The above was the original title of an essay I wrote some 15 years ago, a bit of a rant really, in response to constant needling by some people wondering why I was studying tiny nondescript little warblers for my Ph.D. research instead of something more important… you know… like tigers. After all I was doing field work in a Tiger Reserve anyway, and there aren’t any warbler reserves, so why was I wasting my time? Hence, eventually, my response, outlining the greater importance of warblers.
That essay somehow landed on the desk of Joanna Van Gruisen, who happened to be editing a coffee-table book on wildlife conservation in India for the Ranthambore Foudation. She liked my contrarian essay well enough to want to include it in the book “In Danger” where most of the other contributions were about much more charismatic megafauna, including tigers! She did tone down the title, turning it into a question – see below. In the years since, I keep hearing from various people in India that they have read that article, which was also reprinted in a magazine, and more recently in another edited book on ornithological writings from India. Sometimes I get the sense that more people have read this article than have ready any (or all) of my academic papers. It is this kind of unexpected (honestly) response which encouraged me to try more science writing for nonscientists, eventually leading to this blog and other writing I am doing currently.
This warblers vs. tigers polemic, though, keeps coming back. Recently, a newfound friend on the internets, Arati Rao, wrote to me about going back to re-read it, wishing she could own a copy, but that the original book is now out-of-print. At her behest, therefore, I am reproducing the article below, and hope it finds new readers. I think I will scan the original print version also and post it online soon. Meanwhile, here it is:
Are Warblers Less Important Than Tigers?
Are Warblers less important than Tigers?
Now what kind of a stupid question is that?! Everyone knows that tigers are more important, being large predators, as apex species, at the top of the food chain, flagship species for conservation… etc. … etc. … etc.!!
These are arguments I have to face often enough when I tell people I am studying warblers—in Kalakad-Mundanthurai Tiger Reserve! For some reason, studying these tiny, nondescript, common birds is thought to be an entirely trivial, indeed arcane, academic pursuit of little practical or conservation value.
“What can studying little birds tell me about the habitat of large mammals, which are my primary concern?”—asks the reserve manager. On the other hand, if we focus on the larger mammals—the apex species philosophy of Project Tiger—and do our best to improve their habitat, other species will also naturally benefit. Given limited funds and manpower for conservation (research and action), is it not better to focus on the mega-fauna and let the mini- and micro-fauna take care of itself? The only small creatures one should worry about then are those that may form part of the food chain leading up to the larger focal species.
Before you accuse me of a biased perspective (which is undoubtedly true, for I make my living watching little warblers!), let me state that, in defending these little creatures, I am also arguing in favor of a broader ecological perspective in conservation—one that goes beyond the charismatic mega-fauna, and starts looking at species more in terms of their ecological role in the system, rather than their appearance/charisma, or tourism potential!
So what is the ecological role of my favoured little leaf-warblers?
Leaf warblers (Genus Phylloscopus) must surely rank among the least glamorous vertebrates, so utterly lacking in charisma that even many die-hard bird watchers dismiss them lightly, scarcely bothering to try and even identify them to species level. Part of the problem is, of course, the fact that they are all small, dull-green coloured, and highly active in the forest canopy, making identification in the field difficult. It is only rarely—either when one is truly nuts about birds or when the fate of one’s Ph.D. thesis hangs on such identification—that one develops the eye for the subtle morphological, auditory and behavioural differences between species. These difficulties in identifying species, however, need not bother our busy manager too much, since they (the leaf-warblers) are all pretty similar ecologically as well—the role they play in the forest is largely independent of their taxonomic status, except insofar as structural aspects of their foraging microhabitat within the forest canopy are concerned.
All 18 species leaf warblers occurring in the Indian subcontinent are migratory, breeding in the temperate summers from Himalaya north to the Arctic circle, and taking over the peninsular (including Himalayan foothills, and much of Northeast India) forests from September through May. While each individual may weigh only 7-11 grams (range includes all species; give or take a gram), one may still emphasize the term take-over, when describing their relationship to their forest habitats: they number in the billions and form probably the most abundant avian guild in the subcontinental forests during our tropical winter. My study at Mundanthurai (in the southern western ghats) records a density of 6-8 leaf warblers (of two species) per hectare of forest—usually any given patch of forest may have 2-3 species, depending on the type of forest; and I doubt there is any forest habitat in India that does not host at least one species some time of year. Picking a random hectare from my 20 ha study plot at Mundanthurai, I find 6 leaf warblers (of 2 species) making it their home for 7-8 months— for these are territorial individuals that remain on site for much of the winter. And what do they do during this period? Well, eat insects, mostly! Humdrum as their lives may sound, they spend over 75% of their waking hours foraging for insects (and other arthropods—but insects predominate) in the foliage. Since they are not concerned about finding mates or raising young during this season, and want merely to survive in good shape for the next summer, their other activities—preening and maintaining territories through vocal and visual dialogue with neighbors—does not take much time. Hmm… a bunch of small, dull birds spending most of their day peering at leaves in search of insects—do I seem to be only weakening the defense? Not really…
Consider the fact that each leaf-warbler, on average, eats 3 insects every waking minute (this is averaging over all their activities throughout the day). Since they forage by picking prey off a substrate—mostly leaf, sometimes also twigs and flowers—the prey largely consists of herbivorous insects. In the case of my one hectare on Mundanthurai, it is mostly caterpillars eating leaves. A single leaf-warbler thus eats an average of 180 insects every hour, or about 1980 per day (assuming an average 11 hour working-day from dawn to dusk). The six individuals on our plot thus rid the plants of almost 12,000 insect pests—every day!! Multiply that with the number of days (200-250) that they are in residence on that one ha plot and you may begin to appreciate the service they render to all the plants. Now I ask you to consider removing these warblers from the study plot, since they seem to take away so much research and conservation energy from your more favoured mammals, and picture the forest as it may appear in a few weeks’ time…! The scenario could become even more dramatic if you (in your large-mammal chauvinism) remove all the other insectivorous birds from the plot as well: I estimate each hectare of Mundanthurai’s forest has at least 40 insectivorous birds, including other warblers and flycatchers (both resident and migrant), minivets, shrikes, drongos, babblers etc. The average number of prey may come down to just over 2 per bird per minute—which gives a total of about 5000 insects per hour, or 55,000 per day in every hectare of forest! Remove those insectivores: …and don’t be surprised if in a few weeks your plants start to appear ragged with their foliage tattered… and your endangered langurs become unhappy because so many leaves are now packed with toxic anti-herbivore compounds produced in response to caterpillar nibblings… and the plants make fewer flowers and fruits as they are forced to spend too much energy in self defense… in turn making the nectarivores and frugivores unhappy… and regeneration of the forest slows down as fewer seeds get produced and dispersed… and the ground starts to dry faster because the canopy is thinner and more sunlight gets in… I leave you to work out the rest of the ecological cascade effects on your own!! For now, I’d be happy if you simply pause to appreciate the job done by the nondescript little green jobs—the leaf warblers—and their insectivore colleagues that travel thousands of kilometers every year to eat all those insects.
Before you start protesting that you will never contemplate removing all those birds, and that I am just another doomsayer, consider the fact that 80% of the warblers (esp. the Green leaf warbler, which is the most common one here) as well as the next most abundant migrant (Blyth’s reed warbler) spending each winter at Mundanthurai come from the forests of the hill regions around the Caspian Sea, from Turkey east through Kashmir, including bits of southern Russia and Afghanistan. Now imagine that these hills—breeding grounds for so many migrant insectivores—are deforested on a large scale, either directly by us or through effects of global climate change, cutting down the bird population by 90%. Such declines is not very unrealistic, as those studying migrant forest birds in the Americas will tell you—though they worry more about forests in the wintering areas being cut down rather than in the breeding grounds. In fact, over the past two decades, Americans and Europeans are increasingly facing the prospect of another Silent Spring. Not, this time, due to the factors mentioned in Rachel Carson’s clarion call in the 1960s—over-use of chemicals in agriculture at the height of the green revolutions—but to a suite of other human activities that have hit the habitat of avian migrants in both their northern breeding grounds and southern wintering grounds. Many species of migrant songbirds, which enliven the northern spring after the dreary and silent winters, have been pushed to the brink of extinction—some like the Kirtland’s warbler down to a few scores of breeding pairs—over the past two decades, even as my ornithologist comrades in the west are racing against time to figure out the causes of these declines, so we may try and reverse the process! The culprits are, of course, us humans: deforesting the tropical wintering grounds; fragmenting the temperate forests into suburban woodlots more accessible to human subsidized nest-predators such as domestic cats and other small carnivores (wild or feral) thriving on our garbage; and directly subsidizing populations of non-migratory nest-parasites like the north-American cowbird through back-yard bird feeders, enabling them to survive the harsh winter, and fool over 200 gullible species of songbirds into raising their offspring! We seem to be particularly adept at causing damage to the ecological fabric of this planet, even when we mean good—feed them poor little birdies in the winter, or the cute raccoons at night!!
Getting back to our continent, where we have no information on population trends of forest birds at all—whether resident or migratory, in tropical south and south-east Asia or temperate Russia, Mongolia and Siberia—declines paralleling those on the other continents are very much on the cards, if, indeed, they haven’t occurred already! Given the contempt that these migrants have for human geopolitical boundaries, their populations are subject to forces beyond the control of any one national conservation agency, let alone the manager of a single Tiger Reserve. And if their populations are found to be declining as drastically as many New World migrants’ have over the past several decades, mammal chauvinists may be reduced to haplessly watching the habitats of their favourite creatures getting degraded.
Do you think even the tigers might get worried about such a scenario??
Is it worth studying these warblers, trying to figure out what makes their populations tick, and how to save them—and ensure they continue to keep all those insects down?
Are warblers less important than tigers?? Isn’t the question itself meaningless?
… of starlings, all over the temperate world, in places where the starlings are from, and where they are invasive commensals who have followed on humanities tailwinds into new continents. Around here in the Central Valley, native blackbirds put on such shows as well, although perhaps not quite in such large numbers as seen here in the European starlings. At least not any flocks I’ve seen locally.
Scanning the sky with his binoculars, he searches carefully for any sign of movement: the steady beat of a blackbird’s wings, the fluttering of a flock of starlings. It has been a week now since he saw the starlings: just four of them flitting from tree to tree, feasting on the autumn berries.
Birds are a real rarity these days. In his boyhood, he recalls, he would watch the acrobatics of entire flocks as they ducked and dived after insects. But now the skies are silent, barring the hum of the odd airplane. Turning back to his fruit and vegetable patch, he continues the laborious task of pollinating the raspberry plants by hand, gently brushing pollen onto the slender stigmas inside the flowers. In the past, bees, wasps, butterflies and flies would have done this job for him; nowadays such insects are likewise a rarity. Farmers instead resort to robot bees to pollinate their crops: tiny motors, encased in fuzzy fabric, which hover from flower to flower.
Will this bleak outlook be a reality for future generations? It is nearly 50 years since Rachel Carson wrote Silent Spring, the book that warned of environmental damage the pesticide DDT was causing. Today, DDT use is banned except in exceptional circumstances, yet we still don’t seem to have taken on board Carson’s fundamental message.
According to Henk Tennekes, a researcher at the Experimental Toxicology Services in Zutphen, the Netherlands, the threat of DDT has been superseded by a relatively new class of insecticide, known as the neonicotinoids. In his book The Systemic Insecticides: A Disaster in the Making, published this month, Tennekes draws all the evidence together, to make the case that neonicotinoids are causing a catastrophe in the insect world, which is having a knock-on effect for many of our birds.
Already, in many areas, the skies are much quieter than they used to be. All over Europe, many species of bird have suffered a population crash. Spotting a house sparrow, common swift or a flock of starlings used to be unremarkable, but today they are a more of an unusual sight. Since 1977, Britain’s house-sparrow population has shrunk by 68 per cent.
The common swift has suffered a 41 per cent fall in numbers since 1994, and the starling 26 per cent. The story is similar for woodland birds (such as the spotted flycatcher, willow tit and wood warbler), and farmland birds (including the northern lapwing, snipe, curlew, redshank and song thrush).
Ornithologists have been trying desperately to work out what is behind these rapid declines. Urban development, hermetically sealed houses and barns, designer gardens and changing farming> practices have all been blamed, but exactly why these birds have fallen from the skies is still largely unexplained.
However, Tennekes thinks there may be a simple reason. “The evidence shows that the bird species suffering massive decline since the 1990s rely on insects for their diet,” he says. He believes that the insect world is no longer thriving, and that birds that feed on insects are short on food.
So what has happened to all the insects? In the Nineties, a new class of insecticide – the neonicotinoids – was introduced. Beekeepers were the first people to notice a problem, as their bees began to desert their hives and die, a phenomenon known as Colony Collapse Disorder (CCD).
[via Common Dreams]
This lovely bird is another one I consider myself fortunate to have seen up close (e.g., when I took the above pictures in Pinnacles National Monument recently), given that it is one of those rare endemic species found only in a particular small corner of the world. This one, as you can see in the above map (from the Birds of North America account for the species), happens to be restricted to parts of Central California, west of the Sierra Nevada mountains, along the San Joaquin Valley all the way west to the Pacific coast. You can find a more dynamic, birder-generated current map of sightings via eBird.
The distribution range has shrunk historically with humans taking over much of its habitat for farms and suburbia, but numbers may have been relatively stable until the turn of this millennium. It has remained a species of concern given its limited range, and how much we humans covet its habitat. Nevertheless, the bird appears resourceful enough to have adapted to living amid human enterprise in some of the world’s richest farmland in the valley and the sprawl of the San Francisco Bay Areas! Must be those clever corvid genes that have made the bird flexible enough to deal with some of the insults from us.
Our insults have run quite the gamut, including direct loss of habitat, concerted poisoning and bounty hunting campaigns because the bird is thought to be an agricultural pest (especially for the fruit/nut crops common around here, I think), and most recently, the arrival of West Nile Virus (WNV) in California. That last has landed the Magpie on Audubon’s watchlist, for it has turned out to be perhaps the most susceptible to the virus. The population may be declining in recent years – but we don’t really know what its status is with any certainty! Remarkable that, given how many excellent biologists live and work in and around the species’ range at some of the world’s top universities!
And I include myself among the ornithologists in the region who would like to keep a closer eye on this species. When I arrived in Fresno, West Nile Virus had just hit the state, and I grew curious about the range of the Yellow-billed Magpie because it wasn’t to be found in or around Fresno! The distribution map intrigued me when I first found it because the bird is reasonably abundant in suburban / rural / farmland habitats north of Fresno county all the way up to Sacramento; and along the coast range to the west its range extends farther to the south as well. Yet, for some reason, it wasn’t to be found in Fresno, even in habitat that I would be hard pressed to tell apart from areas 50-100 km north of us where the species is common! I haven’t found a satisfactory explanation for this gap in its distribution, for I’m sure it used to be here, but not any more. Some oldtime bird/wildlife watchers in Fresno have hinted that the species was actively exterminated from the county because of a bounty on its pretty head several decades ago when it was considered a pest! That might explain its disappearance, but its not clear why it hasn’t come back. Is it still being hunted/poisoned by farmers? Or has the habitat been altered enough to deter recolonization, presuming northern populations are productive enough (which they may not be). I suspect there is enough in those questions for a potential masters thesis, but haven’t managed to find a student sufficiently motivated to go chase them. Know any?
Meanwhile, recent studies at UC Davis have focused on modeling habitat needs, on the effects of WNV on the birds, and on loss of genetic diversity through inbreeding. Those studies (follow the link for more info) have drawn upon help from citizen scientists who can report sightings of live and dead birds, the latter being collected for WNV screening. Visit Magpiemonitor.org for more on participation and results.
Right now, we all get a chance to help more broadly as well, by participating in a survey this weekend, organized by California Audubon and eBird. Here’s the invitation:
Yellow-billed Magpie survey set for June 4-7, 2010
If we want to help the Yellow-billed Magpie survive, we need to know where it is living and in what numbers. And that’s where you can help. Audubon California is sponsoring a four-day statewide survey of Yellow-billed Magpies enlisted the help of volunteer birders.
Taking part is simple: All you need to do is log into eBird and record your observations.
Shortly after the survey, we’ll tally up the results and every participant will receive a report of the findings. Audubon California will use these findings to guide our conservation efforts for this bird.
Click on the links to the left to learn more and to take part in this important volunteer project.
I hope you can participate in the survey on what promises to be a nice weekend for birdwatching in the valley. At least, if you are out and about anywhere in this species range this weekend, I hope you will keep en eye out for this not inconspicuous bird and report any sightings.
Happy Magpie tracking!
Reynolds, M. (1995). Yellow-billed Magpie (Pica nuttalli) The Birds of North America Online DOI: 10.2173/bna.180
Coming Fall 2010: an interactive citizen science project that allows you to map your yards and other greenspaces, like parks and community gardens, and share valuable habitat data with Lab of Ornithology scientists.
I just learnt about this upcoming project via @Team_eBird‘s twitter feed earlier today, where they were soliciting feedback on features in preparation for the upcoming beta release of the new YardMap project from Cornell’s Lab of Ornithology, which has become the hub for so many good citizen science projects run on a national scale throughout the US. As you may know, from having read my research or visiting this blog before, I am passionate about citizen science because I see it as a win-win for the citizenry and science. Citizens can really help expand the scope and amount of data available to science, especially ecological science, immensely through well designed citizen science projects. This is particularly valuable for scientists like me at non-research-dominant (R01) institutions where we lack the resources and/or time to gather much data ourselves even though there are many important questions we need to and can address on local/regional/global problems. Case in point, the Fresno Bird Count is now at the core of my lab’s urban ecology research program, and has already produced one Masters thesis (with at least two more on their way), numerous scientific/public presentations, and, hopefully soon, a peer-reviewed paper or two. Meanwhile, the other win can come from engaging ordinary citizens in conducting hands-on science in their own daily lives in ways that might help alleviate some of the anxieties about and suspicions towards science in this age of unreason that seems to be pervading us, especially here in America. Care to join me, and others like my colleagues at the Lab of O, in this effort?
So how does YardMap fit into the growing landscape of citizen science projects? Well, it looks like a pretty exciting project combining interactive online maps and social networking in a neat looking package that might tap into (one can only hope) whatever latent biophilia underlies the immense popularity of games like Farmville on Facebook. Here’s a preview:
If that intrigues you, and especially if you are a birder and/or gardener, consider giving your input to the Lab of O as they finalize the design for YardMap. Start with this online survey, which should take no more than 15 minutes of your time, and also gives you the opportunity to join the beta-test of the site in a few months.
I look forward to sharing my YardMap with you and hope you will let me peek over the hedge into yours…
Now this looks like something worth setting up your DVR to record this sunday: PBS Nature’s upcoming episode (premiering Sunday, Jan 10, 2010) on Hummingbirds. Here are a few excerpts of stunning footage that’ll wow you:
Incredible agility – featuring biologist Doug Altshuler (whom we tried to hire in our department at Fresno State a few years ago… when we were still able to hire anyone at all!):