Columba Livia Research Articles

Cryptococcal Meningitis and Spatial Distribution of Pigeons (Columba livia) in Colombia (P4-8.004)

<h3>Objective:</h3> To analyze the biogeographical distribution of <i>Columba livia</i> (Cl) in Colombia and its association with the density of meningeal cryptococcosis and HIV cases. <h3>Background:</h3> Cryptococcus spp. is widely distributed and the main cause of meningitis in HIV patients from low-income countries. Colombia exhibits a high prevalence of antigenemia and an above average incidence, while the most common (&gt;80%) clinical presentation of cryptococcosis in the country is meningitis. Exposure to pigeons feces has been stated as one of the risk factors and small studies from Colombia have found the fungus in 25% of these samples; nonetheless, it is still unknown if the geographical distribution of common pigeons (Cl) correlates with that of HIV and meningeal cryptococcosis. <h3>Design/Methods:</h3> Occurrences of Cl were extracted from the Global Biodiversity Information Facility and then mapped by municipalities. Information regarding HIV prevalence and mortality were provided by the Ministry of Health and cryptococcal meningitis prevalence was inferred from the passive laboratory-based surveillance system. Densities were calculated per 100 Km². Spearman correlation coefficients and robust linear regression were implemented. <h3>Results:</h3> In Colombia, 32226 occurrences of pigeons have been reported in 698 municipalities (55.25% of the country’s area). Median density of occurrence was 1.66 per 100 Km². Regarding the geographical distribution of HIV cases and fatalities, most were found in the highly populated departments. There was a moderate correlation of Cl occurrence distribution with HIV density by municipality (ρ=0.443, p=0.000) and cryptococcus cases at the departmental level (ρ=0.699, p=0.000). Significant association with occurrence persisted after adjusting by population density (β=0.603 CI 95% 0.258–0.949, p=0.001). <h3>Conclusions:</h3> There is evidence of geographical correlation between pigeons occurrence and density of cryptococcal meningitis. Further studies should address the impact of environmental variables on the fungus niche. <b>Disclosure:</b> Dr. Pinilla Monsalve has nothing to disclose. Miss Forero has nothing to disclose.

Chlamydia psittaci in garden birds in Sweden

Increased numbers of human infections with Chlamydia psittaci have been associated with bird feeding activities in southern Sweden. Information on occurrence and genotype of C. psittaci in garden birds in Sweden is required to corroborate this finding but data are limited. Additionally, pathogenicity of C. psittaci for garden birds is poorly understood. In this study, C. psittaci infection was investigated in 275 garden birds representing 22 species submitted for wildlife disease surveillance between 2009 and 2019. PCR was used to detect C. psittaci DNA in liver and lung. Positive samples were genotyped, additional PCR was performed on feces, and tissues were examined microscopically. C. psittaci was found in six (2.2 %) birds; three great tits (Parus major), two feral (Columba livia) and one wood pigeon (Columba palumbus). Two great tits and the wood pigeon had inflammatory lesions associated with C. psittaci. In the great tits and wood pigeon, C. psittaci genotype A, the cause of most human cases, was detected. Genotype B, considered endemic in pigeons, was detected in the feral pigeons. Low incidence of C. psittaci in dead Swedish garden birds was similar to studies on apparently healthy Swedish birds. Pathological findings were consistent with C. psittaci being fatal in half of the positive birds, which also had higher bacterial loads in feces. This highlights the risk for human infection via infected garden birds, especially regarding great tits and pigeons.

Supplementation of exogenous bile acids improve antitrichomonal activity and enhance intestinal health in pigeon (Columba livia)

The study investigated the effects of supplementation of bile acids in drinking water on antitrichomonal activity, growth performance, immunity and microbial composition of pigeon. A total of 180 pairs of White King parent pigeons were randomly assigned to 5 treatments of 6 replications with 6 pairs of parent pigeons and 12 squabs in each replicate. The control (CON) group drank water without any additions. The metronidazole (MTZ) group drank water with 500 μg/mL metronidazole for 7 d and without any additions in other days. The else groups drank water with 500, 750, and 1,250 μg/mL bile acid (BAL, BAM, BAH) for 28 d. The results showed that Trichomonas gallinae (T. gallinae) in MTZ, BAL, BAM, and BAH groups were lower than that in CON group at 14, 21, and 28 d of parent pigeons (P < 0.05) and at 21 and 28 d of squabs (P < 0.05). Albumin and alanine transaminase in CON group were higher than those in MTZ, BAL, and BAH groups (P < 0.05). The levels of soluble CD8 were higher in MTZ and BAH groups compared with CON group (P < 0.05). The lesions in oral mucosa, thymus, liver, and spleen tissues of CON group could be observed. Abundance-based coverage estimator (ACE) index in BAH group was higher than that in CON and MTZ groups. Simpson index in CON and BAH groups was higher than MTZ group (P < 0.05). Lactobacillus was the highest colonized colonic bacteria in genera that were 77.21, 91.20, and 73.19% in CON, MTZ, and BAH, respectively. In conclusion, drinking water supplemented with 500, 750, and 1,250 μg/mL bile acid could inhibit growth of T. gallinae in both parent pigeons and squabs. Squabs infected with T. gallinae in control group had higher mortality rate and more serious tissue lesions. Squabs in bile acids treated group had more sCD8 in serum and abundant intestinal morphology. Bile acids could be an efficient drinking supplements to inhibit T. gallinae and improve pigeon adaptive immunity and intestinal health.

Rapid assessment of the extent of feral introgression in British and Irish Rock Dove (Columba livia) populations

Interbreeding of related forms following anthropogenic activity can lead to genomic homogenization, contributing to decreasing biodiversity. Assessing spatiotemporal variation in the extent of introgression is important for conservation but can be expensive and logistically complex. The Rock DoveColumba liviais threatened by interbreeding with its feral conspecific and it is difficult to identify wild birds when wild, feral and mixed populations exist. Here, using British and Irish populations, I assess whether the proportion of birds with wild type plumage corresponds to distinctive head morphotypes differing between Rock Doves and feral pigeons, and whether plumage can be used to identify Rock Dove flocks and infer the extent of hybridization. I also determine whether plumage proportions have changed since a prior study was carried out in the 1960s. I show that flocks in which &gt; 75% of individuals have wild type plumage consist of Rock Doves, as determined by head morphotype. Plumage proportions vary geographically, corroborating known genomic assessments of Scottish and Irish Rock Doves. Finally, the number of birds with aberrant plumages has increased since the 1960s, even in regions where no such birds were identified previously. This highlights the value of the Rock Dove as a current case study with which to explore the process of extinction by hybridization.

QUANTIFICATION OF HEAVY METAL RESIDUES IN FECAL MATTER OF BLUE ROCK PIGEON (COLUMBA LIVIA) IN PUNJAB

The present study was done to assess the heavy metal contamination in the excreta of Blue Rock Pigeon from rural areas of Punjab. This study was conceded out in three locations: Location I: Agronomy Farm, Punjab Agricultural University, Ludhiana, Location II: Cold Storage, Jalandhar Bypass and Location III: Cold Storage, Mullanpur. The results revealed that the levels of Arsenic (As), Chromium (Cr) and Cadmium (Cd) were greater than normal levels in excreta of pigeon from all the three locations and for Lead (Pb) it was above the toxic level at Location II and III. Lead (Pb) levels were observed to be more than thetoxic range from both the locations. Concentrations of heavy metals were higher in locations II and III because these locations are close to road and have more industrial units than location I. Therefore, pigeons excreta can be used as bioindicator for heavy metal levels.

Proximity to anthropogenic food sources determine roosting and nesting prevalence of feral pigeons (Columba livia) in a tropical city

AbstractThe feral pigeon (Columba livia) is a globally commensal bird that can cause dis‐amenities such as soiling and is a potential vector of various diseases. Aside to limiting food as a management strategy, reducing the availability of roosting and nesting sites can help regulate feral pigeon populations. Despite their prevalence, current knowledge of their roosting and nesting preferences is lacking.Feral pigeons commonly use railway viaduct expansion gaps in Singapore for roosting and nesting. These gaps provided an ideal experimental platform to examine feral pigeon roost and nest site selection while controlling for differing cavity sizes which can significantly affect their reproductive success and site selection decisions. We also conducted an in‐situ experiment to test the efficacy of nest removal as a management option.Our nationwide surveys of 80.3 km of railway viaducts and 6048 gaps revealed that feral pigeon day roosting and nesting preferences are influenced by structural height and more importantly, their proximity to human food sources. There was a significantly higher probability of feral pigeon roosting in a gap if it had more pigeon feeding incidences in its vicinity and was higher. The probability of feral pigeon nesting in gap was higher if it was closer to a railway station, lower and further from water bodies.In our field experiment, we did not find any significant differences in the proportions of the abundances of feral pigeon to other urban commensal bird species at the gaps before and after nests were removed.Overall, our results suggest that a concerted effort to reduce anthropogenic food availability to feral pigeons is central in limiting their reproductive success and controlling their population.

Fatal Sarcocystis calchasi hepatitis in a captive Indian ringneck parakeet (Psittacula krameri manillensis)

An adult Indian ringneck parakeet (Psittacula krameri manillensis) from an outdoor aviary in Sacramento, California was found dead on the nest box. Postmortem examination showed firm, enlarged, yellow‑tinged liver and splenomegaly. Multifocal to coalescing, acute necrosis with macrophages, lymphocytes, plasma cells, and periportal ductular reaction were seen on liver histology with extra- and intracellular schizonts and merozoites. A few schizonts and lymphohistiocytic inflammation were seen in the spleen. Toxoplasma gondii, Sarcocystis neurona, S. falcatula and Neospora caninum were ruled out by immunohistochemistry. PCR of the liver for Sarcocystis spp. Based on the positive amplification/PCR of ITS1 segment and sequencing of 28S rRNA fragment, S. calchasi was confirmed. The splanchnic presentation of S. calchasi in this parakeet resembles the acute infection described experimentally in domestic pigeons (Columba livia f. domestica) and cockatiels (Nymphicus hollandicus). Since large populations of red-tailed hawks (Buteo jamaicensis) and Cooper's hawk (Accipiter cooperi), the likely definitive hosts of S. calchasi in North America, inhabit the Sacramento area, their presence near outdoor aviaries may account for the source of S. calchasi infective sporocysts.

Diversity and Abundance of Breeding Birds, Habitat, and Nesting Substrate Selection in Urban Areas: A Relevant Case from the Southern Slope of the Mediterranean

Urban areas may affect the richness of avian species. The abundance and diversity of urban landscapes offer breeding habitats and nesting resources for urban-adapted species. In our study, we investigated the breeding birds in urban landscapes of Fez’s historical city (Morocco). We used line-transects to search for nests of breeding species, populations, and habitats counting breeding sites and predicting factors (foraging, nesting resources, and urbanization). Furthermore, four habitats counting green gardens, old city walls, urban farms, and urban forests were prospected to search for nests of breeding birds. Among 13 breeding species including 12 resident-breeders, and one breeding migrant, a total of 109 nests were documented. Five species counting Turdus merula, Sylvia atricapilla, Spilopelia senegalensis, Columba livia, and Coloeus monedula were encountered in green gardens; four species counting Athene noctua, Sturnus unicolor, Passer domesticus, and Tachymarptis melba were observed in old city walls. Falco tinnunculus, Fringilla coelebs, and Accipiter nisus occurred in urban forests; and Streptopelia decaocto in urban farms. The recorded nests were divided between cavities (50 nests) and trees (59 nests). In green spaces, nests were distributed among Olea europaea (17), Citrus aurantium (15), Bambusa vulgaris (11), and Eucalyptus globulus (7). In contrast, Olea oleaster and Cupressus sp. hosted only tree nests each, while Populus sp. and Washingtonia filifera hosted only one nest each. Most nests were recorded in habitats rich in nesting trees and close to water sources. On the contrary, the number of nests decreased as the surface and distance of the habitat to the urban center increased. Our data revealed the diversity, habitat use, and nesting substrates of urban breeding bird communities in Morocco and the Southern slope of the Western Palearctic. Future urban plans must integrate measures to provide suitable breeding resources such as cavities of old walls and a high diversity of urban green spaces for birds to enhance their breeding performances, thus promoting the well-being of the population via increasing biodiversity.

Using blood lead concentrations of wildlife sentinels to identify environmental risk factors of lead exposure for public health and wildlife rehabilitation efforts.

Lead poisoning remains a persistent health issue for both humans and wildlife, despite strides to reduce lead contamination in the environment. Using Geographic Information Systems (GIS), this study explores the associations between blood lead levels (BLLs) in wildlife sentinels and possible built environment lead exposure risk factors in the Minneapolis-Saint Paul, Minnesota urban area. Results show a high-level of heterogeneity in animal BLLs (n = 472) across our urban environment and suggest that each kilometer increase in road density is associated with a 17.07% (95% CI: 1.48%, 35.05%) increase in BLL in our study species of Virginia opossums and Eastern gray squirrels, and a 14.28% (95% CI: 1.16%, 29.09%) increase in BLL of rock pigeons. For squirrels and opossums, we see an additional 5.72% (95% CI: 0.59%, 10.85%) increased risk of BLL for every 1000 people per square-mile. The relationship between animal sentinels and environmental hazards can give us an insight into the potential lead exposure risks for humans. The use of wildlife sentinel data to explore environmental risk factors supports a One Health approach to better address public health questions and aid in wildlife rehabilitation related to residual lead poisoning from ambient environmental exposures.

Lesions and viral loads in racing pigeons naturally coinfected with pigeon circovirus and columbid alphaherpesvirus 1 in Australia.

Columbid alphaherpesvirus 1 (CoHV1) is associated with oral or upper respiratory tract lesions, encephalitis, and occasional fatal systemic disease in naive or immunosuppressed pigeons. Clinical disease is often reported with CoHV1 and coinfecting viruses, including pigeon circovirus (PiCV), which may cause host immunosuppression and augment lesion development. A natural outbreak of CoHV1 and PiCV coinfection occurred in a flock of 60 racing rock pigeons (Columba livia), in which 4 pigeons succumbed within 7 d of clinical onset. Lesions included suppurative stomatitis, pharyngitis, cloacitis, meningitis, and tympanitis, with eosinophilic intranuclear inclusion bodies consistent with herpesviral infection. In addition, large numbers of botryoid intracytoplasmic inclusion bodies were present in the skin, oral mucosa, and bursa of Fabricius, suggestive of circoviral infection, which was confirmed by immunohistochemistry. The concurrent viral load of CoHV1 and PiCV was high in liver, oropharynx, and bursa of Fabricius. We found PiCV in oro-cloacal swabs from 44 of 46 additional birds of variable clinical status, PiCV alone in 23 birds, and coinfection with CoHV1 in 21 birds. Viral copy numbers were significantly higher (p < 0.0001) for both viruses in clinically affected pigeons than in subclinical qPCR-positive birds. The CoHV1-induced lesions might have been exacerbated by concomitant PiCV infection.

Incidence and molecular characterization of extended-spectrum beta-lactamase (ESBL)-producing Salmonella enterica and Escherichia coli of avifauna origin in Pakistan.

Members of Enterobacteriaceae are known to produce extended-spectrum beta-lactamases (ESBL) which hydrolyze the beta-lactam group of antibiotics. The existence of ESBL-producing Salmonella enterica (S. enterica) and Escherichia coli (E. coli) harbored by urban avifauna was investigated in this study. Dropping samples (n= 180) were collected from six different bird species in the district Jhang, Punjab province, Pakistan. Isolation and identification of ESBL isolates were made by using cefotaxime- (4 mg/L) supplemented MacConkey agar and double disc synergy test (DDST). Polymerase chain reaction (PCR) was performed for the detection of four different ESBL genes including blaCTX-M, blaTEM, blaSHV and blaOXA. A total of 42.69% isolates were confirmed as ESBL via DDST including 30.64% S. enterica and 49.54% E. coli. The incidence of ESBL S. enterica and ESBL E. coli was found highest in egret (Ardea alba) and pigeon (Columba livia) as 64.28% and 78.95%, respectively. The blaCTX-M gene was detected in 57.89% and 64.81% of isolates of S. enterica and E. coli, respectively. Among other genes in S. enterica and E. coli, blaTEM (21.05%, 20.4%); blaSHV (15.78%, 9.26%), and blaOXA (5.26%, 5.56%) were detected, respectively. All of the tested isolates were found resistant to at least one of the thirteen antimicrobial agents except meropenem. To the best of our knowledge, this is the first study reporting the incidence and genetic diversity of ESBL bacteria associated with urban avifauna in Pakistan. The urban avifauna can serve as a potential subject of bio-surveillance to monitor the emergence of antimicrobial-resistant bacteria.

Preparing and Presenting a Pigeon Skeleton for Gross Anatomical Study Using Boiling Maceration Method: A Quick and Effective Method

The study’s main objective was to prepare and display the pigeon skeleton using a practical and effective approach. Two matured domestic pigeons (Columba livia), aged 8 months old were purchased from local market, Gazipur sadar, Bangladesh for this purpose. This experiment was carried out in the department of Anatomy and Histology, Faculty of Veterinary Medicine and Animal Science in Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh, in January 2021. The birds were first killed by being injected with MgSO4 directly into the hearts. After dead, they were peeled using a knife. 3% soda water solution was used to boil peeled animals for two hours. Having cooling, the bony samples were cleaned and dipped into 10% solution of bleaching water for 1 hour to avoid further growth of microorganism following washed by tap water. After drying in the sun for eight hours, the skeletal pieces were fully articulated for the skeletal frame. The whole processes were taken 2 days (33 hours). The boiling maceration method for preparation of skeleton is very effective because restrain the chance of losing small bones, requires less expenditure, time and labor. It is also visible that the bone’s original color was preserved. Extracted bones were divided into two parts, axial and appendicular skeleton. Axial skeleton comprises the bones of skull, vertebrae such as-cervical, thoracic, lumbar and sacral vertebrae (fused to form synsacrum) and coccygeal vertebrae or caudal vertebrae then ribs, costal cartilages and breast bone or keel bone. In contrast, the appendicular skeleton comprises the forelimb or wing bone like scapula, coracoid, clavicle, humerus, radius-ulna and manus. On the otherhand hindlimb or pelvic limb comprises of pelvic girdle, femur, tibio-fibula and feet bone (metatarsal and digits). In adult pigeon no developed tarsal bone. Therefore, this is the most efficient way for quickly preparing and presenting skeleton for use in studies of the avian skeletal system.

Metabolomics analysis of the effects of different litter size on reproductive metabolism and oxidative stress in breeding pigeon (Columba livia)

The pigeon breeding industry employs a high-rearing pattern to achieve economic benefits. However, too many squabs consume more energy of the breeding pigeons causing adverse effects on their breeding performance. To determine the optimal rearing patterns and the effects of different numbers of squabs on reproductive performance, oxidative stress, and glucolipid metabolism of lactating breeding pigeons in winter, three rearing patterns consisting of “2 + 2″, “2 + 3″ and “2 + 4" (a pair of breeding pigeons feeding two, three and four squabs, respectively) were adopted using European Mimas white pigeons breed. The feed intake, bodyweight loss, feed-to-meat ratio, and squab mortality were linearly increased with the number of squabs during lactation, while the bodyweight recovery rate and squab growth performance were significantly slowed down after lactation. Similarly, the laying rate was linearly decreased on days 16, 17, and 18 of lactation, with a similar pattern on the re-laying rate on days 11, 12, and 13 after first laying. In addition, the number of non-laying pigeons in the second batch was significantly increased, implying that the number of squabs significantly affected the reproductive performance of female pigeons. The eggshell weight and thickness in the “2 + 3″ group were significantly increased. However, the number of squabs in the “2 + 3″ group had no significant effect on plasma calcium (Ca) and phosphorus (P) levels. Analysis of the glucolipid metabolism index and oxidative stress level of pigeons further revealed that the contents of triglyceride (TG), total cholesterol (T-CHO), and low-density lipoprotein cholesterol (LDL-C) in the plasma of male pigeons were significantly decreased with the increase in the number of squabs, but there was no obvious oxidative stress. On the contrary, glucose (GLU), TG, malondialdehyde (MDA) in the plasma of female pigeons were significantly increased, total antioxidant capacity (T-AOC) were significantly decreased, implying that the female pigeons suffered more oxidative stress and more dramatic changes in glucolipid metabolism. Metabolomics revealed that the differential metabolites in the plasma of female pigeons in “2 + 2″, “2 + 3″, and “2 + 4″ groups were significantly enriched in the fatty acid, phospholipid, sphingolipid metabolism, and the Krebs cycle pathways, especially under “2 + 4″ rearing pattern. Overall, in female pigeons, the available lipids were reduced; hence, their body turned to sugar dysplasia and protein utilization mode, increasing the oxidative stress level and decreasing their reproductive performance. Therefore, an increased number of squabs significantly affects the body condition and reproductive performance of breeding pigeons. The “2 + 3″ rearing pattern is the most suitable for winter breeding pigeon production under the current nutrition level.

Early conversion of maternal androgens affects the embryo already in the first week of development.

Maternal androgen exposure has potent effects on offspring development. As substantial levels of maternal androgens are deposited in avian egg yolks, avian eggs are frequently used to study maternal effects, with a strong focus on post-natal development. However, the underlying pathways are largely unknown. Since the hormones are taken up during the embryonic phase, and these are rapidly metabolized by avian embryos into metabolites such as etiocholanolone, we studied the effects of yolk androgens (testosterone and androstenedione) and their metabolite etiocholanolone during the first few days of embryonic development. As embryonic heart rate is often used as an indicator of embryonic development, we measured the heart rate from day 3 to day 6 of incubation by using a shell-less culture technique in rock pigeon eggs (Columba livia). Increased androgen exposure increased heart rate, and increased etiocholanolone mimicked this effect, albeit in a small sample size. This indicates that exposure to maternal androgens increases embryonic overall metabolism which may account for the developmental outcomes found in previous studies such as increased growth. Moreover, etiocholanolone is likely to be an important metabolite in a non-genomic pathway underlying the androgen-mediated maternal effect.

SEASONAL DYNAMICS OF THE DIET OF IMPERIAL EAGLES (&lt;i&gt;AQUILA HELIACA&lt;/i&gt;, ACCIPITRIDAE, ACCIPITRIFORMES) IN THE LEFT-BANK MIDDLE VOLGA REGION

The seasonal and between-year dynamics in the diet of a pair of Imperial eagles (Aquila heliaca) were observed at a nesting site on the left bank of Volga River in the Ulyanovsk Region, European Russia. The research covered three seasons (2019–2021) using an autonomous video surveillance system. During the research period, 555 prey objects brought by eagles to the nest were identified, these representing 30 taxa of wild vertebrates and four species of domestic animals, all from four vertebrate classes. The predominant prey objects were the Russet ground squirrel (Spermophilus major) (35%), the Rock pigeon (Columba livia) (22%), and the Common hamster (Cricetus cricetus) (14%). Rodents prevailed in nutrition during nest construction (April), hatching (May), and at the initial stages of feeding the chick(s) (June–July). The proportion of pigeons and corvines increased significantly in nutrition during the feeding period of grown-up chicks and fledglings (August–September). Raising two chicks compared to one chick led to an average of 1.5 times increase in food intake, mainly due to rodents.

Osmotic pump maintains plasma concentrations of meloxicam for 6 days after orthopedic surgery in pigeons (Columba livia).

To determine the plasma concentration of meloxicam delivered via an osmotic pump in pigeons undergoing orthopedic surgery and if an osmotic pump is a suitable alternative to repeated oral administration of this drug. 16 free-ranging pigeons presented for rehabilitation with a wing fracture. An osmotic pump filled with 0.2 mL of 40 mg/mL meloxicam injectable solution was implanted subcutaneously in the inguinal fold of 9 pigeons under anesthesia for orthopedic surgery. The pumps were removed 7 days postsurgery. Blood samples were collected before pump implantation (time 0) and 3, 24, 72, and 168 hours after pump implantation in 2 pigeons in a pilot study then at 12, 24, 72, and 144 hours in the 7 pigeons of the main study. The blood of 7 other pigeons receiving meloxicam at 2 mg/kg, PO, every 12 hours was also sampled between 2 to 6 hours after the last meloxicam administration. Plasma meloxicam concentrations were measured via high-performance liquid chromatography. The plasma concentration of meloxicam was maintained at significant levels from 12 hours to 6 days after osmotic pump implantation. Median and minimum plasma concentrations in implanted pigeons were maintained at the same or higher level than those measured in pigeons that received meloxicam at a dose known to be analgesic in this species. No adverse effects attributable to either osmotic pump implantation and removal or meloxicam delivery were observed in this study. Plasma concentrations levels of meloxicam in pigeons implanted with osmotic pumps were maintained at a similar concentration or higher than the suggested analgesic meloxicam plasma concentration in this species. Thus, osmotic pumps could represent a suitable alternative to the frequent capture and handling of birds for analgesic drug administration.

Dynamics of collective motion across time and species.

Most studies of collective animal behaviour rely on short-term observations, and comparisons of collective behaviour across different species and contexts are rare. We therefore have a limited understanding of intra- and interspecific variation in collective behaviour over time, which is crucial if we are to understand the ecological and evolutionary processes that shape collective behaviour. Here, we study the collective motion of four species: shoals of stickleback fish (Gasterosteus aculeatus), flocks of homing pigeons (Columba livia), a herd of goats (Capra aegagrus hircus) and a troop of chacma baboons (Papio ursinus). First, we describe how local patterns (inter-neighbour distances and positions), and group patterns (group shape, speed and polarization) during collective motion differ across each system. Based on these, we place data from each species within a 'swarm space', affording comparisons and generating predictions about the collective motion across species and contexts. We encourage researchers to add their own data to update the 'swarm space' for future comparative work. Second, we investigate intraspecific variation in collective motion over time and provide guidance for researchers on when observations made over different time scales can result in confident inferences regarding species collective motion. This article is part of a discussion meeting issue 'Collective behaviour through time'.

Neuronal circuits within the homing pigeon hippocampal formation.

The current study aimed to reveal in detail patterns of intrahippocampal connectivity in homing pigeons (Columba livia). In light of recent physiological evidence suggesting differences between dorsomedial and ventrolateral hippocampal regions and a hitherto unknown laminar organization along the transverse axis, we also aimed to gain a higher-resolution understanding of the proposed pathway segregation. Both in vivo and high-resolution in vitro tracing techniques were employed and revealed a complex connectivity pattern along the subdivisions of the avian hippocampus. We uncovered connectivity pathways along the transverse axis that started in the dorsolateral hippocampus and continued to the dorsomedial subdivision, from where information was relayed to the triangular region either directly or indirectly via the V-shaped layers. The often-reciprocal connectivity along these subdivisions displayed an intriguing topographical arrangement such that two parallel pathways could be discerned along the ventrolateral (deep) and dorsomedial (superficial) aspects of the avian hippocampus. The segregation along the transverse axis was further supported by expression patterns of the glial fibrillary acidic protein and calbindin. Moreover, we found strong expression of Ca2+ /calmodulin-dependent kinase IIα and doublecortin in the lateral but not medial V-shape layer, indicating a difference between the two V-shaped layers. Overall, our findings provide an unprecedented, detailed description of avian intrahippocampal pathway connectivity, and confirm the recently proposed segregation of the avian hippocampus along the transverse axis. We also provide further support for the hypothesized homology of the lateral V-shape layer and the dorsomedial hippocampus with the dentate gyrus and Ammon's horn of mammals, respectively.

Observations and analysis of Ayres’s Hawk-Eagle Hieraaetus ayresii occurrence and behaviour over the Linksfield Ridge, Johannesburg, South Africa

A series of sightings of the Ayres’s Hawk-Eagle (Hieraaetus ayresii) were made over two summers in 2020-2021 and 2021-2022 from a property in Fellside, north-eastern Johannesburg. Sightings of the species were of individual birds in flight over the Linksfield Ridge and Louis Botha Avenue, both located a short distance to the south of the observation location. It is postulated that the combination of an abundance of prey in the form of Rock Doves (Columba livia) that inhabit the built-up urban environment of Louis Botha Avenue in high densities and the presence of a well vegetated (effectively wooded) ridge in close proximity appear to be the factors that draw the species to this particular location within Johannesburg. Although the sighting records did not form part of a dedicated monitoring protocol, the observations of the species were submitted to the SABAP2 project, and these and other records of the species in Johannesburg and Pretoria have been analysed to gain an understanding of the timing of the species’ occurrence within the urban centres of Gauteng. The wider SABAP2 dataset indicates that the species has been most commonly recorded in mid-summer (the months of December and February), with the next highest monthly recording rates being for spring and early summer. Further monitoring and observations for the presence of this species are recommended in areas of suitable habitat within Johannesburg (ridges in close proximity to concentrations of Rock Dove populations) to determine if it favours such location and occurs more widely and commonly than currently understood.

Molecular and retrospective analysis of pigeon paramyxovirus type 1 infections in confinement-reared pigeons (Columbia livia); 2010–2020

Molecular and retrospective analysis of pigeon paramyxovirus type 1 infections in confinement-reared pigeons (Columbia livia); 2010–2020