targeted strategy to address the (local) problem of orphan poo. Find a developing poo-crisis at some location? Then identify the dog owners in the buildings that lie within the poo-radius. Distribute informational leaflets. Talk to them. Instead of writing angry letters about the ‘*torrent of dog urine and feces turning [the] urban lawn into a fetid, stinking mire of matted, brown mush*‘, a poo-advocate could simply notify the 25 (say) surrounding dog-households to put each on notice that *one of them* was creating a developing poo-crisis.

Prediction: *problem solved*.

What an awesome post!!!

As a scientist, I really appreciate this kind of thinking, not perfect at the beginning, but perfectly refineable, given continuing thought and analysis. I would like to contribute to that.

I will become a ‘dog-poo reporter’ for this on-going analysis, for sure! Given that people and their dogs are habitual, it only follows that the ‘poo bandits’ are, too. I say get ’em!! And teach them to pick up their poo!!!

Thanks for the kind comments.

It’s almost a trivial idea – one that wouldn’t matter if you lived in the suburbs, for example: Of course you know that it’s Mrs. Smith’s dog down the street that’s leaving poo on your lawn!

Damn you Mrs Smith!In an urban environment, however, whodunit and whattodo can be overwhelming and alienating.

The point is, I think, that even in the city –

all poo is local.