Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Falco”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
USGS2022

Hepatic gene expression profiling of American kestrels (Falco sparverius) exposed in ovo to three alternative brominated flame retardants

A number of brominated flame retardants (BFRs) have been reported to interfere with the thyroid signaling pathway and cause oxidative stress in birds, yet the underlying shifts in gene expression associated with these effects remain poorly understood. In this study, we measured hepatic transcriptional responses of 31 genes in American kestrel ( Falco sparverius ) hatchlings following in ovo exposure to one of three high-volume alternative BFRs: 1,2-bis(2,4,6-tribromophenoxy) ethane (BTPBE), bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), or 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB). Hatchling kestrels exhibited shifts in the expression of genes related to oxidative stress ( CYP, GSTA, SOD, and GPX1 ), thyroid hormone metabolism and transport ( DIO1, DIO2 , and TTR ), lipid and protein metabolism (PPAR, HMGCR, FAB1, and LPL), and cytokine-mediated inflammation ( TLR3, IL18, IRF7, STAT3, RACK1, and CEBPB ). Male and female hatchlings differed in which genes were differentially expressed, as well as the direction of the effect (up- vs. downregulation). These results build upon our previous findings of increased oxidative stress and disrupted thyroid signaling pathway in the same hatchlings. Furthermore, our results indicate that inflammatory responses appear to occur in female hatchlings exposed to BTBPE and EHTBB in ovo. Gene expression analysis revealed multiple affected pathways, adding to the growing evidence that sublethal physiological effects are complex and are a concern for birds exposed to BTBPE, EHTBB, or TBPH in ovo.

Biology↗
USGS1994

Organochlorine pesticides, chlorinated dioxins and furans, and PCBs in peregrine falcon Falco peregrinus eggs from the Kola peninsula, Russia

Nesting of a bog-associated population of mlgfatory Peregrine Falcons, Falco peregrinus, along the Ponoy River depression, Kola Peninsula, Russia, has been studied since 1977. In 1987 91 production rates averaged 1.94 young per active nest and the number of breeding pairs increased from 4 to 10. In 1991, most eyrie sites were visited during the egg stage and a 'sample' egg was collected for contaminant analysis. Eight Peregrine Falcon eggs contained relatively low concentrations of p,p' -DOE (DOE) (geometric mean 3.5 g/g) and of other organochlorine pesticides. These DOE concentrations are similar to those reported in Peregrine Falcon eggs from an Alaskan population that had also showed a recent population increase. Eggshell thinning (11.4%) was similar to that found in Alaska. Concentrations of polychlorinated biphenyls (PCBs) were higher than DOE concentrations, comparable to the contamination profile shown by Peregrine Falcon populations in Fennoscandia, and were higher than those found in Alaskan birds. Before this study, no Peregrine Falcon eggs from Russia had 'been analyzed for PCB congeners, polychlorinated dibenzo- p-dioxins (PCDDs), or pol ychlorinated dibenzofurans (PCD Fs). Conversions of analytical concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), other PCDDs, PCDFs and PCB congeners based on relative aryl hydrocarbon hydroxylase induction potencies allowed the estimation of total 2,3,7,8- TCDD equivalents (TEQs). The TEQs are in the range that is associated with embryonic mortality in other species. Even though the Peregrine Falcon population now seems to be released from decades of a DOT problem, exposure to other contaminant continues. There is an obvious need to assess further the sources and longer-term trends of the PCBs. We also report residue concentrations from one White-tailed Eagle, Haliaeetus albicilla, egg.

Book chapter↗
USGS1982

Migratory peregrine falcons, Falco peregrinus, accumulate pesticides in Latin America during winter

Blood samples from 433 Peregrine Falcons (Falco peregrinus) during fall and spring migrations, 1976-80, indicated that most of their pesticide burden, primarily DDE, was accumulated on wintering grounds in Latin America. DDE in spring migrants returning from Latin America for the first time declined significantly from 1979 to 1980. Only about 10% of breeding-age females contained organochlorine residues likely to adversely affect reproduction. The organochlorine pesticide threat in Latin America may be diminishing.

Canadian Field-Naturalist↗
USGS1995

What is Falco Altaicus Menzbier?

The systematics of the Altay falcon (Falco altaicus/lorenzi) remains enigmatic. First reported in 1811, it has been treated as a gyrfalcon (F. rusticolus), a saker (F. cherrug), and two separate species (F. lorenzi and F. altaicus). Of 53 'altaicus' specimens examined, at least two are misidentified gyrfalcons, many are typical sakers, but 34 (the core group) are considered to be the true Altay falcon type. Adults have red, brown, and gray color morphs. The red (backed) morph closely resembles some eastern sakers; the chocolate and gray morphs resemble respective gyrfalcon morphs. While the true affinities of the Altay falcon will be resolved by molecular genetics, the ecological, geographical, and morphological information suggest that the core group represents a gyrfalcon-saker cross that is being swamped through back crosses with the saker. The breeding range of the core group (i.e., the Altay and Sayan Mountains) is much smaller than previously reported.

Journal of Raptor Research↗
USGS1997

Remarkable saker falcon ( Falco cherrug ) breeding records for Mongolia

During 1994-95 surveys, we located over 80 Saker Falcon ( Falco cherrug ) breeding sites in Mongolia. Over half of the sites had features that were in some way remarkable or previously undescribed in the scientific literature. Ten were on utility poles, two on bridges, three on abandoned buildings and one was on a truck tire on a pole. Seven sites were very near buzzard nests and two more were in buzzard nests that were used the same season. Five sites were on cliff tops accessible by walking. Four were on very short cliffs, two were on broken/sloping cliffs and one was at the base of a cliff. Five were on the tops of stone pillars. Six were in very short elm trees. Nest composition was also sometimes remarkable: one was a suspended uric acid (excrement) platform without underlying support, three were trash nests and two were composed largely of bones.

Journal of Raptor Research↗
USGS1982

Inclusion body hepatitis in kestrels (Falco sparverius)

Inclusion body disease of suspected adenovirus etiology was the apparent cause of death of 9 captive kestrels (Falco sparverius). Cloacal hemorrhage was the only prominent gross lesion; disseminated hepatocellular necrosis and intranuclear inclusion bodies were evident microscopically. Attempts to reproduce the disease, and to propagate and serologically characterize the agent were unsuccessful.

Wildlife Disease Association Conference Proceeding↗
USGS2009

Toxicity of polybrominated diphenyl ethers (de-71) in chicken (Gallus gallus), mallard (Anas platyrhynchos), and American kestrel (Falco sparverius) embryos and hatchlings

Embryonic survival, pipping and hatching success, and sublethal biochemical, endocrine, and histological endpoints were examined in hatchling chickens (Gallus gallus), mallards (Anas platyrhynchos), and American kestrels (Falco sparverius) following air cell administration of a pentabrominated diphenyl ether (penta-BDE; DE-71) mixture (0.01-20 mu g/g egg) or polychlorinated biphenyl (PCB) congener 126 (3,3', 4,4', 5-pentachlorobiphenyl; 0.002 mu g/g egg). The penta-BDE decreased pipping and hatching success at concentrations of 10 and 20 mu g/g egg in kestrels but had no effect on survival endpoints in chickens or mallards. Sublethal effects in hatchling chickens included ethoxyresorufin-O-dealkylase (EROD) induction and histological changes in the bursa, but these responses were not observed in other species. Polychlorinated biphenyl congener 126 (positive control) reduced survival endpoints in chicken and kestrel embryos and caused sublethal effects (EROD induction, reduced bursal mass and follicle size) in chickens. Mallards were clearly less sensitive than the other species to administered penta-BDE and PCB 126. In a second experiment, the absorption of penta-BDE (11.1 mu g/g egg, air cell administered during early development) into the contents of chicken and kestrel eggs was determined at various intervals (24 h postinjection, midincubation, and pipping). By pipping, 29% of the penta-BDE administered dose was present in the egg contents in chickens, and 18% of the administered dose was present in kestrel egg contents. Based on uptake in kestrels, the lowest-observed-effect level on pipping and hatching success may be as low as 1.8 mu g total penta-BDE/g egg, which approaches concentrations detected in eggs of free-ranging birds. Because some penta-BDE congeners are still increasing in the environment, the toxic effects observed in the present study are cause for concern in wildlife.

Environmental Toxicology and Chemistry↗
USGS2017

Are nest boxes ecological traps for red-footed falcons Falco vespertinius at Naurzum

Nest box programs are frequently implemented for conservation of cavity-nesting birds, but their effectiveness is rarely evaluated in comparison to birds not using nest boxes. In the European Palearctic, Red-Footed Falcon ( Falco vespertinus ) populations are both of high conservation concern and are strongly associated with nest box programs in heavily managed landscapes. We used a 21-year monitoring dataset developed from monitoring 753 nesting attempts by Red-footed Falcons at the Naurzum Zapovednick to evaluate response of demographic parameters of Redfooted Falcons to environmental factors including use of nest boxes. Variations in lay date and in numbers of eggs were not well explained by any one model, but instead by combinations of models with terms for nest type, land cover type and degree of coloniality. In contrast, variation in both offspring loss and numbers of fledglings produced were fairly well explained by a single model including terms for nest type, land cover type, and an interaction between the two parameters (65% and 81% model weights respectively). Because, for other species, early lay dates are associated with individual fitness, this interaction highlighted a potential ecological trap where falcons using nest boxes on forest edges at Naurzum lay eggs earlier but suffer greater offspring loss and produce lower numbers of fledglings than do those in other nesting settings.

Kostanay Oblast↗
USGS2021

Red-footed Falcon Falco vespertinus

Red-footed falcons (Falco vespertinus) are a small, long-distance and obligate migrant falcon that breeds at the forest-steppe interface in Eurasia and winters in Southern Africa. Research carried out with geolocators and satellite transmitters show that during the southbound migration Central Asian birds migrate through the Caucasus and the Middle East, while those from Eastern Europe cross the Eastern Mediterranean. Once in Africa, they cross the Sahara, the Sahel, where they perform short stopovers, and the Congo rainforest or the Rift valley, heading towards the wintering grounds. Northbound migration involves stopovers in West Africa and long crossings over the Mediterranean Sea. Both visual observations and tracking studies show that at least some populations of the species perform a clockwise loop migration that involves extensive longitudinal movements and. for some sub-populations, crossing the Central Mediterranean only during spring. Pre-breeding migration has a longer duration than post-breeding migration, probably because stopovers are longer and wind assistance lower. Red-footed falcons also face substantial anthropogenic threats along migration, particularly the risk of shooting at migratory bottlenecks.

Book chapter↗
USGS2019

Brodifacoum toxicity in American Kestrels (Falco sparverius) with evidence of increased hazard upon subsequent anticoagulant rodenticide exposure

A seminal question in ecotoxicology is the extent to which contaminant exposure evokes prolonged effects on physiological function and fitness. A series of studies were undertaken with American kestrels ingesting environmentally realistic concentrations of the second-generation anticoagulant rodenticide (SGAR) brodifacoum (BROD). Kestrels fed BROD at 0.3, 1.0 or 3.0 µg/g diet wet wt for 7 d exhibited dose-dependent hemorrhage, histopathological lesions and coagulopathy (prolonged prothrombin and Russell’s viper venom times). Following termination of a 7 d exposure to 0.5 µg BROD/g diet, prolonged blood clotting time returned to baseline values within a week, but BROD residues in liver and kidney (terminal half-life estimates >50 d) persisted during the 28 d recovery period. In order to examine the hazard of sequential AR exposure, kestrels were exposed to either the firstgeneration AR chlorophacinone (CPN; 1.5 µg/g diet) or the SGAR BROD (0.5 µg/g diet) for 7 d, and following a recovery period, were challenged with a low dose of CPN (0.75 µg/g diet) for 7 d. In BROD-exposed kestrels, the challenge exposure clearly prolonged prothrombin time compared to naïve controls and kestrels previously exposed to CPN. These data provide evidence that the SGAR BROD may have prolonged effects that increase toxicity of subsequent AR exposure. As free-ranging predatory and scavenging wildlife are often repeatedly exposed to ARs, such protracted toxicological effects need to be considered in hazard and risk assessments.

Environmental Toxicology and Chemistry↗
USGS1985

Biochemical and hematological effects of lead ingestion in nestling American kestrels ( Falco sparverius )

1. One-day old American kestrel ( Faico sparverius ) nestlings were orally dosed daily with 5 μl/g of corn oil (controls), 25, 125 or 625 mg/kg of metallic lead in corn oil for 10 days. 2. Forty per cent of the nestlings receiving 625 mg/kg of lead died after 6 days and growth rates were significantly depressed in the two highest lead dosed groups. At 10 days hematocrit values were significantly lower in the two highest lead treated groups, and hemoglobin content and red blood cell (δ-aminolevulinic acid dehydratase (ALAD) activity was depressed in all lead treated groups. Plasma creatine phosphokinase decreased in the two highest treatment groups. 3. Brain, liver and kidney ALAD activities, brain RNA to protein ratio and liver protein concentration decreased after lead exposure whereas liver DNA, DNA to RNA ratio and DNA to protein ratio increased. Brain monoamine oxidase and ATPase were not significantly altered. 4. Measurements of the ontogeny of hematological variants and enzymes in normal development, using additional untreated nestlings, revealed decreases in red blood cell ALAD, plasma aspartate amino transferase, lactate dehydrogenase, brain DNA and RNA and liver DNA, whereas hematocrit, hemoglobin, plasma alkaline phosphatase, brain monoamine oxidase, brain ALAD and liver ALAD increased during the first 10 days of posthatching development. 5. Biochemical and hematological alterations were more severe than those reported in adult kestrels or precocial young birds exposed to lead. Alterations may be due in part to delayed development.

Comparative Biochemistry and Physiology, Part C: C↗
USGS2009

Experimental infection of a North American raptor, American kestrel (Falco sparverius), with highly pathogenic avian influenza virus (H5N1)

Several species of wild raptors have been found in Eurasia infected with highly pathogenic avian influenza virus (HPAIV) subtype H5N1. Should HPAIV (H5N1) reach North America in migratory birds, species of raptors are at risk not only from environmental exposure, but also from consuming infected birds and carcasses. In this study we used American kestrels as a representative species of a North American raptor to examine the effects of HPAIV (H5N1) infection in terms of dose response, viral shedding, pathology, and survival. Our data showed that kestrels are highly susceptible to HPAIV (H5N1). All birds typically died or were euthanized due to severe neurologic disease within 4-5 days of inoculation and shed significant amounts of virus both orally and cloacally, regardless of dose administered. The most consistent microscopic lesions were necrosis in the brain and pancreas. This is the first experimental study of HPAIV infection in a North American raptor and highlights the potential risks to birds of prey if HPAIV (H5N1) is introduced into North America.

PLoS ONE↗
USGS1983

Effects of chronic dietary lead in American kestrels (Falco sparverius)

American kestrels were fed a diet containing 0, 10, or 50 ppm lead (Pb) powder for at least 5 mo. Blood delta-aminolevulinic acid dehydratase (ALAD) activity in birds receiving 50 ppm Pb was as low as 20% of controls but no significant effects were noted in packed cell volume (PCV) or hemoglobin concentration (Hb). Mean liver Pb residues in birds fed 50 ppm Pb were 1.3 and 2.4 ppm (dry wt) for males and females, respectively. Liver Pb residues in birds fed 10 ppm Pb were not significantly greater than controls. There was no significant correlation between blood ALAD activity and blood Pb concentration, no consistent histopathological lesions were noted, and body and organ weights were not affected.

Journal of Wildlife Diseases↗
USGS1983

Hemorrhagic enteritis in captive American kestrels (Falco sparverius)

Hemorrhagic enteritis and hepatitis of suspected adenovirus etiology were the apparent cause of death of nine captive American kestrels. Cloacal hemorrhage was the only prominent gross lesion: disseminated hepatocellular necrosis, and intranuclear inclusion bodies were evident microscopically. Electron microscopy revealed numerous adenovirus-like particles associated with the hepatic lesions. Attempts to serologically identify the agent were unsuccessful.

Journal of Wildlife Diseases↗
USGS1984

Tissue lead distribution and hematologic effects in American kestrels (Falco sparverius) fed biologically incorporated lead

American kestrels were fed a diet containing 0.5, 120, 212, and 448 ppm (dry wt) biologically incorporated lead (Pb) for 60 days. The diet consisted of homogenized 4-wk-old cockerels raised on feed mixed with and without lead. No kestrels died and weights did not differ among treatment groups. The control group (0.5 ppm Pb) had the lowest mean concentration of lead and the high dietary group had the highest for the following tissues: Kidney, liver, femur, brain, and blood. Concentrations of lead were significantly correlated among tissues. There were no differences among treatment groups for packed cell volume, hemoglobin concentration, or erythrocyte count.

Journal of Wildlife Diseases↗
USGS1995

Productivity of saker falcons (Falco cherrug) in Mongolia

During the summers 1994-1995, over 80 eyries were located on over 10,000 km of survey routes in Mongolia. Where possible, production and hatch dates were assessed when the eyries were found. For 75 nesting attempts, breeding success was found to be 92%. The average number of young per brood was 28 for 68 attempts. The number of young fledged per pair by year were 3.2 in 1994 and 2.6 in 1995. Productivity values for western Mongolia were 3.1, central 3.4, and eastern 2.5. Similar values for three habitat types were 2.8 in mountain, 3.1 in foothill, and 2.4 in flat habitat. Support type comparisons were: 2.9 young for cliff nests, 3.5 young for trees, 1.9 young for utility poles, and 2.5 young for other artificial structures. These values (except for the utility pole sites) represent a highly productive population.

Book chapter↗
USGS2006

Gyrfalcon (Falco rusticolus) in Yakutia: Distribution, nesting areas, and features of nutrition

In Yakutia, gyrfalcon nests in tundra, forest-tundra, and taiga and may occur in the northeastern and, sometimes, in the northwestern parts, being almost absent or occasional over the large area separating these regions. The southern boundary of the nesting site is nowhere below 64 degrees N. In central Yakutia, gyrfalcon was suggested to be met as a visitant or migratory species. The long-term studies showed that this species occurred there in all the seasons, including winter periods. This fact became a reason to consider the bird as a migratory and wintering (not always) species, despite its repeated comings to inhabited localities that indicated difficulties in birds during winter periods. There are about 30 and 6 species of birds and mammals, respectively, in the gyrfalcon diet in Yakutia. The prevalence of birds is evident (65.4 to 91.3%). In the composition of food species, the share of willow and rock ptamigans is high everywhere, although in the Lower Kolyma tundra, they give way to ducks (19.2 and 30.7%, respectively). Ptamigans as an diet item seems to be of particular importance for the survival of the species. Gyrfalcons prey birds of medium size, such as ptamigans, ducks, and sandpipers. Large (geese. caterpillars) and small (small passerines) birds become gyrfalcon's prey less often. Species of open and semi-open habitats are mostly preferable among mammals. Drastic changes in the forage reserves of gyrfalcon are one of the most serious causes leading to the changes in its number and participation in the reproductive cycles.

Zoologicheskii Zhurnal↗