Is population growth conducive to the sustainability of cooperation?

This paper asks whether population growth is conducive to the sustainability of cooperation. A simple model is developed in which farmers who live around a circular lake engage in trade with their adjacent neighbors. The payoffs from this activity are governed by a prisoner's dilemma “rule of engagement.” Every farmer has one son when the population is not growing, or two sons when it is growing. In the former case, the son takes over the farm when his father dies. In the latter case, one son stays on his father's farm, whereas the other son settles around another lake, along with the “other” sons of the other farmers. During his childhood, each son observes the strategies and the payoffs of his father and of the trading partners of his father, and imitates the most successful strategy when starting farming on his own. Then mutant defectors are introduced into an all-cooperator community. The defector strategy may spread. A comparison is drawn between the impact in terms of the sustainability of cooperation of the appearance of the mutants in a population that is not growing, and in one that is growing. It is shown that the ex-ante probability of sustaining the cooperation strategy is higher for a community that is growing than for a stagnant community.     

The other side of the border: Austrian local residents’ attitudes towards the neighbouring Czech Šumava National Park

Attitudes towards protected areas are seen as a key factor in influencing their success. While the majority of park–people relation research has addressed local residents’ attitudes towards protected areas in their own country, analyses on their attitudes towards a neighbouring national park on the other side of the border have rarely been carried out. This study investigated the attitudes of local residents in Upper Austria towards the Czech ?umava National Park. In 2008, residents (N = 468) of four rural communities bordering the ?umava National Park answered a mailed questionnaire. Compared to national parks in general, the ?umava National Park was perceived as not providing as many ecological, social, and economic benefits as others. Psychological reactance, past visits to the ?umava National Park, and attitudes towards landscape change and national parks in general predicted attitudes towards the ?umava National Park, while group membership, except for that of being a farmer, was not significant. Variables that have been previously identified as influencing the attitudes of local residents towards protected areas also seem to be relevant for protected areas on the other side of the border, while items addressing local trans-border issues and group membership appear to be less important. Management implications are discussed.     

Musculoskeletal anatomy of the Eurasian lynx,Lynx lynx (Carnivora: Felidae) forelimb: Adaptations to capture large prey?

Mammalian carnivores adhere to two different feeding strategies relative to their body masses. Large carnivores prey on animals that are the same size or larger than themselves, whereas small carnivores prey on smaller vertebrates and invertebrates. The Eurasian lynx (Lynx lynx) falls in between these two categories. Lynx descend from larger forms that were probably large prey specialists, but during the Pleistocene became predators of small prey. The modern Eurasian lynx may be an evolutionary reversal toward specializing in large prey again. We hypothesized that the musculoskeletal anatomy of lynx should show traits for catching large prey. To test our hypothesis, we dissected the forelimb muscles of six Eurasian lynx individuals and compared our findings to results published for other felids. We measured the bones and compared their dimensions to the published material. Our material displayed a well‐developed pectoral girdle musculature with some uniquely extensive muscle attachments. The upper arm musculature resembled that of the pantherine felids and probably the extinct sabertooths, and also the muscles responsible for supination and pronation were similar to those in large cats. The muscles controlling the pollex were well‐developed. However, skeletal indices were similar to those of small prey predators. Our findings show that lynx possess the topographic pattern of muscle origin and insertion like in large felids. J. Morphol. 277:753–765, 2016. © 2016 Wiley Periodicals, Inc.     

The effect of reintroductions on the genetic variability in Eurasian lynx populations: the cases of Bohemian–Bavarian and Vosges–Palatinian populations

Over the past ~40 years, several attempts were made to reintroduce Eurasian lynx to suitable habitat within their former distribution range in Western Europe. In general, limited numbers of individuals have been released to establish new populations. To evaluate the effects of reintroductions on the genetic status of lynx populations we used 12 microsatellite loci to study lynx populations in the Bohemian–Bavarian and Vosges–Palatinian forests. Compared with autochthonous lynx populations, these two reintroduced populations displayed reduced genetic diversity, particularly the Vosges–Palatinian population. Our genetic data provide further evidence to support the status of ‘endangered’ and ‘critically endangered’ for the Bohemian–Bavarian and Vosges–Palatinian populations, respectively. Regarding conservation management, we highlight the need to limit poaching, and advocate additional translocations to bolster genetic variability.     

Is landscape fragmentation always detrimental for species conservation? The case of the Iberian lynx in central Spain

The patch-corridor-matrix is the most commonly used model when dealing with landscape characterization studies, but it shows relevant limitations to detect landscape heterogeneity. Other authors have used a functional approach, since it is well known that nutrient, mineral and energy flows exist among ecosystems. These flows can be perceived in boundaries between different landcovers, making possible the identification of spatial units sharing a common pattern of ecological interactions known as mosaics. While the influence of each mosaic over a certain species has been previously addressed, no attention has been given to the intra-mosaic variation. The aim of this research is to assess the influence of functional diversity and connectivity, on the habitat suitability of the Iberian lynx (Lynx pardinus). For this, we built two GLMs to test if these features show a differential effect on lynxes’ habitat suitability depending on the mosaic. Both GLMs built show that the influence of these landscape features on lynxes’ habitat suitability depends on the landscape spatial organization and landcover composition, suggesting that there is no unique response of a species to changes in landscape diversity and/or connectivity. Thus, we conclude that considering both landscape and species features would allow to a better integration of land management strategies and conservation actions, which could favor species adaptation to highly human-modified landscapes.     

Seasonal variation in the population growth rate of a dominant zooplankter: what determines its population dynamics?

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The anatomy of population change in a black grouse population 1992–2008

We interrogate an 18-year-long dataset containing counts of displaying male black grouse Tetrao tetrix and incidental counts of females within an 800-km² region of Perthshire, Scotland. We examine the trends in the population and investigate how different components of the population might act as signposts of different stages of overall population change. We found statistical evidence for a decline in black grouse numbers between 1992 and 2000, and then a recovery from 2002 to 2008, but little evidence for a link between population change and weather during the decline phase. There was some evidence for a positive relationship between male and female counts. The two main components of male population size, lek size and lek frequency followed the overall population trend while it was increasing, but during the earlier decline, the two became uncoupled, to expose a complex structure within the data. During the decline, when black grouse numbers were approaching their minimum, mean lek size was actually increasing. Small leks lost proportionally more birds than did large leks, and lek longevity was positively correlated with lek size, indicating that maintenance of large leks is crucial in buffering the population against serious declines. During the decline, the spatial arrangement of leks changed, with remnant leks showing tight clustering at larger spatial scales, before expanding out to fill the large areas of unoccupied landscape during the population increase. We discuss these findings in terms of species monitoring and suggest that counts of young males may add much useful demographic information with little extra effort.     

The role of Quaternary environmental change in plant macroevolution: the exception or the rule?

The Quaternary has been described as an important time for genetic diversification and speciation. This is based on the premise that Quaternary climatic conditions fostered the isolation of populations and, in some instances, allopatric speciation. However, the 'Quaternary Ice-Age speciation model' rests on two key assumptions: (i) that biotic responses to climate change during the Quaternary were significantly different from those of other periods in Earth's history; and (ii) that the mechanisms of isolation during the Quaternary were sufficient in time and space for genetic diversification to foster speciation. These assumptions are addressed by examining the plant fossil record for the Quaternary (in detail) and for the past 410 Myr, which encompasses previous intervals of icehouse Earth. Our examination of the Quaternary record indicates that floristic responses to climate changes during the past 1.8 Myr were complex and that a distinction has to be made between those plants that were able to withstand the extremes of glacial conditions and those that could not. Generation times are also important as are different growth forms (e.g. herbaceous annuals and arborescent perennials), resulting in different responses in terms of genetic divergence rates during isolation. Because of these variations in the duration of isolation of populations and genomic diversification rates, no canonical statement about the predominant floristic response to climatic changes during the Quaternary (i.e. elevated rates of speciation or extinction, or stasis) is currently possible. This is especially true because of a sampling bias in terms of the fossil record of tree species over that of species with non-arborescent growth forms. Nevertheless, based on the available information, it appears that the dominant response of arborescent species during the Quaternary was extinction rather than speciation or stasis. By contrast, our examination of the fossil record of vascular plants for the past 410 Myr indicates that speciation rates often increased during long intervals of icehouse Earth (spanning up to 50 Myr). Therefore, longer periods of icehouse Earth than those occurring during the Quaternary may have isolated plant populations for sufficiently long periods of time to foster genomic diversification and allopatric speciation. Our results highlight the need for more detailed study of the fossil record in terms of finer temporal and spatial resolution than is currently available to examine the significance of intervals of icehouse Earth. It is equally clear that additional and detailed molecular studies of extant populations of Quaternary species are required in order to determine the extent to which these 'relic' species have genomically diversified across their current populations.     

What shapes Eurasian lynx distribution in human dominated landscapes: selecting prey or avoiding people?

In the multi-use landscape of southern Norway, the distribution of lynx is likely to be determined both by the abundance of their favoured prey – the roe deer – and the risk associated with the presence of humans because most lynx mortalities are caused by humans (recreational harvest, poaching, vehicle collisions). We described the distribution of the reproductive portion of the lynx population based on snow-track observations of females with dependent kittens collected over 10  yr (1997–2006) in southern Norway. We used the ecological-niche factor analysis to examine how lynx distribution was influenced by roe deer, human activity, habitat type, environmental productivity and elevation. Our first prediction that lynx should be found in areas of relatively high roe deer abundance was supported. However, our second prediction that lynx should avoid human activity was rejected, and lynx instead occupied areas more disturbed in average than those available (with the exception of the most densely occupied areas). Lynx, however, avoided the most disturbed areas and our third prediction of a trade-off between abundance of prey and avoidance of human activity was supported. On the one hand, roe deer in the most disturbed areas benefit to a large extent from current human land use practices, potentially allowing them to escape predation from lynx. On the other hand, the situation is not so favourable for the predators who are restricted in competition refuges with medium to low prey densities. The consequence is that lynx conservation will have to be achieved in a human modifed environment where the potential for a range of conflicts and high human-caused mortality will remain a constant threat.     

Is auxin the repressor signal of branch growth in apical control?

"Apical control" is the repression of branch growth by a higher dominating branch or shoot. There has been some confusion in the literature concerning the meaning and causal mechanisms of this correlative phenomenon with those of "apical dominance," which term is often used in a strict sense to connote the repression of the initiation of axillary bud outgrowth by an active shoot apex. Although the term "apical control" is most commonly employed with respect to woody species, this phenomenon also widely occurs in herbaceous plants. Because of the strong evidence for a role of auxin as a repressor signal in apical dominance and partly because of this lack of distinction in terminology, a similar role for auxin in apical control is often assumed in spite of the obvious acropetal auxin transport difficulty and the lack of direct evidence for the acropetal transport of any inhibitor influence. In the present study with the herbaceous Ipomoea nil, it has been clearly demonstrated that while exogenous auxin (1% NAA) strongly restores apical dominance in the Thimann-Skoog experiment, auxin treatments to decapitated dominant shoots do not, in any observable way, restore apical control in lower dominated branches. Hence, in this fast-growing species, the hypothesis for the role of auxin as a repressor signal for apical control is not supported.     

Eurasian lynx hunting red deer: is there an influence of a winter enclosure system?

As in several Central European areas, in the Bohemian Forest Ecosystem (Germany and the Czech Republic), fenced feeding enclosures are used for the winter management of red deer (Cervus elaphus), which is an important component of the Eurasian lynx’s (Lynx lynx) winter diet. Using GPS telemetry data, we tested whether (1) lynx hunted red deer mainly selecting for high prey densities and environmental characteristics like a good level of habitat heterogeneity, independently of the enclosures’ presence; (2) enclosures attracted lynx and (3) positively influenced their predation on red deer, being predictable and abundant prey sources throughout the winter; or (4) extremely high deer densities inside the enclosures rather negatively influenced lynx predation on this species. We first compared lynx space usage and predation on red deer inside and outside the enclosures. Then, we investigated the effects of the environment, prey densities and the enclosure distance for the area outside of enclosures. Prey densities positively influenced lynx space usage, whilst the probability of predation on red deer was highest at medium to low red deer densities. Habitat heterogeneity and terrain ruggedness influenced both lynx space usage and probability of predation on red deer. Regarding the effect of enclosures, the ratio “area used during night vs. daytime” was larger by a factor of 2 inside compared to outside enclosures, and the probability of predation on red deer was three times higher inside rather than outside of enclosures; however, these differences were not statistically significant, suggesting that the influence of the enclosures is not very pronounced.     

Is climate warming more consequential towards poles? The phenology of Lepidoptera in Finland

The magnitude and direction of phenological shifts from climate warming could be predictably variable across the planet depending upon the nature of physiological controls on phenology, the thermal sensitivity of the developmental processes and global patterns in the climate warming. We tested this with respect to the flight phenology of adult nocturnal moths (3.33 million captures of 334 species) that were sampled at sites in southern and northern Finland during 1993–2012 (with years 2005–2012 treated as an independent model validation data set). We compared eight competing models of physiological controls on flight phenology to each species and found strong support for thermal controls of phenology in 66% of the species generations. Among species with strong thermal control of phenology in both the south and north, the average development rate was higher in northern vs. southern populations at 10 °C, but about the same at 15 and 20 °C. With a 3 °C increase in temperature (approximating A2 scenario of IPPC for 2090–2099 relative to 1980–1999) these species were predicted to advance their phenology on average by 17 (SE ± 0.3) days in the south vs. 13 (±0.4) days in the north. The higher development rates at low temperatures of poleward populations makes them less sensitive to climate warming, which opposes the tendency for stronger phenological advances in the north from greater increases in temperature.     

Does a reduction in the price of rhino horn prevent poaching?

Rhino poaching around the world has increased inordinately, to the extent that concerns exist over the possible survival of the species. An open access rhino poaching model is developed for South African rhino. The model is a hybrid dynamical model, as both a system dynamics model as well as a Bayesian network model are developed. The system dynamics model is used to estimate the unknown parameter values (through optimisation) and also to determine the intervals for the parameters. These intervals are then used in the Bayesian Belief Network model to assess uncertainty. Hybrid approaches improve the ability to validate models compared with conventional modelling. The resultant model indicates that reducing the price of rhino horn would not be effective at curbing poaching, unless poacher costs are also increased. However, increasing poacher costs is not a realistic policy option since these costs are largely beyond the control of decision-makers. The insensitivity of price to poaching effort has implications for methods proposed to reduce the value of rhinos, such as introducing synthetic rhino horn and the de-horning of rhinos.     

Use of human buildings by Eurasian badgers in the Moravskoslezské Beskydy Mountains,Czech Republic

An inspection of human buildings used by Eurasian badgersMeles meles (Linnaeus, 1758) in 28 sites in the Moravskoslezské Beskydy Mountains, Czech Republic, was carried out in 2001. The buildings inhabited or visited by badgers were as follows: wooden barns (18 cases), masonry buildings used for residential purposes (4), abandoned buildings (1), wooden sheds (2), wooden beehouses (2) and a non-residential part of a house (1). In three sites, female badgers with their cubs inhabited buildings. Badgers use the buildings more frequently in winter than in summer. Use of human buildings and the occurrence of badgers in setts in the wild in these mountains was observed in detail on a study area of 950 ha around the village of Lubno. In total, 12 setts were discovered. Eight of them were in the wild: two setts were located closer than 50 m, five between 100 m and 300 m, and one 700 m from human buildings. In four sites badgers inhabited human buildings.     

The socioecology of infant handling in primates: Is the current model convincing?

A strong interest shown by females towards infants other than their own is one of the most consistent behavioral traits found in primates, including humans. Species differences exist, however, in the extent mothers allow other group members to interact with their offspring. Socioecological theory predicts that in species characterized by relaxed, egalitarian dominance relations mothers should allow extensive interactions between their infants and other individuals from the first weeks of life, while in species characterized by nepotistic and despotic dominance relations maternal tolerance of infant handling should be low. While this model received some support from a comparison between colobines and some cercopithecines, several other species, including the Barbary macaque, do not appear to fit easily into the framework. In fact, only about half of all well-studied species follow the predicted pattern, suggesting that other factors, associated with the costs and benefits of the behavior, must be invoked to explain the variation in mothering styles and infant handling found in primates.