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

Beginning with Emlen (1966) and MacArthur and Pianka (1966) and extending through the last ten years, several authors have sought to predict the foraging behavior of animals by means of mathematical models. These models are very similar,in that they all assume that the fitness of a foraging animal is a function of the efficiency of foraging measured in terms of some "currency" (Schoener, 1971) -usually energy- and that natural selection has resulted in animals that forage so as to maximize this fitness. As a result of these similarities, the models have become known as "optimal foraging models"; and the theory that embodies them, "optimal foraging theory." The situations to which optimal foraging theory has been applied, with the exception of a few recent studies, can be divided into the following four categories: (1) choice by an animal of which food types to eat (i.e., optimal diet); (2) choice of which patch type to feed in (i.e., optimal patch choice); (3) optimal allocation of time to different patches; and (4) optimal patterns and speed of movements. In this review we discuss each of these categories separately, dealing with both the theoretical developments and the data that permit tests of the predictions. The review is selective in the sense that we emphasize studies that either develop testable predictions or that attempt to test predictions in a precise quantitative manner. We also discuss what we see to be some of the future developments in the area of optimal foraging theory and how this theory can be related to other areas of biology. Our general conclusion is that the simple models so far formulated are supported are supported reasonably well by available data and that we are optimistic about the value both now and in the future of optimal foraging theory. We argue, however, that these simple models will requre much modification, espicially to deal with situations that either cannot easily be put into one or another of the above four categories or entail currencies more complicated that just energy.

Citation classic - optimal foraging - a selective review of theory and tests

Urban effects on native avifauna: a review

▪ Abstract Edge effects have been studied for decades because they are a key component to understanding how landscape structure influences habitat quality. However, making sense of the diverse patterns and extensive variability reported in the literature has been difficult because there has been no unifying conceptual framework to guide research. In this review, we identify four fundamental mechanisms that cause edge responses: ecological flows, access to spatially separated resources, resource mapping, and species interactions. We present a conceptual framework that identifies the pathways through which these four mechanisms can influence distributions, ultimately leading to new ecological communities near habitat edges. Next, we examine a predictive model of edge responses and show how it can explain much of the variation reported in the literature. Using this model, we show that, when observed, edge responses are largely predictable and consistent. When edge responses are variable for the same species ...

Ecological Responses to Habitat Edges: Mechanisms, Models, and Variability Explained

The wildland-urban interface (WUI) is the area where houses meet or intermingle with undeveloped wildland vegetation. The WUI is thus a focal area for human-environment conflicts, such as the destruction of homes by wildfires, habitat fragmentation, introduction of exotic species, and biodiversity decline. Our goal was to conduct a spatially detailed assessment of the WUI across the United States to provide a framework for scientific inquiries into housing growth effects on the environment and to inform both national policymakers and local land managers about the WUI and associated issues. The WUI in the conterminous United States covers 719 156 km? (9% of land area) and contains 44.8 million housing units (39% of all houses). WUI areas are particularly widespread in the eastern United States, reaching a maximum of 72% of land area in Connecticut. California has the highest number of WUI housing units (5.1 million). The extent of the WUI highlights the need for ecological principles in land-use planning as well as sprawl-limiting policies to adequately address both wildfire threats and conservation problems.

https://www.nrs.fs.fed.us/pubs/gtr/gtr_nrs1/stewart_1_197.pdf

The wildland-urban interface in the United States

African elephants (Loxodonta africana) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. Elephant populations in survey areas with historical data decreased by an estimated 144,000 from 2007 to 2014, and populations are currently shrinking by 8% per year continent-wide, primarily due to poaching. Though 84% of elephants occurred in protected areas, many protected areas had carcass ratios that indicated high levels of elephant mortality. Results of the GEC show the necessity of action to end the African elephants' downward trajectory by preventing poaching and protecting habitat.

/pdf/continent-wide-survey-reveals-massive-decline-in-african-4iczxm5s0w.pdf

Continent-wide survey reveals massive decline in African savannah elephants.

Autocorrelation in animal movements can be both a serious nuisance to analysis and a source of valuable information about the scale and patterns of animal behavior, depending on the question and the techniques employed. In this paper we present an approach to analyzing the patterns of autocorrelation in animal movements that provides a detailed picture of seasonal variability in the scale and patterns of movement. We used a combination of moving window Mantel correlograms, surface correlation and crosscorrelation analysis to investigate the scales and patterns of autocorrelation in the movements of three herds of elephants in northern Botswana. Patterns of autocorrelation of elephant movements were long-range, temporally complicated, seasonally variable, and closely linked with the onset of rainfall events. Specifically, for the three elephant herds monitored there was often significant autocorrelation among locations up to lags of 30 days or more. During many seasonal periods there was no indication of decreasing autocorrelation with increasing time between locations. Over the course of the year, herds showed highly variable and complex patterns of autocorrelation, ranging from random use of temporary home ranges, periodic use of focal areas, and directional migration. Even though the patterns of autocorrelation were variable in time and quite complex, there were highly significant correlations among the autocorrelation patterns of the different herds, indicating that they exhibited similar patterns of movement through the year. These major patterns of autocorrelation seem to be related to patterns of rainfall. The strength of correlation in movement patterns of the different herds decreased markedly at the cessation of major rain events. Also, there was a strong crosscorrelation between strength of autocorrelation of movement and rainfall, peaking at time lags of between three and four weeks. Overall, these approaches provide a powerful way to explore the scales and patterns of autocorrelation of animal movements, and to explicitly link those patterns to temporally variable environmental attributes, such as rainfall or vegetation phenology.

/pdf/elephants-in-space-and-time-4qw5bwxutr.pdf

Elephants in space and time

We examined whether nest monitoring and other research activities influenced rates of red fox (Vulpes vulpes) predation on both natural and artificial piping plover (Charadrius melodus) nests in Massachusetts. The percentage of nests depredated did not differ significantly (P > 0.05) between nests where we trapped and banded incubating adults and nests where we did not trap. Nest predation was significantly lower (P 0.05) predation rates compared to artificial nests monitored from a distance. Daily monitoring of piping plover nests is not likely to result in increased fox predation, and it seems to be an acceptable practice; but, nest visits should be conducted in a manner that minimizes disturbance to nesting plovers. Further research should test whether human scent at piping plover nests is a deterrent to red foxes. J. WILDL. MANAGE. 54(3):443-447 For scientific and ethical reasons, researchers must be concerned about the influence their activities may have on nesting success of groundnesting birds and on the behavior of nest predators (Livezey 1980, Nol and Brooks 1982, Galbraith 1987). This concern extends to piping plovers that nest on beaches, dunes, and sand spits along the Atlantic Coast of North America. Because of its threatened status (Dyer et al. 1988), the piping plover is the focus of intensive conservation efforts, including protection of nests from human disturbance, censuses of breeding pairs, monitoring of nest success and productivity, and trapping and banding of incubating adults to determine movement patterns and survival rates. During studies of the population ecology of piping plovers on outer Cape Cod, Massachusett , between 1985 and 1987, predators destroyed 52-81% of all active plover nests at one of our principal study sites. Red foxes were responsible for 71-100% of the nests that were lost to predators at that site each year. These results led us to examine whether our activities attracted predators, particularly red foxes, to plover nests and thus reduced nest success. Our objectives were (1) to examine effects of research activities on fates of both natural and artificial plover nests and (2) to determine if foxes located plover nests by following researcher tracks and scent trails. Financial and logistical support for our study we e provided by the National Park Service, Massachusetts Division of Fisheries and Wildli e, U.S. Fish and Wildlife Service, Cape Cod M seum of Natural History, and several private contributors. J. F. Milton monitored artificial nests at Parker River National Wildlife Refuge (NWR), and M. J. Croonquist monitored red fox movements at Coast Guard Beach. Conversa'Present address: Maine Department of Inland Fisheries and Wildlife, P.O. Box 1298, Bangor, ME 04401. This content downloaded from 207.46.13.25 on Mon, 12 Sep 2016 04:05:07 UTC All use subject to http://about.jstor.org/terms 444 PLOVER NEST PREDATION * Maclvor et al. J. Wildl. Manage. 54(3):1990 tions with J. J. Hatch stimulated the artificial nest portion of the study. We gratefully acknowledge the assistance of V. A. Rosenberg, E. M. Hoopes, R. C. Humphrey, B. A. Samora, and K. Carlson. We thank R. M. Erwin, A. Hecht, and an anonymous reviewer for their comments on an earlier draft of this manuscript.

Effects of Research Activity on Piping Plover Nest Predation

Federal listing of the piping plover as endangered and threatened (Federal Register 1985) has prompted intensive management to reduce impacts of predation and other factors limiting piping plover productivity (Dyer et al. 1988, Haig et al. 1988, Melvin et al. 1991). While studying piping plover breeding biology at 6 sites on Cape Cod, Massachusetts, during 1985-1987, we determined that at least 79 of 126 (63%) piping plover nests were destroyed by red foxes (Vulpes vulpes), striped skunks (Mephitis mephitis), American crows (Corvus brachyrhynchos), and gulls (Larus spp.) (MacIvor 1990). These results led us to investigate the use of predator exclosures (Nol and Brooks 1982, Post and Greenlaw 1989, Rimmer and Deblinger 1990) to reduce predation of piping plover nests. We first used an exclosure to protect a piping plover nest at Coast Guard Beach on Cape Cod in 1987. Although foxes destroyed 5 previous clutches laid by that pair of plovers that summer, the protected nest hatched successfully and 1 chick fledged. We describe the construction, installation, and success of circular, wire predator exclosures that we placed around individual piping plover nests in Massachusetts in 1988 and 1989.

/pdf/predator-exclosures-a-technique-to-reduce-predation-at-6ixj32d3dt.pdf

Predator exclosures: a technique to reduce predation at piping plover nests

Artificial nests are widely used in avian field studies. However, it is unclear how well predation rates on artificial nests reflect predation rates on natural nests. Therefore, we compared survival rates of artificial nests (unused natural nests baited with House Sparrow eggs) with survival rates of active bird nests in the same habitat at the same sites. Survival rates of artificial nests (27.7%) were significantly lower than nest survival rates of natural nests (58.6%). Logistic regression analysis indicated that the inclusion of an index of nest concealment in addition to nest type (natural or artificial) significantly increased the amount of the variability in nest predation accounted for by the regression. However, because the relationship between nest survival and nest type (natural or artificial) was still highly significant even with nest concealment included in the model, we conclude that higher rates of nest predation on artificial nests were not entirely due to the greater conspicuousness of artificial nests. We suggest that lack of parental defense is an additional contributing factor responsible for higher predation rates on artificial nests and, therefore, is likely to be a potential confounding factor in future nest predation experiments using artificial nests.

https://www.fs.fed.us/ne/newtown_square/publications/other_publishers/OCR/ne_1999_king001.pdf

Curtice R. Griffin

Papers

Continent-wide survey reveals massive decline in African savannah elephants.

Elephants in space and time

Effects of Research Activity on Piping Plover Nest Predation

Predator exclosures: a technique to reduce predation at piping plover nests

Do Predation Rates on Artificial Nests Accurately Reflect Predation Rates on Natural Bird Nests