Help us understand mimicry!

Picture1I have written about mimicry before, describing why most mimics are imperfect and how some mimics imitate not only the appearance of other animals but also their sounds and behaviour. Now, I need your help with an ambitious experiment to test theories about the evolution of mimicry. Most people know that there are harmless animals that have yellow and black stripes to look like stinging bees and wasps. But did you know that there are many thousands of such species, all with different degrees of “bee-ness” or “waspiness”? The new experiment is designed to compare 56 harmless hoverflies with 42 wasps and bees to measure how similar they are. That’s 2,352 unique comparisons! This information will allow us to test exciting new ideas about the evolution of mimicry. There’s only one catch…

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With his beard and odd dress sense, Uncle Sam would have made a fine entomologist!

This particular experiment will use the human brain as a processing tool and the power of the crowd to generate data. It’s a bit like “Strictly Come Mimicking” (or “Mimicking with the Stars“, if you’re in the US): you just need to rate how similar you think the two insects appear out of 10. I’d appreciate it greatly if you could take some time to run through the experiment below. Don’t do it thinking that there is an end, though – there are 2,352 combinations, remember, and the images are randomly paired on each screen! You can access the experiment here:

www.mimicryexperiment.net

My goal is to reach 10 ratings of each pair of insects. That means a total of 23,520 ratings. I know this is a long shot, but that’s the aim, people! Please do share it far and wide! I’ll share regular updates on the blog as the ratings come in (however many or few there are!).

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Is battling biodiversity decline like tackling terrorism?

brain-512758_640I attended a talk recently given by Dr Sara Savage from Cambridge University entitled “Bad Religion: when is faith healthy or unhealthy?”. The title was a bit of a misnomer, as there was little discussion of religion per se, but there was a greater deal of fascinating psychological research on the drivers of extremist ideology. Dr Savage outlined the theory of “integrative complexity“, developed by Peter Suedfeld over the past 30 years. Integrative complexity is a method of metacognitive reasoning (i.e. being aware of how and what you are thinking, and why) that incorporates empathic and diverse approaches towards the views of others in an attempt to construct a coherent and objective view of a given situation. The argument has been made that extremist ideologies (whether these are religious, political or social) tend to stem from a narrowing of perspectives (a drop in integrative complexity, or “IC”), and that conflict resolution is best achieved by those who “see complexity”. Indeed, Suedfeld and colleagues have published analyses of IC within the context of the Cuban missile crisis and surprise attacks.Read More »

How helpful are urban ponds for biodiversity?

pond-84855_1280Background: Urban ecosystems are becoming increasingly important as areas for biodiversity conservation, as we begin to recognise the importance of preserving natural habitat within heavily modified environments for both wildlife and human well being. Urban ponds are a key part of this network of habitats within cities, and are commonly found in parks, gardens and industrial estates. In fact, there are an estimated 2.5-3.5 million garden ponds in the UK alone, which could have an area the size of Lake Windermere!

What we did: I was invited to submit a review of the biodiversity value of urban ponds. This later expanding beyond simply describing biodiversity patterns to include the ecological processes that generate those patterns. I describe a wide-ranging set of potential negative impacts on urban pond biodiversity, including invasive species, mismanagement, pollution, and habitat destruction.  However, I also took great care to highlight the benefits of these habitats in terms of their use in controlling stormwater, their role in local aesthetics, and the way in which they provide access to nature in inner cities. These ponds can be a fantastic resource if managed well.

Importance: Research on urban water bodies has been growing, and this review highlights both the work that has been done up to now and the gaps in our current knowledge that should be filled in the future.

This is part of a series of short lay summaries that describe the technical publications I have authored.  This paper, entitled “The ecology and biodiversity of urban ponds”, was published in the journal WIREs Water in 2014. You can find this paper at the publisher’s website or for free at Figshare.

Image credit: noitulos, http://bit.ly/1C0x7cA, Public Domain.

Rain, not temperature, seems to have driven fossil mammal diversity in North America

skeletons-268954_1280Background: One of the fundamental questions in ecology is “what drives changes in the numbers of species in time and space?” We can look around us today and see that there are generally many more species in the tropics than nearer the poles. However, another way in which we can look around ourselves is to delve into the fossil record to look back in time. Dani Fraser is a PhD student at Carleton University working on large-scale patterns in fossil mammal biodiversity. Dani was interested in looking at spatial patterns and how they changed through time, but rather than just calculating the number of animals living in each area at each time, we looked at the rate at which the communities changed as we moved further north. The idea is that when climates are relatively stable and warm there is little variability in climate and so there is gradual change in species as you move north. However, as the climate becomes more polarised (i.e. colder at the pole relative to the tropics) the rate of change in animal communities becomes more pronounced.

What we did: We looked at extinct mammals in North America during the Cenozoic (36 million years to the present) and showed that there was greater variability in species between regions when mean annual precipitation was lowest. This is consistent with theory, which suggests that when precipitation is (on average) higher communities are more similar to one another as you move north. We then looked at what might be expected from current mammal species under climate change. We used climate models to predict where these species might occur in the future and saw little evidence of the precipitation relationships that we found in the fossil data.

Importance: Much of the work done on biological responses to climate change has focused on temperature, looking at the number of species in each area, and purely ecological responses (i.e. over short time periods). We demonstrate that precipitation can also play an important role in driving responses to global climate. We also show that it isn’t just the number of species that changes in space but the relationship between communities: there is a greater rate of turnover (a greater dissimilarity) in communities as well. Finally, we show that these relationships seem to be present in the evolutionary record but cannot be predicted from the ecological responses of current mammals, suggesting that the patterns we saw in the fossil record are due (at least in part) to evolutionary processes that are not incorporated into climate models.

This is part of a series of short lay summaries that describe the technical publications I have authored.  This paper, entitled “Mean annual precipitation explains spatiotemporal patterns of Cenozoic mammal beta diversity and latitudinal diversity gradients in North America”, was published in the journal PLOS ONE in 2014. You can find this paper for free at the publisher’s website.

Image credit: 134213, http://bit.ly/1C0v0Fy, Public Domain.

Bradford’s ponds aren’t reaching their potential, and we think we know why

central-park-143473_1280Background:  When we build ponds in urban areas, they can play a number of important roles: managing floodwater, cooling the urban environment, removing pollution, improving the appearance of built-up areas and providing a habitat for wildlife. However, these different functions often require different forms of management, and so urban managers typically prioritise one or a small number of purposes. We were interested in the biodiversity value of ponds in Bradford in the UK.

What we did: My MSc student, Andrew Noble, surveyed a series of 21 sites across Bradford including 11 ponds that were prioritised for biodiversity, 6 ponds that were prioritised for amenity (usually park lakes and other ornamental features), and 4 ponds that were used as overflow ponds for water management. He surveyed aquatic plants and aquatic invertebrates to investigate patterns of biodiversity. This was then compared against what would be expected from high quality ponds of similar size (called a “reference site approach”). The results showed that the urban ponds were generally of very low quality, and that unsurprisingly the biodiversity ponds tended to contain higher numbers of animals and plants. However, this was not always the case and some amenity and overflow ponds contained more species despite not being managed for biodiversity. Finally, Andrew talked with managers who, while obviously enthusiastic about biodiversity, were unaware of important local factors that were influencing their sites, such as run-off from local sports fields which were likely contributing to algal blooms.

Importance: There have been a range of studies (including some by me) which have suggested that urban ponds can provide substantial benefits for biodiversity. However, these high value ponds are relatively rare, and it is important that we understand what factors result in some ponds being of high value while others are not. This study suggests that management could play a major role.

This is part of a series of short lay summaries that describe the technical publications I have authored.  This paper, entitled “Poor ecological quality of urban ponds in northern England: causes and consequences”, was published in the journal Urban Ecosystems in 2014. You can find this paper at the publisher’s website.

Image credit: tpsdave, http://bit.ly/11ozTHF, Public Domain.

Urban ponds can contain as many species as ponds outside of cities

UrbanPondBackground:  The management of water in urban areas can be a problem, because rainfall rapidly runs off impervious surfaces like pavements and roads. This means the water quickly enters rivers and streams, which then flood. City managers reduce the rate at which water enters rivers using stormwater management facilities, which often include ponds to hold back the stormwater. These ponds are usually managed just for water retention, but they could potentially form a very useful habitat for aquatic plants and animals in cities.

What we did: We looked at 20 of these stormwater management ponds (SMPs) to see how many animals and plants were using them. We also compared those 20 ponds against 10 other ponds that were not used for stormwater management, but were found in roughly the same area. We showed that the water chemistry in the SMPs was often high in salt, and that the amount of salt in the ponds was related to the amount of urban land cover (which makes sense: much of the salt would have been road salt washed in during snow melt). However, despite some differences in water chemistry there were no significant differences between the SMPs and the other ponds in the diversity of animals. We conclude that it is not the management, per se, that affects the ponds, but the landscape within which they are found.

Importance: Management of particular habitats frequently has to prioritise one function over another. Stormwater management is a major concern in many areas, and so there may not be much willingness to detract from the role of ponds in managing run-off in order to benefit biodiversity. We showed that this may not be necessary: if the ponds are in a relatively low-intensity urban area then they may contain high biodiversity regardless of management.

This is part of a series of short lay summaries that describe the technical publications I have authored.  This paper, entitled “Stormwater ponds can contain comparable biodiversity to unmanaged wetlands in urban areas”, was published in the journal Hydrobiologia in 2014. You can find this paper at the publisher’s website.

Image credit: tpsdave, http://bit.ly/1rb1IKi, Public Domain.

Computer models can predict where rare species might be found

Background:  Species distribution models (SDMs) have been used for a number of different purposes. This approach involves the mapping of species distributions (like the map shown on the right, for the citrine forktail damselfly) onto environmental variables to evaluate the contributions of those variables to determining the species range. This knowledge can then be use to predicted where the species will be in the future under climate change. However, another way in which they can be used is to predict in which areas the species has not been found but could potentially exist.

What we did: My study applied SDMs to this latter problem, predicting where 176 species of North American dragonflies and damselflies occur based on the patchy recording that is currently available.  The models fitted reasonably well, which isn’t surprising given the reliance of dragonflies and damselflies on warm, dry weather for their adult stage.  This highlighted areas for which the models predicted species presence but where those species had not been recorded.  I also demonstrated that the patterns of diversity found in North America were consistent with those found in Europe.

Importance: This kind of study can be used to predict where rare or endangered species may have gone undiscovered as well as directing limited conservation efforts towards areas that are likely to have high diversities of animals or plants but have not been properly explored. We can also look for regions that have been under-surveyed and where resources need to be focused.


This is part of a series of short lay summaries that describe the technical publications I have authored.  This paper, entitled “Predicting the distributions of under-recorded Odonata using species distribution models”, was published in the journal Insect Conservation and Diversity in 2012. You can find this paper online at the publisher, or on Figshare.

Image credit: L. B. Tettenborn, CC BY-SA 3.0, http://bit.ly/XHiqce