The first Passivhaus in Qatar: initial monitoring and modelling energy performance

Buildings, by virtue of the energy they consume, have the biggest impact on the natural environment, and the price, availability and by-products of energy create societal and economic challenges in areas such as health and fuel poverty. Consequently, the key architectural solution to these challenges is to create buildings that are just as energy-efficient as possible. This message is especially important for parts of the world, such as countries of the Middle East, which have previously not embraced sustainable, low energy building standards. This paper describes an initiative to demonstrate the viability of such an energy standard (Passivhaus) in the Middle East. The Passivhaus standard was initially developed in Germany in 1990, with the main aims of reducing energy consumption and maintaining a comfortable indoor temperature all year round. The success of Passivhaus has stretched beyond Germany, although only around 100 Passivhaus projects have been realised outside of Europe. Qatar, a country in the Arabian Peninsula, launched its first Passivhaus Project in 2013. The estimated energy performance and comfort levels obtained through the IES dynamic simulation tool indicated that the building would successfully operate under the hot and arid climate of Qatar, and in accordance with the Passivhaus standards. To validate results obtained through modelling, the Qatar Passivhaus has undergone monitoring since its completion. This paper presents the initial findings of the Passivhaus project in Qatar, exploring the actual energy consumption and comfort levels achieved to date. Comparison between the modelled and monitored data have been made, revealing the actual performance of this Passivhaus standard dwelling in a hot and arid climate

The impact of detoxification costs and predation risk on foraging : implications for mimicry dynamics

This work was supported by the European Research Council (Advanced Grant 250209 to Alasdair Houston), a Natural Environment Research Council Independent Research Fellowship (NE/L011921/1) awarded to A.D.H., a BBSRC-NERC project grant (BB/G00188X/1) awarded to J.S., C.R. and G.D.R. and a faculty fellowship awarded to C.G.H. (Medical Sciences, Newcastle University) with strategic support funding from the Wellcome Trust.Prey often evolve defences to deter predators, such as noxious chemicals including toxins. Toxic species often advertise their defence to potential predators by distinctive sensory signals. Predators learn to associate toxicity with the signals of these so-called aposematic prey, and may avoid them in future. In turn, this selects for mildly toxic prey to mimic the appearance of more toxic prey. Empirical evidence shows that mimicry could be either beneficial (‘Mullerian’) or detrimental (‘quasi-Batesian’) to the highly toxic prey, but the factors determining which are unknown. Here, we use state-dependent models to explore how tri-trophic interactions could influence the evolution of prey defences. We consider how predation risk affects predators’ optimal foraging strategies on aposematic prey, and explore the resultant impact this has on mimicry dynamics between unequally defended species. In addition, we also investigate how the potential energetic cost of metabolising a toxin can alter the benefits to eating toxic prey and thus impact on predators’ foraging decisions. Our model predicts that both how predators perceive their own predation risk, and the cost of detoxification, can have significant, sometimes counterintuitive, effects on the foraging decisions of predators. For example, in some conditions predators should: (i) avoid prey they know to be undefended, (ii) eat more mildly toxic prey as detoxification costs increase, (iii) increase their intake of highly toxic prey as the abundance of undefended prey increases. These effects mean that the relationship between a mimic and its model can qualitatively depend on the density of alternative prey and the cost of metabolising toxins. In addition, these effects are mediated by the predators’ own predation risk, which demonstrates that, higher trophic levels than previously considered can have fundamental impacts on interactions among aposematic prey species.Publisher PDFPeer reviewe

The peppered moth <i>Biston betularia</i>

Hannah Rowland and colleagues introduce the peppered moth whose industrial melanism was an early evidence for evolution

Pattern contrast influences wariness in naïve predators towards aposematic patterns

This work was funded by BBSRC grants awarded to J.M.H. and O.P. (BB/N006569/1), C.R. and J.S (BB/N00602X/1), P.G.L (BB/N005945/1), and I.C.C. (BB/N007239/1).An apparent and common feature of aposematic patterns is that they contain a high level of achromatic (luminance) contrast, for example, many warning signals combine black spots and stripes with a lighter colour such as yellow. However, the potential importance of achromatic contrast, as distinct from colour contrast, in reducing predation has been largely overlooked. Here, using domestic chicks as a model predator, we manipulated the degree of achromatic contrast in warning patterns to test if high luminance contrast in aposematic signals is important for deterring naïve predators. We found that the chicks were less likely to approach and eat prey with high contrast compared to low contrast patterns. These findings suggest that aposematic prey patterns with a high luminance contrast can benefit from increased survival through eliciting unlearned biases in naïve avian predators. Our work also highlights the importance of considering luminance contrast in future work investigating why aposematic patterns take the particular forms that they do.Publisher PDFPeer reviewe

The antipredator benefits of postural camouflage in peppered moth caterpillars.

Funder: Churchill College, University of Cambridge; doi: http://dx.doi.org/10.13039/501100000742Funder: Projekt DEALCamouflage is the most common form of antipredator defense, and is a textbook example of natural selection. How animals' appearances prevent detection or recognition is well studied, but the role of prey behavior has received much less attention. Here we report a series of experiments with twig-mimicking larvae of the American peppered moth Biston betularia that test the long-held view that prey have evolved postures that enhance their camouflage, and establish how food availability and ambient temperature affect these postures. We found that predators took longer to attack larvae that were resting in a twig-like posture than larvae resting flat against a branch. Larvae that were chilled or food restricted (manipulations intended to energetically stress larvae) adopted a less twig-like posture than larvae that were fed ad libitum. Our findings provide clear evidence that animals gain antipredator benefits from postural camouflage, and suggest that benefits may come at an energetic cost that animals are unwilling or unable to pay under some conditions

The biology of color

Coloration mediates the relationship between an organism and its environment in important ways, including social signaling, antipredator defenses, parasitic exploitation, thermoregulation, and protection from ultraviolet light, microbes, and abrasion. Methodological breakthroughs are accelerating knowledge of the processes underlying both the production of animal coloration and its perception, experiments are advancing understanding of mechanism and function, and measurements of color collected noninvasively and at a global scale are opening windows to evolutionary dynamics more generally. Here we provide a roadmap of these advances and identify hitherto unrecognized challenges for this multi- and interdisciplinary field

The biology of color

Coloration mediates the relationship between an organism and its environment in important ways, including social signaling, antipredator defenses, parasitic exploitation, thermoregulation, and protection from ultraviolet light, microbes, and abrasion. Methodological breakthroughs are accelerating knowledge of the processes underlying both the production of animal coloration and its perception, experiments are advancing understanding of mechanism and function, and measurements of color collected noninvasively and at a global scale are opening windows to evolutionary dynamics more generally. Here we provide a roadmap of these advances and identify hitherto unrecognized challenges for this multi- and interdisciplinary field

Avian chemical perception and the evolution of insect defences

EThOS - Electronic Theses Online ServiceGBUnited Kingdo