Molecular and morphological description of Sarcocystis kutkienae sp. nov. from the common raven (Corvus corax).

Until now, two Sarcocystis species, S. cornixi and S. corvusi, were known to employ members of the family Corvidae as intermediate hosts. Between 2013 and 2019, having examined leg muscles of 23 common ravens in Lithuania, sarcocysts were detected in 18 birds (78.3%). Using light microscopy, transmission electron microscopy (TEM), and molecular analysis (three genetic loci, 18S rDNA, 28S rDNA, and ITS1), sarcocysts found in the common raven were described as a new species S. kutkienae. Under a light microscope, the observed sarcocysts were ribbon-shaped (1500-8147 × 53-79 µm) and had a wavy striated cyst wall that reached up to 1.5 µm. Lancet-shaped bradyzoites were 7.7 × 2.2 µm (6.1-9.0 × 1.2-3.0 µm) in size. Ultrastructurally, the sarcocyst wall was 1.5-1.8 µm in thickness and had conical-like protrusions with minute invaginations of a parasitophorous vacuolar membrane. The cyst wall was type 1e-like. Limited genetic variability was observed between the 18S rDNA and 28S rDNA sequences of S. kutkienae and other Sarcocystis spp. using birds as intermediate hosts. In contrast, S. kutkienae could be clearly identified by comparing sequences. At this locus, sequences of S. kutkienae shared the highest similarity (89.5-89.7%) with those of S. cornixi. Phylogenetic analysis showed that S. kutkienae was most closely related to Sarcocystis spp. that employs birds as intermediate and definitive hosts. The issue relating to which species might serve as definitive hosts of S. kutkienae in Lithuania is addressed.

Parasitological and molecular survey of scattered parasitism by trichomonads in some avian species in Iran.

Outbreaks of avian trichomonosis are being reported worldwide; meanwhile, the genetic and virulence variations are under investigation. In this study, the occurrence and genetic variability of oral or faecal trichomonads among various avian species were investigated. Samples obtained from either the oropharyngeal cavity, crop/oesophagus, droppings/cloaca, or conjunctival swabs of avian species were inspected for flagellates. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples was performed to investigate the genetic diversity of the isolates. Investigation of 737 birds revealed an infection rate of 15.7% in the upper gastrointestinal tract, 7.3% in the faecal samples, and 0.7% involvement of the conjunctiva. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples, identified genotypes A and B of Trichomonas gallinae and genogroups A-C and E of Tetratrichomonas gallinarum. A novel ITS genotype of intestinal trichomonads was also detected in hooded crow (Corvus cornix) and common mynah (Acridotheres tristis). In the present study, in addition to Columbiformes and Falconiformes, trichomonads were detected in Passeriformes and Galliformes with the involvement of organs other than the gastrointestinal tract. Genotype A T. gallinae was detected in domestic pigeons (Columba livia domestica), a laughing dove (Spilopelia senegalensis), a common kestrel (Falco tinnunculus), a budgerigar (Melopsittacus undulates), and a canary (Serinus canaria). Distinct genotype B was detected in a common mynah and a budgerigar. Genogroups A-C of T. gallinarum were also demonstrated in Galliformes and Anseriformes. Furthermore, two novel trichomonad ITS genotypes were detected in hooded crows and a common mynah warranting detailed multi-locus molecular analysis.RESEARCH HIGHLIGHTSITS diversity of trichomonads was shown in various avian species.Diversity of the parasites' target organ and clinical manifestations was demonstrated.Two novel ITS genotype trichomonads from common mynah and hooded crow were identified.

The Genus Brueelia (Phthiraptera: Ischnocera: Philopteridae) of North American Jays and Allies (Aves: Passeriformes: Corvidae), with Descriptions of Five New Species.

Five new species of chewing lice in the genus Brueelia Kéler, 1936 , are described from North American jays and allies. They are Brueelia mexicana n. sp. from Aphelocoma woodhouseii cyanotis Ridgway, 1887 ; Brueelia bonnevillensis n. sp. from Aphelocoma woodhouseii nevadae Pitelka, 1945 ; Brueelia diblasiae n. sp. from Cyanocitta stelleri frontalis ( Ridgway, 1873 ); Brueelia tempestwilliamsae n. sp. from Gymnorhinus cyanocephala Wied-Neuwied, 1841 ; Brueelia mcnewae n. sp. from Nucifraga columbiana ( Wilson, 1811 ). An identification key to the Brueelia on corvid hosts is provided.

Isospora coronoideae n. sp. (Apicomplexa: Eimeriidae) from the Australian raven (Corvus coronoides) (Passeriformes: Corvidae) (Linnaeus, 1758) in Western Australia.

A new Isospora (Apicomplexa: Eimeriidae) species is described from an Australian raven (Corvus coronoides) in Western Australia. Sporulated oocysts (n = 21) are ovoid, 21.2 (18.4-23.9) µm in length and 18.8 (16.9-20.6) µm in width, with a shape index of 1.13. The bi-layered oocyst wall is smooth and colourless, 1.2 µm thick. A polar granule and oocyst residuum is present, but the micropyle is absent. The sporocysts are ovoid-shaped, 16.3 (13.7-18.9) × 10.7 (8.4-12.9) µm, with a shape index (length/width) of 1.52. Stieda and substieda bodies are present, the Stieda body being small and hemidome-shaped and the substieda being indistinct. Each sporocyst with four vermiform sporozoites arranged head to tail. The sporozoites are crescent-shaped, 9.0 (8.9-9.2) × 2.7 (2.3-3.0) µm, with a shape index (length/width) of 3.33. The sporocyst residuum is present. The isolated oocysts had different morphological characteristics when compared with all known Isospora spp. The coccidian parasite was analysed at the 18S and 28S ribosomal RNA and the mitochondrial cytochrome oxidase (COI) loci. At the 18S locus, I. coronoideae n. sp. exhibited 98.9% similarity to I. neochmiae from a captive-bred red-browed finch (KT224380) and Isospora sp. from domestic pigeons (Columba livia domestica) (AB757860), 98.5% similarity to I. gryphoni (AF080613) from an American goldfinch and 98.3% similarity to I. manorinae (KT224379) from a yellow-throated miner. At the 28S locus, it exhibited 95.4% and 94.8% similarity to I. manorinae (KT224381) and I. anthochaerae (KF766053), respectively. At the COI locus, it exhibited 99.8% and 99.7% similarity to I. butcherae (KY801687) and I. neochmiae (KT224378), respectively. Based on morphological and molecular data, this isolate is a new species of Isospora, which is named Isospora coronoideae n. sp. after its host, the Australian raven (Corvus coronoides) (Passeriformes: Corvidae) (Linnaeus, 1758).

Prevalence and diversity of avian blood parasites in a resident northern passerine.

BACKGROUND: Climate-related changes are expected to influence the prevalence and distribution of vector-borne haemosporidian parasites at northern latitudes, although baseline information about resident birds is still lacking. In this study, we investigated prevalence and genetic diversity of Plasmodium, Haemoproteus, and Leucocytozoon parasites infecting the northwestern crow (Corvus caurinus), a non-migratory passerine with unique life-history characteristics. This species occupies both intertidal and forested habitats and is subject to high prevalence of avian keratin disorder (AKD), a disease that causes gross beak deformities. Investigation of avian blood parasites in northwestern crows at sites broadly distributed across coastal Alaska provided an opportunity to evaluate specific host factors related to parasite infection status and assess geographical patterns of prevalence. RESULTS: We used molecular methods to screen for haemosporidian parasites in northwestern crows and estimated genus-specific parasite prevalence with occupancy modeling that accounts for imperfect detection of parasite infection. We observed considerable geographical and annual variation in prevalence of Plasmodium, Haemoproteus, and Leucocytozoon, but these patterns were not correlated with indices of local climatic conditions. Our models also did not provide support for relationships between the probability of parasite infection and body condition or the occurrence of co-infections with other parasite genera or clinical signs of AKD. In our phylogenetic analyses, we identified multiple lineages of each parasite genus, with Leucocytozoon showing greater diversity than Plasmodium or Haemoproteus. CONCLUSIONS: Results from this study expand our knowledge about the prevalence and diversity of avian blood parasites in northern resident birds as well as corvids worldwide. We detected all three genera of avian haemosporidians in northwestern crows in Alaska, although only Leucocytozoon occurred at all sites in both years. Given the strong geographical and annual variation in parasite prevalence and apparent lack of correlation with climatic variables, it appears that there are other key factors responsible for driving transmission dynamics in this region. Thus, caution is warranted when using standard climatic or geographical attributes in a predictive framework. Our phylogenetic results demonstrate lower host specificity for some lineages of Leucocytozoon than is typically reported and provide insights about genetic diversity of local haemosporidian parasites in Alaska.

First molecular identification and subtype distribution of Blastocystis sp. isolated from hooded crows (Corvus cornix) and pigeons (Columba livia) in Tehran Province, Iran.

Blastocystis is a common intestinal parasite among humans and animals such as non-human primates, pigs, cattle, birds, amphibians, and less frequently, rats, reptiles and insects. Since Blastocystis is a widely transmissible parasite between humans and mammals or birds, it is prominent to determine whether newly secluded non-human isolates are zoonotic. There are no comprehensive studies in Iran assessing the prevalence and molecular identification of Blastocystis infection in birds, especially in pigeons and crows. So, the aim of this study was to identify Blastocystis subtypes (STs) in crows and pigeons in Tehran province, Iran, using Nested PCR-RFLP and sequencing. Overall, 300 Blastocystis isolates from birds (156 pigeons and 144 crows) were subtyped by PCR, and the homology among isolates was then confirmed by RFLP analysis of the 18S rRNA gene. The prevalence of Blastocystis infection was detected 42.9% in pigeons and 44.4% in crows. All positive pigeons were owned by ST13 (100%). Among crows, 46 samples (71.8%) like pigeons were ST13, and 13 samples (20.3%) were ST14. Five samples (7.9%) remained unknown. This study was the first report of ST13 and ST14 of Blastocystis from birds. In the present study, our data revealed a high prevalence of Blastocystis sp. in pigeon's and crow's samples and the isolates from these birds were classified into two genetically distinct STs. Therefore, birds appear to be infected with various STs. It is important to determine the phylogenetic relationships between unknown STs from these birds and the multiple STs of Blastocystis.

Molecular assessment of Neospora caninum and Toxoplasma gondii in hooded crows (Corvus cornix) in Tehran, Iran.

Neospora caninum and Toxoplasma gondii are two closely related protozoan parasites that have been detected from various species of bird hosts. However, little is known about the prevalence of N. caninum and T. gondii in crows. Hence, we examined the molecular frequency of N. caninum and T. gondii in the brain samples of hooded crows (Corvus cornix) that collected from different public parks of Tehran, Iran by nested-PCR method. We used the primers targeting the Nc5 and GRA6 genes for detection of N. caninum and T. gondii, respectively. From a total of 55 brain samples, 5 (9.9%) and 9 (16.36%) samples were positive for N. caninum and T. gondii, respectively. Sequencing of a N. caninum isolate revealed 95%-100% identity with the deposited N. caninum in GenBank. Genotyping of T. gondii isolates by PCR-RFLP analysis of the GRA6 gene revealed type III genotype in 8 isolates. The results of this study indicate that hooded crows may have a putative role in transmission of N. caninum and T. gondii to canines and felines definitive hosts, respectively.

Great spotted cuckoo nestlings have no antipredatory effect on magpie or carrion crow host nests in southern Spain.

Host defences against cuckoo parasitism and cuckoo trickeries to overcome them are a classic example of antagonistic coevolution. Recently it has been reported that this relationship may turn to be mutualistic in the case of the carrion crow (Corvus corone) and its brood parasite, the great spotted cuckoo (Clamator glandarius), given that experimentally and naturally parasitized nests were depredated at a lower rate than non-parasitized nests. This result was interpreted as a consequence of the antipredatory properties of a fetid cloacal secretion produced by cuckoo nestlings, which presumably deters predators from parasitized host nests. This potential defensive mechanism would therefore explain the detected higher fledgling success of parasitized nests during breeding seasons with high predation risk. Here, in a different study population, we explored the expected benefits in terms of reduced nest predation in naturally and experimentally parasitized nests of two different host species, carrion crows and magpies (Pica pica). During the incubation phase non-parasitized nests were depredated more frequently than parasitized nests. However, during the nestling phase, parasitized nests were not depredated at a lower rate than non-parasitized nests, neither in magpie nor in carrion crow nests, and experimental translocation of great spotted cuckoo hatchlings did not reveal causal effects between parasitism state and predation rate of host nests. Therefore, our results do not fit expectations and, thus, do not support the fascinating possibility that great spotted cuckoo nestlings could have an antipredatory effect for host nestlings, at least in our study area. We also discuss different possibilities that may conciliate these with previous results, but also several alternative explanations, including the lack of generalizability of the previously documented mutualistic association.

Systemic Collyriclum faba (Trematoda: Collyriclidae) Infection in a Wild Common Raven ( Corvus corax ).

A hatch-year Common Raven ( Corvus corax ) with subcutaneous and internal pseudocysts, filled with fluid, containing a pair of adult trematodes and numerous eggs consistent with Collyriclum faba, died near a riverbank in California, US. While C. faba is incidental in many Passeriformes, this case was a fatal systemic infection.

First molecular detection of Sarcocystis ovalis in the intestinal mucosa of a Japanese jungle crow (Corvus macrorhynchos) in Hokkaido, Japan.

Although cysts of Sarcocystis spp. have been detected in domestic and wild animals throughout Japan, their natural definitive hosts have not been fully elucidated. Additionally, in Hokkaido, several Sarcocystis spp. are highly prevalent among wild sika deer (Cervus nippon yesoensis), one of which is S. ovalis. The life cycle of S. ovalis is maintained in corvid birds. To identify the definitive host for S. ovalis in Hokkaido, we investigated its prevalence among corvid birds (Corvus macrorhynchos and C. corone). A total of 42 crow carcasses were collected during August 2015-July 2016 in southern Hokkaido. Examination for coccidian sporocysts in rectal feces and intestinal mucosa, detection of Sarcocystis DNA (18S rRNA gene) from intestinal mucosa samples, and histological observation of intestinal tissue were conducted. No Sarcocystis sporocysts were detected in fecal and mucosal samples by flotation. DNA from intestinal mucosa was positive in one crow (C. macrorhynchos). Phylogenetic analysis demonstrated the isolate clustered with S. ovalis and was closely related to isolates obtained from sika deer in Hokkaido. Histologically, S. ovalis gamogenesis (gamonts or gametes) and oocyst production were observed in the villi of the crow positive for S. ovalis DNA. However, the crow was negative for other coccidian parasites, such as Eimeria, by fecal examination. Our results suggested that crows harbor S. ovalis in the intestine and may serve as a definitive host of S. ovalis in Hokkaido. To our knowledge, this is the first report on a natural definitive host for Sarcocystis spp. prevalent among sika deer in Japan.

Genetic sequence data reveals widespread sharing of Leucocytozoon lineages in corvids.

Leucocytozoon, a widespread hemosporidian blood parasite that infects a broad group of avian families, has been studied in corvids (family: Corvidae) for over a century. Current taxonomic classification indicates that Leucocytozoon sakharoffi infects crows and related Corvus spp., while Leucocytozoon berestneffi infects magpies (Pica spp.) and blue jays (Cyanocitta sp.). This intrafamily host specificity was based on the experimental transmissibility of the parasites, as well as slight differences in their morphology and life cycle development. Genetic sequence data from Leucocytozoon spp. infecting corvids is scarce, and until the present study, sequence data has not been analyzed to confirm the current taxonomic distinctions. Here, we predict the phylogenetic relationships of Leucocytozoon cytochrome b lineages recovered from infected American Crows (Corvus brachyrhynchos), yellow-billed magpies (Pica nuttalli), and Steller's jays (Cyanocitta stelleri) to explore the host specificity pattern of L. sakharoffi and L. berestneffi. Phylogenetic reconstruction revealed a single large clade containing nearly every lineage recovered from the three host species, while showing no evidence of the expected distinction between L. sakharoffi and L. berestneffi. In addition, five of the detected lineages were recovered from both crows and magpies. This absence of the previously described host specificity in corvid Leucocytozoon spp. suggests that L. sakharoffi and L. berestneffi be reexamined from a taxonomic perspective.

Blood parasites in hooded crows (Corvus corone cornix) in Northwest Italy.

Haemoparasites and their effects on hooded crows (Corvus corone cornix) are poorly studied. The aims are to evaluate the prevalence of Haemoproteus spp./Plasmodium spp. or Leucocytozoon spp., to correlate this with gross and histopathological findings, and to investigate the association among infection and geographical origin, age, gender, parasite distribution and prevalence among organs. Hooded crows (n = 47) were collected within a regional culling programme from 3 districts in the province of Turin (Italy) and subjected to necropsy. Histological and molecular analyses were carried out on some tissues. Leucocytozoon spp. was detected in 46 crows (97.9%) by polymerase chain reaction (PCR), whereas 28 birds (59.6%) were found to be positive for Haemoproteus spp./Plasmodium spp. The distribution of parasites in several organs varied significantly, showing that Leucocytozoon spp. is ubiquitous in organs in contrast with Haemoproteus spp./Plasmodium spp., which have a specific predilection for spleen and lungs. The prevalence of Haemoproteus spp./Plasmodium spp. also differed significantly among the crows captured in the areas of the study. The high prevalence of haemoparasites emphasizes the success of ornithophilic vectors and the susceptibility of this species to infection. Differences in prevalence among the sites are probably due to orographic features of the areas, variations in vector species and density, or to crow population size or structure. In spite of the high infection rate, no gross and histological lesions were found. This finding further suggests an evolutionary adaptation between crows and avian blood parasites.

Density-dependent regulation of fecundity in Syngamus trachea infrapopulations in semi-naturally occurring ring-necked pheasants (Phasianus colchicus) and wild Carrion Crows (Corvus corone).

Previous work has highlighted increased opportunities for the transmission of Syngamus trachea within pheasant release pens, due in part to high levels of environmental contamination around communal areas. Despite this, the distribution of adult worms within their definitive hosts is not significantly different from predicted distributions under Taylor's power law. Therefore, density-dependent processes are probably acting to regulate S. trachea population dynamics. Patterns of nematode fecundity were investigated in a semi-naturally occurring population of ring-necked pheasants (Phasianus colchicus) and a wild population of carrion crows (Corvus carone). Worm length was a reliable indicator of nematode fecundity, and a negative association between mean worm length and mean worm burden was identified within both the species. The stunting of worms at greater parasite densities was present in both immunologically naïve and previously exposed pheasants, so is unlikely to be a function of age-dependent acquired immunity. Interestingly, the effect of parasite crowding in the crow population explained more of the variation in mean worm length, apparently driven by a greater mean worm burden when compared with pheasants. The findings of the present study suggest that fecundity is a function of parasite density, i.e. parasite-mediated competition and not host-mediated heterogeneities in immunocompetence.

Chicks of the great spotted cuckoo may turn brood parasitism into mutualism by producing a foul-smelling secretion that repels predators.

The great spotted cuckoo (Clamator glandarius) is an important brood parasite of carrion crows (Corvus corone corone) in northern Spain. We recently found that, unlike what is commonly known for cuckoo-host interactions, the great spotted cuckoo has no negative impact on average crow fitness in this region. The explanation for this surprising effect is a repulsive secretion that the cuckoo chicks produce when they are harassed and that may protect the brood against predation. Here, we provide details on the chemical composition of the cuckoo secretion, as well as conclusive evidence that the dominating volatile chemicals in the secretion are highly repellent to model species representative of common predators of the crows. These results support the notion that, in this particular system, the production of a repulsive secretion by the cuckoo chicks has turned a normally parasitic interaction into a mutualistic one.

Toxoplasma gondii prevalence in Israeli crows and Griffon vultures.

A cross-sectional Toxoplasma gondii seroprevalence study was performed on free ranging crows (Corvus cornis, Corvus monedula, Corvus splendens) and Griffon vultures (Gyps fulvus) from Israel in order to assess exposure to this pathogen in scavenger birds that feed on animal carcasses and their possible role in the epidemiology of toxoplasmosis. Using the modified agglutination test (MAT) with a cutoff titer of 1:25, 52 of 122 crows (42.6%) and 40 of 101 Griffon vultures (39.6%) were found to be T. gondii seropositive. Crow T. gondii seroprevalence was significantly higher in northern areas of Israel (p=0.007) where annual precipitation is higher and annual summer maximum temperatures are lower than in the drier and warmer south. Seroprevalence in crows was positively associated with higher human population densities possibly related to the increased cat population in these areas. PCR analysis of brain extracts from crows resulted in the detection of T. gondii DNA in 1 seropositive crow from northern Israel. Genetic analysis of DNA from the positive crow brain confirmed infection with T. gondii type 2 using a multiplex multilocus nested PCR-RFLP (Mn-PCR-RFLP) of the SAG1, 5-3' SAG2, alt.SAG2, SAG3, BTUB, GRA6, C22-8, c29-2, L358, PK1 and Apico loci. The high T. gondii seroprevalence in these bird species suggests that infected carrion may be responsible for widespread infection of carcass scavenger birds which may further transmit infection to other carnivorous intermediate hosts or feline definitive hosts when consumed post-mortally.

Molecular and morphological investigations of Sarcocystis corvusi sp. nov. from the jackdaw (Corvus monedula).

One type of sarcocyst was found in two of eight investigated jackdaws (Corvus monedula) and proposed as Sarcocystis corvusi sp. nov. By light microscope, cysts resembled a thick thread and were very long (the largest fragment found amounted to 6 mm) and relatively thin (up to 60 µm). The cyst wall measured <1 µm and seemed smooth. Using a computerized image analysis system, knolls, which resembled protrusions, were visible on the wall surface. Ultrastructurally, the cyst wall was wavy and reached up to 1.1 µm. The waves were of different heights and resembled low protrusions. The parasitophorous vacuolar membrane had many invaginations. Lancet- or orange segment-shaped cystozoites were 5.9-7.3 µm long. These sarcocysts had type-1 tissue cyst wall. According to 18S rRNA, 28S rRNA genes and ITS-1 region sequences, it was shown that S. corvusi is a genetically separate species. On the basis of these genetic markers, S. corvusi was most closely related to S. columbae, S. calchasi and S. wobeseri which parasitize birds and are characterized by the same type of sarcocyst wall.

High seroprevalence of Toxoplasma gondii and Neospora caninum in the Common raven (Corvus corax) in the Northeast of Spain.

In recent years, multiple cases of aggressive behavior of Common ravens (Corvus corax) have been reported by farmers in Catalonia (NE Spain), including attacking of newborn animals and consumption of dead foetuses. In the present study, seroprevalence of Toxoplasma gondii and Neospora caninum was determined from 113 legally trapped and released Common ravens. T. gondii antibodies were found in 91 (80.5%; CI 95%:72-87) of 113 sera tested by the modified agglutination test. Antibodies to N. caninum were found in 24 (35.8%; IC 95%: 24.5-48.5) of 67 Common ravens tested by an indirect fluorescence antibody test with titers ranging from 1:50 (n=18) to ≥1:100 (n=6). To the author's knowledge, this is the first report of the presence of T. gondii and N. caninum antibodies in C. corax. The seroprevalence detected is one of the highest reported worldwide in wild birds, suggesting an important role for this species in the epidemiology of both parasites.

The first report of Knemidocoptes intermedius Fain et Macfarlane, 1967 (Acari: Astigmata) in naturally infected European birds.

According to the latest taxonomical review, the genus Knemidocoptes (Epidermoptidae: Knemidocoptinae) comprises 15 species of mites responsible for skin lesions on the face, legs, or body of various wild and domestic birds. A number of 54 common ravens, Corvus corax (Aves: Passeriformes: Corvidae) were found dead (accidental poisoning) in March 2009, in Târgu Mures, Romania. One individual presented bilateral symptoms of scaly leg disease. Microscopic examination revealed the presence of Knemidocoptes intermedius (Epidermoptidae, Knemidocoptinae) in one bird. The lesions were present on both feet (bilateral) and consisted of moderate hypertrophic crusts on the dorsal and ventral part of the toes as well as the distal part of the tarsometatarsal region. It is the first reliable record of K. intermedius in Europe and also the first record of this species in the common raven. The host range and specificity of this parasite is discussed, along with a revision of occurrences in wild birds.

Mosquito blood-meal analysis for avian malaria study in wild bird communities: laboratory verification and application to Culex sasai (Diptera: Culicidae) collected in Tokyo, Japan.

We conducted laboratory experiments to verify molecular techniques of avian malaria parasite detection distinguishing between an infected mosquito (oocysts on midgut wall) and infective mosquito (sporozoites in salivary glands) in parallel with blood-meal identification from individual blood-fed mosquitoes prior to application to field survey for avian malaria. Domestic fowl infected with Plasmodium gallinaceum was exposed to a vector and non-vector mosquito species, Aedes aegypti and Culex pipiens pallens, respectively, to compare the time course of polymerase chain reaction (PCR) detection for parasite between competent and refractory mosquitoes. DNA of the domestic fowl was detectable for at least 3 days after blood feeding. The PCR-based detection of P. gallinaceum from the abdomen and thorax of A. aegypti corresponded to the microscopic observation of oocysts and sporozoites. Therefore, this PCR-based method was considered useful as one of the criteria to assess developmental stages of Plasmodium spp. in mosquito species collected in the field. We applied the same PCR-based method to 21 blood-fed C. sasai mosquitoes collected in Rinshi-no-mori Park in urban Tokyo, Japan. Of 15 blood meals of C. sasai successfully identified, 86.7% were avian-derived, 13.3% were bovine-derived. Plasmodium DNA was amplified from the abdomen of three C. sasai specimens having an avian blood meal from the Great Tit (Parus major), Pale Thrush (Turdus pallidus), and Jungle Crow (Corvus macrorhynchos). This is the first field study on host-feeding habits of C. sasai in relation to the potential role as a vector for avian malaria parasites transmitted in the Japanese wild bird community.