Results of studies conducted in the mid-1990s are providing new understanding of the distribution and occurrence of birds in the boreal forest of Russia.
"The purpose of this study was to assess the geographic pattern in the abundance, species richness, and importance of different migration patterns of the avifauna boreal forest of Eurasia from Europe to East Asia as well as their relationship to climate and forest productivity,"according to an article recently published in the Journal of Biogeography.
Standard point counts that record the bird species present were conducted at 14 sites in the boreal forest from the western border near Finland to the far east of Russia. There were also two study sites in Canada that were surveyed for comparative purposes.
Observations were made primarily by experienced Russian ornithologists, with North American observers newly training on Palearctic bird identification doing the field surveys at the Central Siberian and Kostroma study areas.
"The distribution patterns for migrant types were related to both climatic and locational variables, and thus the patterns could be explained by either climatic regime or the accessibility of winter habitats, both historically and currently," according to the article authored by Russell Greenberg, director of the Smithsonian Migratory Bird Center, Anna Kozlenko, currently of Ohio, Matthew Etterson, currently with the U.S. Environmental Protection Agency, and Thomas Dietsch, at the Center for Tropical Research, U.C.L.A.
Results indicated a lesser number of species in the Siberia area in comparison to sites in European Russia and the far east part of the country. Also, there were a greater number of tropical migrants in the eastern study areas, than in the western portion of the boreal forest evaluated. Also, "the numerical dominance of short-distance migrants increased from east to west.
The paper presented two hypotheses for the variability in the bird occurrence.
- 1) "bird populations are responding to the two major climatic gradients ...: a continental pattern in temperature regimes resulting in more extreme temperatures and shorter growing seasons in the mid-continent, and a gradient of summer precipitation from west to east.
- 2) "the accessibility of tropical and non-tropical wintering areas plays a role either in patterns of overall abundance or in the relative importance of tropical vs. within-temperate migration patterns."
In an email interview Dr. Greenberg provided further details on the research.
What were some of the particular challenges during the field surveys?
"Lots of logistical challenges. Rural Russia is very poor and you can not count on being able to get much – so you have to set up your expedition in advance. We could not have done it without the hard work of a couple of Russian colleagues on the project Anna Kozlenko and Olga Romaneski. Other Russians helped enormously and most of the field work done across Russia was done by Ornithologists at the Russian Scientific Nature Reserves. One thing that makes these projects easier in Russia is that there are a lot of really competent field ornithologists. They are really having a tough time. But many joined in for this effort.
"Of course there are the usual clouds of mosquitoes and endless supplies of horseflies and the long rides up Yennessey River on a tiny motorized canoe crammed with supplies and two huskies and completely without life jackets... ."
How many species were noted in Russia?
"I should be clear that a number of different people did all of the surveys. The total recorded on our surveys was around 160 – but more species were seen than this. This list was accumulated on Nature Reserves from extreme western to extreme eastern Russia."
What were some of the more exciting finds?
"We collected a lot of foraging data – particularly for canopy foliage gleaning species. People have wondered how well the MacArthur’s warbler story (6 or so insectivorous wood warblers in the same spruce/fir forest in Maine) translates to the old world system. Some have suggested that tits (which are far more diverse in the old world) have a parallel system of partitioning the trees.
"We found that a single unspecialized species dominates all forest habitat in the European boreal (west of the Ural Mountains) – the Chaffinch and that very few Russian boreal birds are specialized on coniferous trees the way the North American birds are – at least for the insect eating birds.
"We also found that in terms of climate and bird assemblages – eastern North America boreal is more similar to the Russian Far East than it is to the Fenno-Scandinavean region. For the most part, comparative studies have focused on comparing the eastern Nearctic with the Western Palearctic. But it looks like we need to head to the Amur River."
How were you involved in the research?
"I got a research fellowship with research money from the Pew Fellows Program in conservation and the environment in 1991. I used much of this support to fund this work. This was shortly after the fall of the Soviet Union and I had always thought the studying Russian birds was the key to understanding boreal forest birds. I had lots of help and collaborators from the United States, Canada and Russia."
What is the value of the Russian boreal forest for bird species and variety?
"The Russian Boreal is a little more species rich than ours. It seems to have a less specialized avifauna – particularly in the realm of warblers and flycatchers etc. But its sheer geographic extent makes it home to a lot of species of migratory birds – and in the east this includes a lot of tropical migratory species."
What are some of the challenges to learning more about birds in Russia?
"The secret is that a lot is known about the distribution and ecology of Russian birds. Russia has a rich history of bird research. But most of it does not get published outside of Russia or the Russian language. Many of the publications are hard to come by. So connecting more with the Russian Ornithologists is the a great first step. Of course, Siberia and the Russian Far East are vast areas with few field stations supporting long-term research. But there are some."
How are biogeographic studies such as this one helpful with conserving birds?
"I think getting people aware of the abundance and diversity of birds in this vast biome – much of which is still intact but threatened by resource exploitation (particularly the Far East). We found that it was very hard to find any pristine habitat in the European boreal – much harder than in North America, So the few stands of old growth dark coniferous forest need protection. We conducted the work in the Scientific Nature Reserve system – which has considerable value but it suffering with the Russian economy."
"Research continues within Russia, but little is getting out still. Some papers have come out on the Phylloscopus warblers studied at the Myrnoe field station in central Siberia, but I have seen very little else. There has been some genetic and phylogeographic work across the Beringian region (Siberia and Alaska)."
Dr. Greenberg, associated with the Smithsonian Institution, is a co-author of "Biology of Two Worlds - the Ecology and Evolution of Migration," published in 2005; and a co-editor of "Forest Patches in Tropical Landscapes" published in 1996.