Planet Earth: Our Unsustainable Biosphere

Planet Earth. Our home. Our only life-support system. Clearly then something to be regarded in the highest terms, to be respected, and to be protected at all costs. Yet in 2006, nothing seems further from the truth. The reality is that we are inhabiting an increasingly unstable and unsustainable biosphere

Feathered competitors: what birds can teach ecologists about species interactions

Interspecific Competition in Birds. André A. Dhondt.\ud Oxford University Press, Oxford. 27 October 2011. pbk. pp 296. ISBN 978-0-19-958902-9

Are the ecological impacts of alien species misrepresented? A review of the “native good, alien bad” philosophy

The study of invasion ecology usually focuses on the negative impacts of alien species, while potential positive impacts are often overlooked. Understanding of biotic interactions may thus be skewed towards the negative, which could have important implications for ecological management and conservation. This article provides a comprehensive review of all types of impacts, both beneficial and detrimental, that can result from species translocation. An extensive review of literature on species introductions to terrestrial, freshwater and marine ecosystems and involving a wide range of taxa (including microorganisms, parasites, plants, insects, amphibians, reptiles, birds, mammals, fish and Crustacea) showed that, despite limited research into facilitative alien-native interactions, such interactions occur surprisingly frequently. Examples were found of introduced species acting as hosts, food sources, pollinators or seed dispersers for native species, as well as providing herbivory, predatory or parasite release. However, research showed that numerous negative interactions also occurred and combination impacts (when an alien benefits some natives but disadvantages others) were common. In many cases, the traditional view that biological invasions constitute a significant threat to native biota is both accurate and appropriate. Efforts to prevent translocation and control non-native species can be vital. However, the “native good, alien bad” maxim does not convey the complexity of invasion ecology: alien species do not axiomatically pose a threat to native biota. In order to move understanding of invasion ecology forward and to develop maximally-effective management strategies, facilitative alien-native interactions need to be added into the alien species debate

Development of a Rapid and Precise Method of Digital Image Analysis to Quantify Canopy Density and Structural Complexity

Estimation of canopy density is necessary for ecological research and woodland management. However, traditional manual methods are time consuming and subject to interobserver variability, while existing photographic methods usually require expensive fish-eye lenses and complex analysis. Here we introduce and test a new method of digital image analysis, CanopyDigi. This allows user-defined threshold to polarise the 256 grey shades of a standard monochrome bitmap into dark “canopy” and light “sky” pixels (the threshold being selected using false-colour images to ensure its suitability). Canopy density data are calculated automatically and rapidly, and, unlike many other common methods, aggregation data are obtainable using Morisita’s index to differentiate closed (diffuse light) and open (direct light) canopies. Results were highly repeatable in both homogeneous and heterogeneous woodland. Estimates correlated strongly with existing (nondigital) canopy techniques, but quicker and with significantly lower interobserver variability (CV = 3.74% versus 20.73%). We conclude that our new method is an inexpensive and precise technique for quantifying canopy density and aggregation

Differences in two species-at-risk classification schemes for North American mammals

Several classification systems are used to rank species’ extinction risk. Assessments from two of these, IUCN and NatureServe, are often used to inform prioritisation of conservation resources and management strategies. However, despite their widespread use, they have rarely been compared. No research has assessed rank concordance specifically for mammals, while factors increasing the chance of mismatches between systems have not been investigated. In this study, consistency of IUCN/NatureServe extinction risk categorisation is compared for 409 classified extant American and Canadian mammals. Taxonomic bias in between-system mismatches is then analysed, and common ecological factors associated with mismatches are also identified. There was a significant positive correlation between IUCN and NatureServe ranks, although this was not strong (rs = 0.504). Agreement was good for non-threatened categories: 97% of species classified as non-threatened by one system were classified likewise by the other. However, there was considerable discord in threatened categories, with 40% of species classified as threatened by one system and non-threatened by the other. In 89% of such cases, this was due to higher ranking by NatureServe, suggesting that this system is more conservative. Mismatches were identified for 102 of the 373 species with exact rankings on both systems (27%), and these were biased taxonomically with significantly more mismatches for Cetacea and fewer for Rodentia. Mismatches were more common for species with longer gestation periods, fewer offspring per year, and longer life expectancies (all traits associated with K-strategist species), as well as for species in higher trophic levels. Many mismatched species also had fragmented ranges and/or uncertain data. Recognition that IUCN and NatureServe ranks are not synonymous is essential. Assessments should be viewed as complementary and dual results should be used to inform species management. The need for more detailed population demographic data to improve extinction risk calculations should also be addressed

Developing a Supportive Framework for Learning on Biosciences Field Courses through Video-Based Resources

Field courses are an essential component of the undergraduate experience in many subjects, but are intensive and expensive for participating students. Unpreparedness often means time is used teaching the basics rather than challenging students in exciting and novel situations. Moreover, universal participation is not always possible. Video-based resources covering key concepts and techniques could help participant preparedness and could be used independently by non-participants. This reflective case study details a collaborative project in which students and instructors worked together to make conceptual and instructional videos during a highly applied biosciences field course in South Africa. In 2012, after training from a professional wildlife filmmaker, students were involved in planning, presenting, and filming 25 videos. Students benefited considerably from the filmmaking process as explaining concepts and filming techniques helped reinforce their understanding: an example of "see one, do one, teach one." The online, open-access videos were used by the 2013 cohort to increase preparedness and independently by non-participants to good effect, both internally and at several external institutions. New videos will be added each year to expand the resource base and allow students to gain from the filmmaking experience. This teaching and learning strategy is multidisciplinary, with relevance for a range of subjects

The Role of Citizen Science and Volunteer Data Collection in Zoological Research

In many ways, science has never been as popular as it is now. With an ever-increasing number of popular science books on everything from astronomy to climate change and evolution and entire TV channels devoted to science output, the public seems spoilt for choice. However, paradoxically, there is also an increasing disconnect between science—and scientists—and society, and this is certainly evident in the life sciences. This disconnect comes in two forms: interest and level of knowledge. Indeed, one has only to look at the 2012 US presidential election campaign to see the lack of scientific knowledge possessed by many of the political elite about topics such as climate change. If high profile scientific topics are still so widely misunderstood by those in the public eye, it is unsurprising that there is such a lack of understanding of, and interest in, scientific topics in the general public. It should, in theory, be the easiest to address this discontent in subjects like zoology, where the evidence is all around us and can be easily seen, appreciated, and studied by the world’s citizens

Managing calcareous grassland for the declining Duke of Burgundy Hamearis lucina butterfly: effects of grazing management on Primula host plants

Many butterfly species are declining in range and abundance, sometimes to the point of becoming vulnerable to extinction. Several traits increase a species’ vulnerability to population decline through stochastic processes, including high larval specificity and poor dispersal rate. The Duke of Burgundy Hamearis lucina relies on Primula as its sole larval host plant. This monophagus dependency, coupled with susceptibility to environmental stochasticity, low dispersal and poor recolonization potential, means it is vital that sites supporting this rapidly-declining species are managed optimally. Here, we use two calcareous grassland sites in the UK with different grazing systems to identify optimal grazing management for Primula abundance and, for the first time, Primula characteristics linked previously to Duke oviposting preference and success: size, condition, succulence and surrounding sward height. We find that autumn and winter grazing intensity are both positively associated with Primula abundance, but there is a trade-off for winter grazing with negative effects on plant size, condition and succulence. Winter grazing also decreased the sward height below the optimum. Plants were bigger and better at the site managed using continuous (free-roaming) grazing versus the site managed using rotational (paddock-based) grazing. We recommend moderately high grazing intensity during autumn using a free-roaming system where possible to attain abundant Primula, with a reduction in grazing intensity or grazing removal during winter to ensure suitability of individual plants. This management would also benefit other host plants, such as bird’s foot trefoil Lotus corniculatus, which are vital for other declining butterflies that frequently co-occur with Dukes

Beneficial impacts of Eurasian beaver (Castor fiber) reintroduction on bat communities and aquatic macroinvertebrate prey: a case study from lowland Britain

Riparian ecosystems are valuable habitats for bats, due to high densities of emergent aquatic invertebrates that provide high-quality feeding areas. Throughout Europe, decline and extirpation of European beaver (Castor fiber) has been a key driver in the decline of the extent and quality of riparian habitat, and thus recolonisation has considerable potential to restore degraded areas. Previous research has shown that beaver-modified ecosystems can support more bats, but the assumed causal link (an increase in invertebrate prey) has not been tested. Here, we study bat activity and richness/abundance of aquatic macroinvertebrates at a site where freeroaming beavers have colonised naturally from a nearby (unofficial) release location versus a nearby control site with very similar hydrology and habitat matrix. Bat activity was recorded using walked activity transects and fixed-point acoustic detectors. Although bat species richness was similar, bat activity was substantially and significantly higher at the beaver site versus the control site overall (42.7%) and for four specific taxa: soprano pipistrelle (Pipistrellus pygmaeus; 8.4%), Daubenton’s (Myotis daubentonii; 46.5%), common pipistrelle (Pipistrellus pipistrellus; 110.4%) and common noctule (Nyctalus noctula; 170.9%). Richness of the larvae/nymphs of emergent aquatic macroinvertebrate species known to form an important part of bat diet was 205.5% higher at the beaver site compared to the control site, while abundance was 817.4% higher. Overall bat activity was also linked to habitat (lotic > lentic), survey method (transect > fixed-point), and season (May–July peak). This is the first evidence of a likely causal link between beaver recolonisation and bat activity via an increase in abundance of key aquatic invertebrate prey and we recommended that benefits of beaver reintroduction on bats be considered in future feasibility studies