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1.
Am Nat ; 200(2): 292-301, 2022 08.
Article in English | MEDLINE | ID: mdl-35905407

ABSTRACT

AbstractAnts disperse oak galls of some cynipid wasp species similarly to how they disperse seeds with elaiosomes. We conducted choice assays in field and laboratory settings with ant-dispersed seeds and wasp-induced galls found in ant nests and found that seed-dispersing ants retrieve these galls as they do myrmecochorous seeds. We also conducted manipulative experiments in which we removed the putative ant-attracting appendages ("kapéllos") from galls and found that ants are specifically attracted to kapéllos. Finally, we compared the chemical composition and histology of ant-attracting appendages on seeds and galls and found that they both have similar fatty acid compositions as well as morphology. We also observed seed-dispersing ants retrieving oak galls to their nests and rodents and birds consuming oak galls that were not retrieved by ants. These results suggest convergence in ant-mediated dispersal between myrmecochorous seeds and oak galls. Based on our observations, a protective advantage for galls retrieved to ant nests seems a more likely benefit than dispersal distance, as has also been suggested for myrmecochorous seeds. These results require reconsideration of established ant-plant research assumptions, as ant-mediated seed and gall dispersal appear strongly convergent and galls may be far more abundant in eastern North American deciduous forests than myrmecochorous seeds.


Subject(s)
Ants , Quercus , Seed Dispersal , Animals , Plants , Seeds
2.
Ecology ; 102(11): e03484, 2021 11.
Article in English | MEDLINE | ID: mdl-34289121

ABSTRACT

Standing dead trees (snags) decompose more slowly than downed dead wood and provide critical habitat for many species. The rate at which snags fall therefore influences forest carbon dynamics and biodiversity. Fall rates correlate strongly with mean annual temperature, presumably because warmer climates facilitate faster wood decomposition and hence degradation of the structural stability of standing wood. These faster decomposition rates coincide with turnover from fungal-dominated wood decomposer communities in cooler forests to codomination by fungi and termites in warmer regions. A key question for projecting forest dynamics is therefore whether temperature effects on wood decomposition arise primarily because warmer conditions facilitate faster decomposer metabolism, or are also influenced indirectly by belowground community turnover (e.g., termites exert additional influence beyond fungal-plus-bacterial mediated decomposition). To test between these possibilities, we simulate standing dead trees with untreated wooden posts and follow them in the field across 5 yr at 12 sites, before measuring buried, soil-air interface and aerial post sections to quantify wood decomposition and organism activities. High termite activities at the warmer sites are associated with rates of postfall that are three times higher than at the cooler sites. Termites primarily consume buried wood, with decomposition rates greatest where termite activities are highest. However, where higher microbial and termite activities co-occur, they appear to compensate for one another first, and then to slow decomposition rates at their highest activities, suggestive of interference competition. If the range of microbial and termite codomination of wood decomposer communities expands under climate warming, our data suggest that expansion will accelerate snag fall with consequent effects on forest carbon cycling and biodiversity in forests previously dominated by microbial decomposers.


Subject(s)
Forests , Wood , Carbon Cycle , Ecosystem , Trees
3.
Ecol Lett ; 21(5): 724-733, 2018 05.
Article in English | MEDLINE | ID: mdl-29575384

ABSTRACT

Vegetative dormancy, that is the temporary absence of aboveground growth for ≥ 1 year, is paradoxical, because plants cannot photosynthesise or flower during dormant periods. We test ecological and evolutionary hypotheses for its widespread persistence. We show that dormancy has evolved numerous times. Most species displaying dormancy exhibit life-history costs of sprouting, and of dormancy. Short-lived and mycoheterotrophic species have higher proportions of dormant plants than long-lived species and species with other nutritional modes. Foliage loss is associated with higher future dormancy levels, suggesting that carbon limitation promotes dormancy. Maximum dormancy duration is shorter under higher precipitation and at higher latitudes, the latter suggesting an important role for competition or herbivory. Study length affects estimates of some demographic parameters. Our results identify life historical and environmental drivers of dormancy. We also highlight the evolutionary importance of the little understood costs of sprouting and growth, latitudinal stress gradients and mixed nutritional modes.


Subject(s)
Biological Evolution , Herbivory , Demography , Flowers
4.
PLoS One ; 12(8): e0182502, 2017.
Article in English | MEDLINE | ID: mdl-28817593

ABSTRACT

The language that scientists use to frame biological invasions may reveal inherent bias-including how data are interpreted. A frequent critique of invasion biology is the use of value-laden language that may indicate context bias. Here we use a systematic study of language and interpretation in papers drawn from invasion biology to evaluate whether there is a link between the framing of papers and the interpretation of results. We also examine any trends in context bias in biological invasion research. We examined 651 peer-reviewed invasive species competition studies and implemented a rigorous systematic review to examine bias in the presentation and interpretation of native and invasive competition in invasion biology. We predicted that bias in the presentation of invasive species is increasing, as suggested by several authors, and that bias against invasive species would result in misinterpreting their competitive dominance in correlational observational studies compared to causative experimental studies. We indeed found evidence of bias in the presentation and interpretation of invasive species research; authors often introduced research with invasive species in a negative context and study results were interpreted against invasive species more in correlational studies. However, we also found a distinct decrease in those biases since the mid-2000s. Given that there have been several waves of criticism from scientists both inside and outside invasion biology, our evidence suggests that the subdiscipline has somewhat self-corrected apparent biases.


Subject(s)
Ecology/standards , Introduced Species/statistics & numerical data , Animals , Bias , Data Interpretation, Statistical , Ecology/methods , Ecosystem
5.
PLoS One ; 11(3): e0150707, 2016.
Article in English | MEDLINE | ID: mdl-26982877

ABSTRACT

A long-term assumption in ecology is that species distributions correspond with their niche requirements, but evidence that species can persist in unsuitable habitat for centuries undermines the link between species and habitat. Moreover, species may be more dependent on mutualist partners than specific habitats. Most evidence connecting indigenous cultures with plant dispersal is anecdotal, but historical records suggest that Native Americans transported and cultivated many species, including Gleditsia triacanthos ("Honey locust"). Gleditsia triacanthos was an important medicinal/culinary (e.g., sugar), cultural (e.g., game sticks) and spiritual tree for the Cherokee (southeastern U.S. Native Americans). This study tests the hypothesis that a Cherokee cultivation legacy drives current regional G. triacanthos distribution patterns. Gleditsia triacanthos occurs in rocky uplands and xeric fields, but inexplicably also occurs in mesic riverine corridors and floodplains where Cherokee once settled and farmed. I combined field experiments and surveys in the Southern Appalachian Mountain region (U.S.) to investigate G. triacanthos recruitment requirements and distribution patterns to determine whether there is a quantifiable G. triacanthos association with former Cherokee settlements. Moreover, I also investigated alternate dispersal mechanisms, such as stream transport and domestic cattle. The results indicate that a centuries-old legacy of Native American cultivation remains intact as G. triacanthos' current southern Appalachian distribution appears better explained Cherokee settlement patterns than habitat. The data indicate that the tree is severely dispersal limited in the region, only moving appreciable distances from former Cherokee settlements where cattle grazing is prevalent. Human land use legacy may play a long-term role in shaping species distributions, and pre-European settlement activity appears underrated as a factor influencing modern tree species distributions.


Subject(s)
Agriculture , Fabaceae/growth & development , Indians, North American , Trees/growth & development , Appalachian Region , Germination , Humans
6.
Vaccine ; 33(5): 726-33, 2015 Jan 29.
Article in English | MEDLINE | ID: mdl-25539804

ABSTRACT

Prion disease is a unique category of illness, affecting both animals and humans, in which the underlying pathogenesis is related to a conformational change of a normal, self-protein called PrP(C) (C for cellular) to a pathological and infectious conformer known as PrP(Sc) (Sc for scrapie). Bovine spongiform encephalopathy (BSE), a prion disease believed to have arisen from feeding cattle with prion contaminated meat and bone meal products, crossed the species barrier to infect humans. Chronic wasting disease (CWD) infects large numbers of deer and elk, with the potential to infect humans. Currently no prionosis has an effective treatment. Previously, we have demonstrated we could prevent transmission of prions in a proportion of susceptible mice with a mucosal vaccine. In the current study, white-tailed deer were orally inoculated with attenuated Salmonella expressing PrP, while control deer were orally inoculated with vehicle attenuated Salmonella. Once a mucosal response was established, the vaccinated animals were boosted orally and locally by application of polymerized recombinant PrP onto the tonsils and rectal mucosa. The vaccinated and control animals were then challenged orally with CWD-infected brain homogenate. Three years post CWD oral challenge all control deer developed clinical CWD (median survival 602 days), while among the vaccinated there was a significant prolongation of the incubation period (median survival 909 days; p=0.012 by Weibull regression analysis) and one deer has remained CWD free both clinically and by RAMALT and tonsil biopsies. This negative vaccinate has the highest titers of IgA in saliva and systemic IgG against PrP. Western blots showed that immunoglobulins from this vaccinate react to PrP(CWD). We document the first partially successful vaccination for a prion disease in a species naturally at risk.


Subject(s)
Deer , Prions/administration & dosage , Prions/immunology , Salmonella Vaccines/administration & dosage , Wasting Disease, Chronic/prevention & control , Administration, Mucosal , Animals , Blood/immunology , Immunoglobulin A/analysis , Immunoglobulin G/blood , Prions/genetics , Saliva/immunology , Salmonella Vaccines/genetics , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/genetics , Vaccines, Attenuated/immunology , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology , Wasting Disease, Chronic/immunology
7.
Ecol Lett ; 17(11): 1447-54, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25199542

ABSTRACT

A hierarchical view of niche relations reconciles the scale-dependent effects of abiotic and biotic processes on species distribution patterns and underlies most current approaches to distribution modeling. A key prediction of this framework is that the effects of biotic interactions will be averaged out at macroscales - an idea termed the Eltonian noise hypothesis (ENH). We test this prediction by quantifying regional variation in local abiotic and biotic niche relations and assess the role of macroclimate in structuring biotic interactions, using a non-native invasive grass, Microstegium vimineum, in its introduced range. Consistent with hierarchical niche relations and the ENH, macroclimate structures local biotic interactions, while local abiotic relations are regionally conserved. Biotic interactions suppress M. vimineum in drier climates but have little effect in wetter climates. A similar approach could be used to identify the macroclimatic conditions under which biotic interactions affect the accuracy of local predictions of species distributions.


Subject(s)
Biota , Climate , Models, Biological , Poaceae/physiology , Bayes Theorem , Introduced Species , Linear Models
8.
Clin Ophthalmol ; 8: 1147-55, 2014.
Article in English | MEDLINE | ID: mdl-24970993

ABSTRACT

OBJECTIVE: The aim was to evaluate the efficacy of Optive Plus(®), an artificial tear containing castor oil, in patients with dry eye, in a routine clinical setting. METHODS: This was a prospective, noninterventional study of patients with dry eye who switched from a prior therapy or who were naïve to treatment (n=1,209). Patients were issued Optive Plus(®) artificial tears. Dry eye severity, tear break-up time (TBUT), Schirmer score, Ocular Surface Disease Index (OSDI) score, and patient assessment of symptoms were recorded at baseline and at the follow-up visit (4 weeks after starting Optive Plus(®)). RESULTS: The cause of dry eye was determined to be aqueous deficiency, lipid deficiency, or a mixture of aqueous and lipid deficiency (in 19.5%, 20.1%, and 47.8%, respectively, of the total study population). The severity of dry eye decreased from baseline to the follow-up visit, showing a decrease of the more severe levels (2-4) and a concurrent increase in mild level (1) of the rating scale. Patients reported an improvement in dry eye symptoms over the duration of the study, specifically 74.2% (n=152), 85.4% (n=182), and 82.4% (n=417) of patients in the aqueous-deficient, lipid-deficient, and mixed-deficiency groups, respectively. TBUT was measured in 475 patients. Baseline measurements for mean and standard deviation were 9.0±3.5, 7.1±3.6, and 6.6±3.0 seconds for the aqueous-deficient, lipid-deficient, and mixed-deficiency groups, respectively. These increased to 10.5±3.5, 10.0±3.6, and 9.2±3.1 seconds at the final visit. Overall, 92.5% of all patients were satisfied with the use of Optive Plus(®), and 86% said they would purchase Optive Plus(®). Ten percent of patients reported adverse events, and 1.8% of all patients experienced treatment-related adverse events. CONCLUSION: Optive Plus(®) was well tolerated and effective in reducing the signs and symptoms of all types of dry eye but is recommended for lipid-deficient dry eye patients.

9.
Clin Ophthalmol ; 8: 725-32, 2014.
Article in English | MEDLINE | ID: mdl-24748767

ABSTRACT

OBJECTIVE: To compare a fixed combination of 0.03% bimatoprost and 0.5% timolol (BTFC) with latanoprost monotherapy (LM) in treatment-naïve patients with open-angle glaucoma (OAG) and risk factors for glaucomatous progression. METHODS: Patients were enrolled at 15 sites in Spain and Portugal, and were randomized 1:1 to BTFC or LM. Patients instilled one drop of medication once per day at 8 pm for 12 weeks. The primary outcome was change in intraocular pressure (IOP) at 12 weeks. RESULTS: Of 81 patients enrolled, 43 were randomized to BTFC and 38 to LM. Mean (SD) change in IOP from baseline to 12 weeks was significantly greater for BTFC than for LM: -13.5 mmHg (4.48) versus -11.4 mmHg (3.19), respectively (P=0.003). Similarly, at 12 weeks, significantly more BTFC patients than LM patients had IOP reductions of ≥40% (74.4% versus 47.4%, P=0.015) or ≥50% (46.5% versus 15.8%, P=0.003). Adverse events were more frequent with BTFC than with LM (33 versus 13 events), but most were mild in severity. The only serious adverse event (colon cancer) was adjudged unrelated to the study medication. CONCLUSION: BTFC was effective and well tolerated in treatment-naïve patients with OAG at high risk of progression.

10.
Glob Chang Biol ; 20(2): 466-74, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24399754

ABSTRACT

Successful species interactions require that both partners share a similar cue. For many species, spring warming acts as a shared signal to synchronize mutualist behaviors. Spring flowering plants and the ants that disperse their seeds respond to warming temperatures so that ants forage when plants drop seeds. However, where warm-adapted ants replace cold-adapted ants, changes in this timing might leave early seeds stranded without a disperser. We investigate plant seed dispersal south and north of a distinct boundary between warm- and cold-adapted ants to determine if changes in the ant species influence local plant dispersal. The warm-adapted ants forage much later than the cold-adapted ants, and so we first assess natural populations of early and late blooming plants. We then transplant these plants south and north of the ant boundary to test whether distinct ant climate requirements disrupt the ant-plant mutualism. Whereas the early blooming plant's inability to synchronize with the warm-adapted ant leaves its populations clumped and patchy and its seedlings clustered around the parents in natural populations, when transplanted into the range of the cold-adapted ant, effective seed dispersal recovers. In contrast, the mutualism persists for the later blooming plant regardless of location because it sets seed later in spring when both warm- and cold-adapted ant species forage, resulting in effective seed dispersal. These results indicate that the climate response of species interactions, not just the species themselves, is integral in understanding ecological responses to a changing climate. Data linking phenological synchrony and dispersal are rare, and these results suggest a viable mechanism by which a species' range is limited more by biotic than abiotic interactions - despite the general assumption that biotic influences are buried within larger climate drivers. These results show that biotic partner can be as fundamental a niche requirement as abiotic resources.


Subject(s)
Anemone/physiology , Ants/physiology , Asarum/physiology , Climate Change , Seed Dispersal , Symbiosis , Animal Distribution , Animals , Georgia , Seasons , Species Specificity
11.
PLoS One ; 8(10): e75843, 2013.
Article in English | MEDLINE | ID: mdl-24116079

ABSTRACT

Earthworms, termites, and ants are common macroinvertebrates in terrestrial environments, although for most ecosystems data on their abundance and biomass is sparse. Quantifying their areal abundance is a critical first step in understanding their functional importance. We intensively sampled dead wood, litter, and soil in eastern US temperate hardwood forests at four sites, which span much of the latitudinal range of this ecosystem, to estimate the abundance and biomass m(-2) of individuals in macroinvertebrate communities. Macroinvertebrates, other than ants and termites, differed only slightly among sites in total abundance and biomass and they were similar in ordinal composition. Termites and ants were the most abundant macroinvertebrates in dead wood, and ants were the most abundant in litter and soil. Ant abundance and biomass m(-2) in the southernmost site (Florida) were among the highest values recorded for ants in any ecosystem. Ant and termite biomass and abundance varied greatly across the range, from <1% of the total macroinvertebrate abundance (in the northern sites) to >95% in the southern sites. Our data reveal a pronounced shift to eusocial insect dominance with decreasing latitude in a temperate ecosystem. The extraordinarily high social insect relative abundance outside of the tropics lends support to existing data suggesting that ants, along with termites, are globally the most abundant soil macroinvertebrates, and surpass the majority of other terrestrial animal (vertebrate and invertebrate) groups in biomass m(-2). Our results provide a foundation for improving our understanding of the functional role of social insects in regulating ecosystem processes in temperate forest.


Subject(s)
Ants , Ecosystem , Isoptera , Trees , Animals , Biomass , Soil , United States
12.
Clin Ophthalmol ; 7: 1219-25, 2013.
Article in English | MEDLINE | ID: mdl-23814459

ABSTRACT

OBJECTIVE: The aim of this study was to evaluate the safety and efficacy of a fixed combination of bimatoprost 0.03% and timolol (BTFC) in a clinical setting, in a large sample of patients with primary open-angle glaucoma or ocular hypertension and insufficient intraocular pressure (IOP) lowering on prior therapy. METHODS: Patient data were combined (n = 5556) from five multicenter, observational, non-controlled, open-label studies throughout Europe. Patients were identified from 830 sites in Austria, France, Germany, The Netherlands, and Switzerland. Assessments were made at baseline, 6 weeks (in Austrian, German and Swiss centers), and 12 weeks in all centers. RESULTS: BTFC lowered mean IOP from baseline by 5.4 mmHg over the 12-week duration of the studies (P < 0.0001). At study entry, 92.9% of patients were receiving another ocular hypotensive medication. In patients with no previous treatment (n = 311), BTFC reduced IOP by -9.1 mmHg, corresponding to a reduction from baseline of 36.4% (P < 0.0001). In patients receiving prior therapy of a prostaglandin analog, a ß-blocker, or a fixed combination, BTFC reduced IOP by a further 24.5%, 25.9%, and 21.4%, respectively. The majority of patients (90.3%) reported no adverse events. The most common adverse events were conjunctival hyperemia (3.2%) and eye irritation (2.8%). BTFC was rated as "good" or "very good" by 92.5% of physicians and 88.0% of patients. Most patients (96.3%) were equally or more compliant with BTFC than with their previous treatment. CONCLUSION: In routine clinical practice, BTFC achieved consistent IOP lowering in both previously treated and untreated patients with primary open-angle glaucoma or ocular hypertension. BTFC was associated with significant IOP reductions, good tolerability, and good compliance.

13.
Glob Chang Biol ; 19(7): 2082-8, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23504958

ABSTRACT

Rapid climate change may prompt species distribution shifts upward and poleward, but species movement in itself is not sufficient to establish climate causation. Other dynamics, such as disturbance history, may prompt species distribution shifts resembling those expected from rapid climate change. Links between species distributions, regional climate trends and physiological mechanism are needed to convincingly establish climate-induced species shifts. We examine a 38-year shift (1974-2012) in an elevation ecotone between two closely related ant species, Aphaenogaster picea and A. rudis. Even though A. picea and A. rudis are closely related with North American distributions that sometimes overlap, they also exhibit local- and regional-scale differences in temperature requirements so that A. rudis is more southerly and inhabits lower elevations whereas A. picea is more northerly and inhabits high elevations. We find considerable movement by the warm-habitat species upward in elevation between 1974 and 2012 with A. rudis, replacing the cold-habitat species, A. picea, along the southern edge of the Appalachian Mountain chain in north Georgia, USA. Concomitant with the distribution shifts, regional mean and maximum temperatures remain steady (1974-2012), but minimum temperatures increase. We collect individuals from the study sites and subject them to thermal tolerance testing in a controlled setting and find that maximum and minimum temperature acclimatization occurs along the elevation gradient in both species, but A. rudis consistently becomes physiologically incapacitated at minimum and maximum temperatures 2 °C higher than A. picea. These results indicate that rising minimum temperatures allow A. rudis to move upward in elevation and displace A. picea. Given that Aphaenogaster ants are the dominant woodland seed dispersers in eastern deciduous forests, and that their thermal tolerances drive distinct differences in temperature-cued synchrony with early blooming plants, these climate responses not only impact ant-ant interactions, but might have wide implications for ant-plant interactions.


Subject(s)
Acclimatization , Animal Migration/physiology , Ants/physiology , Climate Change , Temperature , Animals , Biodiversity , Georgia , Population Dynamics
15.
J Virol ; 87(3): 1890-2, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23175370

ABSTRACT

While the facile transmission of chronic wasting disease (CWD) remains incompletely elucidated, studies in rodents suggest that exposure of the respiratory mucosa may be an efficient pathway. The present study was designed to address this question in the native cervid host. Here, we demonstrate aerosol transmission of CWD to deer with a prion dose >20-fold lower than that used in previous oral inoculations. Inhalation of prions may facilitate transmission of CWD and, perhaps, other prion infections.


Subject(s)
Aerosols , Wasting Disease, Chronic/transmission , Animals , Deer , Inhalation
16.
New Phytol ; 196(2): 462-471, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22924486

ABSTRACT

Community and ecosystem responses to global environmental change are contingent on the magnitude of change and interacting global change factors. To reveal whether responses are also contingent on the magnitude of each interacting factor, multifactor, multilevel experiments are required, but are rarely conducted. We exposed model grassland ecosystems to six levels of atmospheric CO2 and six levels of nitrogen enrichment, applying the latter both chronically (simulating deposition) and acutely (simulating fertilization). The 66 treatments were maintained for 6 months under controlled growing conditions, with biomass harvested every 28 d and sorted to species. Aboveground plant productivity responses to CO2 were contingent on nitrogen amount, and the responses to nitrogen amount were dependent on whether applications were chronic or acute. Specifically, productivity responses to increasing CO2 concentrations were accentuated with higher nitrogen enrichments, and productivity was greater when higher nitrogen enrichments were applied acutely. Plant community composition was influenced only by nitrogen enrichment, where the co-dominant grass species with the greatest leaf trait plasticity increasingly dominated with higher nitrogen amounts. Community processes are considered to be unpredictable, but our data suggest that the prediction of the impacts of simultaneous global changes is more complex for ecosystem processes, given that their responses are contingent on the levels of interacting factors.


Subject(s)
Biota , Climate Change , Plant Physiological Phenomena , Biomass , Carbon Dioxide/pharmacology , Nitrogen/pharmacology , Plant Leaves/drug effects , Plant Leaves/physiology , Plant Physiological Phenomena/drug effects , Soil
17.
Environ Entomol ; 41(3): 463-8, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22732603

ABSTRACT

The complex interplay between species along environmental gradients ultimately shapes their distributions and additional community interactions. Ant-mediated seed dispersal fails in the wettest habitat of deciduous forest in eastern North America, and we examine whether this pattern corresponds with colony distributions for seed-dispersing ants and associated heterogeneity in abiotic and biotic variables. Specifically, we used spatial variation in soil moisture, temperature and diffuse light along natural habitat gradients and experimentally manipulated soil moisture gradients to examine ant habitat selection. We also examined niche segregation between effective (Aphaenogaster spp.) and ineffective (Lasius alienus Foerster) seed-dispersing ants across these environmental gradients. Whereas most research links ant foraging and nesting with temperature gradients, we find niche segregation between Aphaenogaster spp. and L. alienus by soil moisture along naturally occurring gradients and in experimentally irrigated upland habitat. The failure of Aphaenogaster spp. to occupy the wettest habitats, where L. alienus is present, is consistent with observed seed dispersal failure in these habitats. These results indicate that environmental heterogeneity drives niche segregation between effective (Aphaenogaster spp.) and ineffective (L. alienus) seed dispersers so each occupies distinct habitat. Most forest understory plants rely on ants for seed dispersal. Our research implies that climate-mediated interactions between effective and ineffective seed dispersing ant species may structure the microhabitat distributions for woodland herbs.


Subject(s)
Ants/physiology , Ecosystem , Food Chain , Nesting Behavior , Animals , Georgia , Humidity , North Carolina , Population Density , Seasons , Seeds/growth & development , Species Specificity
18.
J Wildl Dis ; 48(2): 458-61, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22493122

ABSTRACT

Physiologic monitoring is important when chemically immobilizing wildlife. Blood oxygenation is usually monitored by pulse oximetry in the field; however, there is some question whether this technique accurately reflects oxygen saturation in wild white-tailed deer (Odocoileus virginianus). We evaluated different doses of medetomidine (125, 150, 175, or 200 µg/kg) mixed with ketamine (1.5 mg/kg), and tiletamine-zolazepam (1.0 mg/kg) in 22 female white-tailed deer at the University of Georgia Whitehall Deer Research Facility in Athens, Georgia on 14-15 and 21 May 2009. Deer were hand-injected intramuscularly while physically restrained in a squeeze chute, and then they were released into a pen for monitoring. Hemoglobin saturation estimated using pulse oximetry (SpO(2)) was compared with hemoglobin saturation value from arterial blood gases (SaO(2)) at 0, 10, and 20 min postimmobilization with deer in a sternal position. We made 56 simultaneous comparisons of oxygen saturation using SpO(2) (range, 54-95%) and SaO(2) (range, 60-95%). We used a Bland-Altman analysis for determining agreement between the two methods. Hemoglobin saturation estimated using SpO(2) was generally greater than SaO(2) when the mean of the two measurements was >80%. At mean values <80% oxygen saturation, there is not sufficient agreement between the techniques. Multiple readings over time may help recognition of outliers.


Subject(s)
Deer , Immobilization/veterinary , Oximetry/veterinary , Oxygen/blood , Animals , Animals, Wild , Dose-Response Relationship, Drug , Female , Immobilization/physiology , Monitoring, Physiologic/veterinary , Oximetry/methods
19.
J Wildl Dis ; 48(2): 477-82, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22493126

ABSTRACT

Chemical immobilization is often needed for safe and effective capture and handling of wildlife. We evaluated medetomidine (125, 150, 175, or 200 µg/kg; for synergistic effects and relaxation) mixed with ketamine (1.5 mg/kg; for relatively shorter recovery) and tiletamine-zolazepam (1.0 mg/kg; for rapid induction) in 22 female white-tailed deer (Odocoileus virginianus) at the University of Georgia Whitehall Deer Research Facility in Athens, Georgia, USA, on 14-15 and 21 May 2009. Deer were weighed before treatment, hand-injected intramuscularly (IM) while restrained in a squeeze chute, and released into a pen for monitoring. We measured rectal temperature, respiration rate, heart rate, hemoglobin saturation (using pulse oximetry), and arterial blood gases at 0, 10, and 20 min postimmobilization. We found no differences in induction time with different doses of medetomidine. Deer became laterally recumbent for all treatments combined at a median of 4.2 (2.6-21.3) min and were approachable by a median of 4.8 (3.5-21.8) min. Twelve of the 22 deer had rectal temperatures >40 C at time 0 and were treated with a cold-water enema. Hemoglobin saturation, estimated using pulse oximetry, was 79.5, 82.0, and 82.3% at times 0, 10, and 20, respectively. We injected atipamezole (0.35 mg/kg, IM) for reversal. Recovery occurred sooner and was more consistent for 125 and 150 µg/kg medetomidine whereby deer stood with minimal sedation to moderate ataxia within 60-90 min after atipamezole administration. We recommend using 150 µg of medetomidine with ketamine (1.5 mg/kg) and tiletamine-zolazepam (1.0 mg/kg) to provide effective and safe chemical immobilization of white-tailed deer.


Subject(s)
Deer/physiology , Hypnotics and Sedatives/administration & dosage , Immobilization/veterinary , Medetomidine/administration & dosage , Anesthetics/administration & dosage , Anesthetics, Dissociative/administration & dosage , Animals , Animals, Wild , Body Temperature/drug effects , Dose-Response Relationship, Drug , Drug Combinations , Drug Synergism , Female , Heart Rate/drug effects , Immobilization/methods , Injections, Intramuscular/veterinary , Ketamine/administration & dosage , Respiration/drug effects , Tiletamine/administration & dosage , Zolazepam/administration & dosage
20.
PLoS One ; 6(3): e17342, 2011 Mar 09.
Article in English | MEDLINE | ID: mdl-21408063

ABSTRACT

The rank abundance of common and rare species within ecological communities is remarkably consistent from the tropics to the tundra. This invariant patterning provides one of ecology's most enduring and unified tenets: most species rare and a few very common. Increasingly, attention is focused upon elucidating biological mechanisms that explain these species abundance distributions (SADs), but these evaluations remain controversial. We show that college basketball wins generate SADs just like those observed in ecological communities. Whereas college basketball wins are structured by competitive interactions, the result produces a SAD pattern indistinguishable from random wins. We also show that species abundance data for tropical trees exhibits a significant-digit pattern consistent with data derived from complex structuring forces. These results cast doubt upon the ability of SAD analysis to resolve ecological mechanism, and their patterning may reflect statistical artifact as much as biological processes.


Subject(s)
Basketball , Biota , Residence Characteristics , Universities , Internet , Periodicals as Topic
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