Hematological responses of broiler chickens exposed to simulated crude petroleum emissions

Hematological responses of broiler chicken exposed to simulated crude petroleum emissions at varying distances over a period of 16 h daily were evaluated for 56 days in a poultry house. The burning of crude petroleum was simulated with a specially designed burner. The measured distances were 4, 8, or 12 m from the flame point. Control birds were located in a separate poultry building without the flame treatment. Gaseous emissions from the burning crude oil were monitored. Proprietory broiler starter and finisher diets were fed ad libitum. Blood samples were taken at the fourth and eighth weeks for hematological assay from each treatment. The hematological parameters assayed were hemoglobin (Hb), packed cell volume (PCV), white blood cells (WBC), neutrophils, and lymphocytes. Results indicated that the treatment did not significantly affect the Hb, PCV, and WBC constituents. Neutrophils significantly decreased while lymphocytes increased. The age of birds significantly increased Hb, PCV, and WBC levels in the blood.     

Air quality and micro-meterological monitoring of gaseous pollutants/flame emissions from burning crude petroleum in poultry house

Air quality of gaseous emissions from crude petroleum flames and fumes were monitored in a poultry house at 10 min intervals; from 10.10am–11.10am daily for 14 days. The crude petroleum burning was simulated in a metal burner, 22.86 cm high with a diameter of 17.80 cm and a thickness of 1.27 cm designed for the purpose. The micro-climate (ambient temperature, relative humidity and light intensity) of the experimental environment (poultry houses) was recorded. Results showed that the mean gaseous pollutants emitted before and during the experiments varied within the poultry house. Gases such as sulphur dioxide (SO₂), hydrogen sulphide (H₂S), methane(CH₄) and carbon monoxide (CO) were higher in the brooding than finishing phase, while volatile organic carbon (VOC) and suspended particulate matter (SPM) levels were lower at the brooding than finishing phase. The values obtained in this study for 60 min (at 10 min intervals) are far higher than the values elucidated by the Federal Environmental Protection Agency, which are outdoor air quality measurements as compared to those in this study measured indoors.     

Biodegradation of crude petroleum and petroleum products by fungi isolated from two oil seeds (melon and soybean)

Crude petroleum oil degrading fungi were isolated from two oil seeds, Cucumeropsis mannii (melon) and Glycine max (soybean) seeds in the presence and absence of petroleum fumes. An assessment of the relative ability of each fungus to degrade crude petroleum, diesel and kerosene on minimum salt solution was done using change in optical density read on spectrophotometer. Twenty-one fungal species (14 genera) were isolated altogether during this experiment. These include eight species of Aspergillus; one species each of Botryodiplodia, Bipolaris, Cladosporium, Cunnighamella, Dreschlera, Fusarium, Helminthosporium, Macrophomina, Mucor, Paeciliomyces, Penicillium, Rhizopus and Talariomyces. It was evident that most of the fungi tested were able to biodegrade the crude petroleum oil, though at different rates. Bipolaris had a low rate of biodegradation of the petroleum oil of all the fungal species isolated Botryodiplodia theobromae had the highest degrading ability on the crude oil, while Aspergillus flavus had the least after 40 days of incubation. Aspergillus flavus had the highest ability to biodegrade diesel while A. niger had the least ability. In kerosene, Macrophomina phaseolina had the highest ability while A. niger had the least ability to biodegrade it. There was fluctuation in the growth pattern of the fungi in the petroleum oil medium. The implication of these are discussed.     

重质原油和轻质原油水溶性组分对紫贻贝(Mytilus edulis)毒理效应的研究

近年来,海洋石油开采与运输泄漏、石油及产品离岸排放等事故逐年增多,对近海海域生态环境产生了巨大破坏。为探究重质原油和轻质原油对紫贻贝(Mytilus edulis)毒理效应,测定了不同浓度重质原油和轻质原油暴露下紫贻贝鳃和外套膜中过氧化氢酶(CAT)和超氧化物歧化酶(SOD)的活性及体内石油烃的含量变化。结果显示,石油污染暴露下,紫贻贝腮和外套膜中CAT和SOD活性变化明显,与暴露浓度和暴露时间有关。CAT活性在轻质原油组随着浓度的增大,呈现下降趋势,且随着暴露时间的延长呈现先下降后上升趋势;在重质原油暴露组,随着浓度的增大,呈现先上升后下降趋势,且随着暴露时间的延长呈现先下降后上升趋势。SOD活性在轻质原油与重质原油暴露组,随着浓度的增大,呈现下降趋势,且随着暴露时间的延长呈现上升趋势并存在一定的剂量-效应关系。重质原油和轻质原油暴露168 h后紫贻贝体内总石油烃含量呈线性递增,生物富集系数(BCF)随着暴露浓度的增加不断减小并最终趋于平稳。结果表明,以紫贻贝腮和外套膜中SOD和CAT活性作为石油烃污染的生物标志物具有一定应用前景,紫贻贝对原油溶液中石油烃的生物富集作用可用来判断污染原油的来源和性质。     

Homing behavior of wood thrushes (Hylocichla mustelina)

Summary Using the wood thrush (Hylocichla mustelina) as an example of a typical nocturnal migrant, we employed radio telemetry to follow breeding birds during the course of homing movements following displacements. Seven thrushes were displaced over distances of 6.5 to 17.3 km in a variety of directions from their nesting territories. The thrushes moved in a series of short flights (mean = 2.1 km) performed primarily at dawn. Consequently, the birds took several days to home from even these relatively short displacements. Thrushes flew under clear and solid overcast skies and even in light rain. The pooled individual flights of the birds were significantly oriented in the homeward direction (Fig. 2). Their orientation relative to home did not improve significantly as they progressed toward the goal. Three of the birds were documented to have returned to their home territories. The detailed tracks of the birds preclude the possibility that they homed by random search.     

Effects of exposure to sublethal concentrations of crude oil on the copepod Centropages hamatus

Female copepods of the species Centropages hamatus show decreased ingestion rates and decreased egg viability when exposed to crude oil/seawater dispersions having crude oil concentrations of 10–80 ppb. However, rates of egg production were not significantly affected by these exposure levels. In addition, we found no evidence for accumulation of petroleum hydrocarbons by copepods exposed to 200 ppb of South Louisiana crude oil. The results imply that biosynthetic pathways involved in oogenesis may be influenced by sublethal concentrations of crude oil or that petroleum hydrocarbons directly affect the viability of eggs. Recruitment into field populations of copepods could be severely reduced as a consequence of exposure to low levels of physically dispersed crude oil.     

Pattern-oriented modeling of bird foraging and pest control in coffee farms

We develop a model of how land use and habitat diversity affect migratory bird populations and their ability to suppress an insect pest on Jamaican coffee farms. Bird foraging—choosing which habitat patch and prey to use as prey abundance changes over space and time—is the key process driving this system. Following the “pattern-oriented” modeling strategy, we identified nine observed patterns that characterize the real system's dynamics. The model was designed so that these patterns could potentially emerge from it. The resulting model is individual-based, has fine spatial and temporal resolutions, represents very simply the supply of the pest insect and other arthropod food in six habitat types, and includes foraging habitat selection as the only adaptive behavior of birds. Although there is an extensive heritage of bird foraging theory in ecology, most of it addresses only the individual level and is too simple for our context. We used pattern-oriented modeling to develop and test foraging theory for this across-scale problem: rules for individual bird foraging that cause the model to reproduce a variety of patterns observed at the system level. Four alternative foraging theories were contrasted by how well they caused the model to reproduce the nine characteristic patterns. Four of these patterns were clearly reproduced with the “null” theory that birds select habitat randomly. A version of classical theory in which birds stay in a patch until food is depleted to some threshold caused the model to reproduce five patterns; this theory caused lower, not higher, use of habitat experiencing an outbreak of prey insects. Assuming that birds select the nearby patch providing highest intake rate caused the model to reproduce all but one pattern, whereas assuming birds select the highest-intake patch over a large radius produced an unrealistic distribution of movement distances. The pattern reproduced under none of the theories, a negative relation between bird density and distance to trees, appears to result from a process not in the model: birds return to trees at night to roost. We conclude that a foraging model for small insectivorous birds in diverse habitat should assume birds can sense higher food supply but over short, not long, distances.     

Experimental evidence of specialised phenotypic roles in a mobbing raptor

Group living is associated with costs but also with potential benefits, such as a decrease in predation risk through, for example, higher defence efficiency. Mobbing is among the most specialised forms of anti-predator strategies involving group defence and has mainly been investigated in passerine birds and some mammals. Variation in the mobbing response has been found in several species according to phenotypic variation such as sex or age. This suggests that there are differential benefits between mobbers, which may have promoted individual specialisation in mobbing behaviour. We studied mobbing behaviour in a communal roosting raptor, the Marsh harrier (Circus aeruginosus), which shows active group defence. Our study population exhibits extreme colour polymorphism, with two colour morphs in males, as well as sexual dichromatism and colour variation with age. We used different decoys, placed at different distances from the roost, to manipulate experimentally the perceived predation risk and to elicit mobbing behaviour. Using the experimental design that maximised mobbing response in harriers, we then focused on the sequence and the specific behaviours involved in recruitment of mobbers, and whether individual investment in terms of defence was associated with phenotypic characteristics of individuals (i.e. sex, age and colour morph). We found that the main behaviour involved in successfully attracting mobbers was alarm calling. We also detected differential individual investment in relation to sex and age, but more importantly, we provide the first evidence for specialised male phenotypic roles during mobbing events, signalled by colour polymorphism: grey males tended not to be involved in mobbing and almost never behaved as recruiters or mobbers, while brown males behaved mainly as recruiter birds. These findings suggest that colour morph may signal the individual’s anti-predatory abilities through different behavioural strategies between males.     

Inorganic nutrient utilisation by "adapted" Pseudomonas putida strain used in the bioremediation of agricultural soil polluted with crude petroleum

Garden soil samples polluted with crude petroleum were bioremediated by inorganic nutrient monitoring with appropriate adjustment and inoculation with crude oil-adapted strain of Pseudomonasputida (PP) isolated from oil-impacted soils. Soil samples without PP inoculation served as the control samples to compare the abilities of the native soil microflora with the adapted PP strain in biodegrading crude oil pollutant. In the experimental samples, oil concentration and all the inorganic nutrient sources tested decreased more rapidly with a proportional increase in the population densities of both PP and the native soil microflora than were observed in the control samples. This trend was particularly strong for PO4(3-) and NO3- which eventually became limiting both in all the experimental samples and in some control samples. Inoculation of crude oil-impacted agricultural soils by oil -adapted PP strain with nutrient monitoring and adjustment can be effective as bioremediation methods of agricultural land upon pollution with petroleum or petroleum products.     

Loft features influence the processing of navigational information by pigeons

The present study evaluates the impact of lofts on the development of the navigational system of pigeons. A series of results obtained between 2000 and 2004 were analyzed. The H-loft was placed 10 m above the ground, with a ring format and seven windows all around it as well as three external aviaries that allowed birds to have a wide view of the outdoors and of the sky and knowledge of the wind dynamics. The L-loft was placed at ground level, with a single window transformed into an external aviary. The L-loft was protected from the wind by surrounding trees, reducing the ability of the pigeons to access the wind dynamics and also restricting their access to information regarding the outside area and the sky. In a preliminary analysis, we found the parameter of “vanishing time” to differ significantly between lofts in two of the five age classes. A thorough analysis of this parameter throughout the ontogenetic development of the birds demonstrated a pronounced improvement in the information-processing system with age, with adults vanishing quicker than younger birds, although an impairment of development occurred during the third month of age, perhaps due to a reorganization of the system. This result was obtained when the effect of lofts was considered in the different age classes. Results suggest that loft features are an important factor in the ability of the young pigeons to exploit navigational cues.     

Age,experience and reproductive performance in a long-lived bird: a hormonal perspective

The ultimate factors influencing age-specific reproductive performance in birds have been widely discussed, and several hypotheses have been suggested to explain why young/inexperienced breeders have lower reproductive success than older individuals. In comparison, proximate factors and, particularly, hormonal mechanisms influencing age-related reproductive performance have received lesser attention. In this paper, we examined how baseline levels of corticosterone and prolactin, two hormones involved in reproduction, changed with age and experience in a long-lived bird, the Black-browed albatross (Thallasarche melanophris) during the brooding stage. Corticosterone levels were not linked to age, whereas prolactin levels increased until individuals reached 15 years of age. First-time breeders had higher corticosterone levels and lower prolactin levels than experienced ones. Corticosterone levels were not correlated with breeding experience among experienced birds, whereas prolactin levels slightly increased with advancing experience. Among experienced breeders, there was no effect of individual quality on corticosterone and prolactin levels. Baseline corticosterone and prolactin levels were respectively, positively and negatively correlated to time spent fasting/brooding on the nest. Moreover, the probability of successfully fledging a chick was negatively related to corticosterone levels, but not to prolactin levels. Elevated corticosterone levels in first time breeders may serve as evidence for depleted body reserves resulting from lower foraging/brooding capabilities and therefore support the constraint hypothesis. Low prolactin levels in young/inexperienced birds may be interpreted either as evidence for their lower breeding capacities (constraint hypothesis) or for their limited breeding investment (restraint hypothesis). Finally, we report, for the first time, the hormonal changes associated with the onset of senescence. The very old and most experienced birds, which had the lowest probability of successfully fledging a young, displayed elevated corticosterone levels and low prolactin levels, possibly indicating a degradation of breeding skills and/or a disruption of the endocrine system in senescent birds.     

植物-微生物修复石油烃污染土壤与根际微生态环境变化

石油烃作为一类持久性难降解有机污染物对土壤环境质量产生严重的危害。以天津大港油田原油污染土壤中筛选出的耐低温高效石油烃降解菌为靶细胞,以小麦、紫花苜蓿作为供试植物,利用盆栽试验,对植物-外源菌协同修复体系中的脱氢酶活性和土壤微生物多样性进行研究,分析其变化及其与石油烃降解率的关系。结果表明植物-微生物协同修复对石油烃具有较好的降解能力,其中小麦-固定化外源菌组具有最高的降解率,石油烃含量从最初的30 600 mg獉kg-1下降为24 300 mg獉kg-1,降解率为20.6%,并且其试验后期石油烃的降解率最大,远远高于其他时期,表现出良好的修复潜力。外源菌投加的初始阶段会迅速提高脱氢酶活性,然而这种影响随着降解时间延长而逐渐减弱。初期脱氢酶活性与总石油烃的降解存在较好的相关性,脱氢酶活性可以在一定程度上表征土壤石油烃的降解情况。微生物多样性与总石油烃降解也存在一定的相关性。     

Are white-crowned sparrow badges reliable signals?

Status badges, such as crown plumage, mediate intraspecific interactions. The reliability of crown morphology as a status badge in male mountain white-crowned sparrows (Zonotrichia leucophrys oriantha) is uncertain. We examined morphological and physiological correlates of the proportion of crown that was white (“crown-white”) in 178 male mountain white-crowned sparrows during the 2008–2009 breeding seasons. Using a paired experimental design, we presented territory-holding males with white-enhanced and white-reduced decoys and recorded aggressive behaviors. To assess physiological constraints on signal bluffing, a subsample of birds was captured and released after manipulating natural crowns to simulate bluffed white-enhanced or white-reduced crowns; corticosterone concentrations were assayed from blood drawn upon recapture and after a restraint-induced stressor. We found a significant positive association between crown-white and a measure of body size—tarsus length—which is an established indicator of resource-holding potential. In the decoy challenge, males responded more aggressively toward white-enhanced than white-reduced decoys. In the hormone experiment, white-enhanced birds had higher baseline corticosterone levels, whereas white-reduced birds had similar concentrations to controls. Furthermore, white-enhanced birds had an attenuated restraint-induced corticosterone response, while white-reduced birds mounted a significantly larger increase in corticosterone than controls. Taken together, these findings indicate that crown-white is a reliable status badge of resource-holding potential in male mountain white-crowned sparrows during the breeding season.     

Simulating wildfire patterns using a small-world network model

This paper presents the development and validation results of a weighted small-world network model designed to simulate fire patterns in real heterogeneous landscapes. Fire spread is simulated on a gridded landscape, a mosaic in which each cell represents an area of the land surface. In this model, the interaction between burning and non-burning cells (here, due to flame radiation) may extend well beyond nearest neighbors, and depends on local conditions of wind, topography, and vegetation. An approach based on the coupling of the solid flame model with the Monte Carlo method is used to predict the radiative heat flux from the flame generated by the burning of each combustible cell to its neighbors. The weighting procedure takes into account latency (a combustible cell will only ignite when it has accumulated enough energy along time) and flaming persistence of burning cells. The model is applied to very different fire scenarios: a historical Mediterranean fire that occurred in southeastern France in 2005 and experimental fires conducted in arid savanna fuels in South Africa in 1992. Model results are found to be in agreement with real fire patterns, in terms both of rate of spread, and of the area and shape of the burn. This work also shows that the fractal properties of fire patterns predicted by the model are similar to those observed from satellite images of three other Mediterranean fire scars.     

兽药类环境内分泌干扰效应及评价研究进展

兽药在保障动物健康、提高畜禽产品质量尤其在畜牧业集约化发展等方面起着至关重要的作用,然而兽药和饲料添加剂的大量使用成为生态环境污染和人体健康损害的一个重要因素。研究表明许多抗生素类和激素类兽药是典型的环境内分泌干扰物,通过多种方式干扰生物体雄激素、雌激素、甲状腺激素等内分泌过程,产生内分泌干扰效应。本文介绍了典型兽药的污染现状及其内分泌干扰效应研究最新进展;以环境内分泌干扰物的最新研究方法为基础,较全面地评述了可用于兽药类内分泌干扰物的快速筛选、检测及评价方法,并对该领域未来研究提出了展望和建议,以期为环境和农业等管理部门制定兽药的使用、排放、管理政策提供科学依据。     

兽药类环境内分泌干扰效应及评价研究进展

兽药在保障动物健康、提高畜禽产品质量尤其在畜牧业集约化发展等方面起着至关重要的作用,然而兽药和饲料添加剂的大量使用成为生态环境污染和人体健康损害的一个重要因素。研究表明许多抗生素类和激素类兽药是典型的环境内分泌干扰物,通过多种方式干扰生物体雄激素、雌激素、甲状腺激素等内分泌过程,产生内分泌干扰效应。本文介绍了典型兽药的污染现状及其内分泌干扰效应研究最新进展;以环境内分泌干扰物的最新研究方法为基础,较全面地评述了可用于兽药类内分泌干扰物的快速筛选、检测及评价方法,并对该领域未来研究提出了展望和建议,以期为环境和农业等管理部门制定兽药的使用、排放、管理政策提供科学依据。     

Chemical composition and effects of water extracts of petroleum on eggs of the sand dollar Melitta quinquiesperforata

Sperm and eggs of sand dollars, Melitta quinquiesperforata (Leske), were subjected to two petroleum oils, and effects determined. The oils chosen were Kuwait crude and No. 2 fuel oil, supplied by the American Petroleum Institute. Water-soluble extracts (WSF) from oil-sea water mixes were prepared and the major aromatic components in the WSF of the fuel oil were identified. WSF of No. 2 fuel oil depressed respiration, mobility of sperm, interfered with fertilization and cleavage, and retarded larval development. The effects were detectable at dilutions of 4% and less (about 0.6 ppm of WSF). Kuwait crude was much less toxic. There was no effect on water permeability of the egg membrane. Results are compared with similar studies on other marine organisms.     

The ghosts of predators past: population cycles and the role of maternal programming under fluctuating predation risk

Maternal effects may be a major factor influencing the demography of populations. In mammals, the transmission of stress hormones between mother and offspring may play an important role in these effects. Laboratory studies have shown that stressors during pregnancy and lactation result in lifelong programming of the offspring phenotype. However, the relevance of these studies to free-living mammals is unclear. The 10-year snowshoe hare (Lepus americanus) cycle is intimately linked to fluctuating predation pressure and predation risk. The enigma of these cycles is the lack of population growth following the decline phase, when the predators have virtually all disappeared and the food supply is ample. We have shown that a predator-induced increase in maternal stress hormone levels resulted in a decline in reproduction. Here we examine population and hormone changes over a four-year period from the increase (2005) to the decline (2008). We report (1) that an index of maternal stress (fecal corticosteroid metabolite [FCM] concentrations) fluctuates in synchrony with predator density during the breeding season; (2) that maternal FCM levels are echoed in their offspring, and this occurs at a population-wide level; and (3) that higher maternal FCM levels at birth are correlated with an increased responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis in their progeny. Our results show an intergenerational inheritance of stress hormones in a free-ranging population of mammals. We propose that the lack of recovery of reproductive rates during the early low phase of the hare cycle may be the result of the impacts of intergenerational, maternally inherited stress hormones caused by high predation risk during the decline phase.     

Effects of petroleum products on bull kelp (Nereocystis luetkeana)

Although research has been conducted on the effects of oil on the giant kelp Macrocystis pyrifera, no similar studies have been completed on bull kelp, Nereocystis leutkeana, the dominant kelp in Washington State, British Columbia, and Alaska. The effects of three petroleum products [diesel fuel, intermediate fuel oil (IFO), and crude oil] were tested before and after weathering on N. luetkeana. Whole plants were exposed to petroleum product for 4 or 24 h and then transferred to the field; observations on the condition of the plants were made daily for 7 d. In addition, controlled bioassays were performed to measure the effects of petroleum exposure on net photosynthetic rate (NP) and respiration rate (R), using light-and dark-bottle techniques. These experiments verified the susceptibility of N. luetkeana tissue to the damaging effects of direct exposure to several oil types. The 4 h exposures to weathered diesel and unweathered IFO, and 24 h exposures to unweathered and weathered diesel and IFO resulted in moderate to severe damage to kelp tissue (i.e., clearly delineated bleached line accompanied by tissue necrosis). Weathered diesel was more toxic than unweathered diesel. The most severe damage to bull kelp was concentrated at the meristematic zone (junction of stipe and bulb) where new tissue growth occurs. Petroleum type significantly affected stipe and blade NP, R, and NP:R ratios. Diesel treatments had a greater negative effect on NP than did the IFO treatments. Based on these experiments, the relative ranking of the damaging effects of petroleum treatment on bull kelp are weathered diesel>unweathered IFO>unweathered diesel>weathered IFO>unweathered crude>weathered crude.     

Grassland Bird Responses to Land Management in the Largest Remaining Tallgrass Prairie

Abstract: Extensive habitat loss and changing agricultural practices have caused widespread declines in grassland birds throughout North America. The Flint Hills of Kansas and Oklahoma—the largest remaining tallgrass prairie—is important for grassland bird conservation despite supporting a major cattle industry. In 2004 and 2005, we assessed the community, population, and demographic responses of grassland birds to the predominant management practices (grazing, burning, and haying) of the region, including grasslands restored under the Conservation Reserve Program (CRP). We targeted 3 species at the core of this avian community: the Dickcissel (Spiza americana), Grasshopper Sparrow (Ammodramus savannarum), and Eastern Meadowlark (Sturnella magna). Bird diversity was higher in native prairie hayfields and grazed pastures than CRP fields, which were dominated by Dickcissels. Although Dickcissel density was highest in CRP, their nest success was highest and nest parasitism by Brown‐headed Cowbirds (Moluthrus ater) lowest in unburned hayfields (in 2004). Conversely, Grasshopper Sparrow density was highest in grazed pastures, but their nest success was lowest in these pastures and highest in burned hayfields, where cowbird parasitism was also lowest (in 2004). Management did not influence density and nest survival of Eastern Meadowlarks, which were uniformly low across the region. Nest success was extremely low (5–12%) for all 3 species in 2005, perhaps because of a record spring drought. Although the CRP has benefited grassland birds in agricultural landscapes, these areas may have lower habitat value in the context of native prairie. Hayfields may provide beneficial habitat for some grassland birds in the Flint Hills because they are mowed later in the breeding season than elsewhere in the Midwest. Widespread grazing and annual burning have homogenized habitat—and thus grassland‐bird responses—across the Flint Hills. Diversification of management practices could increase habitat heterogeneity and enhance the conservation potential of the Flint Hills for grassland birds.