The botanist effect: counties with maximal species richness tend to be home to universities and botanists

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72800/1/j.1365-2699.2006.01549.x.pd

Is there anybody out there? Occupancy of the carnivore guild in a temperate archipelago

Carnivores are important components of ecological communities with wide-ranging effects that vary with carnivore size, natural history, and hunting tactics. Researchers and managers should strive to understand both the presence and distribution of carnivores within their local environment. We studied the carnivore guild in the Apostle Islands, where the distribution and occupancy of carnivores was largely unknown. We monitored 19 islands with 160 functioning camera traps from 2014-2017, from which we collected 203,385 photographs across 49,280 trap nights. We documented 7,291 total wildlife events with 1,970 carnivore events, and detected 10 of the 12 terrestrial carnivores found in Wisconsin. Detection rates for species were generally higher in summer than winter, except for coyotes (Canis latrans) and red foxes (Vulpes vulpes). Finitesample occupancy estimates for carnivores varied across islands, with mean estimated occupancy across islands varying from a high of 0.73 for black bears to a low of 0.21 for gray wolves. Of the potential island biogeography explanatory variables for carnivore occupancy we considered, island size was the most important, followed by distance to the mainland, and then interisland distance. We estimated that terrestrial carnivore species varied in the number of islands they were detected on from 1 island for gray wolves to 13 islands for black bears. Estimated carnivore richness across islands (i.e., the number of carnivores occupying an island) also varied substantively from 1 species on Michigan Island to 10 species on Stockton Island. Island size and connectivity between islands appear important for the persistence of the carnivore community in the Apostle Islands

Evolutionary Entropy: A Predictor of Body Size, Metabolic Rate and Maximal Life Span

Body size of organisms spans 24 orders of magnitude, and metabolic rate and life span present comparable differences across species. This article shows that this variation can be explained in terms of evolutionary entropy, a statistical parameter which characterizes the robustness of a population, and describes the uncertainty in the age of the mother of a randomly chosen newborn. We show that entropy also has a macroscopic description: It is linearly related to the logarithm of the variables body size, metabolic rate, and life span. Furthermore, entropy characterizes Darwinian fitness, the efficiency with which a population acquires and converts resources into viable offspring. Accordingly, entropy predicts the outcome of natural selection in populations subject to different classes of ecological constraints. This predictive property, when integrated with the macroscopic representation of entropy, is the basis for enormous differences in morphometric and life-history parameters across species

‘Island Life’ before man: biogeography of palaeo-insular mammals

Aim: To assess the relative contributions of colonization, speciation and human activities on species richness (S) of mammalian communities among oceanic islands. Location: Palaeo-islands world-wide. Methods: We compiled species lists from published works and compared species–area and species–isolation relationships for mammalian taxa of 36 islands over three stages of community development during the late Pleistocene and Holocene: at colonization, or founding (Sf); after in situ speciation, but before colonization by humans (Ss); and during the Anthropocene (SA), that is, following human colonization and subsequent extinctions and species introductions. We used regression and correlation analyses to compare Sf and Ss patterns to assess the impact of speciation on the native assemblages, and compared these patterns to those expected by island biogeography theory (largely based on patterns for extant insular faunas). We then compared patterns for Ss and SA to assess impacts of human activities on insular community structure. Results: Although patterns for Sf were consistent with those expected based on island biogeography theory (Sf increasing with area and decreasing with isolation), patterns for Ss were quite anomalous, with uncharacteristically steep log-log slopes (high z-values) of the species–area relationship, and no significant influence of isolation on Ss. Analyses based on contemporary assemblages (SA) indicated that human activities have rendered native assemblages highly depauperate, while anthropogenic introductions have inflated richness far above Ss on all but the largest islands. Main conclusions: Long-standing models of island biogeography may prove inadequate unless their conceptual domains are expanded to include the effects of all three fundamental, biogeographical processes (immigration, extinction and speciation), the impact of human activities on each of these processes, and the likelihood that, at least for very large and isolated islands, a long-term equilibrium among these processes is seldom achieved. © 2016 John Wiley & Sons Lt

‘On being the right size’ – Do aliens follow the rules?

Aim: To assess whether mammalian species introduced onto islands across the globe have evolved to exhibit body size patterns consistent with the ‘island rule,’, and to test an ecological explanation for body size evolution of insular mammals. Location: Islands worldwide. Methods: We assembled data on body mass, geographical characteristics (latitude, maximum elevation) and ecological communities (number of mammalian competitors, predators and prey) for 385 introduced populations across 285 islands, comprising 56 species of extant, non-volant mammals. We used linear regression, ANCOVA and regression tree analyses to test whether introduced populations of mammals exhibit the island rule pattern, whether the degree of body size change increased with time in isolation and whether residual variation about the general trend can be attributed to the geographical and ecological characteristics of the islands. Results: Introduced populations follow the predicted island rule trend, with body size shifts more pronounced for populations with greater residence times on the islands. Small mammals evolved to larger body sizes in lower latitudes and on islands with limited topographic relief. Consistent with our hypothesis on the ecology of evolution, body size of insular introduced populations was influenced by co-occurring species of mammalian competitors, predators and prey. Conclusion: The island rule is a pervasive pattern, exhibited across a broad span of geographical regions, taxa, time periods and, as evidenced here, for introduced as well as native mammals. Time in isolation impacts body size evolution profoundly. Body size shift of introduced mammals was much more pronounced with increasing residence times, yet far less than that exhibited by native, palaeo-insular mammals (residence times > 10,000 years). Given the antiquity of many species introductions, it appears that much of what we view as the natural character and ecological dynamics of recent insular communities may have been rendered artefacts of ancient colonizations by humans and commensals. © 2018 The Authors. Journal of Biogeography Published by John Wiley & Sons Lt