Science, Health and Technology
6:35 pm
Thu August 2, 2012

Harvesting guano to help Peruvian penguins: Saint Louis Zoo digs in

Unlike their cold-weather relatives, Humboldt penguins live only in South America, along the rocky Pacific coast of Chile and Peru. The Saint Louis Zoo’s Michael Macek has been monitoring the penguins there, tracking their health and numbers.

Macek is back in Peru again, in a coastal reserve called Punta San Juan, where Humboldt penguins nest by the thousands. Before he left, he told St. Louis Public Radio's Véronique LaCapra that this time he’s helping to lead a sustainable guano harvest.

MACEK: Guano is poop. Guano is basically bird feces. It sounds really gross. When you actually get there it’s not as gross as it sounds, I mean! The guano actually comes from a bird called a Guanay cormorant, and they nest by the millions in Punta San Juan.

And so through the years, through the centuries, the millennia, they have nested in these areas, and it builds up, and believe it or not it can be as thick as 10, 20 feet. Now as you’re approaching Punta San Juan, you smell Punta San Juan before you see it! It’s a very sort of ammonia kind of smell to it. Once you get there it kind of — you get used to it.

But the guano itself, because it’s such dry desert, it actually looks like clay. So you’re not walking on a bunch of bird poop, it looks like clay. But it’s very, very high in nitrogen, and it’s a very valued commodity for domestic use in Punta San Juan, for fertilizer.

So they still harvest it — they call them guaneros, the people who actually harvest the guano. But it used to be that they just went in there and they brought in trucks, and people digging, and they didn’t pay any attention to where the animals were. And there’s not just penguins there, there’s fur seals, and sea lions, and the cormorants, and Inca terns, and gannets, and all sorts of other birds and animals.

The last time they looked at this, in 1995, when it was not done sustainably, about one-tenth of the Peruvian penguin population was lost through the harvest.

LACAPRA: What is the major threat of harvesting guano, to penguins?

MACEK: Yeah, well so, these coastal areas are very rugged. Lot’s of rocks, sort of like the Northwest. And these birds burrow into the ground. Well, they can’t burrow into bedrock. So they actually burrow into the guano. That provides a substrate for them.

Well, if you remove all that — and they take it down to the bedrock — they’re on their hands and knees with little tools, just taking the very last bits off —

LACAPRA: The guaneros.

The guaneros are, yeah. So that basically leaves the penguins to lay their eggs on the rocks, and they become very vulnerable, and the survivability decreases dramatically. So that’s probably the greatest impact, is that it removes their substrate for nesting habitat.

LACAPRA: Tell me about the sustainable harvest, how does that work?

MACEK: Well, so the first sustainable harvest we had in 2001, and we had another one in 2007. So what we do, we bring a group of both American and European and Peruvian biologists down.

We do some education with the guaneros. The guaneros are not local people, they’re actually the Andean people that come from the Andes, and they traditionally have always come down to the coast to harvest the guano.

So we do a little — a number of presentations with them, telling them why this is important. We do mark off the area, so we basically delineate the areas that can be harvested, and the areas that should not be touched, and of course that’s where all the animals live. So they do not go beyond that.

And then we act as international observers, we basically just sort of have a presence with them, so if they know they’re being watched — and they’re very good about it actually, they’re very — at the end of the harvest all of the guaneros get a little diploma saying that they’ve participated in a sustainable guano harvest.

LACAPRA: OK, so I have to say, I having a little bit of a reaction like this is Americans and Europeans sort of parachuting in, and telling the Peruvians what to do. So how have you handled that, have you — what’s the reaction been, of local Peruvians?

MACEK: Well, everything is through collaboration. And I should say our original involvement in 2001 was by invitation. It was actually our Peruvian colleagues — primarily at the university, the Cayetano Heredia in Lima — it was actually them that invited us in, because they felt, having the presence of people from the outside would have a greater impact, knowing that other people were watching.

And of course the success would be walking away from all of that, and having it being taken over by Peruvian colleagues, and more and more, we have more Peruvian students working there. So this is probably the one project where we have the most sort of American and Europeans there. Generally, we’re just there to help.