Genetic relationships in the peregrine falcon (Falco peregrinus) analysed by microsatellite DNA markers

Microsatellite DNA markers were developed from a peregrine falcon (Falco peregrinus) and genetic relationships among peregrine falcons in southern Norway were analysed using the markers. The genomic DNA library was screened for the presence of dinucleotide microsatellite repeats. Twelve loci revealed polymorphism through the initial analysis of 24 unrelated peregrine falcons, and Mendelian inheritance was confirmed in two peregrine falcon families bred in captivity. The estimated mean probability of identical genotypes in two unrelated individuals was 3 x 10-8, and the combined exclusion probability for parentage testing was 0.99 and 0.94 for one or both parents unknown, respectively. The markers were used to investigate the parentage of peregrine broods from the same nest site from different breeding seasons, and subsequently the nest-site fidelity of the breeding peregrines. High nest-site fidelity was found by studying pairwise comparisons of relatedness (rxy) estimates among chicks at six nest sites from three different breeding seasons. Cross-species amplifications showed that most loci also appeared to amplify polymorphic products in the gyrfalcon (F. rusticolus), merlin (F. columbarius), hobby (F. subbuteo) and kestrel (F. tinnunculus), demonstrating that the loci will provide powerful genetic markers in these falcons too.     

Network topology of stable isotope interactions in a sub-arctic raptor guild

Predation is an ecologically important process, and intra-guild interactions may substantially influence the ecological effects of predator species. Despite a rapid expansion in the use of mathematical graph theory to describe trophic relations, network approaches have rarely been used to study interactions within predator assemblages. Assemblages of diurnal raptors are subject to substantial intra- and interspecific competition. Here we used the novel approach of applying analyzes based on network topology to species-specific data on the stable isotopes ¹³C and ¹⁵N in feathers to evaluate patterns of relative resource utilization within a guild of diurnal raptors in northern Sweden. Our guild consisted of the golden eagle (Aquila chrysaetos), the gyrfalcon (Falco rusticolus), the peregrine falcon (Falco peregrinus) and the rough-legged buzzard (Buteo lagopus). We found a modular trophic interaction structure within the guild, but the interactions were less nested than expected by chance. These results suggest low redundancy and hence a strong ecological importance of individual species. Our data also suggested that species were less connected through intra-guild interactions than expected by chance. We interpret our results as a convergence on specific isotope niches, and that body size and different hunting behaviour may mediate competition within these niches. We finally highlight that generalist predators could be ecologically important by linking specialist predator species with disparate dietary niches.     

Salmonella Amager, Campylobacter jejuni, and urease-positive thermophilic Campylobacter found in free-flying peregrine falcons (Falco peregrinus) in Sweden

Rare species with small population sizes are vulnerable to perturbations such as disease, inbreeding, or random events. The threat arising from microbial pathogens could be large and other species could act as reservoirs for pathogens. We report finding three enteric bacterial species, Salmonella Amager, Campylobacter jejuni, and urease-positive thermophilic Campylobacter, in nestling free-flying peregrine falcons (Falco peregrinus) in Sweden in 2000. Campylobacter jejuni isolates exhibited marked genetic similarities to an isolate from a human, providing a possible association between a human-associated strain of this bacterium and peregrine falcons.     

Gyrfalcon nest distribution in Alaska based on a predictive GIS model

The gyrfalcon (Falco rusticolus) is an uncommon, little studied circumpolar Arctic bird that faces conservation concerns. We used 455 historical nest locations, 12 environmental abiotic predictor layers, Geographic Information System (ArcGIS), and TreeNet modeling software to create a spatially explicit model predicting gyrfalcon breeding distribution and population size across Alaska. The model predicted that 75% of the state had a relative gyrfalcon nest occurrence index value of <20% (where essentially no nests are expected to occur) and 7% of the state had a value of >60%. Areas of high predicted occurrence were in northern and western Alaska. The most important predictor variable was soil type, followed by sub-surface geology and vegetation type. Nine environmental factors were useful in predicting nest occurrence, indicating complex multivariate habitat relationships exist. We estimated the breeding gyrfalcon population in Alaska is 546 ± 180 pairs. The model was 67% accurate at predicting nest occurrence with an area under the curve score of 0.76 when assessed with independent data; this is a good result when considering its application to the entire state of Alaska. Prediction accuracy estimates were as high as 97% using 10-fold cross validation of the training data. The model helps guide science-based management efforts in times of increasing and global pressures for this species and Arctic landscapes.     

Genetic Diversity of the Chukotka–Kamchatka Gyrfalcon (Falco rusticolus,Falconiformes, Falconidae) Population,Based on an Analysis of Nuclear Microsatellite Loci

Biology Bulletin - Abstract—We identified the main genetic characteristics of the Kamchatka–Chukotka gyrfalcon (Falco rusticolus) population using nine nuclear microsatellite loci....     

Molecular evidence predicts aryl hydrocarbon receptor ligand insensitivity in the peregrine falcon (<Emphasis Type="Italic">Falco peregrines</Emphasis>)

Some wild populations of fish-eating birds and raptors are exposed to high concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds such as other 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans and coplanar polychlorinated biphenyls, resulting in accumulation in their tissues. It has been demonstrated that TCDD-like chemicals cause toxic effects via aryl hydrocarbon receptor (AHR)-mediated signaling pathways. The aim of this study was to characterize the AHR from the peregrine falcon (Falco peregrines) to predict its sensitivity to TCDD-like chemicals. The AHR1, AHR2, and AHR nuclear translocator 1 of the peregrine falcon are more similar in amino acid sequence to avian species less sensitive to TCDD-like chemicals such as the cormorant (95%) than to more sensitive species such as the chicken (90%). From the amino acid sequence, it is likely that the ligand-binding affinity of peregrine falcon AHR1 and AHR2 would be very low compared with the chicken or other sensitive species, and it was actually proved by an in vitro reporter gene assay. We concluded that the peregrine falcon, one of raptor species, may be relatively resistant to TCDD-like chemicals.     

Territory occupancy rate of goshawk and gyrfalcon: no evidence of delayed numerical response to grouse numbers

Two recent studies on territory occupancy rates of goshawk Accipiter gentilis and gyrfalcon Falco rusticolus report a 2–3-year-delayed numerical response to grouse numbers, which is a requirement for a hypothesis of predator-generated grouse cycles. The time lags were assumed to reflect the average age of sexual maturity in the raptor species. In southern Norway, however, subadult (two-year-old) goshawk hens occupied only 18–25% of territories where occupancy was not recorded in the preceding year, and there was no significant relationship between the proportion of subadults among recruits and grouse indices two years earlier. We argue that territory occupancy rates are not appropriate indices of total raptor population levels, but rather reflect the proportion of territorial pairs that attempt to nest. Because this depends on the body condition of the hens, fluctuations in other important winter resident prey species (most important for the goshawk) and winter weather (most important for the gyrfalcon) should also be addressed. During 1988–2006, the annual proportion of goshawk territories with recorded nesting attempts in southern Norway was most closely related to the preceding autumn’s population indices of black grouse Tetrao tetrix and mountain hare Lepus timidus, whereas the annual proportion of gyrfalcon territories with observations of falcons or with confirmed breeding attempts in central Norway were best explained by population indices of willow grouse Lagopus lagopus and ptarmigan L. mutus from the previous autumn, and by December temperatures. Hence, our studies do not support the predation hypothesis for grouse cycles.     

A suite of falcon single-locus minisatellite probes: a powerful alternative to DNA fingerprinting

Nine falcon single-locus minisatellite probes have been cloned, characterized and shown to provide a powerful alternative to multilocus DNA fingerprinting for determining the parentage of broods of young. Eight clones derived from size-selected peregrine Falco peregrinus and merlin F. columbarius charomid libraries were found to detect single minisatellite loci in all tested members of the genus Falco . A further clone (c Fti 1) randomly selected from a kestrel F. tinnunculus library identified a single locus in other members of the genus and certain species of the Accipitridae. The nine loci display a mean heterozygosity of 88% and considerable allelic diversity in the peregrine and merlin. Pedigree analysis provides evidence consistent with the clustering of minisatellites in linkage groups that are conserved between species. Mutations were observed at five loci among families of peregrines and kestrels. Composite profiles produced with this suite of probes provide an excellent means of confirming identity and parentage. The use of profiling for investigating familial relationships, population dynamics and combating the illegal trade in wild falcons is discussed.     

Isolation and molecular characterization of a highly polymorphic centromeric tandem repeat in the family Falconidae

An abundant tandem repeat has been cloned from genomic DNA of the merlin (Falco columbarius). The cloned sequence is 174 bp in length, and maps by in situ hybridization to the centromeric regions of several of the large chromosomes within the merlin karyotype. Complementary sequences have been identified within a variety of falcon species; these sequences are either absent or in very low copy number in the family Accipitridae. The cloned merlin repeat reveals highly polymorphic restriction patterns in the peregrine falcon (Falco peregrinus). These polymorphisms, which have been shown to be stably inherited within a family of captive peregrines, can be used to differentiate the Greenland and Argentina populations of this endangered raptor species.     

Legacy or colonization? Posteruption establishment of peregrine falcons (Falco peregrinus) on a volcanically active subarctic island

How populations and communities reassemble following disturbances are affected by a number of factors, with the arrival order of founding populations often having a profound influence on later populations and community structure. Kasatochi Island is a small volcano located in the central Aleutian archipelago that erupted violently August 8, 2008, sterilizing the island of avian biodiversity. Prior to the eruption, Kasatochi was the center of abundance for breeding seabirds in the central Aleutian Islands and supported several breeding pairs of peregrine falcons (Falco peregrinus). We examined the reestablishment of peregrine falcons on Kasatochi by evaluating the genetic relatedness among legacy samples collected in 2006 to those collected posteruption and to other falcons breeding along the archipelago. No genotypes found in posteruption samples were identical to genotypes collected from pre‐eruption samples. However, genetic analyses suggest that individuals closely related to peregrine falcons occupying pre‐eruption Kasatochi returned following the eruption and successfully fledged young; thus, a genetic legacy of pre‐eruption falcons was present on posteruption Kasatochi Island. We hypothesize that the rapid reestablishment of peregrine falcons on Kasatochi was likely facilitated by behavioral characteristics of peregrine falcons breeding in the Aleutian Islands, such as year‐round residency and breeding site fidelity, the presence of an abundant food source (seabirds), and limited vegetation requirements by seabirds and falcons.     

Complete mitochondrial genome of the peregrine falcon Falco peregrinus (Aves, Falconiformes, Falconidae): genetic differences between the two individuals

The peregrine falcon Falco peregrinus (Aves, Falconiformes, Falconidae) is one of the most common and widespread raptor species in the world. Here, the complete mitochondrial genome of F. peregrinus from Korea, which is one of the breeding ranges, was sequenced and characterized in detail.     

Lead exposure in an "urban" peregrine falcon and its avian prey

Necropsy of a 7-yr-resident peregrine falcon (Falco peregrinis) from Baltimore showed a Pseudomonas infection involving the pharynx as the immediate cause of death. Concentrations of lead in liver and kidney measured 0.74 and 1.40 ppm, respectively. A survey of lead exposure was performed on 40 urban rock doves (Columbia livia). Thirteen additional rock doves were collected from sites removed from lead contamination and served as controls. The mean concentration of lead in the blood of the urban rock doves was 0.96 ppm (range 0.29-17.0 ppm) compared to 0.05 ppm (0.01-0.07 ppm) for control birds. Ninety-eight percent (39/40) of the urban rock doves had elevated concentrations of lead in their blood, while 27% (11/40) had sublethal concentrations. None of the control birds had increased concentrations of lead in their blood. Concentrations of lead in liver and kidney of 13 urban rock doves were 3.48 ppm and 9.53 ppm, respectively, compared to concentrations of 0.43 ppm and 0.50 ppm for four control rock doves. From these data a mean total concentration of lead per rock dove was calculated at 4.60 ppm for urban birds and 0.33 ppm for control birds.     

Hematological, protein electrophoresis and cholinesterase values of free-living nestling peregrine falcons in Spain

Protein electrophoresis, hematological and cholinesterase values were determined in 32 nestling free-living peregrine falcons (Falco peregrinus) (15- to 27-days-old) in order to establish normal reference values for this population. The following values (mean +/- SD) were observed: prealbumin 0.31 +/- 0.04 g/dl, albumin 1.25 +/- 0.06 g/dl, alpha1 and alpha2-globulin 0.23 +/- 0.02 and 0.16 +/- 0.02 g/dl respectively, beta-globulin 1.02 +/- 0.05 g/dl, gamma-globulin 0.060 +/- 0.08 g/dl, total protein 3.79 +/- 0.18 g/dl, 21.26 +/- 1.30 white blood cells/microl (1 x 10(3)), 2.17 +/- 0.07 red blood cells/microl (1 x 10(6)), packed cell volume 37.58 +/- 0.82%, hemoglobin 20.96 +/- 0.29 g/dl, heterophils 61.14 +/- 2.50% and cholinesterase 1,184 +/- 75 IU/L. There were no difference in any of these parameters among males and females. The hematological values obtained could be considered as representative values in free-living nestling peregrine falcons.     

New data on avifauna of the Ustyurt plateau in the Holocene

Bone remains of birds from a location of the middle Subboreal period and from three locations of the early Subatlantic period were studied on the Ustyurt plateau (Kazakhstan). Three out of 17 avian species that have been identified (Phalacrocorax pygmaeus, Falco peregrinus, and Nyctea scandiaca) proved to be absent in the modern fauna of the region. Our data on the bird fauna of the Ustyurt Plateau in the second half of the Middle Holocene and at the beginning of the Late Holocene indicate that, in that time, the migration routes of the little cormorant, peregrine, and snowy owl passed across the Ustyurt territory and the wintering sites of peregrine and snowy owl were more extensive and were also situated in Ustyurt. In the second half of the Late Holocene, the number of wintering sites of these species diminished and their migration routes have been altered.     

Prey availability influences habitat tolerance: an explanation for the rarity of peregrine falcons in the tropics

The density and productivity of peregrine falcon Falco peregri nus populations correlate positively with distance from the Equator, while habitat specificity increases with proximity to the Equator. Low peregrine densities in the tropics may he a result of competition with similar conveners (e.g. the lanner falcon F. biarmicus in Africa), which replace them in many areas. Alternatively, tropical peregrines may he limited by resource deficiencies that do not affect their close relatives. Data from peregrine and lanner populations in South Africa support the resource deficiency hypothesis, and there is no evidence to suggest direct competition between the two species. In areas where prey are not spatially or temporally concentrated, or otherwise particularly vulnerable to attack, morphological and behavioural specializations of peregrines probably restrict them to optimal foraging conditions. The relative dynamics of.Arctic and temperate vs tropical prey populations is suggested as an important factor determining peregrine distribution globally. Populations of other widespread hut particularly specialized avian predators (e.g. osprey Pandion haliaetus) may he similarly controlled. Food limitation (in terms of a dearth of particularly vulnerable prey) in the tropics has resulted in specialization and rarity in peregrines and generalization and relative abundance in similar congeners.     

Lack of genetic polymorphism among peregrine falcons Falco peregrinus of Fiji

We compared levels of genetic diversity and isolation among peregrine falcons Falco peregrinus from two South Pacific island complexes (Fiji and Vanuatu: F. p. nesiotes), relative to other island and mainland populations. Fragment data from 12 microsatellite loci and sequence information from the control region of the mitochondrial DNA indicated levels of genetic variation in the South Pacific populations were lower than other island and mainland populations. Indeed, diversity varied from extremely low (Vanuatu) to completely absent (Fiji). We find little support for a hypothesis that populations on Fiji or Vanuatu were colonized via Australia. The complete lack of polymorphism in peregrine falcons of Fiji is remarkable, and to our knowledge has not been observed in a natural avian population. This lack of polymorphism, and the inability to test for decrease in polymorphism using museum samples, precludes testing whether the lack of genetic diversity in the population on Fiji is due to a recent bottleneck, or sustained isolation over evolutionary time. Increased fertility in eggs of Fiji peregrines upon outbreeding with males from other areas is consistent with inbreeding depression within a population typified by heterozygote deficiency.     

Species variation in osmotic, cryoprotectant, and cooling rate tolerance in poultry, eagle, and peregrine falcon spermatozoa

Potential factors influencing spermatozoa survival to cryopreservation and thawing were analyzed across a range of the following avian species: domestic chicken (Gallus domesticus), domestic turkey (Meleagris gallopavo), golden eagle (Aquila chrysaetos), Bonelli's eagle (Hieraaetus fasciatus), imperial eagle (Aquila adalberti), and peregrine falcon (Falco peregrinus). Studies focused on spermatozoa tolerance to the following: 1) osmotic stress, 2) different extracellular concentrations of the cryoprotectant dimethylacetamide (DMA), 3) equilibration times of 1 versus 4 h, 4) equilibration temperature of 4 versus 21 degrees C, and 5) rapid versus slow cooling before cryopreservation and standard thawing. Sperm viability was assessed with the live/dead stain (SYBR-14/propidium iodine). Sperm viability at osmolalities >/=800 mOsm was higher (P: < 0.05) in raptor than poultry semen. Return to isotonicity after exposure to hypertonicity (3000 mOsm) decreased (P: < 0.05) number of viable spermatozoa in chicken, turkey, and golden and Bonelli's eagle spermatozoa but not in imperial eagle or peregrine falcon spermatozoa. Differences were found in spermatozoa resistance to hypotonic conditions, with eagle species demonstrating the most tolerance. Semen, equilibrated for 1 h (4 degrees C) in diluent containing DMA (> or =2.06 M), experienced decreased (P: < 0. 05) spermatozoa survival in all species, except the golden eagle and peregrine falcon. Number of surviving spermatozoa diminished progressively with increasing DMA concentrations in all species. Increased equilibration temperature (from 4 to 21 degrees C) markedly reduced (P: < 0.05) spermatozoa survival in all species except the Bonelli's eagle and turkey. Rapid cooling was detrimental (P: < 0.05) to spermatozoa from all species except the imperial eagle and the chicken. These results demonstrate that avian spermatozoa differ remarkably in response to osmotic changes, DMA concentrations, equilibration time, temperature, and survival after fast or slow freezing. These differences emphasize the need for species-specific studies in the development and enhancement of assisted breeding for poultry and endangered species.     

Helminth community structure in birds of prey (Accipitriformes and Falconiformes) in southern Italy

We compared helminth communities in 6 species of birds of prey from the Calabria region of southern Italy. In total, 31 helminth taxa, including 17 nematodes, 9 digeneans, 3 acanthocephalans, and 2 cestodes, were found. All helminth species were observed in the gastrointestinal tract, except for 3 spirurid nematodes. Most of the parasite species were detected in at least 2 hosts, but 13 helminth species were found in only 1 host. At the infracommunity level, the overall species richness and Brillouin's index of diversity varied by host, with the highest values in a generalist feeder, the Eurasian buzzard (Buteo buteo), and the lowest in a specialist, the western honey buzzard (Pernis apivorus). Species richness was gender dependent only in the sparrow hawk (Accipiter nisus). The helminth communities were characterized by different dominant species, namely, Centrorhynchus spp. (Acanthocephala) in the Eurasian buzzard and common kestrel (Falco tinnunculus), Parastrigea intermedia (Digenea) in the marsh harrier (Circus aeruginosus), Physaloptera alata (Nematoda) in the sparrow hawk, Serratospiculum tendo (Nematoda) in the peregrine falcon (Falco peregrinus), and Strigea falconis (Digenea) in the western honey buzzard. Statistical analyses confirmed a highly significant difference of helminth infracommunity structure among host species. We conclude that in the Calabria region of southern Italy, each of the raptor species studied is distinct in terms of its helminth communities, and more diverse feeding habits of the host correspond with richer helminth communities.     

Plasmodium berghei: development of an irreversible experimental malaria model in Wistar rats

A protocol to infect five-week-old Wistar rats by Plasmodium berghei which resulted in 100% mortality was developed in this work. In order to accomplish this goal, the effect of the administration of 10(7) and 10(8) parasitized erythrocytes by i.v. and i.p. route was investigated. The animals inoculated with 10(7) parasitized red blood cells by i.p. and i.v. routes showed 25 and 50% mortality, respectively. Inoculation with 10(8) parasitized erythrocytes by both routes resulted in a 100% lethal infection. The i.v. inoculation showed less scattered results and it was preferred over the i.p. route. The suitability of the protocol developed was evaluated by treating infected Wistar rats with chloroquine (30 mg/kg/day). A decreased parasitemia after the treatment was observed until the complete eradication of the parasite, around 10 days post-inoculation. Parasitemia depression after chloroquine treatment demonstrates the utility of the model developed to test new antimalarial drugs.     

Habitat loss and raptor predation: disentangling long- and short-term causes of red grouse declines

The number of red grouse (Lagopus lagopus scoticus) shot in the UK has declined by 50% during the 20th century This decline has coincided with reductions in the area of suitable habitat and recoveries in the populations of some avian predators. Here we use long-term records of shooting bags and a large-scale manipulation of raptor density to disentangle the effects of habitat loss and raptor predation on grouse populations. The numbers of grouse harvested on the Eskdale half of Langholm Moor in southern Scotland declined significantly during 1913-1990 and grouse bags from the whole moor from 1950 to 1990 exhibited an almost identical but non-significant trend. Hen harriers (Circus cyaneus) and peregrine falcons (Falco peregrinus) were absent or bred at low densities on this moor throughout this period but heather-dominant vegetation declined by 48% between 1948 and 1988. Harrier and peregrine breeding numbers on Langholm Moor increased to high levels following protection in 1990 whilst grouse density and grouse bags declined year after year until shooting was abandoned in 1998. The prediction of a peak in grouse bags on Langholm Moor in 1996 based on the patterns of bags during 1950-1990 was supported by the observed peaks in 1997 on two nearby moors with few raptors which formerly cycled in synchrony with Langholm Moor. This study demonstrates that, whilst long-term declines in grouse bags were most probably due to habitat loss, high levels of raptor predation subsequently limited the grouse population and suppressed a cycle. This study thus offers support to theoretical models which predict that generalist predators may suppress cycles in prey populations.