Spotlight: Cessation? Intensification? Maybe moderation? What is best for farmland waders?
‘Moderation’: What does this simple word have to do with waders? Perhaps nothing at all, though it might help to explain some intriguing facts. For example, in their article in this issue of Wader Study1, Mischenko and Sukhanova report on rapidly decreasing population trends in farmland breeding waders in the Vinagradovo Floodplain near Moscow, Russia. The population declines in Russia are much like those seen in Western Europe, where farming intensification is a problem, but in the Vinagradovo Floodplain agriculture is not intensifying; indeed the opposite is true: farmlands are being abandoned.
Perhaps moderation is in order? Most likely this is too simplistic. Clearly the population health of breeding birds depends not only on factors within the breeding areas, but also on factors in other parts of the world and other times in the annual cycle. But let’s focus on the idea of moderation on the breeding grounds for a moment.
Mischenko and Sukhanova give us an idea of what is happening in the Vinagradovo floodplain where they find that a strong reduction in low-intensity traditional farming and a decrease in the strength of floods are the main factors influencing a decrease in wader abundance.
Agricultural activities in Vinogradovo Floodplain were drastically reduced between 1986 and 2000. Agriculture was heavily subsidized during the era of the Soviet Union. When the Union and these subsidies collapsed, farmland was abandoned across the country. In the early 1980s, haymaking, cattle grazing and the cultivation of maize, potatoes and other vegetables were common in the Vinogradovo Floodplain. These meadows and croplands flooded in spring and the resulting bare ground was used for nesting by waders. By the early 2000s grazing and crop production had ceased and today even land used for haymaking has decreased from 46% in the 1980s to 4–17% in 2010–2014. Without cattle and haymaking to keep the vegetation low, abandoned hay meadows and pastures are now full of dense grass and shrubs that are unsuitable for wader nesting. To make matters worse, these overgrown lands are also regularly burned between the end of April and the first week of May.
To examine seasonal flooding, the authors collected data from a hydrological station on the Moskva River and generated an index of flood intensity. They examined these data for each year during 1982–1985, 1995–1996 and 2002–2014 and categorized each year as having strong or weak flooding. They found that the height of spring flooding has decreased from the 1980s to the 2000s. Lower and shorter floods indicate a shift towards a drier and warmer climate in the area, a decrease in the area of temporarily flooded land, and hence a decrease in the preferred habitat of breeding and foraging waders.
To study the effect of these changes on wader numbers, Mischenko and Sukhanova studied the abundance and distribution of waders using counts of territorial pairs within the floodplain (ca. 50 km²). They counted birds from the end of April to the beginning of June each year from 2002 to 2014. They then compared these data with published survey data for the study area taken in the early 1980s and during 1995–1996.
The populations of several species of breeding wader decreased during the period of agricultural cessation and reduced flooding. Terek Sandpipers disappeared altogether, along with their preferred habitat of wet plough-lands. Ruffs, Northern Lapwings and Black-tailed Godwits also declined, as the short vegetation they prefer was no longer maintained by grazing and late-season haymaking. On the other hand, Marsh Sandpiper and Great Snipe numbers remained stable, and Common Snipe numbers have even increased a little since the 1980s.
Some species were able to use short-term responses to capitalize on open habitats when they existed. For example, Great Snipes established temporary leks in years and areas where flooding created suitable habitats, and Black-tailed Godwits made use of open habitats created when floods matted down the otherwise tall vegetation. These rapid adjustments allowed species to continue to persist in the study area despite significant habitat change. However in the longer term, the authors suggest that agro-environment schemes that focus on traditional farming activities in the floodplain will be needed for the conservation of breeding waders.
Changes in farming in Russia led to the northward expansion of several wader species including Black-tailed Godwit, Redshank, Marsh Sandpiper, and Northern Lapwing2. Waders began to colonize Russian farmland between the 1950s and the 1970s — a time of intense agricultural development. For example, lapwings bred in bogs and were very rare in farmland even at the beginning of the 20th century, but they are now one of the most common farmland birds in Russia. But even as waders colonized farmland, it was clear that not all aspects of farming were good for them — and intensive farming is deadly. Waders can be killed and their nests destroyed by mechanical cultivation, early spring harvesting and early hay harvesting. And even though a moderate amount of cattle grazing is required to keep vegetation at optimum heights for waders, cattle often trample nests. Finally, intensive agriculture requires chemical pesticides, herbicides and fertilizers, which are toxic to adult birds, chicks, and humans.
It comes back to this idea of moderation.
In a recent study of farmland bird communities in NW Russia3, Herzon and colleagues surveyed birds in a 450 km² agricultural landscape near St. Petersburg. They compared breeding densities of farmland bird species among different agricultural uses from May to July in 2005, 2006, 2008, 2010 and 2011. They found that pastures, multispecies grasslands and abandoned fields were particularly valuable habitats for farmland birds (of all types, not just waders). They recommended using grasslands for non-intensive haymaking and pasturing, retention of some of the abandoned fields as open fallows, and production of certain cereals as a nature-friendly way to increase agricultural production in the region.
Thus, in NW Russia a mix of non-intensive agricultural land-uses is recommended for farmland birds, in W Europe farmland breeding waders are suffering under agricultural intensification, and on the Vinogradovo Floodplain waders are suffering under agricultural abandonment. Taken together this suggests that moderate farming might be a good thing for waders and for biodiversity in general. Tscharntke and others discuss this idea in a review paper in which they examine land sparing (where land for nature and land for agriculture are segregated and production is intense in agricultural areas) versus land sharing (wildlife-friendly farming)4. Clearly land sharing should not happen everywhere. Wild lands must be preserved, as untouched by humans as possible, for those species that cannot tolerate even the most wildlife-friendly human use. But where agriculture does take place, a system of land sharing practiced under non-intensive small landowner farming seems to be the most nature-friendly option. Such a scheme would also nurture the biodiversity that exists within agricultural systems and recognize that this biodiversity functionally supports the agriculture itself (through pollination, pest control, soil fertility, etc.).
Moderation certainly won’t fix everything. Wader population trends depend on a multitude of factors: the climate, what habitats the birds originally needed and whether farming helps to create these, and myriad factors that affect the birds when not on their breeding grounds. Still, the idea of moderation in all things, or finding the middle ground between excess and deficiency5, might provide insight. This insight, coupled with more careful study, might allow us to find a true middle ground. Of course, this middle ground will differ from place to place and species to species, but working close to this middle ground might make things more sustainable for birds and humans alike.
Deborah M. Buehler
Outreach Editor, ‘Wader Study’
- Mischenko , A. L & O. V. Sukhanova. 2016. Response of wader populations in the Vinogradovo Floodplain (Moscow Region, Russia) to changes in agricultural land use and spring flooding. Wader Study 123(2): 136-142.
- Lebedeva, E. A. 1998. Waders in agricultural habitats of European Russia. International Wader Studies 10: 315–324 (and references therein).
- Herzon, I., R. Marja, S. Menshikova, & A. Kondratyev. 2014. Farmland bird communities in an agricultural landscape in Northwest Russia: Seasonal and spatial patterns. Agriculture, Ecosystems and Environment 183: 78–85.
- Tscharntke, T., Y. Clough, T.C. Wanger, L. Jackson, I. Motzke, I. Perfecto, J. Vandermeer & A. Whitbread. 2012. Global food security, biodiversity conservation and the future of agricultural intensification. Biological Conservation 151(1): 53–59.
- Moderation in all things, or finding the mean, or middle ground, between excess and deficiency (extrapolation of Aristotle’s Doctrine of the Mean (see https://ethicsinpr.wikispaces.com/Doctrine+of+the+Mean for a summary).
PDF version can be downloaded here.