Blood Of Nestlings Research Articles

Domestic Waste and Wastewaters as Potential Sources of Pharmaceuticals in Nestling White Storks (Ciconia ciconia).

Information on the exposure of wild birds to pharmaceuticals from wastewater and urban refuse is scarce despite the enormous amount of drugs consumed and discarded by human populations. We tested for the presence of a battery of antibiotics, NSAIDs, and analgesics in the blood of white stork (Ciconia ciconia) nestlings in the vicinity of urban waste dumps and contaminated rivers in Madrid, central Spain. We also carried out a literature review on the occurrence and concentration of the tested compounds in other wild bird species to further evaluate possible shared exposure routes with white storks. The presence of two pharmaceutical drugs (the analgesic acetaminophen and the antibiotic marbofloxacin) out of fourteen analysed in the blood of nestlings was confirmed in 15% of individuals (n = 20) and in 30% of the nests (n = 10). The apparently low occurrence and concentration (acetaminophen: 9.45 ng mL-1; marbofloxacin: 7.21 ng mL-1) in nestlings from different nests suggests the uptake through food acquired in rubbish dumps rather than through contaminated flowing water provided by parents to offspring. As with other synthetic materials, different administration forms (tablets, capsules, and gels) of acetaminophen discarded in household waste could be accidentally ingested when parent storks forage on rubbish to provide meat scraps to their nestlings. The presence of the fluoroquinolone marbofloxacin, exclusively used in veterinary medicine, suggests exposure via consumption of meat residues of treated animals for human consumption found in rubbish dumps, as documented previously at higher concentrations in vultures consuming entire carcasses of large livestock. Control measures and ecopharmacovigilance frameworks are needed to minimize the release of pharmaceutical compounds from the human population into the environment.

Timing of infestation influences virulence and parasite success in a dynamic multi-host\u2013parasite interaction between the invasive parasite, Philornis downsi, and Darwin\u2019s finches

Recently commenced host–parasite interactions provide an excellent opportunity to study co-evolutionary processes. Multi-host systems are especially informative because variation in virulence between hosts and temporal changes provides insight into evolutionary dynamics. However, empirical data under natural conditions are scarce. In the present study, we investigated the interaction between Darwin’s finches and the invasive fly Philornis downsi whose larvae feed on the blood of nestlings. Recently, however, the fly has changed its behavior and now also attacks incubating females. Two sympatric hosts are affected differently by the parasite and parasite load has changed over time. Our study observed a reversal of trends described two decades ago: while, currently, small tree finches (Camarhynchus parvulus) experience significantly higher parasite load than warbler finches (Certhidea olivacea), this was the opposite two decades ago. Currently, fledging success is higher in warbler finches compared to small tree finches. Our data indicate that not only intensity but also timing of infestation influences hosts’ reproductive success and parasite fitness. During incubation, prevalence was higher in warbler finches, but once chicks had hatched, prevalence was 100% in both species and parasite load was higher in small tree finches. Furthermore, our results suggest faster development and higher reproductive success of P. downsi in small tree finch nests. A change in host preference driven by larvae competition could have led to the reversal in parasite load.

Zinc concentrations in Blue-footed booby (Sula nebouxii) eggs, nestlings, and adults

Zinc is essential for animal metabolism, but the variation in Zn concentrations within seabird populations has been seldom explored. We collected Blue-footed booby (Sula nebouxii) eggs during 2012 and 2013 and blood samples from nestlings and adults during 2011 and 2012 in Sinaloa, Mexico, to evaluate differences in Zn concentrations among years, ages, sexes, and breeding stages. Zinc concentrations in eggs ranged between 27.3 and 64.9 ppm (dry weight), whereas Zn levels in the blood of nestlings and adults ranged between 16.1 and 53.1 ppm (dry weight). Egg Zn concentrations did not differ due to developmental stage, although Zn concentrations were significantly higher in 2013 than in 2012. Nestling Zn concentrations differed between years and decreased gradually with age. Chicks had significantly higher Zn concentrations than those of adults. Once nestlings stopped growing, females presented higher Zn concentrations than males. Adult Zn concentrations were higher during the pre-laying period than during the other breeding stages. Our results suggest that growth, sex, and breeding stage affect blood Zn concentrations, which may be due to stage-specific requirements. When compared with those of other seabird species, the Zn concentrations reported here are intermediate, and we did not detect adverse effects on either nestlings or adults.

Experimental test of the effect of introduced hematophagous flies on corticosterone levels of breeding Darwin’s finches

Parasites can negatively affect the evolutionary fitness of their hosts by eliciting physiological stress responses. Parasite-induced stress can be monitored by measuring changes in the adrenal steroid hormone corticosterone. We examined the effect of an invasive parasite on the corticosterone concentrations of a common species of Darwin’s finch, the medium ground finch (Geospiza fortis). Philornis downsi (Diptera: Muscidae) is a parasitic nest fly recently introduced to the Galapagos Islands, where it feeds on the blood of nestlings and breeding adult female finches. Previous work shows that P. downsi significantly reduces the reproductive success of several species of finches. We predicted that the effect of P. downsi on host reproductive success is mediated by stress responses in breeding female finches. High stress levels could reduce the ability of females to invest in offspring, thus decreasing their reproductive success. To test this hypothesis, we experimentally manipulated the abundance of P. downsi in nests, then measured baseline and acute stress-induced corticosterone levels, body condition, and hematocrit (red blood cell content). Acute stress-induced corticosterone levels increased over baseline levels, but this response did not differ significantly with parasite treatment. There was also no significant difference in the body condition or hematocrit of females from parasitized versus non-parasitized nests. Our results suggest that the lower reproductive success of females from parasitized nests is not mediated by a physiological stress response.

Effect of Sampling Blood of Nestlings on Success of Fledging in White-eyed Vireos (Vireo griseus)

Abstract Because the white-eyed vireo (Vireo griseus) is a less sensitive species than the endangered black-capped vireo (V. atricapilla), it served as a proxy to quantify potentially adverse effects of sampling blood. Success of fledging was quantified using split-sampled broods with non-bled nestlings serving as a control. Sex ratio of broods was determined, and sampling and storage methods for blood were assessed. Obtaining blood from nestlings did not affect success of fledging. The male:female ratio of nestlings was 65:35.

A first evaluation of the usefulness of feathers of nestling predatory birds for non-destructive biomonitoring of persistent organic pollutants

In previous studies, feathers of adult predatory birds have been evaluated as valid non-destructive biomonitor matrices for persistent organic pollutants (POPs). In this study, we assessed for the first time the usefulness of nestling raptor feathers for non-destructive biomonitoring of POPs. For this purpose, we collected body feathers and blood of nestlings from three avian top predators from northern Norway: northern goshawks (Accipiter gentilis), white-tailed eagles (Haliaeetus albicilla) and golden eagles (Aquila chrysaetos). We were able to detect a broad spectrum of legacy POPs in the nestling feathers of all three species (Σ PCBs: 6.78–140ng g−1; DDE: 3.15–145ng g−1; Σ PBDEs: 0.538–7.56ng g−1). However, these concentrations were lower compared to other studies on raptor species, probably due to the aspect of monitoring of nestlings instead of adults. Besides their analytical suitability, nestling feathers also appear to be biologically informative: concentrations of most POPs in nestling feathers showed strong and significant correlations with blood plasma concentrations in all species (p<0.050; 0.775<r<0.994). In addition, the reported correlations between feathers and blood plasma were much higher than those previously reported for adult individuals. Accumulation profiles and species-specific differences were in accordance with other toxicological studies on avian species and generally in agreement with the specific ecology of the studied species. In summary, our results indicate that the use of nestling feathers of northern raptors may be a valid and promising non-destructive biomonitoring strategy for POPs in their ecosystems.

Haemoglobin concentration and body condition of nestling Great Tits Parus major : a comparison of first and second broods in two contrasting seasons

The physiological condition of nestling altricial birds depends on the quantity and quality of food delivered to them by parents. One indicator of the condition of Great Tit Parus major nestlings is the haemoglobin concentration in their blood. The present study demonstrates the influence of weather conditions (temperature and rainfall) on nestling haemoglobin concentrations during two consecutive breeding seasons in two different habitat types (parkland vs. woodland) in the city of Łódź in Central Poland. This influence probably results from the effects of weather on the trophic base of the Tits. Dry, hot weather strongly affected bush and herbal foliage later in the breeding season (mid‐June to mid‐July) in 2006, presumably by interfering with the development of herbivorous arthropod populations. This in turn caused food shortages for second broods of Great Tits, which resulted in nestlings having low haemoglobin levels. In the following year, temperature was on average lower, and rainfall was regular but not very heavy. These conditions enabled the development of arthropod assemblages, and the trophic base for birds was much richer. Haemoglobin concentrations in the blood of nestlings from second broods were significantly higher than those of first broods and, unexpectedly, second‐brood nestlings in 2007 were on average in better physiological state than first‐brood nestlings in 2006 in both habitats. The relationship between haemoglobin concentration, brood category and year was very similar to that for nestling body mass. However, it was independent of both body mass and brood size. In some years and under certain conditions, second broods can be more successful than first broods.

The Function of Feathers in Tree Swallow Nests: Insulation or Ectoparasite Barrier?

Abstract. Altricial young face two significant energetic challenges in the nest: thermoregulation and stress caused by ectoparasites. Ectoparasites feed on blood of nestlings and serve as vectors for bacterial and viral infections. Many bird species line their nests with feathers, which insulate the nest and reduce heat loss from chicks. Feathers may also affect ectoparasite numbers by serving as a parasite barrier. We tested the possible roles of nest feathers and the effects of nest parasites on the growth and survival of Tree Swallow (Tachycineta bicolor) nestlings by comparing young in control nests with those in nests from which we removed feathers and removed feathers plus used an insecticide in an attempt to reduce ecotoparasites. On the day chicks fledged, control nests had seven times more feathers in them than both categories of nests from which we removed feathers. Nestlings in control nests were larger than those in nests from which feathers were removed, and chick growth was positively relate...

Concentrations of Metals in Blood and Feathers of Nestling Ospreys (Pandion haliaetus) in Chesapeake and Delaware Bays

In 2000, 2001, and 2002, blood and feather samples were collected from 40-45-day-old nestling ospreys (Pandion haliaetus) from Chesapeake Bay and Delaware Bay and River. Concentrations of 18 metals, metalloids, and other elements were determined in these samples by inductively coupled plasma-mass spectroscopy, and Hg concentrations were measured by cold vapor atomic absorption spectroscopy. When compared to concurrent reference areas (South, West, and Rhode Rivers), mean As and Hg concentrations in blood were greater (p < 0.05) in two of three Chesapeake Bay regions of concern (Baltimore Harbor [As: 1.18 vs. 0.548 microg/g dw], Anacostia River [Hg: 0.305 vs. 0.178 microg/g dw], and Elizabeth River [As: 0.876 vs. 0.663 microg/g dw; Hg: 0.260 vs. 0.180 microg/g dw]). Lead was detected more frequently in blood of nestlings from the highly industrialized Elizabeth River compared to the rural reference area. When compared to the concurrent reference area, mean Al, Ba, Hg, Mn, and Pb concentrations in feathers were substantially greater (p < 0.05) in one or more Chesapeake regions of concern (Anacostia River [Al: 206 vs. 62.1 microg/g dw; Ba: 3.31 vs. 0.823 microg/g dw; Mn: 65.4 vs. 22.9 microg/g dw] and Elizabeth River [Al: 165 vs. 63.5 microg/g dw; Hg: 1.24 vs. 0.599 microg/g dw; Pb 1.47 vs. 0.543 microg/g dw]). When compared to the coastal Inland Bays reference area, feathers of nestlings from northern Delaware Bay and River had greater concentrations (p < 0.05) of Ba (1.90 vs. 0.660 microg/g dw), Fe (258 vs. 109 microg/g dw), Mn (18.5 vs. 4.66 microg/g dw), Mo (0.130 vs. 0.040 microg/g dw), Pb (1.96 vs. 0.624 microg/g dw), and V (0.671 vs. 0.325 microg/g dw), presumably due to extensive metal-working and petroleum refinery activities. Concentrations of Hg in nestling feathers from Delaware were frequently greater than in the Chesapeake. The present findings and those of related reproductive studies suggest that concentrations of several heavy metals (e.g., Cd, Hg, Pb) in nestling blood and feathers from Chesapeake and Delaware Bays were below toxicity thresholds and do not seem to be affecting chick survival during the nestling period.

Hematological and immunological properties of herring gull (Larus argentatus) nestlings experimentally infected with Diphyllobothrium dendriticum (Cestoda: Pseudophyllidae)

The morphological structure of the blood in herring gull nestlings and their immune system response to experimental infection with tapeworm Diphyllobothrium dendriticum have been studied. The leukocyte reaction pattern and the dynamics of immunoglobulin synthesis and populations of immunocompetent cells in the blood of nestlings during early invasion indicated a short duration of the cellular immune response and an insignificant humoral immune response. A pronounced trend to decrease in the hemoglobin level in the blood of infected nestlings has been revealed and this reduction was in part compensated by intensified erythropoiesis. It is shown, that the changes in hematologic and immune responses of the obligate definitive host provide for the mutual host-parasite adaptation.

The life-cycle of Philornis downsi (Diptera: Muscidae) parasitizing Darwin's finches and its impacts on nestling survival

The fly, Philornis downsi Dodge & Aitken, was first collected in 1964 on the Galápagos Islands and is now widespread across the archipelago. Virtually nothing is known about the behaviour and ecology of the fly as well as for the genus in general. Here, we describe all larval instars for the first time, and discuss infection intensity and impacts of parasitism on nestling survival of Darwin's finches. Adult P. downsi are non-parasitic free-living flies, whereas the larvae are obligate blood-feeding parasites on nestling birds. The larvae show a marked shift in their host site specificity--a novel finding for the genus Philornis: the first and early second larval instars live as agents of myiasis in finch nostrils and other tissues, while the older second and third instar larvae reside in the nest material and feed externally on the blood of nestlings, leading to blood losses in nestlings of 18-55%. Pupation occurs in the bottom layer of the nest. The combined effects of tissue damage by the endoparasitic instar larvae and anaemia by nest-dwelling haematophagous instar larvae account for the high nestling mortality (76%) due to Philornis parasitism. This represents the highest mortality by Philornis reported in the literature and emphasizes the extremely serious threat this parasite poses for the endemic passerine fauna of the Galápagos Islands.

Effects of the parasitic flies of the genus Philornis (Diptera: Muscidae) on birds

Little is known about the genus Philornis (comprising ~50 species), a group of muscid flies that parasitise birds and may be highly detrimental to host nestlings. Philornis species affect at least 115 species of bird, particularly in the Neotropics. The main distribution of Philornis is in Central and South America, extending to the southern United States. Larvae of the genus Philornis reside in bird nests and may feed on either nestling faeces (coprophagous scavengers), the blood of nestlings (semi-haematophagous parasites), or on nestling tissue and fluid (subcutaneous parasites). Depending on the species of Philornis, larval development can occur in bird faeces, in nesting material or inside nestlings. Nestling mortality depends on the species of Philornis, the intensity of infestation and nestling susceptibility, which in turn depends on the nestling species, age, brood size, body condition and the anatomical site of infestation. Consequently, variable effects of Philornis parasitism are observed in relation to nestling growth, development and fledging success. The impetus for this review is the recent discovery of Philornis downsi on the Galapagos Archipelago, combined with high Philornis-induced mortality in Darwin's finches. The potential for ectoparasites such as Philornis to compromise the viability of small, isolated bird populations is highlighted by this recently documented parasite invasion.

Monitoring of Contaminants in Nestling Bald Eagles of Grand Teton National Park

We report on contaminants identified in nestling bald eagles of Grant Teton National Park (GTNP) and the Snake River Unit (SRU), Wyoming, during summers of 2006 and 2007. We focus primarily on mercury (Hg), lead (Pb), and selenium (Se) because each was detected in all nestlings during both summers at moderate levels. Independent t-tests were performed both on the raw data and log­transformed data (using the natural logarithm) as a comparative analysis to investigate if contaminant loads had significantly increased from summer 2006 to summer 2007. Also, as a comparative analysis and alternative procedure, nest site was treated as the experimental unit and a repeated-measures analysis (longitudinal study) was conducted on the raw data to investigate if contaminant loads had significantly increased from summer 2006 to summer 2007. Results of the analysis indicate that levels of Se essentially remained unchanged from summer 2006 to summer 2007 (p=0.466, log-transformed data). Levels of Pb in nestlings increased from summer 2006 to summer 2007 (p=0.000, log-transformed data). There was no difference in levels of Hg in nestlings from summer 2006 to summer 2007 (p=0.058, log-transformed data). The molar ratio (2.54ppm Se: 1 ppm Hg) of Se to Hg did not change from 2006 to 2007 (p=0.337, raw data), although a 45% decrease in molar ratio was observed. Analyses of contaminants (using geometric means) in the blood of nestlings (from summer 2006 to 2007) showed a 64% increase in Hg, a five-fold increase in Pb ( 481% ), and a 21% increase in Se. Potential localized sources of Pb contamination should be identified and removed from the proximity of any nest site(s) and the study area in general. Advancing global climate change and associated desiccation and emolation of temperate and boreal forests, exacerbated by extensive clear-cutting may increase poisoning of aquatic ecosystems with high levels of contaminants, especially Hg, in the future. A monitoring program may be indicated to identify potential long-term changes within the GYE. (p=O.OOO, log-transformed data). There was no difference in levels of Hg in nestlings from summer 2006 to summer 2007 (p=0.058, log­ transformed data). The molar ratio (2.54ppm Se: 1ppm Hg) of Se to Hg did not change from 2006 to 2007 (p=0.337, raw data), although a 45% decrease in molar ratio was observed. Analyses of contaminants (using geometric means) in the blood of nestlings (from summer 2006 to 2007) showed a 64% increase in Hg, a five-fold increase in Pb (481%), and a 21 % increase in Se. Potential localized sources of Pb contamination should be identified and removed from the proximity of any nest site(s) and the study area in general.

Lead in feathers and delta-aminolevulinic acid dehydratase activity in three raptor species from an unpolluted Mediterranean forest (Southeastern Spain).

This paper presents the levels of lead found in the feathers of adult and blood of nestlings of booted eagle (Hieraaetus pennatus), European buzzard ( Buteo buteo), and goshawk (Accipiter gentilis) sampled in the 1999 and 2000 breeding seasons in a Mediterranean forest of the Province of Murcia (Southeastern Spain) located far from potential sources of metal contamination. Levels of delta-aminolevulinic acid dehydratase activity (delta-ALAD) in blood were also measured in the nestlings. Lead concentrations ranged from 1.1 to 11.21 microg/dl in blood of nestlings and from 0.35 to 1.66 mg/kg d.w. in the feathers of their parents. A significant relationship was found between blood delta-ALAD and lead (rho = -568), showing a negative correlation with blood lead levels even at lead concentrations below 5 microg/dl. This fact suggests the usefulness of this enzymatic biomarker for low lead exposure in forest raptors. There were also positive relationships between the lead concentrations in blood of nestlings and those in feathers of their parents (rho = 0.817), suggesting the usefulness of feathers for biomonitoring environmental exposure to lead.

Environmental Contaminants in Bald Eagles in the Columbia River Estuary

Eggs, blood, and carcasses of bald eagles (Haliaeetus leucocephalus) and fish were collected and breeding success of eagles was monitored in the Columbia River estuary, 1980-87, to determine if contaminants were having an effect on productivity. High levels of dichloro diphenyl dichloroethylene (DDE), polychlorinated biphenyls (PCB's), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were found in eggs, blood from adults, and 2 eagle carcasses. Detectable levels of DDE and PCB's were found in blood of nestlings indicating they were exposed to these contaminants early in life. Increasing concentrations of DDE and PCB's with age also indicated accumulation of these contaminants. Adult eagles also had higher levels of mercury (Hg) in blood than subadults or young indicating accumulation with age. The high levels of DDE and PCB's were associated with eggshell thinning ([bar x] = 10%) and with productivity ([bar x] = 0.56 young/occupied site) that was lower than that of healthy populations (i.e., [ge]1.00 young/occupied site). DDE and PCB's had a deleterious effect on reproduction of bald eagles in the estuary. The role dioxins play in eagle reproduction remains unclear, but concentrations in eagle eggs were similar to those in laboratory studies on other species where dioxins adversely affected hatchability of eggs. Probable sourcemore » of these contaminants include dredged river sediments and hydroelectric dams, and the proper management of each may reduce the amount of contaminants released into the Columbia River estuary. 46 refs., 1 fig., 4 tabs.« less

Notes upon the biology and morphology of the immature stages of Neottiophilum praeustum (Meigen, 1826) (Diptera: Neottiophilidae) parasitic on birds.

1. The feeding habits of second- and third-instar larvae of Neottiophilum praeustum have been observed and show that this species is a true parasite of birds and feeds by sucking the blood of nestlings.2. If they are too numerous the larvae may kill the nestlings. Although they will continue to feed upon dead birds, and even penetrate into the viscera, such food is unsuitable for the development of the larvae and they become greatly distended and die within a few days.3. The morphology of the hitherto unknown second-instar larva is described and is compared with that of the third instar.4. Within the puparium of Neottiophilum praeustum there is a fourth moult resulting in the formation of a cast prepupal cuticle which resembles that described by Snodgrass in Rhagoletis pomonella and is much better developed than the prepupal cuticle in Calliphora erythrocephala.5. The better development of the prepupal cuticle in the acalypterates than in calypterates indicates that the presence of a prepupal stage in the cyclorrhaphous Diptera is a primitive character and is progressively reduced until in the higher families it is almost vestigial.