Grebes Take a Dive Toward Extinction, the World Over
By David S. Wilcove
July 15, 2013
Notwithstanding my lifelong interest in bird watching, there are very few birds that can take my breath away. The Junín Grebe (Podiceps taczanowskii) is one of them, but that’s mainly because it lives at 13,390 feet in the Peruvian Andes. It is not one of the world’s most colorful birds, but it is one of the rarest. Last summer, when I visited cold, windy Lake Junín, the grebe’s only home, my objective was simply to see the bird. But I found myself pondering a bigger puzzle: Why have a third of the world’s grebe species either disappeared or been driven to the brink of extinction in the last couple decades?
Certain families of birds are well known for having lots of endangered species. Most of the world’s albatrosses, for example, are now imperiled due to incidental capture by fisheries. Parrots are heavily trapped for the pet trade in both the New and Old World, and they are also victims of habitat destruction. Cranes have suffered from hunting and habitat destruction, too. But grebes? They seem so innocuous, and they’re certainly not coveted as pets, food, or trophies. Yet three species have vanished since the 1970s and five others are acutely endangered, out of a total of 22 species worldwide.
In the case of the near-flightless Junín Grebe, it has always been restricted to Lake Junín, one of the largest of the high-altitude lakes that dot the Andes. Reports from the late 1930s indicated the grebe was abundant throughout the lake. When exactly its population started to decline is unknown, but between 1961 and 1979, the number of grebes fell from more than 1,000 birds to only 250 to 300. Standardized counts undertaken in 2001, 2002, and 2007 generated population estimates of 304, 249, and 217 individuals, respectively, suggesting a continuing decline. The Junín Grebe has disappeared from the northern parts of the lake and, according to a spokesperson for BirdLife Peru, is now “probably the most threatened bird in our country,” which is saying a lot for a country with more than 1,800 species of birds.
No single factor appears to be responsible for the Junín Grebe’s demise. Rather, as human and industrial activities have increased in and around Lake Junín, so too have the threats to the grebes. Run-off from nearby mining operations has contaminated the lake, killing off the small fish that are the grebes’ preferred prey. The mines in turn are powered by a hydroelectric dam, which causes fluctuations in lake levels that have ruined stands of bulrushes that the grebes use for nesting. Burning and cattle grazing in the marsh also contribute to the loss of nesting habitat.
Despite these problems, Lake Junín remains quite a birdy place. The morning I arrived, there were flocks of Yellow-billed Pintails, Puna Teal, and coots spread out across the lake, along with Puna Ibis, Chilean Flamingos, Andean Gulls, and various shorebirds. I had arranged to meet up with Cesar Donato Zevallos Bashualdo, a local conservationist who has spent several years observing Junín Grebes. Climbing into a kayak, we set out in search of the birds, with Cesar standing at the bow like a Venetian gondolier, using a long pole to push us through the shallows. The water itself was rich in algae, mud, and suspended organic matter, but it seemed strangely devoid of fish. For two hours we traveled between islands of bulrushes, scanning the flocks of waterbirds for Junín Grebes, but to no avail. Ever optimistic, Cesar insisted we press onward to the deeper portions of the lake where the grebes might be lurking. Eventually he pulled the kayak onto a large “island” of matted vegetation and sprinted across 100 yards of cold, knee-high muck to a spot where he could scan the deeper waters. Afflicted with altitude sickness, cold, and tired, I was debating whether I could even get out of the kayak, when I heard Cesar call out, “Si, hay greebees!”— Yes, there are grebes! I slogged my way over to Cesar, frequently pausing to catch my breath, until I reached him and the spotting scope. Peering through the scope, I saw two gray-and-white grebes picking something, presumably midges or other insects, off the water. While I watched them, Cesar kindly talked me through the field marks that distinguish the endangered Junín Grebe from its common, widespread relative, the Silvery Grebe (P. occipitalis), which also occurs on Lake Junín. (Watching the grebes seemed to do wonders for my altitude sickness, and I now recommend watching rare birds as a supplement to the standard medications for this illness.)
Conservation biologist Michael Soulé once observed that, when it comes to saving endangered species, there are no hopeless cases, only people without hope, and expensive cases. For the most part, I agree with him, but that doesn’t make me optimistic about the future for the Junín Grebe. The birds are suffering not because of a single, preventable problem, but rather because the land in and around Lake Junín is being used more intensively for mining, agriculture, livestock grazing, and settlement. Moreover, the mining industry appears to be an important part of the regional economy (although that does not necessarily mean the particular mines polluting Lake Junín are important).
All of the Junín Grebe’s current range falls within a protected area, the Junín National Reserve, but no reserve is an island, and Lake Junín is vulnerable to pollution and human activities throughout its basin. And that’s the irony: the fact that Lake Junín is, in an evolutionary sense, an island—an isolated lake high in the Andes— which is what allowed an endemic grebe to evolve there. Yet because the lake is not, in an environmental sense, isolated from surrounding land uses, the Junín Grebe now finds itself nearly extinct.
And what of the other grebes that have disappeared in recent decades? The Colombian Grebe (Podiceps andinus) was last sighted in 1977, a likely victim of pollution, wetland drainage, and the introduction of predatory fish. The Atitlán Grebe (Podilymbus gigas), endemic to Guatemala’s Lake Atitlán, vanished sometime in the late 1970s or early ’80s, done in by a combination of water pollution, predation by introduced largemouth bass, destruction of the reed beds where it nested, and ultimately, hybridization with Pied-billed Grebes (Podilymbus podiceps). Madagascar’s Alaotra Grebe (Tachybaptus rufolavatus) disappeared in the early 1980s, succumbing to gillnets, predation by introduced fish, soil erosion from nearby deforested hillsides, conversion of marshes to rice farms, and hybridization with Little Grebes (T. ruficollis). Joining the Junín Grebe in the ranks of the acutely endangered are the Hooded Grebe (Podiceps gallardoi), New Zealand Grebe (Poliocephalus rufopectus), Titicaca Grebe (Rollandia microptera), and Madagascar Grebe (T. pelzelnii). I suspect each of these grebes represents the tip of an endangered-species iceberg, indicative of a much longer list of poorly known fish, aquatic plants, and aquatic invertebrates that also cannot abide the pollution and habitat destruction.
Of course, as human populations and economies continue to grow in the developing world, aquatic ecosystems such as lakes and rivers will be further degraded. In the short term, people stand to benefit from the economic progress. But in the long run, continued degradation can’t be good for the cities, towns, and villages that depend on these same lakes and rivers for clean drinking water, food, recreation, and other ecosystem benefits.
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