Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

Genetics and analysis of quantitative traits

Human-mediated species invasions are a significant component of current global environmental change. There is every indication that the rate at which locations are accumulating non-native species is accelerating as free trade and globalization advance. Thus, the need to incorporate predictive models in the assessment of invasion risk has become acute. However, finding elements of the invasion process that provide consistent explanatory power has proved elusive. Here, we propose propagule pressure as a key element to understanding why some introduced populations fail to establish whereas others succeed. In the process, we illustrate how the study of propagule pressure can provide an opportunity to tie together disparate research agendas within invasion ecology.

https://www.cell.com/trends/ecology-evolution/pdf/S0169-5347(05)00032-7.pdf

The role of propagule pressure in explaining species invasions.

Worldwide decline of the entomofauna: A review of its drivers

▪ Abstract The latitudinal gradient of decreasing richness from tropical to extratropical areas is ecology's longest recognized pattern. Nonetheless, notable exceptions to the general pattern exist, and it is well recognized that patterns may be dependent on characteristics of spatial scale and taxonomic hierarchy. We conducted an extensive survey of the literature and provide a synthetic assessment of the degree to which variation in patterns (positive linear, negative linear, modal, or nonsignificant) is a consequence of characteristics of scale (extent or focus) or taxon. In addition, we considered latitudinal gradients with respect to generic and familial richness, as well as species evenness and diversity. We provide a classification of the over 30 hypotheses advanced to account for the latitudinal gradient, and we discuss seven hypotheses with most promise for advancing ecological, biogeographic, and evolutionary understanding. We conclude with a forward-looking synthesis and list of fertile areas f...

LATITUDINAL GRADIENTS OF BIODIVERSITY:Pattern,Process,Scale,and Synthesis

Calopteryx splendens males exhibit a remarkable variation in wing pigmentation both within and between populations. In this study, we examined whether the wingspots of male C.splendens are related ...

/pdf/immunocompetence-developmental-stability-and-wingspot-size-484r68djbs.pdf

Immunocompetence, developmental stability and wingspot size in the damselfly Calopteryx splendens L.

Distribution and habitat selection of wintering birds in urban environments

Summary 1. Pheromones are chemical signals that function not only as mate attractors, but may also relay important information to prospective mates. In order for the information to be reliable, the signal must be costly to produce and this is likely to result in condition dependent expression of the signal. 2. We present results from two experiments on the grain beetle Tenebrio molitor examining phenotypic condition dependence of pheromones and patterns of female preference for pheromones. We also analysed condition dependence of two measures of immunocompetence: encapsulation response and phenoloxidase activity. 3. By manipulating the nutritional condition of the males we found that the attractiveness of the male pheromones to virgin females was condition-dependent, indicating that the production of the pheromones is affected by the condition of the male. We also found that the phenoloxidase activity of the males was affected by the nutritional condition of the male but that encapsulation rate was not. 4. Our results show that pheromones are condition-dependent signals, the quantity of which females use in their mate choice.

/pdf/condition-dependence-of-pheromones-and-immune-function-in-c5wex59max.pdf

Condition dependence of pheromones and immune function in the grain beetle Tenebrio molitor

Pheromones function not only as mate attractors, but they may also relay important information to prospective mates. It has been shown that vertebrates can distinguish, via olfactory mechanisms, major histocompatibility complex types in their prospective mates. However, whether pheromones can transmit information about immunocompetence is unknown. Here, we show that female mealworm beetles (Tenebrio molitor) prefer pheromones from males with better immunocompetence, indicated by a faster encapsulation rate against a novel antigen, and higher levels of phenoloxidase in haemolymph. Thus, the present study indicates that pheromones could transmit information about males' parasite resistance ability and may work as a reliable sexual ornament for female choice.

Do pheromones reveal male immunocompetence

In coniferous forests of Central Finland, tits (Paridae) and the Goldcrest (Regulus regulus) exploit nonrenewable resources in their group territories during the winter. Results of many studies have indicated that interspecific competition restricts the use of foraging sites in mixed—species winter flocks. However predation is a significant mortality factor in these species, and predation risk might also restrict the selection of foraging sites. The Pygmy Owl (Glaucidium passerinum) is the main diurnal predator of these small passerines during winter. Predation risk from the Pygmy Owl varies greatly with the availability of voles as alternative prey. The purpose of this study is to examine the effects of predation risk on the use of foraging sites in coniferous forest tits during winter. I collected foraging data from Willow (Parus montanus) and Crested Tits (P. cristatus) during one winter when vole populations had crashed and another winter when vole density was high to see if predation risk affects the selection of foraging sites by these species. Both Willow and Crested Tits changed to foraging in the inner parts of coniferous trees after the vole populations had crashed and when the Pygmy Owls started to hunt the tits. Additionally, in both pine and birch Willow Tits moved towards the treetops under high predation risk. Since all the foraging shifts were towards sites that are regarded to be safest from predation risk, it seems that predation risk in addition to interspecific competition influences the use of foraging sites by tits in coniferous forest.

Jukka Suhonen

Papers

Immunocompetence, developmental stability and wingspot size in the damselfly Calopteryx splendens L.

Distribution and habitat selection of wintering birds in urban environments

Condition dependence of pheromones and immune function in the grain beetle Tenebrio molitor

Do pheromones reveal male immunocompetence

Predation Risk Influences the Use of Foraging Sites by Tits