Host Species, And Not Environment, Predicts Variation In Blood Parasite Prevalence, Distribution, And Diversity Along A Humidity Gradient In Northern South America, Robert Ricklefs, Paulo C. Pulgarín‐R, Juan P. Gómez
Mar 2018
Host Species, And Not Environment, Predicts Variation In Blood Parasite Prevalence, Distribution, And Diversity Along A Humidity Gradient In Northern South America, Robert Ricklefs, Paulo C. Pulgarín‐R, Juan P. Gómez
Robert Ricklefs
Environmental factors strongly influence the ecology and evolution of vector‐borne infectious diseases. However, our understanding of the influence of climatic variation on host–parasite interactions in tropical systems is rudimentary. We studied five species of birds and their haemosporidian parasites (Plasmodium and Haemoproteus) at 16 sampling sites to understand how environmental heterogeneity influences patterns of parasite prevalence, distribution, and diversity across a marked gradient in water availability in northern South America. We used molecular methods to screen for parasite infections and to identify parasite lineages. To characterize spatial heterogeneity in water availability, we used weather‐station and remotely sensed climate data. We …
Emma Lucy Braun's Forest Plots In Eastern North America, Robert E. Ricklefs
Dec 2017
Emma Lucy Braun's Forest Plots In Eastern North America, Robert E. Ricklefs
Robert Ricklefs
No abstract provided.
Phylogenetic Patterns Of Rarity In A Regional Species Pool Of Tropical Woody Plants, M. Isabel Loza, Iván Jiménez, Peter M. Jørgensen, Gabriel Arellano, Manuel J. Macía, Vania W. Torrez, Robert E. Ricklefs
Jan 2017
Phylogenetic Patterns Of Rarity In A Regional Species Pool Of Tropical Woody Plants, M. Isabel Loza, Iván Jiménez, Peter M. Jørgensen, Gabriel Arellano, Manuel J. Macía, Vania W. Torrez, Robert E. Ricklefs
Robert Ricklefs
Aim
Rarity, which is believed to influence extinction risk, can be defined in terms of local abundance, geographical range size and habitat breadth. Phylogenetic patterns in these attributes provide insight into the extent to which rarity and extinction risk are conserved during evolution and the potential for species‐level heritability. We evaluated phylogenetic signal (i.e., related species resembling each other more than species drawn at random) and evolutionary conservatism (similarity among related species exceeding that expected from a Brownian model of evolution) in three axes of rarity (local abundance, geographical range size and habitat breadth) among species in a regional pool …
Passerine Morphology: External Measurements Of Approximately One-Quarter Of Passerine Bird Species, Robert E. Ricklefs
Jan 2017
Passerine Morphology: External Measurements Of Approximately One-Quarter Of Passerine Bird Species, Robert E. Ricklefs
Robert Ricklefs
Studies of community organization and clade diversification that include functional traits have become an important component of the analysis of ecological and evolved systems. Such studies frequently are limited by availability of consistently collected data. Here, I present a data set including eight measurements of the external morphology of 1642 species, roughly one‐quarter of all passerine birds (Aves: Order Passeriformes), from all parts of the world, characterizing the relative proportions of the wing, tail, legs, and beak. Specimens were measured opportunistically over the past 40 years in museums in the United States and Europe. Numbers of individuals measured per species …
Overlap In The Seasonal Infection Patterns Of Avian Malaria Parasites And West Nile Virus In Vectors And Hosts, Matthew C. I. Medeiros, Robert E. Ricklefs, Jeffrey D. Brawn, Marilyn O. Ruiz, Tony L. Goldberg, Gabriel L. Hamer
Nov 2016
Overlap In The Seasonal Infection Patterns Of Avian Malaria Parasites And West Nile Virus In Vectors And Hosts, Matthew C. I. Medeiros, Robert E. Ricklefs, Jeffrey D. Brawn, Marilyn O. Ruiz, Tony L. Goldberg, Gabriel L. Hamer
Robert Ricklefs
Multiple vector-borne pathogens often circulate in the same vector and host communities, and seasonal infection dynamics influence the potential for pathogen interactions. Here, we explore the seasonal infection patterns of avian malaria (Haemosporida) parasites (Plasmodium and Haemoproteus) and West Nile virus (WNV) in birds and mosquitoes in suburban Chicago. We show that both pathogens vary seasonally in Culex mosquitoes and avian hosts, but that patterns of covariation are complex. Different putative Plasmodium species varied asynchronously across the season in mosquitoes and birds, suggesting that different forces may govern their transmission. Infections of Culex mosquitoes with Plasmodium parasites were positively associated …
An Inverse Association Between West Nile Virus Serostatus And Avian Malaria Infection Status, Robert Ricklefs, Matthew Ci Medeiros, Tavis K. Anderson, Jenni M. Higashiguchi, Uriel D. Kitron, Edward D. Walker, Jeffrey D. Brawn, Bethany L. Krebs, Marilyn O. Ruiz, Tony L. Goldberg, Gabriel L. Hamer
Jul 2014
An Inverse Association Between West Nile Virus Serostatus And Avian Malaria Infection Status, Robert Ricklefs, Matthew Ci Medeiros, Tavis K. Anderson, Jenni M. Higashiguchi, Uriel D. Kitron, Edward D. Walker, Jeffrey D. Brawn, Bethany L. Krebs, Marilyn O. Ruiz, Tony L. Goldberg, Gabriel L. Hamer
Robert Ricklefs
Background
Various ecological and physiological mechanisms might influence the probability that two or more pathogens may simultaneously or sequentially infect a host individual. Concurrent infections can have important consequences for host condition and fitness, including elevated mortality risks. In addition, interactions between coinfecting pathogens may have important implications for transmission dynamics.
Methods
Here, we explore patterns of association between two common avian pathogens (West Nile virus and avian malaria parasites) among a suburban bird community in Chicago, IL, USA that share mosquito vectors. We surveyed 1714 individual birds across 13 species for both pathogens through established molecular protocols.
Results
Field …
Mixed Species Flock, Nest Height, And Elevation Partially Explain Avian Haemoparasite Prevalence In Colombia, Angie D. González, Nubia E. Matta, Vincenzo A. Ellis, Eliot T. Miller, Robert E. Ricklefs, H. Rafael Gutiérrez
Jun 2014
Mixed Species Flock, Nest Height, And Elevation Partially Explain Avian Haemoparasite Prevalence In Colombia, Angie D. González, Nubia E. Matta, Vincenzo A. Ellis, Eliot T. Miller, Robert E. Ricklefs, H. Rafael Gutiérrez
Robert Ricklefs
No abstract provided.
Different Meal, Same Flavor: Cospeciation And Host Switching Of Haemosporidian Parasites In Some Non-Passerine Birds, Diego Santiago-Alarcon, Adriana Rodríguez-Ferraro, Patricia G. Parker, Robert E. Ricklefs
Dec 2013
Different Meal, Same Flavor: Cospeciation And Host Switching Of Haemosporidian Parasites In Some Non-Passerine Birds, Diego Santiago-Alarcon, Adriana Rodríguez-Ferraro, Patricia G. Parker, Robert E. Ricklefs
Robert Ricklefs
Background
Previous studies have shown that haemosporidian parasites (Haemoproteus(Parahaemoproteus) and Plasmodium) infecting passerine birds have an evolutionary history of host switching with little cospeciation, in particular at low taxonomic levels (e.g., below the family level), which is suggested as the main speciation mechanism of this group of parasites. Recent studies have characterized diverse clades of haemosporidian parasites (H. (Haemoproteus) and H. (Parahaemoproteus)) infecting non-passerine birds (e.g., Columbiformes, Pelecaniiformes). Here, we explore the cospeciation history of H. (Haemoproteus) and H. (Parahaemoproteus) parasites with …
Evolutionary Biology For The 21st Century, Robert Ricklefs, Jonathan B. Losos, Stevan J. Arnold, Gill Bejerano, E. D. Brodie Iii, David Hibbett, Hopi E. Hoekstra, David P. Mindell, Antonia Monteiro, Craig Moritz, H. Allen Orr, Dmitri A. Petrov, Susanne S. Renner, Pamela S. Soltis, Thomas L. Turner
Dec 2012
Evolutionary Biology For The 21st Century, Robert Ricklefs, Jonathan B. Losos, Stevan J. Arnold, Gill Bejerano, E. D. Brodie Iii, David Hibbett, Hopi E. Hoekstra, David P. Mindell, Antonia Monteiro, Craig Moritz, H. Allen Orr, Dmitri A. Petrov, Susanne S. Renner, Pamela S. Soltis, Thomas L. Turner
Robert Ricklefs
No abstract provided.
Daily Energy Expenditure In Precocial Shorebird Chicks: Smaller Species Perform At Higher Levels, Robert Ricklefs, Karen L. Krijgsveld, G. Henk Visser
Sep 2012
Daily Energy Expenditure In Precocial Shorebird Chicks: Smaller Species Perform At Higher Levels, Robert Ricklefs, Karen L. Krijgsveld, G. Henk Visser
Robert Ricklefs
We measured daily energy expenditure (DEE) during the development periods of precocial chicks of five species of Arctic shorebirds spanning a broad range in size, in order to investigate the relationships between DEE, body size, and growth rate. We also quantified the effect of weather conditions on the energy expenditure of chicks to establish the impact of cold arctic weather on their time and energy budgets. We used the doubly labeled water method to measure DEE at ambient temperatures in an outside enclosure on the subarctic tundra at Churchill, Manitoba, Canada. Growth rate was highest in the smallest species, and …
Diversity, Loss, And Gain Of Malaria Parasites In A Globally Invasive Bird, Alfonso Marzal, Robert E. Ricklefs, Gediminas Valkiunas, Tamer Albayrak, Elena Arriero, Camille Bonneaud, Gábor A. Czirják, John Ewen, Olof Hellgren, Dita Hořáková, Tatjana A. Iezhova, Henrik Jensen, Asta Križanauskienė, Marcos R. Lima, Florentino De Lope, Eyðfinn Magnussen, Lynn B. Martin, Anders P. Møller, Vaidas Palinauskas, Péter L. Pap, Javier Pérez-Tris, Ravinder N.M. Sehgal, Manuel Soler, Eszter Szöllősi, Helena Westerdahl, Pavel Zetindjiev, Staffan Bensch
Jul 2011
Diversity, Loss, And Gain Of Malaria Parasites In A Globally Invasive Bird, Alfonso Marzal, Robert E. Ricklefs, Gediminas Valkiunas, Tamer Albayrak, Elena Arriero, Camille Bonneaud, Gábor A. Czirják, John Ewen, Olof Hellgren, Dita Hořáková, Tatjana A. Iezhova, Henrik Jensen, Asta Križanauskienė, Marcos R. Lima, Florentino De Lope, Eyðfinn Magnussen, Lynn B. Martin, Anders P. Møller, Vaidas Palinauskas, Péter L. Pap, Javier Pérez-Tris, Ravinder N.M. Sehgal, Manuel Soler, Eszter Szöllősi, Helena Westerdahl, Pavel Zetindjiev, Staffan Bensch
Robert Ricklefs
Invasive species can displace natives, and thus identifying the traits that make aliens successful is crucial for predicting and preventing biodiversity loss. Pathogens may play an important role in the invasive process, facilitating colonization of their hosts in new continents and islands. According to the Novel Weapon Hypothesis, colonizers may out-compete local native species by bringing with them novel pathogens to which native species are not adapted. In contrast, the Enemy Release Hypothesis suggests that flourishing colonizers are successful because they have left their pathogens behind. To assess the role of avian malaria and related haemosporidian parasites in the global …
Prevalence And Lineage Diversity Of Avian Haemosporidians From Three Distinct Cerrado Habitats In Brazil, Nayara O. Belo, Renato T. Pinheiro, Elivânia S. Reis, Robert E. Ricklefs, Érika M. Braga
Mar 2011
Prevalence And Lineage Diversity Of Avian Haemosporidians From Three Distinct Cerrado Habitats In Brazil, Nayara O. Belo, Renato T. Pinheiro, Elivânia S. Reis, Robert E. Ricklefs, Érika M. Braga
Robert Ricklefs
No abstract provided.
110 Years Of Avipoxvirus In The Galapagos Islands, Robert Ricklefs
Jan 2011
110 Years Of Avipoxvirus In The Galapagos Islands, Robert Ricklefs
Robert Ricklefs
No abstract provided.
Potential Biases In Estimating The Rate Parameter Of Sigmoid Growth Functions, Robert Ricklefs, Suzanne H. Austin, Tara Rodden Robinson, W. Douglas Robinson
Aug 2010
Potential Biases In Estimating The Rate Parameter Of Sigmoid Growth Functions, Robert Ricklefs, Suzanne H. Austin, Tara Rodden Robinson, W. Douglas Robinson
Robert Ricklefs
1. We compare biases in estimates of the rate constant of the logistic and Gompertz functions applied to avian growth using three methods of parameter estimation. The methods differ in how the asymptote is determined, and consist of either floating asymptotes estimated from the full data (floating A) or data truncated at 70% of the adult mass (70%A), or fixing the asymptote at the adult mass (fixed A).
2. First, using data for two passerine species exhibiting different growth patterns, we truncated mass measurements at different ages to explore how each method of growth rate estimation responded to simulated differences …
Comparative Gene Evolution In Haemosporidian (Apicomplexa) Parasites Of Birds And Mammals, Robert Ricklefs, Diana Cumings Outlaw
Feb 2010
Comparative Gene Evolution In Haemosporidian (Apicomplexa) Parasites Of Birds And Mammals, Robert Ricklefs, Diana Cumings Outlaw
Robert Ricklefs
Haemosporidian parasites of birds and mammals reproduce asexually inside nucleated and nonnucleated host erythrocytes, respectively. Because of these different parasite environments and because bird parasites are paraphyletic, we evaluated whether patterns of parasite molecular evolution differ between host groups. We compared two mitochondrial (mt) genes and one apicoplast gene across mammal Plasmodium, bird Plasmodium, and bird Parahaemoproteus. Using a molecular phylogenetic approach, we show that the parasite mt cytochrome b (cyt b), mt cytochrome oxidase I (COI), and the apicoplast caseinolytic protease C (ClpC) exhibit similar levels of sequence divergence, yet each gene tree presents a strikingly different pattern of …
Domestic Exotics And The Perception Of Invasibility, Qinfeng Guo, Robert E. Ricklefs
Jan 2010
Domestic Exotics And The Perception Of Invasibility, Qinfeng Guo, Robert E. Ricklefs
Robert Ricklefs
Susceptibility of an area to invasion by exotic species is often judged by the fraction of introduced species in the local biota. However, the degree of invasion, particularly in mainland areas, has often been underestimated because of the exclusion of ‘domestic exotics’ (those introduced to internal units from within the national border) in calculations. Because all introduced species on islands are considered as exotics, this contributes to the perception that islands are more susceptible to invasion than are continental regions. Here, we determine the contribution of domestic exotic species to the degree of invasion (exotic fraction) in mainland areas. We …
Insights From Comparative Analyses Of Aging In Birds And Mammals, Robert E. Ricklefs
Jan 2010
Insights From Comparative Analyses Of Aging In Birds And Mammals, Robert E. Ricklefs
Robert Ricklefs
Many laboratory models used in aging research are inappropriate for understanding senescence in mammals, including humans, because of fundamental differences in life history, maintenance in artificial environments, and selection for early aging and high reproductive rate. Comparative studies of senescence in birds and mammals reveal a broad range in rates of aging among a variety of taxa with similar physiology and patterns of development. These comparisons suggest that senescence is a shared property of all vertebrates with determinate growth, that the rate of senescence has been modified by evolution in response to the potential life span allowed by extrinsic mortality …
Allometry Of The Duration Of Flight Feather Molt In Birds, Sievert Rohwer, Robert E. Ricklefs, Vanya G. Rohwer, Michelle M. Copple
Jun 2009
Allometry Of The Duration Of Flight Feather Molt In Birds, Sievert Rohwer, Robert E. Ricklefs, Vanya G. Rohwer, Michelle M. Copple
Robert Ricklefs
No abstract provided.
The Dynamic Evolutionary History Of The Bananaquit (Coereba Flaveola) In The Caribbean Revealed By A Multigene Analysis, Eva Bellemain, Eldredge Bermingham, Robert E. Ricklefs
Dec 2007
The Dynamic Evolutionary History Of The Bananaquit (Coereba Flaveola) In The Caribbean Revealed By A Multigene Analysis, Eva Bellemain, Eldredge Bermingham, Robert E. Ricklefs
Robert Ricklefs
Background
The bananaquit (Coereba flaveola) is a small nectivorous and frugivorous emberizine bird (order Passeriformes) that is an abundant resident throughout the Caribbean region. We used multi-gene analyses to investigate the evolutionary history of this species throughout its distribution in the West Indies and in South and Middle America. We sequenced six mitochondrial genes (3744 base pairs) and three nuclear genes (2049 base pairs) for forty-four bananaquits and three outgroup species. We infer the ancestral area of the present-day bananaquit populations, report on the species' phylogenetic, biogeographic and evolutionary history, and propose scenarios for its diversification and range …
Variation In The Innate And Acquired Arms Of The Immune System Among Five Shorebird Species, Luisa Mendes, Theunis Piersma, Dennis Hasselquist, Kevin D. Matson, Robert E. Ricklefs
Jan 2006
Variation In The Innate And Acquired Arms Of The Immune System Among Five Shorebird Species, Luisa Mendes, Theunis Piersma, Dennis Hasselquist, Kevin D. Matson, Robert E. Ricklefs
Robert Ricklefs
To contribute to an understanding of the evolutionary processes that shape variation in immune responses, we compared several components of the innate and acquired arms of the immune system in five related, but ecologically diverse, migratory shorebirds (ruff Philomachus pugnax L., ruddy turnstone Arenaria interpres L., bar-tailed godwit Limosa lapponica L., sanderling Calidris alba Pallas and red knotC. canutus L.). We used a hemolysis-hemagglutination assay in free-living shorebirds to assess two of the innate components (natural antibodies and complement-mediated lysis), and a modified quantitative enzyme-linked immunosorbent assay in birds held in captivity to assess the acquired component (humoral antibodies …
Metabolic Responses Of Shorebird Chicks To Cold Stress: Hysteresis Of Cooling And Warming Phases, Robert E. Ricklefs, Joseph B. Williams
Aug 2003
Metabolic Responses Of Shorebird Chicks To Cold Stress: Hysteresis Of Cooling And Warming Phases, Robert E. Ricklefs, Joseph B. Williams
Robert Ricklefs
We developed a protocol for determining the maximum rate of oxygen consumption of shorebird chicks (Scolopacidae and Charadriidae) in response to cold challenge. We first subjected the chicks to gradually decreasing temperatures until their metabolism peaked and began to decrease. We ended the cooling phase of a trial when a chick’s body temperature Tb had declined typically to 32–34°C. After this point, we gradually increased the temperature in the metabolism chamber until normal Tb values and thermoneutral resting metabolism were restored. We refer to this cycle as the down–up (DU) protocol. We estimated instantaneous oxygen consumption (V . O∑) using …
Biological Implications Of The Weibull And Gompertz Models Of Aging, Robert Ricklefs, Alex Scheuerlein
Jan 2002
Biological Implications Of The Weibull And Gompertz Models Of Aging, Robert Ricklefs, Alex Scheuerlein
Robert Ricklefs
Gompertz and Weibull functions imply contrasting biological causes of demographic aging. The terms describing increasing mortality with age are multiplicative and additive, respectively, which could result from an increase in the vulnerability of individuals to extrinsic causes in the Gompertz model and the predominance of intrinsic causes at older ages in the Weibull model. Experiments that manipulate extrinsic mortality can distinguish these biological models. To facilitate analyses of experimental data, we defined a single index for the rate of aging (ω) for the Weibull and Gompertz functions. Each function described the increase in aging-related mortality in simulated ages at death …
