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Simple Summary: The Syringophilidae family is one of the most diverse groups of prostigmatic mites (Acari: Prostigmata) parasitising birds. In this paper, we describe a new genus and species, Corvisyringophilus krummi, which parasitises the Common Raven (Corvus corax) in Iceland. This new genus belongs to a group of primitive genera that retain a complete set of idiosomal and leg setae. Our phylogenetic analysis suggests that Corvisyringophilus is morphologically closely related to the genera Blaszakia Skoracki & Sikora, 2008 and Charadriphilus Bochkov & Mironov, 1998, which are associated with birds of different and phylogenetically unrelated orders: Musophagiformes and Charadriiformes, respectively. This research highlights the importance of examining the genus Corvus in order to better understand the specialised host–parasite relationships. Furthermore, the study emphasises the significance of using museum collections to study parasitic interactions. Syringophilidae is one of the most species-rich families in the superfamily Cheyletoidea, comprising approximately 420 species across 62 genera and two subfamilies. In this paper, we propose a new genus, Corvisyringophilus, and a new species, C. krummi gen. n. et sp. n., found in the wing covert quills of the Common Raven, Corvus corax Linnaeus, in Iceland. Corvisyringophilus is placed among the primitive genera of syringophilid mites, which possess the full complement of idiosomal and leg setae. Phylogenetic analysis based on morphological characters suggests that this genus forms a sister clade to Blaszakia Skoracki & Sikora, 2008, and Charadriphilus Bochkov & Mironov, 1998, which inhabit birds of the orders Musophagiformes and Charadriiformes, respectively. The study proposes that the current distribution patterns of quill mites, based on their morphological characteristics, may result from multiple host switching followed by co-speciation events, highlighting the complex evolutionary dynamics within this family. [ABSTRACT FROM AUTHOR]

Vertebrate scavengers represent important taphonomic agents that can act on a body, particularly when in an outdoor environment. Understanding the effects of these agents will direct how and where to search for human remains and influence the likelihood of discovery in a particular region. The current study aimed to identify the taphonomic impact of scavenger guilds in the peri‐urban and rural regions of southeastern British Columbia. Vertebrate scavenger activity on pig carcasses was recorded remotely using trail cameras and analyzed to determine temporal scavenging profiles. Both the peri‐urban and rural environments produced comparable scavenger guilds, namely: turkey vultures, American crows/northern ravens (classified as “corvids”), American black bears, and coyotes. Although the two locations had different study lengths due to variable degrees of scavenging, for the period that was common to both locations (summer to early fall), the black bear was the most frequent scavenger followed by coyote. However, the dispersal of remains by the mammalian scavengers was distinctly different between sites. Only 12%–33% of skeletal elements were recovered at the rural sites compared to 80%–90% recovered at the peri‐urban sites, even though the latter sites had a longer study timeframe. The extended timeframe of the peri‐urban sites confirmed that certain scavengers (e.g., turkey vultures and black bears) are only seasonally active in this region. These findings demonstrate the variability of scavenger behavior and the need to assign caution and local ecological knowledge when predicting scavenger trends. Such taphonomic information is relevant for human remains searches in regions with comparable scavenger guilds. [ABSTRACT FROM AUTHOR]

Allochthonous inputs often link nutrient cycles between different ecosystems as nitrogen (N) that originates in one ecosystem is transferred to another. Mobile animals such as birds and fish can translocate nutrients between locations. Consequently, animal-mediated nutrient subsidies can shape plant communities, especially in nutrient-poor ecosystems. Terrestrial cliffs are typically nutrient-poor, receiving N from atmospheric deposition and cliff-top runoff. Cliff nesting birds deposit N-rich excrement onto the cliff during nesting, yet this potential nutrient input has rarely been demonstrated. Here we document an allochthonous input of N from cliff-nesting birds to terrestrial cliff vegetation. We sampled mineral N and vegetation on eight cliff systems in western North Carolina (USA) with nests from peregrine falcon (F. peregrinus; two sites) and common raven (Corvus corax ; five sites). Two sites had nests but species identity was not confirmed. Cliff faces below bird nests had higher levels of ammonium (NH 4 +) than did faces without nests. Both ammonium and nitrate (NO 3 −) explained variability in cliff vegetation community composition, but site-level characteristics explained more of the variation than did N inputs alone. Lichens, the dominant taxonomic group, contributed the most to this variation and had higher species richness and diversity below nests. Indicator species analysis identified two nitrophilic lichen species below nests: Flavoplaca citrina and Physcia caesia. A third nitrophilic lichen, Polycauliona candelaria (syn. Xanthoria candelaria) was also found under nests. Bird excrement is likely a significant subsidy to nutrient-poor terrestrial cliff ecosystems, thus linking cliffs to more productive ecosystems and highlighting the need to include birds in conservation and management of cliffs. [Display omitted] [ABSTRACT FROM AUTHOR]

In temperate regions, larger mammalian carrion naturally occurs in terrestrial landscapes as a pulsed resource towards the end of the winter through enhanced ungulate mortality due to starvation or exhaustion. The return of large carnivores in Central Europe provides carrion more equally throughout the year and the active enhancement of carrion for biodiversity by game managers has increased, raising the question of how different scavengers respond to the temporal variation in carrion supply. To address this question, we experimentally deployed 106 cervid carcasses throughout the year in a temperate forest of south-eastern Germany on two types of plots: permanent (i.e., site with multiple subsequent deployments) or random (i.e., site with unique deployment), and reported vertebrate scavenger visitations by camera trapping. Deployment on random or permanent sites did not affect carrion use by any single species. Generalized additive modelling revealed that vertebrate scavenging peaked in the winter season and summer independent of carrion supply. Still, different scavenger species showed different temporal patterns. While wild boar as ungulate omnivores did not display any seasonal patterns, avian scavengers showed significant variation in visitation rates. The mesopredator red fox consumed carrion significantly more often from late winter to summer, while pine marten was present at carrion only during winter. Finally, the specialist large carnivore Eurasian lynx, visited carrion sites most frequently in late winter and early spring. Our results suggest that global warming might impact some groups of vertebrate scavengers more strongly than others by reducing carrion availability in late winter, while returning carnivores could mitigate these impacts. [ABSTRACT FROM AUTHOR]

The Scots Pine Pinus sylvestris is the most widespread tree species in forests of lowland parts of Central and Eastern Europe. In Polish forests, stands dominated by the Scots pine cover almost 60% of the forest area. We analysed the relationship between forest birds and pine trees in an extensive forest complex in north-eastern (NE) Poland. Based on the 20-year-long study, we considered the percentage of broods established on pine trees and the percentage of Scots pine in stands on grouse leks and territory. A total number of over 20 bird species are dependent on the Scots pine trees or stands to locate their nests. Among this group, 11 bird species strongly associated with pine trees were confirmed, and they located at least 90% of broods or nests on pines. The Black Woodpecker Dryocopus martius selects the Scots pine to excavate cavities. Its cavities were regularly used by some species of secondary cavity nesters. In turn, the Common Raven Corvus corax nests were occupied by selected birds of prey. The importance of Scots pine for birds increased with the age of the trees. Old Scots pine trees were chosen by birds that built large nests, placed nests in the tree top, and excavated large cavities. Populations of pine-specialized bird species may be in danger due to the possibility of the Scots pine range moving to the north, which results from global warming. The maintenance of the Scots pine with the modification of the methods of forest regeneration should be included in the Polish forestry's strategies and plans as a critical factor for the care of the population of rare breeding bird species. [ABSTRACT FROM AUTHOR]

Over the last 10 years, the spawning population of invasive pink salmon (Oncorhynchus gorbuscha) has increased in the river systems in northern Norway to a level that is causing concern about their impact on endemic fauna and ecosystem processes. The scale of transfer of pink salmon carcasses into the terrestrial ecosystem is likely to be a key determinant of terrestrial impact. Bears (Ursus sp.) are responsible for most such transfers in North America but are rare in Norway. The white‐tailed eagle (Haliaeetus albicilla) is common however, and a candidate to be a main cause of such transfers. To evaluate this hypothesis, data on the abundance of white‐tailed eagles and pink salmon were collected along the river Skallelv in northern Norway in 2021, a year the pink salmon spawned in the river, and in 2022, a year no pink salmon spawned in the river. The abundance of white‐tailed eagles along the river was much higher the year pink salmon spawned in the river. Furthermore, white‐tailed eagles were observed aggregating and catching pink salmon where and when pink salmon were present at the spawning and post‐spawning stages. Based on our observations, we suggest that the white‐tailed eagle is the main species involved in the transport of pink salmon from the river into the riparian zone in northern Norway and that other scavengers, in particular the red fox (Vulpes vulpes) and common raven (Corvus corax), play an important role in transporting pink salmon carcasses from the riparian zone to the wider terrestrial ecosystem. [ABSTRACT FROM AUTHOR]

Monitoring of breeding success in wildlife is key for evaluating population trends and support conservation measures. However, it is challenging depending on breeding places or non-accessible habitat. In recent years, new technologies were applied to studies of bird biology, i.e. drones. UAV (drones) are available to study new aspects of bird ecology, which are not available using traditional methods. The Raven Corvus corax predominantly nests in upper tree canopies or on high cliffs. Hence, it is challenging to monitor it breeding success from the ground. Our study were conducted in forests in NE Poland, on the 77 arboreal Raven nests in 2021–2022. By using drones, we investigated (i) whether the classic data on breeding success from ground observations differ from those of nest inspections via drone, and (ii) to what extent the adult birds behave when the drone is used at the nest. The inspection from the ground failed to determine the contents of as many as 30% of the occupied nests. Inspections using a drone and those made from the ground yielded different results, as aerial assessment showed a higher number of the young (respectively 1.93 vs. 3.22 per successful brood). Broods with three young accounted for 6.5% of nests controlled from the ground and 23.3% using a drone, while broods with two young accounted for 33.8% and 10.4% of nests, respectively. During most of the inspected nests (65% of the cases), adult birds sat nearby in the tree tops and called. In 12% of the cases, the birds flew close to the nest, passing the drone at a distance of more than 20 m, and did not attempt to approach the device. In four cases, adult birds closed the drone at less than 10 m. A direct collision did not happen. The most vital reactions were recorded in several instances (only 4.2%) in which the birds were not near the nest when the inspection began but arrived during the inspection. Drone surveys have revealed previously un-described behavior of birds, alarmed at the examination of empty nests. In 50 nests, 65% of the cases, the Raven tolerated the drone's presence at the nest, although the birds showed concern and occasionally defensive reactions. It seems that the adverse reaction of birds is weaker when they associate the appearance of a drone with human presence. Key recommendations: control in teams of two - operator and observer, starting end landing in close vicinity of the nest tree, immediate interruption of flight if birds react, forbade flying directly over the nest. It is advisable to check the reaction of adult Ravens to drone inspections of nests with small nestlings. To sum up, our study showed that the drone inspections did not harm the adult birds but provides a more reliable data for reproduction than the observation from ground. [ABSTRACT FROM AUTHOR]

Invasive fungal aspergillosis is a leading cause of morbidity and mortality in many species including avian species such as common ravens (Corvus corax). Methods were developed for mass spectral determination of voriconazole in raven plasma as a means of determining pharmacokinetics of this antifungal agent. Without further development, GC/MS/MS (gas chromatography-tandem quadrupole mass spectrometry) proved to be inferior to LC/MS/MS (liquid chromatography-tandem quadrupole mass spectrometry) for measurement of voriconazole levels in treated raven plasma owing to numerous heat-induced breakdown products despite protection of voriconazole functional groups with trimethylsilyl moieties. LC/MS/MS measurement revealed in multi-dosing experiments that the ravens were capable of rapid or ultrarapid metabolism of voriconazole. This accounted for the animals' inability to raise the drug into the therapeutic range regardless of dosing regimen unless cytochrome P450 (CYP) inhibitors were included. Strategic selection of CYP inhibitors showed that of four selected compounds including cimetidine, enrofloxacin and omeprazole, only ciprofloxacin (Cipro) was able to maintain voriconazole levels in the therapeutic range until the end of the dosing period. The optimal method of administration involved maintenance doses of voriconazole at 6 mg/kg and ciprofloxacin at 20 mg/kg. Higher doses of voriconazole such as 18 mg/kg were also tenable without apparent induction of toxicity. Although most species employ CYP2C19 to metabolize voriconazole, it was necessary to speculate that voriconazole might be subject to metabolism by CYP1A2 in the ravens to explain the utility of ciprofloxacin, a previously unknown enzymatic route. Finally, despite its widespread catalog of CYP inhibitions including CYP1A2 and CYP2C19, cimetidine may be inadequate at enhancing voriconazole levels owing to its known effects on raising gastric pH, a result that may limit voriconazole solubility. [ABSTRACT FROM AUTHOR]

In avian ecosystems, habitat dynamics significantly influence bird activities. This study was conducted from July to November 2019 in the Badgoi coniferous forest, Upper Dir, Khyber Pakhtunkhwa, Pakistan. Distance Sampling Point Count method was utilized in the study to quantify the correlation between bird abundance and habitat structure. Meticulously observing 485 birds spanning 28 species and 20 families, dominant species included the Common Raven (14.4%), Pine Siskin (11.30%), and House Sparrow (10.72%). Conversely, the Red Crossbill, Gray-back Shrike, and Yellow Tit emerged as the rarest inhabitants (0.4%, 0.2%, each). Blue Kail dominated the botanical landscape at 14.599%, while Chinar stood as the rarest species (7.299%). Shrubbery diversity showcased Simru as the most abundant (14.038%) and Kala Simlu as the rarest (6.836%). Correlational analyses highlighted the intimate association between bird species and ecological components, including vegetation structure and microclimate variables. Density analysis unveiled species-specific variations in populations, emphasizing diverse foraging guilds and nuanced resource utilization. The study sets the groundwork for future research, emphasizing genetics, advanced monitoring technologies, and collaborative conservation efforts, contributing to the long-term well-being of bird populations in the Badgoi forest. [ABSTRACT FROM AUTHOR]

Multiple raptors show juvenile plumage that is substantially different from that of their parents. Here, we test the prediction that the colouration of the juvenile northern goshawk Accipiter gentilis resembling the colouration of the common buzzard Buteo buteo acts as a form of aggressive mimicry. The goshawk specialises in hunting larger birds and mammals up to the size of geese or hares, while the buzzard preys mostly on small rodents. Larger birds may thus consider juvenile goshawks as less dangerous raptors, and the juvenile goshawk may thus gain an advantage when hunting. We used the Eurasian magpie Pica pica, a common prey of the goshawk, to test this prediction. We compared the behavioural responses of magpie parents defending their freshly fledged young towards mounts of an adult goshawk, juvenile goshawk, and buzzard. To be able to assess whether this behaviour differs from responses to a nest predator and a harmless bird we also presented a common raven Corvus corax and common pheasant Phasianus colchicus as baseline stimuli. Both juvenile and adult goshawks elicited antipredatory behaviour, but magpies took more risks facing juvenile goshawks. Additionally, the intensity of antipredatory behaviour towards the juvenile goshawk was also higher than towards the buzzard. We thus conclude that magpies do distinguish between juvenile and adult goshawks, as well as they do distinguish juvenile goshawks from buzzards. They are able to assess the threat particular raptors represent and respond accordingly. Analysis of spectral reflectance of stuffed specimens of these three raptors suggests there are differences, which can be used for the appropriate recognition. In conclusion, we cannot confirm the hypothesis of aggressive mimicry in juvenile goshawks that interact with magpies. [ABSTRACT FROM AUTHOR]

OBJECTIVE To determine if a cytochrome (CYP) P450 enzyme inhibitor can maintain therapeutic plasma levels of voriconazole when administered orally. ANIMALS 11 healthy, common ravens (Corvus corax). METHODS Birds were randomly assigned to pilot study groups to receive voriconazole orally alone or combined with a CYP inhibitor. Pilot studies with 3 CYP inhibitors launched the main study using ciprofloxacin (20 mg/kg) followed 1 hour later by voriconazole (6 mg/kg) every 12 hours for 14 days. Plasma voriconazole concentrations were measured at various time points by HPLC-MS. The study period lasted from September 2016 to December 2020. RESULTS The birds failed to maintain therapeutic plasma levels of voriconazole during multidose administration alone or following preadministration with various CYP inhibitors. For the 14-day study period, voriconazole reached a maximum plasma concentration of 2.99 μg/mL with a time-to-peak drug concentration of 1.2 hours following preadministration of ciprofloxacin. One bird was removed from the study due to lethargy, but the other birds completed the study without incident. CLINICAL RELEVANCE Ciprofloxacin (20 mg/kg) followed by voriconazole (6 mg/kg) maintained the concentration of voriconazole within the recommended therapeutic range of 0.5 to 5 μg/mL without toxicity. Ciprofloxacin prevented the saturable metabolism of voriconazole and maintained these levels for the study duration. This drug combination could be used in the treatment of chronic aspergillosis in the common raven. [ABSTRACT FROM AUTHOR]

This article explores the occurrence of alloparental care, or non-genetic parenting behavior, among raptors, with a specific focus on the adoption of Eurasian Kestrel broods by Barbary Falcon pairs in the Canary Islands. The authors provide observations of two cases of adoption and alloparental care, describing the behaviors and interactions between the falcons and kestrels. They suggest that the adoption may have been initiated by the female falcons, potentially due to the loss of their own offspring and the presence of kestrel nestlings in their territories. The authors acknowledge the scarcity of detailed descriptions of such cases and highlight the value of these observations for understanding interspecific alloparental care in raptors. [Extracted from the article]

The article explores the principle of reciprocity, which is the act of individuals helping others with the expectation of receiving help in return. The author discusses how reciprocity is observed in various species, including bacteria, insects, birds, and humans. The article also examines the cognitive abilities required for reciprocity and compares its presence in different animal species, including primates. The author acknowledges that there are still many unanswered questions about reciprocity and calls for further research in this area. The article emphasizes the interdisciplinary nature of studying reciprocity and highlights the importance of collaboration between different academic fields. [Extracted from the article]

Small mammals are often key components in ecological monitoring programs, and live trapping is often used to obtain small mammal density estimates or other metrics. However, an aspect of such trapping that has received little attention is opportunistic predation of captured animals. Here, we report a Common Raven (Corvus corax) preying on a deermouse (Peromyscus spp.) after it was released from a live trap. The mouse was torpid when removed from the trap. The raven preyed on the deermouse right after it was released, likely because the mouse had not yet fully aroused from torpor and was not able to find adequate shelter or evade the raven. Best practices to avoid similar occurrences include passively warming the animal before releasing it or returning it to the trap to arouse from torpor in safety. Our observation further highlights the need for researchers to be vigilant about opportunistic predation of small mammals captured and released from live traps and to take actions to mitigate the risk, especially if the mammals are exhibiting signs of torpor. [ABSTRACT FROM AUTHOR]

The wild boar (Sus scrofa) is a social animal species native to Eurasia. During the last decade, the wild boar population in Estonia has been severely affected by the African swine fever virus (ASFV), which has also affected domestic pig farming. The potential transmission routes of ASFV remain unclear and are currently under intensive investigation. This pilot study aimed to clarify the frequency and characteristics of contacts between living wild boars and the carcasses of their conspecifics, which could play a role in the transmission of ASFV. Wild animals' contact and scavenging behavior on wild boar carcasses were studied using trail cameras in an experimental setting on Hiiumaa, Western Estonia. Four legally hunted carcasses were used in the present study. This study aimed to determine whether intraspecies scavenging occurs in wild boars. The persistence of ASFV DNA in soil contaminated with infected wild boar carcasses was investigated separately. Among the 17 identified wildlife species that visited wild boar carcasses, the common raven (Corvus corax) was the most frequent one (37.26%), followed by raccoon dogs (Nyctereutes procyonoides; 4.25%), carcass conspecific/wild boars (3.16%), and red foxes (Vulpes vulpes; 2.14%). Regarding the direct contact with the carcass, the same species ranking was detected: common raven (74.95%), raccoon dogs (9.94%), wild boars (4.21%), and red foxes (4.21%). No clear signs of cannibalism were noted among the wild boars, although brief physical contact with the carcasses was evident. The persistence of ASFV DNA in soil contaminated by infected wild boar carcasses was investigated separately. This study revealed that ASFV DNA from infected carcasses could be detected in forest soil for prolonged periods, even after removing the carcasses. Hence, the carcasses of infected wild boarsmay play an important role in spreading the African swine fever virus in wild boar populations; thus, prompt removal and disinfection of the soil could be considered necessary to limit the spread of the infection. [ABSTRACT FROM AUTHOR]

Ravens and other corvids are renowned for their 'intelligence'. For long, this reputation has been based primarily on anecdotes but in the last decades experimental evidence for impressive cognitive skills has accumulated within and across species. While we begin to understand the building blocks of corvid cognition, the question remains why these birds have evolved such skills. Focusing on Northern Ravens Corvus corax, I here try to tackle this question by relating current hypotheses on brain evolution to recent empirical data on challenges faced in the birds' daily life. Results show that foraging ravens meet several assumptions for applying social intelligence: (1) they meet repeatedly at foraging sites, albeit individuals have different site preferences and vary in grouping dynamics; (1) foraging groups are structured by dominance rank hierarchies and social bonds; (3) individual ravens memorize former group members and their relationship valence over years, deduce third-party relationships and use their social knowledge in daily life by supporting others in conflicts and intervening in others' affiliations. Hence, ravens' socio-cognitive skills may be strongly shaped by the 'complex' social environment experienced as non-breeders. [ABSTRACT FROM AUTHOR]