The Red-breasted Parakeet (Psittacula alexandri), a Near Threatened psittacid traditionally restricted to the sub-Himalayan and North-eastern tracts of India, is here documented for the first time in the urban landscape of Patna, Bihar. This extra-limital record and incipient establishment were confirmed through opportunistic field observations and fixed-point counts conducted at Patna University and the National Institute of Technology (NIT) Patna between November 2nd 2025 to 5th December 2025. A stable population of up to four individuals, including at least one confirmed male and one female, persists within these institutional green spaces. Ecological data confirms a dietary reliance on the fruits of Neolamarckia cadamba (Kadam) and documents active interspecific competition with the House Crow (Corvus splendens). These sightings represent a significant southward range expansion in Bihar, identifying urban university campuses as functional refugia and biological corridors for this species within the Gangetic plains. The study provides definitive evidence of the species’ ability to navigate and utilize fragmented urban matrices outside its historical distribution range.

The house crow (Corvus splendens) is a highly adaptable urban bird widely distributed across Pakistan and serves as a potential bioindicator of environmental health. This study evaluated morphometry, feeding ecology, haematology, and tissue trace‑metal burdens in house crows from cultivated and semi‑urban landscapes of Okara District (Central Punjab, Pakistan) during March-June 2023. Sixty adults were captured, and a subset of 24 individuals (12 males and 12 females) was processed for detailed laboratory analyses. Standard morphometrics were recorded using a digital balance and digital calipers. Diet was assessed via gut‑content examination and categorized into major food groups. Blood was collected from the brachial vein for routine haematology, and liver, kidney, and pectoral muscle tissues were digested (HNO₃/HClO₄) and analyzed by atomic absorption spectrophotometry for Zn, Cd, Ni, Fe, and Cr. Sexual dimorphism was limited, with males marginally heavier and slightly larger in wingspan. Gut contents indicated an opportunistic omnivorous diet with a high frequency of insects (83.3%), wheat grains (62.5%), and anthropogenic refuse (50%). Mean haematological indices were within expected avian ranges (e.g., RBC 2.93 ± 0.45 ×10⁶/µL; WBC 26.87 ± 1.02 ×10³/µL; PCV 37.97 ± 2.00%). Trace metals were detected in all tissues, with Zn and Fe generally highest in liver and Cr relatively elevated in muscle. These findings provide baseline ecological and physiological information for C. splendens and support its utility as a sentinel species for monitoring anthropogenic food dependence and trace‑metal exposure in agro‑urban Punjab.

The genus Corvus includes some well-documented cases of hybridization between species. Hybrids are usually concentrated in narrow hybrid zones located along the borders of the parental species’ ranges. However, the hybrid zone between the Somali Crow (Corvus edithae), an all-black endemic of the Horn of Africa, and the Pied Crow (Corvus albus), a conspicuously black-and-white species widespread across much of sub-Saharan Africa, has received little attention. Between 1999 and 2019, we conducted field observations in coastal and insular Eritrea, where both species are common, except in towns and large villages, from which they are largely excluded by the invasive House Crow (Corvus splendens). We recorded hybrids between Somali and Pied Crows at eight sites across a narrow area spanning over 300 km along the Danakil Desert coastline and on the Dahlak and Hawakil archipelagos of Eritrea. Additionally, we updated the known distribution of these hybrids in northeastern Africa by combining our field data with a review of scientific literature, as well as recent online photographs and reports from birdwatchers.

Artificial light at night (ALAN) is a growing environmental pollutant with significant risks to brain health in both animals and humans. This study assessed the ALAN-induced negative impact and examined potential mitigative strategies on neurobehavioural traits and associated neural pathways in diurnal Indian house crows subjected to dim light at night (dLAN, 6 lx) in a 12-hour:12-hour light-dark cycle. The 12-hour dLAN period was either interrupted midway by a 2-hour dark period (controls in 0 lx dark night; experiment 1) or preceded by a 50 µg day⁻¹ crow⁻¹ melatonin pre-treatment 30 min before the dLAN onset (controls received vehicle; experiment 2). dLAN exposure reduced nocturnal melatonin levels, and negatively impacted the circadian behaviour, sleep, mood and cognitive performance as well as the mRNA expression of genes associated with neurogenesis (bdnf, dcx, nr4a2), neuroinflammation (tnfα and tnfr1), and epigenetic regulation (hat1, hdac2, hdac4) in hippocampus and nidopallium caudolaterale brain regions. The midnight 2-hour dark period partially restored, but the evening melatonin pre-treatment completely restored the dLAN-induced disrupted neurobehaviours and associated gene expressions. These results provide mechanistic insights into night-light pollution effects, and suggest a pivotal role of melatonin in preserving the sleep integrity and cognitive functions in animals, perhaps also in humans.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-29401-8.

The Asian koel Eudynamys scolopaceus is a generalist brood parasite that exploits a diverse array of host species across Asia. A previous study using avian visual modeling found no evidence that koels had evolved eggs that mimic the eggs of one of their oldest known hosts, the house crow Corvus splendens, or that they had host‐specific egg types when parasitizing two other common hosts in Bangladesh. In this study, we used museum collections to compare eggs from three koel subspecies to a broader range of host species from multiple areas across Asia. Our goals were to: 1) determine if koel eggs differed in appearance based on the host species they parasitized, and 2) determine if koel eggs appear similar to the eggs of any of the hosts we measured, which might suggest egg mimicry. We found no evidence that koels have evolved host‐specific egg types (all koel eggs were similar in appearance to each other regardless of the host nest) or that koels had evolved egg mimicry with house crows. Rather, koel eggs were the most similar in color to the red‐billed blue magpie Urocissa erythrorynhca in all geographic regions and were more similar in pattern to the other parasitized crow hosts than to house crows in the same geographic region. Thus, there is some evidence that koels may have evolved eggs that mimic the eggs of these other hosts, rather than the eggs of the house crow, but further experimentation to test these hosts for egg rejection ability is warranted.

The House Crow (Corvus splendens), a highly adaptable urban species, thrives in rapidly urbanizing cities like Jaipur, Rajasthan. This review synthesizes current research on its population dynamics, spatial distribution, and feeding behaviors in urban Jaipur, drawing on recent advances in urban ecology. Population densities range from 15.37 ± 2.1 to 34 ± 3.5 birds/km² across Indian cities, with localized peaks exceeding 50 birds/km² in resource-rich areas. The species exhibits behavioral plasticity, with scavenging (78% ± 4.2% of feeding time), predation (12% ± 2.8%), kleptoparasitism (7% ± 1.9%), and human provisioning (3% ± 1.1%) as primary feeding strategies. Spatial analysis reveals a preference for mixed residential-commercial areas, with 89% of populations within 500 m of human settlements. Key research gaps include long-term population monitoring, habitat quality assessment, and climate change impacts in Jaipur’s semi-arid urban ecosystem. These findings underscore the need for integrated urban planning to balance House Crow proliferation with native biodiversity conservation, addressing both ecological benefits (e.g., waste removal) and conflicts (e.g., nest predation).

Recording of Mite Ectoparasites Associated with House Crows (Corvus splendens) in Canal Cities, Egypt

We evaluated the infection and transmission potential of the highly pathogenic avian influenza (HPAI) H5N1 virus from infected crows (Corvus splendens) to healthy in-contact crows. Six crows were inoculated with 106 EID50 of H5N1 virus (A/crow/India/01CA249/2021), and 24 hr later six in-contact crows were introduced with them. All the birds were observed for signs of illness, and swabs were collected up to 14 days postinfection (dpi). One of the infected birds showed dullness, ruffled feathers, shivering, and reluctance to move at 7 dpi, while the other five infected crows showed no significant clinical signs except ruffled feathers and some signs of mental confusion. All the in-contact crows remained asymptomatic throughout the experiment. Virus could be isolated in swabs of infected birds from 1 to 7 dpi, and viral quantification revealed viral shedding up to 8 dpi. Although virus was not isolated from the swabs collected from in-contact birds, low numbers of viral RNA copies were detected in some samples. Virus was isolated from the brain and trachea of most of the infected birds along with other tissues. Virus was also isolated from different tissues collected from three of the in-contact birds, albeit with low numbers of viral copies. All six infected and five in-contact crows were found to be seroconverted against H5N1 virus when analyzed on 14 dpi. These findings suggest that the H5N1 virus was transmitted to in-contact birds, but the infectious doses were low, resulting in only a limited infection. Our study highlights that H5N1 viruses may be transmitted by direct contact within the house crow population, a feature that might play an important role in the epidemiology of avian influenza.

Conspecifics confer survival advantage in the face of night-light polluted environment: Evidence from melatonin secretion, sleep, mood and cognitive performance in Indian house crows.

Widely distributed house crows act as scavengers. This study investigated the prevalence and molecular characterization of potentially zoonotic Raillietina tapeworms. House crows were captured using mist nets. Tapeworms were preserved in 70% ethanol (−20°C) and identified morphologically and molecularly. DNA was extracted using phenol-chloroform; 18S rDNA was amplified by PCR and visualized after gel electrophoresis. Logistic regression analyzed prevalence factors; chi-square tested associations between categorical variables and infection. Raillietina infected 47.22% of crows, with prevalence differing by sex, age, health, area, and month. Females had higher infection rates (60%) than males (31.2%) (OR = 5.00, CI: 1.25–22.70, p > .05; p > .05). Subadults (76.9%) were more susceptible than adults (30.4%), (OR = 0.81, CI = 0.19–3.23, p > .05; p < .05). Weak crows (63.6%) showed higher susceptibility compared to healthy ones (32%), (OR = 4.88, CI = 1.00–36.42, p > .05; p > .05). Urban crows showed significantly higher infection rates (55.5%) than rural crows (38.8%) (OR = 0.0481, CI = −5.119 to −1.405, p < .05; p > .05). Compared to colder months, prevalence was found higher during summer months, highest in June and August (OR = 2.073, CI = 0.7396–8.519, p < .05; p < .05). The study highlights zoonotic Raillietina prevalence and molecular identification, recommending future research on crow-human transmission pathways.

Feeding ecology of house crows in a high-altitude Himalayan urban landscape

Abstract: Nhavare village in Shirur tehsil of Pune district, Maharashtra, India, is known to its rich faunal assemblage. Biodiversity was surveyed during the rainy season in Nhavare using a standardized walking survey technique. The photographed animals were identified with taxonomic keys. There were 24 species that were observed, out of which six species belonging to the Phylum Arthropoda while 18 species belong to the Phylum Chordata. Six resident birs species were found namely: Corvus splendens, Corvus culminates, Passer domesticus, Ardeola grayii, Milvus lineatus, Dicrurus macrocercus. The ecological importance of Nhavare as an essential habitat for bird and other faunal diversity. Also diverse species of insects, arachnids, and reptiles to birds and mammals were identified such as Apis dorsata, Ptyas mucosa, and Milvus lineatus signifies the ecological diversity of the area. The research also emphasizes the contribution of agriculture to local biodiversity. The record of faunal diversity in Nhavare provides a baseline for future ecological monitoring and conservation management planning. The knowledge of species composition and spatial distribution can inform biodiversity conservation and management strategies. This work highlights the importance of ongoing monitoring of biodiversity, especially in rural environments that are increasingly subject to anthropogenic pressures. It is recommended to carry out further long-term studies in different seasons to compare fluctuations in species abundance and habitat choice.

Invasive species such as the Indian House Crow (Corvus splendens) pose a significant ecological threat by disrupting local ecosystems and outcompeting native species. Originally from the Indian subcontinent, this crow has become invasive in Dodoma, Tanzania, where it preys on various organisms, including lizards. Lizards, which are important for pest control and as prey for higher trophic levels, are particularly affected. This study investigates community perceptions of Indian house crows and their impact on lizard populations in Dodoma. Using a combination of cross-sectional surveys and systematic sampling, we assessed local perceptions, lizard diversity and crow abundance. Our results show that approximately 85% of the community is aware of the presence and impact of Indian house crows. The study also shows that lizard diversity, as measured by Shannon's index, is higher in urban areas (1.51) with higher house crow abundance than in peri-urban areas (1.12). However, these urban areas also have significantly higher predation rates, with an average of 12% higher predation on lizards. The study highlights the ecological and socio-economic implications of house crow invasions and stresses the need for targeted management strategies to mitigate their negative impacts on local biodiversity and ecosystems.

The house sparrow (Passer domesticus), one of the most widespread bird species across urban and ruralenvironments globally, has seen a notable decline in population in recent years, raising concerns amongecologists. This study explores the factors influencing house sparrow abundance, including mobile towers,electromagnetic field (EMF) exposure, and predation. House sparrows were recorded in 169 of the 205 studysites, thriving in suburban (94.7%), urban (86.3%), and rural (80.4%) areas. While statistical analysis showedno significant relationship between the presence of mobile towers and sparrow abundance, high-level EMFradiation (E &gt; 40V/m, M &gt; 0.4μT) had a significant negative impact on their population, with a p-value of &lt;0.05. Predators, such as Eurasian sparrow hawks, house crows, monkeys, and cats, were also identified assignificant threats. Interestingly, artificial nests showed a positive influence, with an average encounter rateof 15 ± 1.4 nests per block, indicating their potential for conservation. Soil type also played a role, with redloam and black cotton soils found to support more favorable conditions for foraging and nesting.This study underscores the influence of land-use practices, EMF radiation, and predation on housesparrow populations, highlighting artificial nests as a viable conservation measure. Further research isneeded to explore additional factors affecting house sparrow abundance and refine conservation strategiesthrough artificial nest provisioning.

This Nature note reports the first documented instance of tool use in Sunda crows (Corvus enca) and provides additional evidence of this ability in house crows (Corvus splendens). At Singapore Zoo (December 2023), individuals from both species spontaneously manipulated a hooked stick to extract food rewards from enclosed containers. This observation extends the catalogue of tool-using corvids. We briefly review tool use across the corvid family and examine competing hypotheses regarding its evolution, including inherited predisposition from a tool-using ancestor and the development of general physical intelligence with food caching as a potential precursor. Our findings suggest that the cognitive foundation for tool use may be conserved across the corvid family, with expression contingent upon environmental demands rather than species-specific adaptations. This work contributes to ongoing discussions regarding the evolutionary origins of complex problem-solving in birds and the potential role of general physical intelligence in corvid cognition.

Illuminated nights reduce melatonin peak and disrupt sleep. Using this as the basis of the present experimental paradigm, we investigated whether nocturnal melatonin levels were crucial for sleep regulation in a diurnal vertebrate. Acclimated Indian house crows (Corvus splendens) were randomly segregated into three groups of 12 each. For the next 10 days, one group was maintained on 12 L:12 D, as before (LD control); for the other two groups, the absolute darkness was replaced with dim light at night (dLAN; L = ~150 lux, D = ~6 lux). Under dLAN, half an hour before light off time, the LD control and one dLAN group received intraperitoneally 200 μL of vehicle (0.75% physiological saline), while the other dLAN group received a similar 200 μL vehicle but containing melatonin at a dose of 50 μg bird-1 day-1. Under dLAN, exogenous melatonin elevated nocturnal AANAT mRNA and plasma melatonin levels and induced changes in diurnal expressions of clock genes (PER2, CRY1, BMAL1, NPAS2, REVERB) in the pineal gland and hypothalamus, and of genes encoding melatonin receptors (MEL1a, MEL1b) and epigenetic modifiers (HAT1, HDAC2, HDAC4, DNMT3a) in the hypothalamus. Elevated nocturnal melatonin levels bettered sleep with positive effects on the hypothalamic expression of genes associated with nocturnal sleep (cytokine pathway: TLR4, TNFα, IL-1β, NOS1; calcium pathway: CAMK2, SIK3) and awake (ACHM3, EGR1, HOMER1a, OREXIN) states, and with neurogenesis and synaptic plasticity (BDNF, EGR1, CREB). These suggested the role of melatonin in mitigation of the dLAN-induced sleep disruption. Nocturnal melatonin peak levels are a crucial component of the regulatory transcriptional pathways underlying the daily wake-sleep pattern, with far-reaching implications for sleep-related issues in diurnal species including perhaps humans inhabiting an over-lit environment with pervasive light pollution.

Biodiversity is important in the preservation of ecological balance, and faunal diversity in any area is a reflection of its ecological health. Kesnand-Wadebolhai, being in Pune District, Maharashtra, supports varied habitats like cropland, grassland, and human habitation and hence is an ecologically important place. This research intends to record the faunal diversity of this area, emphasizing species richness and ecological importance. Field surveys involved direct observation, pitfall trap, and opportunistic sampling methods. Species were identified using standard taxonomic keys and literature at hand. There were 47 species from several taxonomic groups, such as Insecta, Arachnida, Chilopoda, Malacostraca, Amphibia, Reptilia, Aves, and Mammalia. The checklist gives clues to the diversity and distribution of the species that can be included in baseline ecological studies in the future. The findings indicate a rich collection of insects, arachnids, amphibians, reptiles, birds, and mammals with key species like Apis dorsata (Giant Honey Bee), Mesobuthus tamulus tamulus (Indian Red Scorpion), Naja naja (Cobra), and Corvus splendens (House Crow). The diversity of these species shows the presence of a well-balanced ecosystem, but growing urbanization is a likely threat to biodiversity. The research highlights the need for conservation measures to safeguard the faunal richness of Kesnand-Wadebolhai. Knowledge of species distribution and their ecological functions can help in formulating biodiversity conservation and sustainable land-use planning strategies. Additional studies and ongoing monitoring are suggested to evaluate long-term environmental alterations and their effects on the fauna of the region.

The Asian Woollynecks were once thought to be a rare winter migrant to the wetlands of Bangladesh, and until very recently, only a few incidents of nesting had been observed. New information shows expanding populations across their habitat, though little is known about their movement ecology, breeding ecology and preferences for artificial nest sites. In this paper, we documented some crucial nesting and breeding information on this species. We used camera traps as a means of passive monitoring and identified Large-billed crow Corvus macrorhynchos and House crow Corvus splendens as potential nest predators. Three nests were found in artificial structures, where anthropogenic activity, like disturbances during cell phone tower maintenance, or predators limit the breeding success of Asian Woollynecks.

Introduced species may pose one of the biggest threats to biodiversity conservation. Today, monitoring their status, distribution and abundance constitutes an important part of ecological and conservation studies throughout the world. In the Afrotropical Region (sub-Saharan Africa), avian introductions have attracted the attention of many researchers, but there is a lack of a comprehensive review of this subject on a continental scale. The presented paper constitutes an attempt to overview the status, distribution, threats and control measures of birds introduced to sub-Saharan Africa in the last 200 years. This review lists 146 bird species introduced to sub-Saharan Africa. Only 49 (33.6%) of them have developed viable populations and only 7 (4.8%) became invasive species, namely Passer domesticus, Sturnus vulgaris, Acridotheres tristis, Corvus splendens, Columba livia var. domestica, Psittacula krameri and Pycnonotus jocosus. Data on distribution of most introduced species are provided, together with information on the place and year of their first introductions. For Passer domesticus and Columba livia var. domestica, data on population densities are also provided from several southern African towns. The most speciose groups of introduced species were parrots (Psittaciformes), comprising 33.6% (including Psittacidae: 13.7%; and Psittaculidae: 15.1%); Anatidae: 12.3%; Phasianidae: 11.0%; and Passeriformes: 30.1%. Most avian introductions in sub-Saharan Africa took place in Southern Africa (mainly the Cape Town, Durban and Johannesburg areas) and in Madagascar and the surrounding islands (mostly Mauritius, Reunion and Seychelles). Most introduced species which have developed viable populations originate from the Afrotropical, Oriental and Palearctic regions (altogether 78%), with only 2% from the New World. The proportions among the introduced species which have not established viable populations are quite different: 29% from the New World and only 60% from the Afrotropical, Oriental and Palearctic regions. The main factors affecting successful avian introductions and introduction pathways have been identified. A review of the control measures undertaken in sub-Saharan Africa (mainly in small oceanic islands) is outlined for the following species: Passer domesticus, Acridotheres tristis, Corvus splendens, Pycnonotus jocosus, Foudia madagascariensis, Psittacula krameri and Agapornis roseicollis.

An integrated approach to understanding Corvus splendens’ invasive behaviour, genetic dynamics, and ecological impact for its strategic management