On Sunday 15 December around 8:45 Jasper Croll will be interviewed at Vroege Vogels on his contribution to the paper on the evolution of aggressive traits in the solitaire; a giant pigeon from the island of Rodrigues in the Indian Ocean. Jasper carried out the demographic modelling component of this paper - whereby he combined demographical model with a game theoretical model (dove-hawk model). The results were surprising and may provide a plausible mechanism to explain how aggression started to dominate the population. The paper is a result of a collaboration between IBED University of Amsterdam and the University of Maastricht and is discussed in Science: Evolution Losing ground, by Sacha Vignieri
Franciska de Vries recently published in Nature about a large-scale, experimental study into the influence of climate change on microbes in soils. The press release about this was picked up by a number of particularly professional international media; a small anthology.
Jan Sevink was recently awarded the Emil Luden Medal. The Baarn emeritus professor of physical geography received this prize for his series of studies into the history of of soil and landscape in the Gooi and its contributions to the protection and restoration of the nature in the region. That nature is more seriously threatened than ever, he warns
The dodo (Raphus cucullatus) and the Rodrigues solitaire (Pezophaps solitaria) are closely related, extinct bird species that evolved from a common ancestor. While the dodo was remarkably tame, the solitaire was remarkably aggressive. Jasper Croll and Kenneth Rijsdijk (both UvA-IBED) recently came up with a new explanation for this; the Flemish popular science magazine EOS reports on it.
While the dodo was the epitome of tameness, the closely related and also extinct solitaire excelled in aggressiveness. Dutch researchers suspected that rising sea levels were the cause of that difference. An international team of scientists, including researchers from Naturalis (Leiden) and the University of Amsterdam, has now come up with a possible explanation. Using a mathematical model by theoretical ecologist Jasper Croll and geologist Kenneth Rijsdijk of the Institute for Biodiversity and Ecosystem Dynamics (IBED) of the University of Amsterdam (UvA), they show that a rapidly shrinking habitat was the basis for the aggression of the solitaire.
In recent years, Gonçalo Piedade studied viruses in water samples that he had fished from the ocean near Antarctica for his PhD research. Of the no fewer than eight thousand different genetic codes that he subsequently analyzed, three quarters turned out not to exist in the world database of viruses. All unknown viruses. Trouw interviewed Piedade and his supervisor Corina Brussaard (UvA-IBED & NIOZ) about this discovery. This is not about viruses that infect people; they target single-celled algae and bacteria in the water.
Researchers from the UvA and from Maastricht University discovered that the reduction of the island of Rodriques after the last ice age caused large-scale aggression in the extinct giant solitary pigeon,. Due to a rapidly increasing shortage of space and food, the peaceful individuals died out in no time. A mathematical model by Jasper Croll and Kenneth Rijsdijk now offers the explanation for the solitaire's behaviour. Rijsdijk: “The model provides insight into the relationship between behaviour and island size. There turns out to be a threshold value below which the proportion of aggressive birds suddenly increases from say 5% on an island with no competition for space to almost 100% on an island that is too small.”
The future of chimpanzees depends on smart conservation strategies, and that requires data, lots of data. Ecologist Adrienne Chitayat has conducted research on chimpanzees in Tanzania and is the first to systematically survey the population density in the entirety of Mahale Mountains National Park.
Out of thousands of marine viruses that were discovered in Antarctic waters in the past two years, 75 percent were new to science. That is shown in a paper that was published in Nature Communications on 24 October 2024, by NIOZ and UvA PhD candidate Gonçalo Piedade and colleagues. “This project has identified an enormous number of pieces in the important jigsaw of viral ecology and, therefore, in the circle of carbon in the oceans and the climate system”, says Professor Corina Brussaard.
Researchers from the University of Massachusetts claim in the journal Science that Darwin's finches may be in for more evolutionary failures due to drought. The scientists based their findings on previous finch research: drought produces hard seeds and therefore larger beaks. Also known: large beaks produce a different singing sound than small beaks. According to Astrid Groot, the American research says something about how extreme weather events, which are becoming more common due to climate change, threaten the survival of animal species. "Imagine: a population of finches experiences a prolonged period of extreme drought. This is at the expense of variation in a species: finches with small beaks die, and only the birds with large beaks remain. If there is a very wet period follows, those birds also die, and the species disappears."
Thanks to a GPS transmitter on the back of a silver plover, a team of biologists, including Chiel Boom, was able to see exactly how this bird tried (in vain) to escape the attack of a peregrine falcon. Dagblad Trouw pays attention to this in their nature column.
Over the next five years, scientists from the UvA and the University of Groningen will be conducting research into microalgae in the ice sea around Antarctica, which may slow down the melting of the ice caps. University magazine Folia interviewed team member Susanne Wilken about this project.
In an online multimedia production, NRC focuses on the recently published research from IBED into how migratory birds adapt their (nocturnal) flying behavior based on, among other things, the presence of wind turbines. As a committed researcher, Bart Hoekstra explains.
PhD candidate Ruben Fijn used small GPS backpacks to investigate whether and, if so, how sandwich terns adapt their behavior with the arrival of large wind farms at sea. One of his main conclusions is that the birds nowadays fly in a wide arc around the parks. This prevents collisions, but the disadvantage is that the habitat and feeding area of the animals is becoming increasingly smaller. Trouw spoke extensively with Fijn about this research. De Telegraaf also has a (shorter) news item about it.
Bas van Geel is one of the paleontologists, who are searching , together with geologists, for a rare piece of peat that is more than a hundred thousand years old on the banks of a canal in the Noordoostpolder.
An international group of scientists, including Jef Huisman, argues this week in the journal Cell that micro-organisms are indispensable for achieving the UN Sustainable Development Goals. The popular weblog Foodlog and the Fries Dagblad write about this and quote Huisman.
Newspapers NRC and De Limburger have jointly delved into the issue of the discharge of thousands of liters of chemicals into the sewer by companies that clean tankers. There appear to be many abuses in this world of tank cleaning: permits are outdated, not specific, control is marginal, and the industry itself decides which chemicals they label as harmful or not. Annemarie van Wezel speaks as an expert and is seriously concerned about the state of affairs.
The quality of Dutch surface water and groundwater is among the worst in all of Europe. In an extensive interview in the AD newspaper, Annemarie van Wezel explains what is wrong with our water and what should be done to improve Dutch water quality. The same piece also appeared in various regional newspapers from publisher DPG Media.
A joint study by TNO and the UVA commissioned by the provinces concerning nitrogen emissions shows that a less strict limit for this emission cannot simply be established and applied. The provinces had requested this study in the hope of being able to grant permits more easily within the current legal limits for, among other things, construction projects and the expansion of agricultural companies. Emiel van Loon from the UvA was the main person involved in the study. Various major media outlets report on this new study; an anthology.
A horticulturist from the municipality of Westland has discharged a large quantity of a banned pesticide. The standard was exceeded by 6,000 times in surface water. Annemarie van Wezel calls this concentration 'very high'. She explains the damage that excessive concentrations of harmful chemicals in surface water can cause: "Some animal species can become extinct in a certain place, so it has consequences for biodiversity and the entire ecosystem. It may also be the case that you cannot have drinking water made from this water. And people can use it less for watering crops."
According to research by the UvA, a very large majority of scientists internationally are concerned about climate change and its consequences. Furthermore, half of the scientists surveyed are prepared to take to the barricades for this issue. Lead researcher Fabian Dablander explained this to various media.
If there is a foam layer on top of the water, the concentration of PFAS is much higher than in water, because the molecules like to attach to foam. This also applies to sea foam on the beach. Avoiding sea foam is therefore wise. "Someone does not play in sea foam for days, which makes creating scenarios difficult," says Annemarie van Wezel. "The concentration of PFAS in the foam is very high, but foam is very airy and so the amount of water in a handful of foam is minimal."
Farmers in the Netherlands are increasingly using pesticides containing PFAS, often without being aware of it. According to the RIVM, food is the main way in which PFAS enters the body. Organic farmers do not use chemical pesticides or fertilizers and PFAS cannot end up on organic products this way but PFAS could also end up unnoticed in biological pesticides. Even if you look beyond pesticides, a PFAS risk remains with organic food. Annemarie van Wezel agrees “Organic cultivation can also take place in a contaminated area. One area is more polluted than another, so the fact that cultivation is organic does not necessarily make food PFAS-free."
Researchers from IBED have spent six years using radar and other methods to map the nighttime routes and flight heights of migratory birds in North Holland. Bart Hoekstra talks to various media about this research and what it makes clear about the risk of wind turbines at hotspot locations.
The trade in nitrogen rights between different sectors leads to more emissions, with likely negative effects on nature. Research by the UvA confirmed last year that a large part of nitrogen emissions ends up in a so-called 'nitrogen blanket' in the air. It is impossible to say where exactly it will end up. In any case, it is certain that more emissions are bad news for nature, which is already suffering from a nitrogen surplus. "Nitrogen trading leads to more emissions, while you would like less," says Emiel van Loon, one of the authors of the UvA study. "That is not a problem for the nearby nature, but on a larger scale it is."
There are too high concentrations of mosquito repellents in the surface water of the Groene Hart. This is the conclusion of the Rijnland Water Board based on research. This is not only a danger to public health, the increasing cleaning costs ultimately end up borne by society.
Pollution from agriculture, industry and sewers is deteriorating the quality of Dutch surface water. Entire ecosystems are in danger of going under and purifying our drinking water is becoming increasingly difficult. Poor water quality can even affect our health. What is stopping us from bringing the quality of our surface water back up to standard?
For thirty years, a group of first-year biology students has been traveling to Limburg together with ecologists from the IBED to conduct a week of research into the plants and animals that occur in the hilly landscape. A permanent part of the weekly program is the evening excursion with one of the rarest toad species in the Netherlands as 'main guest': the yellow-bellied fire toad.
Biodegradable plastics are seen as one of the answers to our plastic problem. But what actually happens when these plastics end up in the ocean? Are they still broken down, and what is the influence of this type of plastics or the breakdown products on ocean life? Linda Amaral-Zettler received a large grant earlier this year to research this. Het Parool now has an interview with her about her work.
More and more PFAS pollution is being discovered in the Netherlands, both in water and soil. This leads to social unrest. Investigative journalism program Pointer has made a radio broadcast about the issue, Annemarie van Wezel as one of the main guests.
Folia interviewed Mariana Gliesch about her and Franciska de Vries' research into the influence of increased droughts on Dutch heathland. An experiment has been running at the UvA for 20 years to see what droughts do to this characteristic landscape type.
Bonobos are known as the most peaceful apes. However, a newly published study shows that more aggression occurs between males than among closely related chimpanzees. Moreover, the most aggressive men are the most successful with women. Great ape experts Evy van Berlo (UvA-IBED) and Karline Janmaat (UvA-IBED & Leiden University) explain this new French research at NOS and NRC respectively.
Linda Amaral-Zettler has received an ERC grant of almost 3.5 million euros for her research into the degradation of bioplastics in the marine environment.
Last week it emerged that no less than 96% of Dutch surface water does not meet European standards for the presence of chemicals such as PFAS. Annemarie van Wezel explained this at NPO Radio 1 and in the studio of current affairs program EenVandaag (see below an earlier item)
NRC has an article about the excessive levels of chemicals in Dutch surface waters. Last week it emerged that no less than 96% of our water does not meet the European standard. The Netherlands has until 2027 to do something about this, but the chance that we will achieve the European standards then seems small. In the article, Annemarie van Wezel explains the pollution and how difficult it is to get rid of.
Nina Witteveen and her supervisor Carina Hoorn investigated what happened to the mangrove forests in French Guiana as a result of the last ice age. These forests then appeared to give way to savannah in a relatively short time. Witteveen talks about this research in university magazine Folia.
The Netherlands is internationally known for its expertise in the field of water. But the quality of our own waters is far below standard. How did that happen? And more importantly: how do we get this in order, so that the Netherlands also complies with the European Water Framework Directive in 2027? Annemarie van Wezel is a guest in BNR's Big Five of Nederland Waterland
Ten organizations, including the military union and action group SchipholWatch, hold the State liable for high PFAS levels in the soil. Knoops law firm files a mass claim on behalf of the organizations. There is too much PFAS in the soil in hundreds of places in the Netherlands. "There are actually many places where PFAS is used. Sometimes without the employees or the factories being fully aware and aware of it," says Annemarie van Wezel.
Climate optimism is necessary but it must be factual. "We are doing well in tackling the climate crisis": Fabian Dablander and Guus Dix hear this regularly. However, the optimists provide weak support for their story.
Southeastern Spain Spain is suffering from desertification, or the process in which increasing droughts set in motion all kinds of processes that turn ecosystems into deserts. Erik Cammeraat is an expert in the field of desertification and goes to this region every year with a group of students. The Reformatorisch Dagblad spoke to him about the problems at hand and what residents of the region can do to prevent further desertification.
On February 28, SBS6 news program Hart van Nederland focused on the ongoing farmers' protests and the nitrogen crisis in our country. Jef Huisman commented.
Due to climate change, nature in our country is 'waking up' earlier and earlier. University magazine Folia asked Gerard Oostermeijer what the consequences of this earlier spring are for nature.
How harmful a substance is depends on how much it is used.' Annemarie Van Wezel points to the world's most used and controversial herbicide, glyphosate. Glyphosate is known as a product that is safer than other pesticides, provided farmers use it selectively. But many crops use a lot of glyphosate, says Van Wezel.
Spring and mineral water from France is not as pure natural as its producers claim. Due to bacteria or chemical contamination (such as traces of pesticides), those brands has been treated for years using filters, carbon and UV light. These purification techniques are permitted for tap water, but are prohibited for water labeled 'spring water' or 'natural mineral water'. “It is not in accordance with the rules, but they are fairly regular methods that the water companies use,” says Annemarie van Wezel. “They are also used in the Dutch drinking water sector, where approximately a third of our drinking water is made from surface water.”
How did complex cells and multicellular life arise? What is the role of the so-called archaea, wonderful single-celled organisms that look a bit like bacteria but are not? Anja Spang (UvA-IBED) talks in NRC about the latest insights into this, following her Inaugural Lecture on 9 February 2024
The coral around Curaçao is doing very badly. In university magazine Folia, PhD students Esmeralda Alcantar and Kelly Latijnhouwers talk about their coral research in the region, recent significant coral mortality and how difficult it is to restore the reefs.
The recent explosion in the middle of a residential area in Rotterdam may have been the result of a problem in an illegal drug lab. Pim de Voogt talks about the potential dangers of the presence of such an illegal laboratory in the middle of a residential area
University magazine Folia has an interview with Giuditta Beretta about her PhD research into natural control of the pest thrips. She discovered, among other things, that the thrips Echinothrip americanus, a problem species in the floriculture of roses and gerberas, among others, easily repels an attack from predatory mites through a kind of swinging movement with its abdomen.
In 2023, a project was launched to construct an infrastructure to identify every living species in the Netherlands and to monitor biodiversity. The digital platform, called ARISE (Authoritative and Rapid Identification System for Essential biodiversity information), is the first of its kind in the world. It will provide researchers with various tools for rapid and automated mapping of the natural world by any method. The partners in the project believe it can help to reverse the loss of biodiversity. The platform is already accessible for researchers.
A new study led by Bart Hoekstra into the effect of lighting fireworks on birds has received a lot of media attention within and outside the Netherlands (see also )