Abundance Of Pigeons Research Articles

Population size and factors influencing the distribution of the urban pigeon Columba livia f. domestica in Pamplona

The environmental and trophic conditions of cities often give rise to very large populations of urban pigeons Columba livia f. domestica, which can cause local health and heritage problems due to accumulations of their droppings. Estimating the size of pigeon populations and defining their spatial patterns of abundance are therefore crucial for effective pigeon management in built-up areas. This article estimates the abundance of pigeons in Pamplona and the factors that explain the variability of pigeon abundance at local level. The Random Forest model of abundance at a local scale of 0.25 km2 cells had very high explanatory power, although its predictive power decreased due to this species’ gregariousness. Abundance decreased with increasing distance from the city centre, and from historic buildings and large parks, but increased as the proportion of the area covered by parks and built-up areas increased. The rock pigeon population in Pamplona was estimated at 8,030 individuals (95% CI: 6,483–9,860). The estimated density of urban pigeons for Pamplona as a whole was, on average, 218 birds/km2, although this figure varied considerably between habitats and areas: the highest values were measured in urban areas with historic buildings (exceeding 600 individuals/km2; in 35.8% of the 0.25 km2 cells, more than 200 individuals were estimated). Pigeon densities fell to ca. 250 birds/km2 in urban areas lacking large parks or green spaces whether near or far from historic buildings. In the peri-urban areas (i.e. arable fields, scrub and woodland), densities decreased to around 10–50 individuals/km2. In the city of Pamplona, although the population density of urban pigeons did not reach the numbers observed in other northern Spanish cities such as Barcelona, the habitat preference patterns in urban gradients are consistent with those documented in other European regions. We identify specific urban areas for population control and recommend measures such as feeding bans and waste and facade management to make it difficult for urban pigeons to access roosting and breeding sites in buildings.

Evaluation of 8 years of fertility control (nicarbazin) to manage urban pigeon populations

Context The common pigeon (Columba livia var. domestica) is a synurbic species widely distributed around the world. High local densities of pigeons have negative impacts on animal and public health. Urban pigeon fouling also damages buildings and infrastructures, resulting in increased maintenance costs. Although the reduction of food and shelter would be the most effective control method, it does not apply in most cases where the amount of shelter and food can be unlimited and control very difficult achieve. However, a reduction and control of the population by fertility control using nicarbazin (NCZ, Ovistop®) could be achieved without the need to capture and remove any specimens. Aim and methods The aims of this study were (1) to describe the experience of up to 8 years of use of fertility control by NCZ on pigeon numbers in 24 towns and cities in Catalonia (Spain), (2) to assess the potential for non-target species to be affected by NCZ, and (3) to quantify the costs of implementing local population control of urban pigeons via NCZ. Local number of pigeons was estimated via population censuses. Key results From the beginning of the treatment, a significant steady decreasing trend (average of −12% per year) in the pigeon abundance was registered. In very few instances, non-target birds species were observed to feed on NCZ. Conclusions and implications NZC was an effective and selective method of animal welfare to reduce the total number of pigeons in the municipalities included in this study, while not affecting other non-target species. The estimated cost of the annual treatment was €33.6 per pigeon; in 68% of the municipalities, the total annual cost was halved after 3 years of treatment. The findings of this study are in agreement with previous experiences controlling pigeon colonies by using NCZ in other countries.

Impact of Supplementary Feeding on Feral Pigeon Abundance: A Brief Review

Impact of Supplementary Feeding on Feral Pigeon Abundance: A Brief Review

Considering passenger pigeon abundance and distribution in the Late Woodland zooarchaeological record of southern Ontario, Canada

AbstractThe passenger pigeon (Ectopistes migratorius) was once the most abundant bird species in North America. Flocks of these birds witnessed in the early 19th century were so vast that they were said to darken the sky for days as they passed. Early syntheses of passenger pigeon remains in archaeological contexts in the eastern United States, in contrast, found them to be relatively rare in relation to other fowl, leading to the suggestion that the colonial‐era hyper‐abundance of passenger pigeons was a post‐European‐contact phenomenon resulting from contact‐induced demographic and ecological changes. In this paper, we provide new insights into passenger pigeon historical ecology through a synthesis and GIS‐based analysis of zooarchaeological data on skeletal remains from 157 Late Woodland (ca. 900–1650 CE) sites in Ontario, Canada. Our results reveal that passenger pigeon bones are common, and often abundant, in Late Woodland archaeological assemblages in Ontario, which speaks to the species' importance to Indigenous peoples in the region. However, the relative abundance of passenger pigeon remains varies over time, suggesting longer‐term trends in their availability and/or in hunting patterns.

A PIGEON'S EYE VIEW OF A UNIVERSITY CAMPUS

Increasing urbanization over the last century has resulted in a greater abundance of invasive species. Invasive feral pigeons (Columba livia) damage critical urban infrastructure and pose risks to human health. Universities, including Texas Tech University (TTU), located in Lubbock, Texas, have difficulty decreasing adverse effects caused by pigeons. Assessing reliable estimates of population demographics is an important first step to understanding and managing damaging pigeon populations. Our goal was to estimate pigeon abundances at TTU and understand the underlying mechanisms that facilitated pigeon persistence on campus. We surveyed 23 independent locations from March to April 2017 to estimate pigeon abundance across the entire campus. Separately, we also examined pigeon densities on two campus buildings from March to December 2017 to assess and quantify variation in pigeon detection probabilities and abundance both during the diurnal period and among calendar seasons. Our estimates suggested campus abundance was comparable to other urban areas (1,584.4 pigeons/km2, SE = 43.58, 95% CI = ±1,969). Our results indicated hot spots (i.e., high pigeon abundances) existed on campus; for example, we estimated ∼2,819 pigeons (SE = 76, 95% CI = ±138) on a single building on campus during our surveys. Enumeration of pigeon abundance on two campus buildings (mean = 326, SE = 16, 95% CI = ±11) indicated abundance was greatest in the fall and during the morning hours, and peak abundance occurred shortly after 0700 h and declined during the day. Our results suggested pigeons were abundant on campus due to structure and composition of buildings that facilitated nesting and loafing spots that likely maximized efficiency and effectiveness of thermal regulation as well as direct access to water during the study period. In general, pigeons clustered on two buildings on campus and our findings suggested success of population-control measures may be maximized if they are implemented around these buildings.

Use of Fertility Control (Nicarbazin) in Barcelona: An Effective yet Respectful Method towards Animal Welfare for the Management of Conflictive Feral Pigeon Colonies.

Simple SummaryFeral pigeon is one of the most common urban species worldwide. Living free in urban areas, pigeons have found a favorable environment with the conditions to have a high fertility, thus leading to overcrowding, which causes thousands of millions in damages yearly. The management of overpopulated pigeon colonies presents numerous challenges, and several methods have been proposed and used. In recent decades, the concern in the society about animal welfare has grown, and now demands non-lethal methods in the management of wildlife, especially in cities. The management of feral pigeons in Barcelona, Spain, used to be carried out, like in many cities, by capture and elimination. However, as this method has been proven to be ineffective and the public concern about animal welfare has increased, in 2016, the Barcelona City Council decided to change the management towards a fertility control method. This study describes and evaluates, during three years, an efficient fertility control protocol that is able to reduce the number of pigeons in the treated colonies by 55.26% at the end of the study. The results of this study provide animal management administrations and companies with a non-lethal protocol to control pigeon populations while respecting animal welfare.This study describes a three-year evaluation (2017–2019) of a fertility control protocol using nicarbazin (Ovistop®) to reduce the abundance of the most conflictive colonies of feral pigeon, Columba livia var. domestica, in Barcelona, Spain, as a long-term strategy based on animal welfare. The treatment was supplied to 34 pigeon colonies by automatic hopper feeders installed in public areas. A superiority study and a population monitoring study were carried out to evaluate differences in the abundance of the colonies, as well as the proportion of juveniles, the possible intake of nicarbazin by non-target species and the movement of individuals among colonies. The results showed statistical differences in the population trends between the test (−22.03%) and control (+12.86%) groups, and a significant steady decreasing trend in the pigeon abundance (−55.26%) was registered until the end of 2019. The proportion of juveniles was significatively lower in the test colonies, and a non-target species (Eurasian collared doves, Streptopelia decaocto) was observed consuming in a residual form. The protocol using nicarbazin is able to both control the abundance of pigeons, with no impact over non-target species, and respond to the public interest about animal welfare by providing an ethical method to manage overabundant and/or conflictive populations.

Restricted human activities shift the foraging strategies of feral pigeons (Columba livia) and three other commensal bird species

Invasive species are a growing concern with increasing global connectivity. Feral pigeons (Columba livia) are widespread and invasive, thus their effective control is of keen international interest. The COVID-19 pandemic has offered an unprecedented opportunity to investigate the impact of a nation-wide Circuit Breaker (restricted human activities) in Singapore on first, the abundance of the feral pigeons and three urban commensals—the Javan myna (Acridotheres javanicus), common myna (A. tristis), and house crow (Corvus splendens) in different food source types; and second, the activity budgets of feral pigeons. A significant and progressive decline in feral pigeon abundance was observed in open food centres and feeding hotspots after the Circuit Breaker was implemented. While the house crow and common myna were less affected, the Javan myna abundance increased moderately at refuse collection centres during the Circuit Breaker and decreased significantly in green spaces after the Circuit Breaker. Changes in food abundance could also predict changes in feral pigeon abundance and its effect was greatest in feeding hotspots. A greater proportion of feral pigeons was observed foraging and moving with a smaller proportion seen resting with probable consequences on their reproductive capacity. Our study also cautions against drawing inferences on biological responses due to similar social restrictions without careful consideration of other ecological factors, like average flock size and time of the day, which also affected the proportion of pigeons foraging on natural versus anthropogenic food. In summary, our results advocate a food limitation approach to control the feral pigeon populations.

Feral pigeon (Columba livia var. domestica) management in low-density urban areas: prevention is better than cure

Currently, there are naturalized populations of feral pigeon (Columba livia var. domestica) worldwide with an estimated global population between 165 and 330 million individuals. Feral pigeons are adapted to urban environments, creating problems related to human health, damage to architectural structures, unpleasant soiling, and foul odors. Thus, local governments usually implement measures to reduce feral pigeon populations in cities to a suitable size. We monitored a feral pigeon trapping campaign to investigate the use of cage traps as control method in residential zones. We analyzed efficiency (daily capture rate), effectiveness (defined as the number of feral pigeons captured relative to the total number of potential pigeon captures), animal welfare, selectivity (the proportion of captured feral pigeons in relation to the total number of captured animals), and the effect on feral pigeon abundance. All procedures were conducted in compliance with current European and Spanish legislation. Overall efficiency was 0.25 feral pigeons/trap-day, effectiveness was 22.5%, and selectivity was 99.7%. Over the study period, there was a decreasing trend in abundances. A significant decrease was found in the relative abundances of feral pigeons after 2 months of extractions, and population abundances remained low up to the end of the extraction period. The use of cage traps was a useful and effective method to reduce local feral pigeon populations in isolated urban areas with low building density in which the feral pigeon population has not yet reached high densities.

PIGEONS, AN URBAN PATHOGENIC PROBLEM?

The pigeon is a “natural” animal inserted into the artificial environment of cities, who provides a new perspective over the dichotomic concepts of Nature and Culture, traditionally understood as mutually exclusive. Ancient Egyptians began using at least 4000 years ago. The abundance of pigeons is positively related to town's area and population, and independent of the surrounding landscape type. The high densities of this urban exploiter species, alongside people in cities provide opportunity for prolonged and frequent contact between humans and animals. This has important consequences, and the greatest number of human–pigeons conflicts arises in larger towns. People have many casual interactions with pigeons that range from feeding in public parks to handling tamed birds nesting on windowsills. They are both reservoirs and horizontal and vertical vectors of infectious diseases, as well as a source of antigens that provoke allergic diseases.<strong> </strong>Solving the problem of these diseases is a modern and important topic to debate and research. Doing so sustainably should be possible and investigations in this area are necessary for the public safety and health of all, both humans and pigeons alike.<strong> </strong>This study review some diseases and topics concerning pigeons and their zoonoses in the urban environment.

Habitat preferences of two sparrow species are modified by abundances of other birds in an urban environment.

Every species has certain habitat requirements, which may be altered by interactions with other co-occurring species. These interactions are mostly ignored in predictive models trying to identify key habitat variables correlated with species population abundance/occurrence. We investigated how the structure of the urban landscape, food resources, potential competitors, predators, and interaction between these factors influence the abundance of house sparrow Passer domesticus and the tree sparrow P. montanus in sixty 25 ha plots distributed randomly across residential areas of the city of Poznań (Poland). The abundance of the house sparrow was positively correlated with the abundance of pigeons but negatively correlated with human-related food resources. There were significant interaction terms between abundances of other urban species and habitat variables in statistical models. For example, the abundance of house sparrow was negatively correlated with the abundance of corvids and tree sparrows but only when food resources were low. The abundance of tree sparrows positively correlated with density of streets and the distance from the city center. The abundance of this species positively correlated with the abundance of corvids when food resources were low but negatively correlated at low covers of green area. Our study indicates that associations between food resources, habitat covers, and the relative abundance of two sparrow species are altered by the abundance of other urban species. Competition, niche separation and social facilitation may be responsible for these interactive effects. Thus, biotic interactions should be included not only as an additive effect but also as an interaction term between abundance and habitat variables in statistical models predicting species abundance and occurrence.

Reducing the availability of food to control feral pigeons: changes in population size and composition.

As feeding by humans is one of the main food resources to pigeons (Columba livia), there is general agreement that public education that aims to reduce the food base may be the most feasible way to reduce pigeon abundance. However, except for the classic example of Basel, the method has rarely been tested or implemented. We provide results from a 1 year study in the city of Barcelona where we tested the effect of public education on pigeon population abundance and composition. The quantity of food provided by people to pigeons was significantly reduced during the study. Feral pigeon density was reduced by 40% in the two experimental districts, but no variation was detected in the control district. Detailed analyses in one of the districts showed that the reduction was mainly related to the reduction in food availability but not to culling. Pigeons captured at the end of the experiment were larger than at the start of the study, but body condition was reduced. Results show the effectiveness of public information to manage feral pigeon populations in a large city, and that control operations can exert important selection pressure on the population, leading to changes in population composition. © 2016 Society of Chemical Industry.

Scale-Dependent Associations of Band-Tailed Pigeon Counts at Mineral Sites

The abundance of Band-tailed Pigeons (Patagioenas fasciata monilis) has declined substantially from historic numbers along the Pacific Coast. Identification of patterns and causative factors of this decline are hampered because habitat use data are limited, and temporal and spatial variability patterns associated with population indices are not known. Furthermore, counts are influenced not only by pigeon abundance but also by rate of visitation to mineral sites, which may not be consistent. To address these issues, we conducted mineral site counts during 2001 and 2002 at 20 locations from 4 regions in the Pacific Northwest, including central Oregon and western Washington, USA, and British Columbia, Canada. We developed inference models that consisted of environmental factors and spatial characteristics at multiple spatial scales. Based on information theory, we compared models within a final set that included variables measured at 3 spatial scales (0.03 ha, 3.14 ha, and 7850 ha). Pigeon counts increased from central Oregon through northern Oregon and decreased into British Columbia. After accounting for this spatial pattern, we found that pigeon counts increased 12% ± 2.7 with a 10% increase in the amount of deciduous forested area within 100 m from a mineral site. Also, distance from the mineral site of interest to the nearest known mineral site was positively related to pigeon counts. These findings provide direction for future research focusing on understanding the relationships between indices of relative abundance and complete counts (censuses) of pigeon populations by identifying habitat characteristics that might influence visitation rates. Furthermore, our results suggest that spatial arrangement of mineral sites influences Band-tailed Pigeon counts and the populations which those counts represent.

The effect of habitat and number of inhabitants on the population sizes of feral pigeons around towns in northern Poland

Most studies on factors influencing density of the feral pigeons Columba livia var. domestica were carried out in large cities and agglomerations. However, also in small towns, pigeons are important epidemiological and sanitary problem. In our studies, feral pigeons were censused in 33 towns located in the Pomeranian Province (northern Poland) during 2006–2008. These birds occurred in 19 (57.6%) towns. The number of pigeons was positively correlated with the area of the town, and it was significantly higher in towns localized in agricultural landscape than in towns surrounded by forests. We also found a significant effect of interactions between type of a landscape surrounding a town and residual number of inhabitants on the abundance of pigeons. In the largest towns of the Pomeranian Province, feral pigeons were concentrated mainly in central quarters. In smaller towns, they were noted in central parts or in areas with blocks of flats and even the suburbs. The obtained results suggest that food conditions in small and middle towns may be not sufficient for colonization by pigeons.

Estima de la abundancia de palomas (Columba livia var.) de la ciudad de Barcelona y valoración de la efectividad del control por eliminación de individuos

Estimate of the abundance of pigeons (Columba livia var.) in the city of Barcelona and evaluation of effectiveness of elimination measures.— Culling is one of the most commonly used methods to control urban pigeon populations. The Barcelona Public Health Agency (ASPB) eliminated a total of 227,479 pigeons using this technique between 1991 and 2006. We compared the estimate of abundance of pigeons in Barcelona city in 1991 (183.667 ± 14.914) with that in 2006 (256.663 ± 26.210) (CI 95%). While pigeon density did not increase in the city centre during this period, density in a ring around the city increased significantly, leading to a general increase in the urban population of these birds. The number of complaints regarding pigeons received per district did not correlate with abundance. ASPB culling per district correlated with abundance and not with numbers of complaints received, indicating interventions generally followed a technical protocol. Pigeon density per district correlated significantly with the human population density but not with the total number of inhabitants. Findings indicate the effectiveness of culling is low in this setting and suggest greater emphasis should be placed on control measures centered on limiting factors, particularly reduction of food availability and nest removal.

Why do raptors take domestic prey? The case of Bonelli's eagles and pigeons

Summary Predator conservation management requires detailed understanding of the ecological circumstances associated with predation, especially that on economically valuable prey. We examined the mechanisms behind Bonelli's eagle Hieraaetus fasciatus predation on prey of domestic origin, using dietary data from 22 pairs breeding in south‐west Portugal (1992–2001) together with information on landscape composition and prey availability. Numerically, 42·7% (37·7% in biomass) of eagle prey comprised domestic species, about 70% of which were rural pigeons Columba livia and the remainder were racing pigeons Columba livia and domestic fowl Gallus gallus. Rabbits Oryctolagus cuniculus, red‐legged partridges Alectoris rufa and jays Garrulus glandarius were the most frequent wild prey (43·1%; 50·8% in biomass). This dietary pattern was remarkably stable over a decade, but within each year the intake of pigeons almost halved over the course of the breeding season. Landscape composition significantly affected the dietary proportion of wild and domestic prey items. This was particularly evident in territories dominated by eucalyptus Eucalyptus globulus plantations, where there was reduced consumption of rural pigeons and partridges, an increased intake of minor avian prey items and greater diversity in the diet overall. Bonelli's eagles showed type II functional responses while preying on the most important wild (rabbit) and domestic (rural pigeon) prey, although the former was much stronger. Eagle predation on rabbits declined with increasing abundance of pigeons, and vice versa, but there was no switching in the traditional sense, as selection between these two species was inversely frequency dependent. Synthesis and applications. Predation by Bonelli's eagle on domestic pigeons results from a combination of high vulnerability of the pigeons to eagles and a shortage of key wild prey such as rabbits and partridges, especially during the early breeding season. Given the relatively low economic value of rural pigeons and their importance in the diet of Bonelli's eagles, they could probably be used as a conservation tool to enhance food resources in breeding territories and to deflect predation from more valuable prey such as partridges and racing pigeons.

The conservation and ecology of rainforest pigeons in northeastern New South Wales

A survey of conservation reserves, rainforest remnants and agricultural districts in northeastern New South Wales was conducted to determine the abundance, movements and habitat requirements of rainforest pigeons, to evaluate the extent and use of suitable habitat in conservation reserves, and to provide guidelines for the conservation and management of rainforest pigeons. Eight species of rainforest pigeon occur in northeastern New South Wales. Commencing with the clearing of rainforest in the 1860s for agriculture, rainforest pigeons declined in abundance throughout New South Wales and by the 1970s five species were thought to be threatened in the state. Since then, rainforest pigeons have apparently increased in abundance and distribution, but the Wompoo, Rose-crowned and Superb Pigeons continue to be listed by the New South Wales National Parks and Wildlife Service as vulnerable and rare. However, populations of all species of rainforest pigeons in New South Wales are relatively small and vulnerable to further loss of habitat. Most rainforest pigeons show a preference for subtropical rainforest habitat, but moist eucalypt forests, gardens and weedy exotic vegetation along roads and on abandoned farmland are also frequented to varying degrees by different species. To investigate recent trends in pigeon abundance we used data collected for up to 12 years from eight sites and during 1988, 1989 and 1990 from 17 rainforest remnants in northeastern New South Wales. The data suggest that rainforest pigeons now occur more frequently in lowland agricultural areas than in the recent past and tend to confirm an increase in abundance since the 1970s. Nesting and foraging habitats for rainforest pigeons are extensive in the conservation reserve system of northeastern New South Wales, but these habitats, which are largely at high elevations, lack winter food resources. Instead, pigeons congregate in remnant rainforest and exotic berry-bearing trees and shrubs in agricultural areas at lower elevations and near the coast. They rely on these habitats for food during winter and it is the restricted extent of this habitat that probably limits their abundance, not the area or quality of habitat at higher elevations. The conservation and management of rainforest pigeons requires the protection of low elevation and coastal rainforest remnants. As development of northeastern New South Wales proceeds, to avoid a decline in the abundances of rainforest pigeons it will be necessary to protect sclerophyll forest with native or exotic fruit bearing trees and shrubs and to extend the area of suitable habitat by the regeneration of rainforest and by the planting of native species used by pigeons as a food source. This will become increasingly important as the control and removal of exotic plants, such as Lantana Lantana camara and Camphor Laurel Cinnamonum camphora, on which some pigeons depend as a winter food source, becomes more successful.

Feeding Ecology of Fruit Pigeons in Subtropical Rainforests of South-Eastern Queensland.

In a 5-yr (1979-84) study of 6 species of fruit pigeon in lowland (dry) and upland (wet) subtropical rain forests in the Jimna and Conondale Ranges, the effects of forest phenology on pigeon abundance were investigated. The pigeons utilized 89 species of plants from 39 families of trees, palms and vines. The seasonal availability of fruit was similar in each forest type: most plant species bore crops during the wet season (Dec.-Mar.) and held crops into the early dry season (April-May); the late dry season (June-Oct.) was a time of general fruit shortage. More than 60% of the species of food plants present in upland forest were rare or absent in lowland forest. In general, each species of pigeon utilized a distinct suite of plant species in each forest type. Certain species of fig (Ficus spp.) fruited asynchronously and were the most important food for sedentary wompoo fruit-doves (Ptilinopus magnificus magnificus) in both forest types. These and other species of fig were the most important food for topknot pigeons (Lopholaimus antarcticus) and rose-crowned fruit-doves (P. regina regina) in lowland forest. An influx of flocks of up to 200 topknot pigeons into upland forest occurred each year in response to the fruiting of Archontophoenix cunninghamiana. The foraging habits of rose-crowned fruit-doves were largely opportunistic in upland forest, utilizing whatever fruit was available at particular times. White-headed pigeons (Columba leucomela) foraged solely in Olea paniculata during irregular visits to lowland forest. A regular summer influx into upland forest occurred in response to the fruiting of a vine, Piper novae-hollandiae. In each forest type, brown cuckoo-doves (Macropygia amboinensis) had a distinct foraging preference for plant species characteristic of disturbed forests; important plant families were the Solanaceae, Ulmaceae, Euphorbiaceae and Araliaceae. Superb fruit-doves (P. superbus) were seldom found in either forest type.