A multi-scale distribution model for non-equilibrium populations suggests resource limitation in an endangered rodent.

Species distributions are known to be limited by biotic and abiotic factors at multiple temporal and spatial scales. Species distribution models, however, frequently assume a population at equilibrium in both time and space. Studies of habitat selection have repeatedly shown the difficulty of estimating resource selection if the scale or extent of analysis is incorrect. Here, we present a multi-step approach to estimate the realized and potential distribution of the endangered giant kangaroo rat. First, we estimate the potential distribution by modeling suitability at a range-wide scale using static bioclimatic variables. We then examine annual changes in extent at a population-level. We define available habitat based on the total suitable potential distribution at the range-wide scale. Then, within the available habitat, model changes in population extent driven by multiple measures of resource availability. By modeling distributions for a population with robust estimates of population extent through time, and ecologically relevant predictor variables, we improved the predictive ability of SDMs, as well as revealed an unanticipated relationship between population extent and precipitation at multiple scales. At a range-wide scale, the best model indicated the giant kangaroo rat was limited to areas that received little to no precipitation in the summer months. In contrast, the best model for shorter time scales showed a positive relation with resource abundance, driven by precipitation, in the current and previous year. These results suggest that the distribution of the giant kangaroo rat was limited to the wettest parts of the drier areas within the study region. This multi-step approach reinforces the differing relationship species may have with environmental variables at different scales, provides a novel method for defining available habitat in habitat selection studies, and suggests a way to create distribution models at spatial and temporal scales relevant to theoretical and applied ecologists

Taxation--Federal Income Tax--Treatment of Nondistributable Capital Gains of Domestic Trust with Foreign Beneficiaries

Taxpayer, trustee of a domestic inter vivos trust, sued for a refund of United States income taxes paid on nondistributable capital gains of the trust. Trustee claimed that since all the beneficiaries of the trust were United Kingdom residents, this income was tax-exempt under the United States-United Kingdom tax convention provision that a United Kingdom resident shall be exempt from United States tax on gains from the sale or exchange of capital assets. On appeal by the United States from a district court judgment for the trustee, held, reversed. Although distributable gains are allowed the exemption, long term capital gains realized by a domestic trust, and accumulated for later distribution, are considered income to the trust regardless of the beneficiaries\u27 residence; the convention was not intended to override United States law which treats a trust as a separate taxable entity. Maximov v. United States, 299 F.2d 565 (2d Cir.), cert. granted, 371 U.S. 810 (1962)

Security-Chattel Mortgages-Mortgage Recorded Under Federal Aviation Act of 1958S as Affected by State Laws

Defendant, a Michigan corporation, ordered a new airplane from Air-O-Fleet, a retailer. Air-O-Fleet financed its purchase from the manufacturer through a loan from plaintiff, a Texas corporation, who took a chattel mortgage on the airplane. One day after Air-O-Fleet had made delivery to defendant and received full payment, plaintiff recorded the chattel mortgage with the Federal Aviation Authority in accordance with the Federal Aviation Act of 1958, section 1403, which provides that no conveyance or instrument ... shall be valid ... against any person other than the person by whom the conveyance or other instrument is made or given, ... or any person having actual notice thereof, until such conveyance is filed for recordation in the office of the Administrator.\u27\u27 Air-O-Fleet became bankrupt, and plaintiff filed suit against the defendant to recover the airplane or, in the alternative, the amount owing on the mortgage. On a motion by the plaintiff for summary judgment, held, denied. Since the conveyance to defendant preceded recordation of the mortgage, defendant took absolute title to the airplane unless he had actual notice of the mortgage. Even upon a trial determination that the defendant had actual notice, if the mortgage were otherwise void as to defendant under state law, federal recording would not save it. Aircraft Investment Corp. v. Pezzani b Reid Equipment Co., 205 F. Supp. 80 (E.D. Mich. 1962)

Insurance-Variable Annuities-Application of Investment Company Act of 1940

Anticipating the sale of variable annuity contracts as a part of its regular business, Prudential, a life insurance company, applied to the Securities and Exchange Commission for complete exemption from the requirements of the Investment Company Act of 1940. Prudential claimed that it qualified for exemption as an insurance company under the definition of insurance company in the Investment Company Act ( a company ... whose primary and predominant business activity is the writing of insurance . . . and which is subject to supervision by the insurance commissioner or a similar official or agency of a state ). In the alternative, Prudential requested exemption from specific provisions of the Investment Company Act relating primarily to investor control and redeemability requirements. On the principal application, asking complete exemption, held, denied. If an insurance company sells equity interests to the public and creates an investment fund, the insurance company\u27s exemption from federal regulation does not carry over to the investment fund, which is treated as a separate entity. Moreover, the Supreme Court decision which initially brought the variable annuity under federal securities regulation as a security classified the annuity contract itself, apart from any consideration of the type of company issuing it. Prudential Ins. Co. of America, SEC Investment Co. Act Release No. 3620, Jan. 22, 1963

Hierarchical Multi-Species Modeling of Carnivore Responses to Hunting, Habitat and Prey in a West African Protected Area

Protected areas (PAs) are a cornerstone of global efforts to shield wildlife from anthropogenic impacts, yet their effectiveness at protecting wide-ranging species prone to human conflict – notably mammalian carnivores – is increasingly in question. An understanding of carnivore responses to human-induced and natural changes in and around PAs is critical not only to the conservation of threatened carnivore populations, but also to the effective protection of ecosystems in which they play key functional roles. However, an important challenge to assessing carnivore communities is the often infrequent and imperfect nature of survey detections. We applied a novel hierarchical multi-species occupancy model that accounted for detectability and spatial autocorrelation to data from 224 camera trap stations (sampled between October 2006 and January 2009) in order to test hypotheses about extrinsic influences on carnivore community dynamics in a West African protected area (Mole National Park, Ghana). We developed spatially explicit indices of illegal hunting activity, law enforcement patrol effort, prey biomass, and habitat productivity across the park, and used a Bayesian model selection framework to identify predictors of site occurrence for individual species and the entire carnivore community. Contrary to our expectation, hunting pressure and edge proximity did not have consistent, negative effects on occurrence across the nine carnivore species detected. Occurrence patterns for most species were positively associated with small prey biomass, and several species had either positive or negative associations with riverine forest (but not with other habitat descriptors). Influences of sampling design on carnivore detectability were also identified and addressed within our modeling framework (e.g., road and observer effects), and the multi-species approach facilitated inference on even the rarest carnivore species in the park. Our study provides insight for the conservation of these regionally significant carnivore populations, and our approach is broadly applicable to the robust assessment of communities of rare and elusive species subject to environmental change

Suite of simple metrics reveals common movement syndromes across vertebrate taxa

ecause empirical studies of animal movement are most-often site- and species-specific, we lack understanding of the level of consistency in movement patterns across diverse taxa, as well as a framework for quantitatively classifying movement patterns. We aim to address this gap by determining the extent to which statistical signatures of animal movement patterns recur across ecological systems. We assessed a suite of movement metrics derived from GPS trajectories of thirteen marine and terrestrial vertebrate species spanning three taxonomic classes, orders of magnitude in body size, and modes of movement (swimming, flying, walking). Using these metrics, we performed a principal components analysis and cluster analysis to determine if individuals organized into statistically distinct clusters. Finally, to identify and interpret commonalities within clusters, we compared them to computer-simulated idealized movement syndromes representing suites of correlated movement traits observed across taxa (migration, nomadism, territoriality, and central place foraging)

Snake prices and crocodile appetites: Aquatic wildlife supply and demand on Tonle Sap Lake, Cambodia

Commercial trade is a major driver of over-exploitation of wild species, but the pattern of demand and how it responds to changes in supply is poorly understood. Here we explore the markets for snakes from Tonle Sap Lake in Cambodia to evaluate future exploitation scenarios, identify entry points for conservation and, more generally, to illustrate the value of multi-scale analysis of markets to traded wildlife conservation. In Cambodia, the largest driver of snake exploitation is the domestic trade in snakes as crocodile food. We estimate that farmed crocodiles consume between 2.7 and 12.2 million snakes per year. The market price for crocodiles has been in decline since 2003, which, combined with rising prices for their food, has led to a reduced frequency of feeding and closure of small farms. The large farms that generate a disproportionate amount of the demand for snakes continue to operate in anticipation of future market opportunities, and preferences for snakes could help maintain demand if market prices for crocodiles rise to pre 2003 levels. In the absence of a sustained demand from crocodile farms, it is also possible that alternative markets will develop, such as one for human snack food. The demand for snakes, however, also depends on the availability of substitute resources, principally fish. The substitutability and low price elasticity of demand offers a relatively sustainable form of consumerism. Given the nature of these market drivers, addressing consumer preferences and limiting the protection of snakes to their breeding season are likely to be the most effective tools for conservation. This study highlights the importance of understanding the structure of markets and the behaviour of consumer demand prior to implementing regulations on wildlife hunting and trade

Human Population Density and Extinction Risk in the World's Carnivores

Understanding why some species are at high risk of extinction, while others remain relatively safe, is central to the development of a predictive conservation science. Recent studies have shown that a species' extinction risk may be determined by two types of factors: intrinsic biological traits and exposure to external anthropogenic threats. However, little is known about the relative and interacting effects of intrinsic and external variables on extinction risk. Using phylogenetic comparative methods, we show that extinction risk in the mammal order Carnivora is predicted more strongly by biology than exposure to high-density human populations. However, biology interacts with human population density to determine extinction risk: biological traits explain 80% of variation in risk for carnivore species with high levels of exposure to human populations, compared to 45% for carnivores generally. The results suggest that biology will become a more critical determinant of risk as human populations expand. We demonstrate how a model predicting extinction risk from biology can be combined with projected human population density to identify species likely to move most rapidly towards extinction by the year 2030. African viverrid species are particularly likely to become threatened, even though most are currently considered relatively safe. We suggest that a preemptive approach to species conservation is needed to identify and protect species that may not be threatened at present but may become so in the near future