Shorebirds as an indicator of climate change impact ****************************************************************************************** * ****************************************************************************************** Interviewer: Michal Andrle November 9, 2018 Recent doctoral graduate Vojtěch Kubelka at Charles University, Prague, is the lead author in the magazine Science that describes trends in the predation of shorebirds nests with re change. The article by the six-member international team was part of his dissertation, whi September at the Department of Ecology, at Charles University in Prague. Many scientists go their entire lifetime without publishing in one of the most prestigious journals. You were able to manage it practically at the start of your scientific career. C bit about the focus species of your research? "As the title suggests, it’s about birds whose lives revolve predominantly around water en There are currently 245 recognized species of shorebirds also called waders. Throughout th ornithology, 52 species have been recorded in the Czech Republic, but most of these were j through. Overall, 8-12 species nest here, though some only rarely. As in the rest of Europ of shorebirds here has declined significantly over recent decades. The most common shorebi Czech Republic is still the Northern Lapwing (Vanellus vanellus), followed by the Eurasian (Scolopax rusticola) with its hidden way of life, and the Little Ringed Plover (Charadrius phylogenetic perspective, shorebirds are a more complicated group. Along with gulls, terns comprise the order of Charadriiformes. For many years, however, it has been known that sho traditional sense, form a paraphyletic group, with certain members being more closely rela and terns than other shorebirds. However, based on eco-morphological traits, we can consid single group, which is not a problem for most research." Why did you choose shorebirds? "Shorebirds are a unique group of birds for a number of reasons. For many years, I have be their ability to inhabit diverse environments and migrate over great distances, as well as of their mating systems and parental care. When investigating the level of predation, ther in the certain uniformity of nesting. Most shorebirds nest on the ground and generally lay so the nests appear similar to potential predators. All over the world, scientists studyin are relatively uniform in the way how they visit nests and record the predation rate. In a supervisor, Prof. Miroslav Šálek from the Czech University of Life Sciences in Prague, I a an expert in comparative studies – Prof. Tamás Székely from the University of Bath, Englan did a six-month internship via Erasmus+ program. I began work in 2015, and since then have poring over available primary literature and gathering the suitable data. The work also in I helped collect in the field, for example on the Northern Lapwing (Vanellus vanellus) in in the Czech Republic or the Red-necked Phalarope (Phalaropus lobatus) in Chukotka, Russia years of intensive work and a great deal of luck, the article is coming out now in Science How much did the other authors contribute? "I chose the topic myself and developed it with the other co-authors, especially my superv trio was joined by Dr. Pavel Tomkovich, who helped with most of the data covering Russia. essential member of the collective was Prof. Robert P. Freckleton from the University of S England, an expert in spatio-temporal modeling on large ecological scales. Dr. Zsolt Végvá University of Debrecen in Hungary, obtained and prepared the necessary climate data for th population of shorebirds. Each of the authors was indispensable in their own way for the f achieve its present form." How big is the community of scientists studying shorebirds throughout the world? "The “International Wader Study Group”, has roughly 500 members and mostly encompasses the “shorebird” community, including scientists, environmentalists and banders, among others. affiliated in the “Western Hemisphere Shorebird Group” have a similar number of members. W are about one thousand professional and competent amateur ornithologists whose research is focused on shorebirds. In our country, I was able to revive the activities of the Czech Wa Conservation Group 11 years ago, which is a work group of the Czech Society for Ornitholog 56 members, most of whom are amateur ornithologists. The largest group of people professio to shorebirds is centered around Prof. Miroslav Šálek at Czech University of Life Sciences Your study works with an extensive set of data. What exactly is the data on and what metho process it? "We were able to obtain mostly previously published data on 111 species of shorebirds in 2 at 149 locations on all continents, including Antarctica for our research. Overall, we use from monitoring of 38,191 nests. Each nest was exposed to predators for a varying number o total period of the exposure of all nests represents an interval of more than thirteen cen predation analysis, we used the Mayfield method, introduced back in 1961. The target varia nest predation, which nearly half the articles directly or indirectly reported. It was fir check this information and carefully incorporate it. This wasn’t always possible directly, there was used a suitable conversion method to get the target variable." What exactly does this key term mean? "Every nest is exposed to potential predators for a certain number of days. The daily nest the number of predated nests divided by the total exposure of all nests in the given set. predation represents the number of nests predated in a single day. Ultimately, we converte predation to the total nest predation rate, which is a species-specific value that tells u of nests of a given species is predated overall throughout the entire incubation cycle. Th incubation is species-specific, generally 20-30 days. The daily nest predation and the tot are two variables, each looking at the same issue from a slightly different perspective." Which species prey on the nests of shorebirds? "Shorebirds don’t have specific predators tied to a particular species. On the contrary, m are opportunists who eat a mixed diet of rodents, for example, and of course bird eggs. In predators mainly include arctic foxes, weasels, skuas, gulls and ravens. In temperate zone primarily at night; these are mostly red foxes, martens, hedgehogs and again, members of t Towards the equator, we also see jackals and smaller predators, rodents become more signif black rats), with lizards (e.g. monitors), snakes, and even crabs preying upon the eggs of higher diversity of predators in tropical areas probably contributes to the high level of In tropics, however, our knowledge of predation is significantly less comprehensive." Can you briefly tell us about the results of your study? "Our results show that as anticipated, there is a latitudinal gradient in the level of nes the most intensive predation in the tropics and a declining level of predation in the temp areas. However, this trend was only apparent in the historical data set up to the year 200 currently remains the same in the southern hemisphere, but there have been fundamental cha North. These concern the temperate zone, but are most apparent in the Arctic, where there three-fold increase in the daily nest predation. At present, nearly 70% of all shorebird n in Arctic, which represents a fundamental change and significant problem for shorebirds." How do explain this change? "There were known changes in the number of lemmings in the Arctic in around 2000. These ro the foundation of the food web here. As a result of more frequent temperature fluctuations and refreezing snow cover, lemmings were unable to find food under the snow, leading to a cyclicity and a decline in the lemming populations in a number of areas. For Arctic predat of shorebirds represents an alternative prey and the level of their predation therefore in decline in the number of lemmings. Before 2000, when lemmings were more numerous, shorebir up to a one hundred percent hatching rate and virtually no predation every few years. The predation was one of the advantages of the long bird migration to the Arctic, which ensure number of young individuals maintaing the global population. However, our results show tha the Arctic nowadays represets an extensive ecological trap for migrating shorebirds from n perspective." Your analysis also examined the southern hemisphere. How does it compare with the north? "The southern hemisphere differs from the north in many ways. For example, there is no maj the temperate zone and we don’t find a mass of rodents analogous to the Arctic there. In r there have been no major changes in ecosystems like in the Arctic, so we do not see any ma nest predation in the southern hemisphere and the latitudinal gradient still matches histo growing intensity of nest predation towards the equator." Your research not only monitors the daily nest predation but also places this in context w What exactly does this correlation involve? "We obtained data on trends in average annual temperature for 30 years before the last yea collection at each location. One of the parameters of climate change was an increase in te time, a second was temperature variability. These are factors of global warming and climat which we then directly linked to the daily and total nest predation rates at the same loca What was the result of these correlations? "It turns out that locations with the most marked global warming and higher degree of clim also showed the highest level of shorebird nest predation." Does your study draw any conclusions that could be used for environmental protection? "Our study is one of the first to show that climate change can impact inter-species relati scale. This has numerous implications for conservationists. Generally, we can say that sho global decline. Of the 245 species, population trends are known for 192 species. We know t of shorebird species are in decline, 12% are increasing, while the other species have a st For species that migrate to the Arctic – the trend is even more pronounced –higher percent species is in decline. There’s not much we can do in the Arctic itself. Fencing nesting ar foxes would only protect a very small area." Does that mean there’s nothing we can do but sit back and watch? "Not at all. Shorebirds have another major problem. The majority of species leave the Arct although there are also species that can stay in the southern part of the Arctic through t spend the winter in temperate or tropical zones. These are mainly vast mudflats in the int the edge of continents, as well as inland wetlands or grasslands in the interior. In Europ wintering sites are intertidal zones in the southern and western part of the continent, wh ocean climate and plentiful food. Because of the destruction of suitable stopovers on the route, especially intertidal zones, the survival rate of adults is dropping, and given the nest predation these birds are in a double bind. This is a fundamental problem, especially Asian – Australian migration flyway, particularly in China and Korea. Protecting these fas stopover sites can, in my opinion, do the most to support the global population of many sh at present."