Hooded Crows (Corvus cornix) May Be Aware of Their Own Body Size

Body-awareness is one of the manifestations of self-awareness, expressed in the ability of people and animals to represent their own body physical properties. Relatively little work has been devoted to this phenomenon in comparison with the studies of the ability of self-recognition in the mirror, and most studies have been conducted on mammals and human infants. Crows are known to be “clever” birds, so we investigated whether hooded crows (Corvus cornix) may be aware of their own body size. We set up an experimental design in which the crows had to pass through one of three openings to reach the bait. In the first experiment, we studied whether crows prefer a larger hole if all the three are suitable for passage, and what other predictors influence their choice. In the second experiment, we assessed the ability of the crows to select a single passable hole out of three on the first attempt, even though the area of the former was smaller than that of the other two. The results of the first experiment suggest that when choosing among three passable holes, crows prefer those holes that require less effort from them, e.g., they do not need to crouch or make other additional movements. In the second experiment, three of the five crows reliably more often chose a single passable hole on the first try, despite its smaller size. We believe that these results suggest that hooded crows may be aware of their own body size.

Internal organs and pathologies in birds in the urban environment

Врановые птицы являются наиболее многочисленными в орнитофауне городов Ивановской области. В связи с этим возрос интерес к изучению эколого-физиологических особенностей врановых птиц. Данная работа просвещена изучению относительной массы внутренних органов и заболеваний у врановых. Анализ данных показал, что наибольшая относительная масса сердца была у ворона; печени - у сойки и галки; желудка - у сойки и серой вороны; кишечника - у серой вороны и сороки; легких - у ворона; почек - у галки и серой вороны; селезенки - у серой вороны; поджелудочной железы - у ворона. Наиболее часто встречаются травмы: ампутация фаланг пальцев, колотые и рваные раны, переломы трубчатых костей ног и крыльев, гемартрозы, трещины грудной кости. Вороны часто страдают пододерматитом и панкреатитом, серые вороны - спленитом, сороки и галки - ожирением, галки и сойки - гепатозом, серые вороны - гистомонозом печени. Corvids are the most numerous birds in the avifauna of the cities of the Ivanovo Region. In this regard, interest in the study of the ecological and physiological characteristics of corvids has increased. This work is enlightened by the study of the relative mass of internal organs and diseases in corvids. Analysis of the data showed that the raven had the highest relative heart mass; jays and jackdaws have the highest relative liver mass; while the highest relative mass of stomach is recorded in jays and hooded crows. The highest relative mass of the intestines is shown in hooded crows and magpies; heaviest lungs are reported for ravens. Kidneys are heaviest at jackdaws and hooded crows; spleen has the highest relative mass in hooded crows; pancreas is heaviest in crows. The most common injuries are loss of the phalanges of toes, stab and laceration wounds, and fractures of the tubular bones of the legs and wings, hemarthrosis, cracks in the chest bone. Ravens often suffer from pododermatitis and pancreatitis, hooded crows suffer from splenitis, magpies and jackdaws shows signs of obesity, jackdaws, and jays often demonstrate hepatosis, while hooded crows are susceptible to liver histomonosis.

Emergence of reflexivity relation without identity matching-to-sample training in hooded crows (Corvus cornix)

The ability to form equivalent relations between sign and referent—symbolization—is one of the important cognitive components of language. Equivalent relations have the properties of symmetry (if A→B then B→A), reflexivity (A→A, B→B), and transitivity (if A→B and B→C, then A→C). The current study evaluates whether reflexivity can be spontaneously revealed in hooded crows (Corvus cornix) without training after the formation of the symmetry relation. These birds were previously taught an arbitrary matching-to-sample task with the letters “S” and “V” as samples, and sets of images (same-sized and different-sized figures) as comparisons. Positive results in the transfer tests showed that the crows associated letters with the concepts of sameness/difference. After that, they successfully passed the symmetry test, in which samples and comparisons were switched around. In the present experiment we found out that the crows passed the reflexivity test (A→A, B→B) without identity training. We hypothesize that if the subject associates the sample not with certain stimuli but rather with concepts, it facilitates the formation of equivalence relations between them.

Epidemiologic Survey on Toxoplasma gondii and Trichinella pseudospiralis Infection in Corvids from Central Italy

Free-ranging corvids—678 magpies (Pica pica) and 120 hooded crows (Corvus cornix) from nine protected areas of the Pisa province (central Italy)—were examined for Toxoplasma gondii and Trichinella pseudospiralis. The intracardiac blood clots from 651 magpies and 120 hooded crows were serologically examined for T. gondii. The DNA extracted from the hearts of seropositive birds was then used to perform a nested PCR for the amplification of the T. gondii B1 gene and for genotyping for SAG genetic markers. Breast muscle samples from 678 magpies and 91 hooded crows were tested by an artificial digestion method for Trichinella. Data were statistically analyzed. Forty-five (5.8%—41 magpies and four hooded crows) out of the 771 examined animals scored seropositive for T. gondii, with titers ranging from 1:25 to 1:100. T. gondii DNA was detected in 15 of the 45 positive birds and T. gondii genotypes II and III were identified. No positivity for T. pseudospiralis was found. No significant differences between the two species of corvids and among the different areas of origin were observed for seropositivity to T. gondii. This is the first extensive study on both T. gondii and T. pseudospiralis in magpies and hooded crows, as well as the first detection of T. gondii SAG genotypes in magpies.

A Sabbatical Year Abroad—Egypt and Greece

This chapter examines Anna Botsford and John Henry Comstock's sabbatical year abroad in Egypt and Greece. On January 1, 1908, the Comstocks boarded the Italian steamer “Perseo,” bounded for Alexandria. Arriving early on January 5 in the city of Euclid and Cleopatra, the Comstocks then visited the Egyptian Quarter—a narrow, crooked street through houses that date back to Cleopatra's time. From Alexandria, they traveled to Cairo, where they wandered through the Ezbekieh Gardens and admired the palm trees and studied the hooded crows. They also took a train to Old Cairo and visited the pyramids. However, one of their most interesting experiences in Cairo was a visit to the University which is held in the Mosque of Gamai el-Azhar. Later, it was on the S.S. Osmaniah that the Comstocks took passage from Alexandria to Greece. They then went to the Acropolis and the Parthenon in Athens.

The effects of frequency-dependent sexual selection, mating-trait architecture and matching rule on hybrid zone dynamics in crows

Hybrid zones provide a window into the evolutionary processes governing species divergence. While the role of postzygotic isolation has been extensively characterized in the context of hybrid zones, the contribution of prezygotic isolation is less well explored. In particular, the effect of assortative mate choice, the underlying preference function, the architecture of the mating trait and the strength of sexual selection are worthy of investigation. Here, we explore this question by means of a mathematical model parameterized with empirical data from the hybrid zone between all-black carrion and grey-coated hooded crows. The best-fit model resulted in narrow clines for two mating-trait loci coding for colour phenotype maintained by a moderate degree of assortative mating. Epistasis between the two loci induced hybrid-zone movement in favor of alleles conveying dark plumage followed by a shift in the opposite direction favouring grey-coated phenotypes ∼1,200 generations after secondary contact. Unlinked neutral loci diffused near-unimpeded across the zone. This study demonstrates that sexual selection created by assortative mating can explain steep transitions in mating-trait loci without generalizing to genome-wide reproductive isolation. It further emphasizes the importance of mating-trait architecture for spatio–temporal hybrid-zone dynamics.

Increasing corvid tolerance to humans in urban ecosystems with increasing latitude

The rapid growth of cities causes behaviour changes in birds in response to urban environmental factors. The avian response to human disturbance has recently been studied by a non-invasive research tool as an alert distance (AD) and a flight initiation distance (FID) assessment. The tolerance of hooded crows (n = 395), jackdaws (n = 394) and rooks (n = 169) to humans was assessed by AD and FID. It was shown that the FID of all species is maximal during the summer, when the parents send clear “danger—fly away” signals to the young and the birds fly away. The AD and FID of the three species reliably correlates with the season. Rooks showed FID species-specificity in seven cities of Eastern Europe. Comparison of the attitude of birds to people in cities that have similarities in human culture showed that tolerance increases with increasing latitude in all species and is statistically significant only in the jackdaw. This should be taken into account in environmental protection measures.