Dale L. Nolte

Why are predator urines aversive to prey

Predator odors often repel prey species. In the present experiments, we investigated whether changes in the diet of a predator, the coyote (Canis latrans) would affect the repellency of its urine. Furthermore, because predator odors have a high sulfur content, reflecting large amounts of meat in the diet, we investigated the contribution of sulfurous odors to repellency. Our results were consistent with the hypothesis that diet composition and sulfurous metabolites of meat digestion are important for the repellency of predator odors to potential prey.

Phylogenetic Diversity and Genotypical Complexity of H9N2 Influenza A Viruses Revealed by Genomic Sequence Analysis

H9N2 influenza A viruses have become established worldwide in terrestrial poultry and wild birds, and are occasionally transmitted to mammals including humans and pigs. To comprehensively elucidate the genetic and evolutionary characteristics of H9N2 influenza viruses, we performed a large-scale sequence analysis of 571 viral genomes from the NCBI Influenza Virus Resource Database, representing the spectrum of H9N2 influenza viruses isolated from 1966 to 2009. Our study provides a panoramic framework for better understanding the genesis and evolution of H9N2 influenza viruses, and for describing the history of H9N2 viruses circulating in diverse hosts. Panorama phylogenetic analysis of the eight viral gene segments revealed the complexity and diversity of H9N2 influenza viruses. The 571 H9N2 viral genomes were classified into 74 separate lineages, which had marked host and geographical differences in phylogeny. Panorama genotypical analysis also revealed that H9N2 viruses include at least 98 genotypes, which were further divided according to their HA lineages into seven series (A–G). Phylogenetic analysis of the internal genes showed that H9N2 viruses are closely related to H3, H4, H5, H7, H10, and H14 subtype influenza viruses. Our results indicate that H9N2 viruses have undergone extensive reassortments to generate multiple reassortants and genotypes, suggesting that the continued circulation of multiple genotypical H9N2 viruses throughout the world in diverse hosts has the potential to cause future influenza outbreaks in poultry and epidemics in humans. We propose a nomenclature system for identifying and unifying all lineages and genotypes of H9N2 influenza viruses in order to facilitate international communication on the evolution, ecology and epidemiology of H9N2 influenza viruses.

A repellent to reduce mouse damage to longleaf pine seed

Direct seeding is a potential method for reforestation of pines on many southern sites. The success of direct seeding, however, depends, at least in part, in reducing seed predation by birds and rodents. We conducted a series of tests to assess the efficacy of capsicum and thiram in reducing mouse damage to longleaf pine (Pinus palustris) seeds. House mice (Mus musculus) predation was reduced (P<0.05) by treating seeds with either capsicum or thiram or a mixture of the two ingredients. Deer mice (Peromyscus maniculatus) avoided seeds treated with a mixture of capsicum and thiram. We conclude that the capsicum and thiram mixture should be pursued as a potential repellent to protect longleaf pine seeds from animal predation when these seeds are used in direct seeding efforts to establish southern pine forests.

Surveillance for highly pathogenic avian influenza in wild birds in the USA

As part of the USAs National Strategy for Pandemic Influenza, an Interagency Strategic Plan for the Early Detection of Highly Pathogenic H5N1 Avian Influenza in Wild Migratory Birds was developed and implemented. From 1 April 2006 through 31 March 2009, 261,946 samples from wild birds and 101,457 wild bird fecal samples were collected in the USA; no highly pathogenic avian influenza was detected. The United States Department of Agriculture, and state and tribal cooperators accounted for 213,115 (81%) of the wild bird samples collected; 31, 27, 21 and 21% of the samples were collected from the Atlantic, Pacific, Central and Mississippi flyways, respectively. More than 250 species of wild birds in all 50 states were sampled. The majority of wild birds (86%) were dabbling ducks, geese, swans and shorebirds. The apparent prevalence of low pathogenic avian influenza viruses during biological years 2007 and 2008 was 9.7 and 11.0%, respectively. The apparent prevalence of H5 and H7 subtypes across all species sampled were 0.5 and 0.06%, respectively. The pooled fecal samples (n= 101,539) positive for low pathogenic avian influenza were 4.0, 6.7 and 4.7% for biological years 2006, 2007 and 2008, respectively. The highly pathogenic early detection system for wild birds developed and implemented in the USA represents the largest coordinated wildlife disease surveillance system ever conducted. This effort provided evidence that wild birds in the USA were free of highly pathogenic avian influenza virus (given the expected minimum prevalence of 0.001%) at the 99.9% confidence level during the surveillance period.

Chemically mediated foraging preference of black bears (Ursus americanus)

The role of chemical constituents in the foraging behavior of black bears ( Ursus americanas ) was investigated using two field studies. Vascular tissue samples were collected from Douglas-fir ( Pseudotsuga menziesii ) trees recently foraged by black bears. Samples were extracted and analyzed by liquid and gas chromatography to determine carbohydrates and terpenes, respectively. Chemical data were subjected to correlation analyses and multiple regression to examine if they adequately describe observed foraging preferences. Free-ranging black bears also were offered a choice of four test diets that differed in content of carbohydrates and terpenes. Results indicated that forage preferences were based in part on chemical constituents in the forage. Black bears maximized intake of carbohydrates and minimized intake of terpenes. In multiple choice tests, free-ranging bears preferred a low-terpene diet to a high-terpene diet with identical carbohydrate content. Bears also preferred a high-carbohydrate diet to a low-carbohydrate diet with identical terpene content.

Tolerance of Bitter Compounds by an Herbivore, Cavia Porcellus

Many plant defensive chemicals are bitter to humans. Because of this taste characteristic, and because bitter compounds are often toxic, such substances, and the plants that contain them, are regarded as generally unpalatable to wildlife. These assumptions may be unwarranted. To test the hypothesis that herbivores are indifferent to ‘bitter’ tastants, we investigated the responsiveness of guinea pigs (Cavia porcellus) to denatonium benzoate, denatonium saccharide, limonene,l-phenylalanine, naringin, quebracho, quinine, Ro-Pel (a commercial animal repellent containing denatonium saccharide) and sucrose octaacetate. Only quinine and sucrose octaacetate slightly but significantly reduced feeding (P<0.05). Our findings are inconsistent with the notion that herbivores generally avoid what humans describe as bitter tastes.

Efficacy of selected repellents to deter deer browsing on conifer seedlings

Abstract Foraging deer can negatively impact agricultural resources. Repellents offer a plausible approach to inhibit browsing. The efficacy of Big Game Repellent-Powder (BGR), Deer Stopper (DST), Plantskydd (PLA) and ECX95BY (ECX) to deter black-tailed deer ( Odocoileus hemionus columbianus ) browsing of ponderosa pine ( Pinus ponderosa ), Douglas-fir ( Pseudotsugamenziesii ) and western red cedar ( Thuja plicata ) seedlings was assessed during the winter. Extent of damage was expressed as number of seedlings damaged, number of terminal buds damaged, number of lateral bites taken and the number of seedlings with severe damage. BGR, DST and PLA significantly reduced deer damage relative to controls for at least 14 weeks. After 1 week, damage to seedlings treated with ECX was similar to that inflicted on control seedlings. Aversive agents contained in BGR, DST and PLA probably produce sulfurous odors, while ECX contained denatonium benzoate, a bittering agent.

Potential repellents to prevent mountain beaver damage

Mountain beaver (Aplodontia rufa) damage to trees in the Pacific Northwest is economically serious. At present, few strategies are available to control damage, and new chemical repellents are being sought. Samples of two preferred plants, Douglas fir (Pseudotsuga menziesii) and salal (Galtheria shallon), were treated with mink urine, coyote urine, o-aminoacetophenone, or denatonium benzoate and presented to mountain beavers. All treatments reduced clipping (p < 0.05) of salal, but mink and coyote urines were most effective. Mink and coyote urines were the only treatments to significantly reduce clipping (p < 0.05) of Douglas fir.

Reassortant H9N2 Influenza Viruses Containing H5N1-Like PB1 Genes Isolated from Black-Billed Magpies in Southern China

H9N2 influenza A viruses have become endemic in different types of terrestrial poultry and wild birds in Asia, and are occasionally transmitted to humans and pigs. To evaluate the role of black-billed magpies (Pica pica) in the evolution of influenza A virus, we conducted two epidemic surveys on avian influenza viruses in wild black-billed magpies in Guangxi, China in 2005 and characterized three isolated black-billed magpie H9N2 viruses (BbM viruses). Phylogenetic analysis indicated that three BbM viruses were almost identical with 99.7 to 100% nucleotide homology in their whole genomes, and were reassortants containing BJ94-like (Ck/BJ/1/94) HA, NA, M, and NS genes, SH/F/98-like (Ck/SH/F/98) PB2, PA, and NP genes, and H5N1-like (Ck/YN/1252/03, clade 1) PB1 genes. Genetic analysis showed that BbM viruses were most likely the result of multiple reassortments between co-circulating H9N2-like and H5N1-like viruses, and were genetically different from other H9N2 viruses because of the existence of H5N1-like PB1 genes. Genotypical analysis revealed that BbM viruses evolved from diverse sources and belonged to a novel genotype (B46) discovered in our recent study. Molecular analysis suggested that BbM viruses were likely low pathogenic reassortants. However, results of our pathogenicity study demonstrated that BbM viruses replicated efficiently in chickens and a mammalian mouse model but were not lethal for infected chickens and mice. Antigenic analysis showed that BbM viruses were antigenic heterologous with the H9N2 vaccine strain. Our study is probably the first report to document and characterize H9N2 influenza viruses isolated from black-billed magpies in southern China. Our results suggest that black-billed magpies were susceptible to H9N2 influenza viruses, which raise concerns over possible transmissions of reassortant H9N2 viruses among poultry and wild birds.

Large-Scale Avian Influenza Surveillance in Wild Birds throughout the United States

Avian influenza is a viral disease that primarily infects wild and domestic birds, but it also can be transmitted to a variety of mammals. In 2006, the United States of America Departments of Agriculture and Interior designed a large-scale, interagency surveillance effort that sought to determine if highly pathogenic avian influenza viruses were present in wild bird populations within the United States of America. This program, combined with the Canadian and Mexican surveillance programs, represented the largest, coordinated wildlife disease surveillance program ever implemented. Here we analyze data from 197,885 samples that were collected from over 200 wild bird species. While the initial motivation for surveillance focused on highly pathogenic avian influenza, the scale of the data provided unprecedented information on the ecology of avian influenza viruses in the United States, avian influenza virus host associations, and avian influenza prevalence in wild birds over time. Ultimately, significant advances in our knowledge of avian influenza will depend on both large-scale surveillance efforts and on focused research studies.