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The range-wide recovery of Bald Eagles (Haliaeetus leucocephalus) is one of the great North American conservation successes, with the Bald Eagle population in Florida contributing substantially to this recovery. Florida has one of the densest concentrations of nesting Bald Eagles in the lower 48 states and sustained a population monitoring program that spanned 45 yr. We used nest monitoring data from 1972–2017 to quantify changes in the size, extent, and productivity of the breeding Bald Eagle population in Florida. We documented an increase in the number of occupied Bald Eagle territories from 88 in 1973 to an estimated 1565 in 2017, with nests recorded in 64 of Florida's 67 counties by the end of the monitoring efforts. Mean annual growth rate in the number of occupied eagle territories in Florida was 5.5 ± 1.1% (SE). High reproductive rates, exemplified by a mean productivity of 1.13 ± 0.02 fledglings per occupied nest, a mean brood size of 1.54 ± 0.01 fledglings per successful nest, and the production of nearly 40,000 fledglings over a 45-yr period, translated into substantial gains for the state and southeastern US Bald Eagle population. Eagles have established a large, spatially expansive, and productive breeding population in Florida, one that exceeded the conservation objectives established when the species was state-delisted in 2008. These data provided key insights into the breeding ecology, recovery, and long-term stability of Bald Eagles in Florida. Given the predicted increase in the human population and landscape modification anticipated in the coming years, the conservation of the eagle population within Florida will require adaptive management strategies. [ABSTRACT FROM AUTHOR]

Throughout Europe, electrocution on distribution power lines is the main cause of mortality for fledgling Bonelli's Eagles (Aquila fasciata) released into the wild through hacking. To attempt to reduce electrocutions, we subjected 17 fledglings that had not previously had any contact with power line pylons to aversive conditioning. To this end, we installed electrified barrier wires on two distribution pylons (one each of the two most common pylon types in northern Spain), which were disconnected from the electric grid. The electrified barriers, which were in place from 2020 through 2022, lightly shocked fledglings alighting on them. We compared the subsequent behavior of conditioned fledglings with that of a control sample of 19 unconditioned fledglings released between 2015 and 2019. The results suggest that conditioning results in (1) a delay in juveniles' use of distribution power line pylons as perches in the wild; (2) juveniles' avoidance of pylons in temporary settlement areas; and (3) a nonsignificant increase in juvenile survival rates during the first year of life. This approach may have applicability in other population reinforcement projects, and in areas with high concentrations (communal roosts and vulture restaurants) of other large raptors. [ABSTRACT FROM AUTHOR]

The article explores the breeding dispersion of raptors in the Junggar Basin, Xinjiang, China, highlighting a unique case of close nesting between Saker Falcons and Golden Eagles. Topics include the factors influencing nesting dispersion, interspecific interactions among raptors, and the observed aggressive behaviors and potential predation attempts between Saker Falcons and Golden Eagles in a spatially limited nesting environment.

Much of the US Southern Great Plains (SGP) continues to undergo intensive energy development that could affect the region's Golden Eagles (Aquila chrysaetos), yet the species' population status there is unknown. During 2011–2020, we used satellite telemetry to assess annual survival rates and causes of mortality among 40 preadult (<3 yr of age) Golden Eagles in the SGP; 29 were monitored beginning at the late nestling stage and 11 immigrated into the SGP from western regions. For comparison we monitored 15 preadult Golden Eagles from nests in the Central Great Plains (CGP), where energy development was less extensive. We estimated survival rates by using a multi-state model in a Bayesian framework that accounted for probabilities of causes of death. Mean annual survival in the SGP during the preadult period was 0.060, versus 0.512 in the CGP and ∼0.7–0.9 reported elsewhere in the coterminous western USA. Mexican chicken bugs (Haematosiphon inodorus) were implicated in deaths of at least seven Golden Eagles during the ∼2-wk late nestling stage and in two deaths <3 mo after fledging. Energy infrastructure especially electrocutions accounted for 12 (57.1%) of 21 deaths of post-fledged preadults. Seven of 11 immigrant eagles died. Overall, probabilities of death of a Golden Eagle during the preadult period in the SGP due to Mexican chicken bugs and to electrocution were both 0.345. We estimated that the SGP population may be declining 9% annually due to poor recruitment; mitigation of underlying factors should be a priority for managing Golden Eagles in the western USA. Buena parte de las Grandes Llanuras del Sur (GLS) de EEUU continúan sometidas a un desarrollo energético intensivo que podría afectar a los individuos de Aquila chrysaetos de la región; sin embargo, el estado de la población de la especie en esta zona es desconocido. Durante 2011–2020, usamos telemetría satelital para evaluar las tasas de supervivencia anuales y las causas de mortalidad entre 40 águilas preadultas (<3 años de edad) de A. chrysaetos en las GLS; 29 fueron monitoreadas a partir de la etapa tardía de polluelo y 11 inmigraron desde regiones del oeste. Para hacer una comparación, monitoreamos 15 águilas preadultas de A. chrysaetos en nidos de las Grandes Llanuras Centrales (GLC), donde el desarrollo energético era menos extenso. Estimamos las tasas de supervivencia utilizando un modelo multi-estado en un marco de trabajo bayesiano que tuvo en cuenta las probabilidades de las causas de muerte. La supervivencia media anual en las GLS durante el periodo preadulto fue de 0.060, en comparación con 0.512 en las GLC y ∼0.7–0.9 en otras partes del oeste contiguo de EEUU. La chinche Haematosiphon inodorus estuvo implicada en la muerte de al menos siete águilas durante las últimas ∼2 semanas de la etapa tardía de polluelo y en dos muertes durante el inicio del postemplumamiento. La infraestructura energética, especialmente las electrocuciones, representaron 12 (57.1%) de las 21 muertes de preadultos después de emplumar. Siete de las 11 águilas inmigrantes murieron. En general, las probabilidades de muerte de un individuo de A. chrysaetos durante el período preadulto en las GLS debido a las chinches y a la electrocución fueron ambas de 0.345. Estimamos que la población de las GLS puede estar disminuyendo un 9% anual debido al bajo reclutamiento; la mitigación de los factores subyacentes debería ser una prioridad para la gestión de A. chrysaetos en el oeste de EEUU. [Traducción del equipo editorial] [ABSTRACT FROM AUTHOR]

Interspecific competition occurs when two sympatric species utilize the same limited supply of a basic resource, such as food; the degree of diet overlap is an essential metric for examining potential competition between the species. The Long-legged Buzzard (Buteo rufinus) is a relative newcomer to the island of Cyprus, where it is sympatric with the larger Bonelli's Eagle (Aquila fasciata), a potential competitor for both food and space (nesting territories). We studied the diet of the Long-legged Buzzard in the 2005, 2006, and 2018 nesting seasons through analysis of pellets and prey remains collected at 38 sites. The most abundant prey class was mammals (68.8% frequency, 58.9% biomass), followed by reptiles (16.8% frequency, 36.3% biomass), and birds (4.3% frequency, 4.6% biomass). The most numerous prey species were black rats (Rattus rattus), starred agamas (Stellagama stelio), house mice (Mus musculus), and large whip snakes (Dolichophis jugularis), but in terms of biomass, the most important prey items were black rats, large whip snakes, long-eared hedgehogs (Hemiechinus auritus dorotheae), and starred agamas. We compared the diet of the Long-legged Buzzard to that of the Bonelli's Eagle, whose diet was dominated by birds (62.1% frequency, 76.1% biomass) and to a lesser degree by mammals (29.5% frequency, 21.9% biomass). The mean prey biomass for the Long-legged Buzzard was estimated as 167 g, compared to 350 g for the Bonelli's Eagle; this difference reflected the almost two-fold difference in mass between females of the two species. Diet overlap measured with Pianka's index was <0.5, suggesting an intermediate niche overlap mainly due to utilization of an abundant prey resource, such as the black rat. Niche breadth for the Long-legged Buzzard measured using Levins' index ranged from 0.485 in 2005 to 0.081 in 2018. This decrease in niche breadth over time in a generalist species can occur when there is a superabundance of a particular prey. The mean Levins' index for the Bonelli's Eagle was also low, 0.271 (1999–2001). Based on the diet comparison, we concluded that there was no evidence for interspecific competition in terms of food. La competencia interespecífica ocurre cuando dos especies simpátricas utilizan el mismo suministro limitado de un recurso básico, como por ejemplo la comida; el grado de solapamiento de la dieta es una métrica esencial para examinar la competencia potencial entre las especies. Buteo rufinus es una especie relativamente nueva en la isla de Chipre, donde se presenta en simpatría con Aquila fasciata, de mayor tamaño, un competidor potencial tanto por comida como por espacio (territorios de nidificación). Estudiamos la dieta de B. rufinus en las temporadas de cría de 2005, 2006 y 2018 mediante el análisis de egagrópilas y restos de presas recolectados en 38 sitios. Las presas más abundantes fueron los mamíferos (68,8% de frecuencia, 58,9% de biomasa), seguido de los reptiles (16,8% de frecuencia, 36,3% de biomasa) y las aves (4,3% de frecuencia, 4,6% de biomasa). Las especies de presa más numerosas fueron Rattus rattus, Stellagama stelio, Mus musculus y Dolichophis jugularis, si bien en términos de biomasa las presas más importantes fueron R. rattus, D. jugularis, Hemiechinus auritus dorotheae y S. stelio. Comparamos la dieta de B. rufinus con la de A. fasciata, cuya dieta estaba dominada por aves (62,1% de frecuencia, 76,1% de biomasa) y en menor medida por mamíferos (29,5% de frecuencia, 21,9% de biomasa). La biomasa de la presa promedio para B. rufinus se estimó en 167 g, en comparación con 350 g para A. fasciata; esta disparidad reflejó la diferencia de masa de casi el doble entre las hembras de las dos especies. El solapamiento de dieta medido con el índice de Pianka fue <0,5, lo que sugiere un solapamiento de nicho intermedio debido principalmente a la utilización de un recurso de presa abundante como R. rattus. La amplitud de nicho para B. rufinus, medido con el índice de Levins, fluctuó entre 0,485 en 2005 y 0,081 en 2018. Esta disminución en la amplitud de nicho a lo largo del tiempo en una especie generalista puede ocurrir cuando hay una sobreabundancia de una presa en particular. El índice de Levins medio para A. fasciata también fue bajo, 0,271 (1999–2001). Basados en la comparación de la dieta, concluimos que no hubo evidencia de competencia interespecífica en términos de alimentación. [Traducción del equipo editorial] [ABSTRACT FROM AUTHOR]

Estimating species density and abundance is challenging but important for establishing conservation and management strategies. Significant progress has been made toward estimating Golden Eagle (Aquila chrysaetos) abundance in the conterminous United States of America (USA) but much less is known about eagle abundance in Alaska. Here, we paired migration count and GPS-tracking data collected near Gunsight Mountain, Alaska, in a Bayesian framework to estimate the number of Golden Eagles in south-central Alaska. We estimated 1204 (95% credible interval: 866, 1526) potentially breeding (≥4 yr old) Golden Eagles annually moved through the Gunsight Mountain migration corridor and summered over an area of 150,325 km2 in south-central Alaska, equating to a density of 0.80 potentially breeding eagles/100 km2. By extrapolating across the species' nesting range in Alaska (1,180,489 km2) and incorporating published productivity and age-specific survival rates for eagles <4 yr old into our hierarchical model, we estimated 12,717 (95% credible interval: 9043, 16,349) Golden Eagles of all ages occur in Alaska, annually. We propose this as a conservative statewide population estimate because we used methods that likely underestimated population size. Even so, our estimate is three to five times larger than previous estimates and likely represents about one quarter of the USA's population. [ABSTRACT FROM AUTHOR]

We estimated occupancy and population abundance of the Andaman Serpent-Eagle (Spilornis elgini) and Crested Serpent-Eagle (Spilornis cheela) in the Andaman Islands, India. We divided the islands that were. 100 km2 into a grid of 84 cells, of which we used 34 cells (5 km 3 5 km each) for surveys of two populations in the districts of (1) the North and Middle Andaman Islands, and (2) the South Andaman Islands, which includes Little Andaman Island. We performed single-season, single-species occupancy modeling independently for both regions and single-season, two-species occupancy modeling for co-occupancy in the surveyed landscapes. The estimated abundance for the Andaman Serpent-Eagle and the Crested Serpent-Eagle was 4–5 and 7–8 individuals per 25 km2, respectively. The Andaman Serpent-Eagle is commonly distributed in both regions and has a high detection probability (detection probability, P ¼ 0.8). The Crested Serpent-Eagle is widely distributed in the South Andaman Islands with a low detection probability (P ¼ 0.5). The single-season, two-species occupancy model showed that the endemic Andaman Serpent-Eagle occupied only 22% of the area and did not co-occur with the Crested Serpent-Eagle. It also indicates the possible avoidance or exclusion of the Crested Serpent-Eagle by the Andaman Serpent-Eagle. We encountered both serpent-eagles in all the identified habitat types. The Crested Serpent-Eagle's habitat use was not restricted to the coastal forests, as previously reported, and the Crested Serpent-Eagle is probably dominating the Andaman Serpent-Eagle in the co-occupied areas. We further conclude that the occupancy dynamics and competition for space between these two Spilornis species might significantly affect the distribution and population of the vulnerable and endemic Andaman Serpent-Eagle in the future. [ABSTRACT FROM AUTHOR]

Accurate estimations of adult mortality are essential for understanding population dynamics and achieving efficient management actions that are directed toward long-lived species. Several noninvasive methods may be used to monitor endangered long-lived birds like raptors, but their performance in real-world scenarios remains poorly studied. We used eight Bonelli's Eagle (Aquila fasciata) breeding pairs (1) to compare the efficiency of direct observations with binoculars and telescopes (2004–2016), camera trapping (2012–2016), and feather genetic analysis (2004–2015) for detecting and identifying individuals over time, (2) to conduct a cost-benefit analysis of methods, and (3) to evaluate the accuracy of the direct observation method for estimating survival by comparing it with camera trapping and feather analysis. Both the feather genetic analysis and camera trapping approaches allowed us to successfully identify individuals and to detect replacements that we did not notice during direct observations. The classic direct observation method overestimated adult survival, which could hamper an accurate understanding of the demographic dynamics of this population. Feather analysis gave a low detection rate of individuals (47%), probably due to difficulties in finding feathers in the rugged habitat of this species. However, identification success at the individual level with this method was 96%. Remote camera surveys had both a high detection rate (100%) and identification success (93%). Given that costs associated with camera surveys were lower than the costs of genetic procedures, we concluded that camera trapping is the most efficient indirect method to assess adult survival in this and other raptors with external features that make individual identification possible. However, because no method showed complete efficiency, genotyping of feathers collected at the end of the breeding season could be a useful additional method, especially when camera trapping is not possible or when it fails. [ABSTRACT FROM AUTHOR]

A secretive and cautious raptor, the Black Eagle (Ictinaetus malaiensis) is challenging to study. Its highly specialized foraging behavior makes it difficult to capture an individual for tracking. However, a tailless eagle provided an opportunity to describe the home range and movements of one bird for 3 yr from 2013 to 2016. A total of 43 independent photo records were provided by a bird photographers' community. The eagle regularly moved between summering and wintering habitats north and south of Taipei City, Taiwan; home range sizes were estimated as 54.1 and 47.1 km2, respectively. This noninvasive case study provides the first estimates of home range size and movement patterns for the Black Eagle, and highlights the contribution of community science to research on endangered raptors. [ABSTRACT FROM AUTHOR]

The article discusses deforestation's effects on raptors, highlighting lessons learned and potential solutions. Topics discussed include impact of with change on raptor conservation and biodiversity; association of raptors with Indigenous cultures providing potential for collaborative conservation; and concern of commercial logging to Philippine Eagle habitat.

The Crested Eagle (Morphnus guianensis) is the second largest Brazilian forest eagle. Crested Eagles are distributed from southeastern Mexico to southern Brazil, northern Argentina, and Paraguay; however, the species is one of the least-studied Neotropical raptors. Our objective was to determine diet and feeding strategies for Crested Eagles in the Brazilian Amazon. We recorded Crested Eagle diet at four nests from 2010–2012 through a combination of direct observations from the ground, remote photographs (camera-traps), and pellets and prey remains collected in and under the nests. We identified a total of 79 prey individuals, composed of 21 different prey species. We found that Crested Eagles fed mainly on medium-sized rodents, and medium-sized to large mammals. Prey were mainly nocturnal (70%), including mostly scansorial, cavity-dwelling marsupials and rodents. Fewer prey were diurnal (20%) and these were typified by arboreal, gregarious mammals (monkeys); rare prey included one owl (Strigidae) and one porcupine (Coendou sp.). We suggest that this may indicate a diet not specialized on a particular prey species or group, but rather focused on specific prey behaviors or microhabitats. [ABSTRACT FROM AUTHOR]

Collision with electric lines is a global conservation concern for many birds but raptor species are generally thought to have a low risk of line collision. Collision risk at electric lines is not well understood for Bald Eagles (Haliaeetus leucocephalus), with only incidental reports of collisions in the literature. Line collisions reported for Bald Eagles predominantly occur where lines intersect movement corridors around foraging, roosting, or nesting areas. During five winters from 2014 to 2018, we monitored 602 Bald Eagle crossings of a 230/500-kV transmission line at the Delaware River to determine collision risk. Eagles successfully crossed the line by flying predominantly below the wire zone. There was no difference in flight heights for immature or adult eagles crossing the line. Wire-marking protocols within the electric industry are primarily focused on marking the top plane of wires to alert birds flying above the wires. Additional development of wire-marking options for energized conductors could further reduce collision risk for eagles and other bird species flying below wires. Overall, collision risk appears low for Bald Eagles making localized movements across transmission lines. [ABSTRACT FROM AUTHOR]

Electrocution is a widespread conservation problem for birds of prey that has received little attention in the Neotropics. Here we present electrocution records involving the endangered Chaco Eagle (Buteogallus coronatus) in central Argentina, and we provide information on the power pole structural characteristics associated with electrocutions. Nine Chaco Eagles were recorded electrocuted during the period 2012–2019 over an area of 9000 km2. Chaco Eagles were found electrocuted in association with five types of power poles, but more than half the electrocutions (55%) were on poles made of steel-reinforced concrete and with jumper wires above the crossarms. With the addition of four previous electrocution reports in this region during the same time period, the annual rate of Chaco Eagle electrocutions was similar to the rate of mortality by other human-related factors such as direct persecution. Future conservation actions and research should focus on retrofitting the small fraction of poles that pose the highest electrocution risks for Chaco Eagles, and on assessing the demographic effects of electrocution mortality for this species and other endangered raptors in Argentina. [ABSTRACT FROM AUTHOR]

Species considered raptors are subjects of monitoring programs, textbooks, scientific societies, legislation, and multinational agreements. Yet no standard definition for the synonymous terms "raptor" or "bird of prey" exists. Groups, including owls, vultures, corvids, and shrikes are variably considered raptors based on morphological, ecological, and taxonomic criteria, depending on the authors. We review various criteria previously used to define raptors and we present an updated definition that incorporates current understanding of bird phylogeny. For example, hunting live vertebrates has been largely accepted as an ecological trait of raptorial birds, yet not all species considered raptors are raptorial (e.g., Palm-nut Vulture [Gypohierax angolensis]), and not all raptorial birds are considered raptors (e.g., skuas [Stercorariidae]). Acute vision, a hooked bill, and sharp talons are the most commonly used morphological characters for delineating raptors; however, using those characters as criteria may cause confusion because they can be vague and exceptions are sometimes made. Old World vultures, for example, are in the family Accipitridae along with hawks and eagles, and thus are usually considered raptors despite their lack of sharp talons. We define raptors as species within orders that evolved from raptorial landbirds (Telluraves) in which most species maintained raptorial lifestyles. Raptors are therefore all species within Accipitriformes, Cathartiformes, Falconiformes, and Strigiformes. Importantly, we believe that seriemas (Cariamiformes) should also be considered raptors. Our definition combines phylogeny with morphology and ecology, and avoids ambiguity associated with owls, vultures, and shrikes. Establishing a common definition of raptors should improve interpretability across studies and lessen ambiguity of research and management recommendations. [ABSTRACT FROM AUTHOR]

We investigated Golden Eagle (Aquila chrysaetos) diet on the Seward Peninsula, Alaska, at 35 and 30 occupied eagle nest sites in July 2014 and 2015, respectively. We used 52 prey remains and 456 regurgitated pellets collected from nest and perch sites to identify 727 individual prey items representing 18 prey categories. Golden Eagles in our study area primarily consumed Arctic ground squirrels (Urocitellus parryii; 52% of total biomass), ptarmigan (Lagopus spp.; 20%), and waterfowl (15%). Dietary breadth differed between years. We detected 13% more ptarmigan and 12% fewer ground squirrels at perch sites compared to nest sites. Our results suggest that Golden Eagles have a relatively broad dietary niche in western Alaska during the first half of the breeding season. [ABSTRACT FROM AUTHOR]

We report late Quaternary fossils of the hind limb (tibiotarsus, tarsometatarsus, hallux, pedal phalanges) of an extinct species of eagle (Accipitridae) from Hispaniola (Haiti, Dominican Republic). We are unable to refer these 24 fossils with confidence to any Accipitrid genus, living or extinct. Among living genera, the Hispaniolan fossils are most similar in nonquantitative characters to leg elements in Geranoaetus Kaup 1844, as represented in our comparisons by the South American species Black-chested Buzzard-Eagle (G. melanoleucus Vieillot 1819). Although it may be that Geranoaetus eventually will be found to accommodate the Hispaniolan eagle and perhaps other large, extinct species of West Indian eagles (from Cuba and Bahamas), the fossil material available at this time is inadequate. Generic assignment is complicated further by uncertain generic limits among surviving New World buteonine/buteogalline hawks and eagles, which themselves also are not well represented in scientific collections. Measures of the tibiotarsus suggest the Hispaniolan eagle was 15–30% larger than the extant Golden Eagle (Aquila chrysaetos). It is likely that the large Hispaniolan eagle went extinct along with, and potentially as a consequence of, the extinction of most endemic species of large- and medium-sized mammals (primates, rodents, and sloths) that once served as prey. [ABSTRACT FROM AUTHOR]

Apex predators are sensitive to human disturbance and persecution, often becoming the first losses in a declining urban wildlife community. A population of Crowned Eagles (Stephanoaetus coronatus) within eThekwini municipality, KwaZulu-Natal, South Africa, persists in a green space network called the Durban Metropolitan Open Space System (DMOSS). We used GPS–UHF telemetry to investigate the home range and habitat use of five breeding adult Crowned Eagles for 1 yr. We documented a mean annual home range for four birds of 13 km2 (Minimum Convex Polygon [MCP] 100%), or 6.3 km2 (Kernel Density Estimator [KDE], bandwith HLSCV 95%), equating to small home ranges for this large eagle, compared with other large eagles. Habitat use within home ranges and correlation with DMOSS area underscored the importance of retaining forest patches in the urban mosaic landscape to encourage the persistence of this large raptor. Our study highlighted the importance of planning green space in future city expansion and land development. The spatial and habitat associations of Crowned Eagles may be used to inform urban planners who wish to support biodiverse communities that include apex predators in an urban landscape. [ABSTRACT FROM AUTHOR]

Abstract Sexual differences in parental care investment may affect individual survival or performance, and also demography. We investigated parental-care behavior of the endangered Chaco Eagle (Buteogallus coronatus) to evaluate implications for population conservation in semiarid habitats of central Argentina. From 2004 to 2012, we monitored three breeding attempts using video recording (275 hr) during the incubation period, and nine pairs during the nestling-rearing period by means of video recording (1087 hr) and focal observations at nests (232 hr). Chaco Eagles showed a strong division of parental care by sex. Females contributed significantly more than males to incubation, shading/brooding, and feeding of the nestling, whereas males provided prey to females during incubation and to nestlings during the early nestling-rearing period. Foraging males, which spend more time away from the nest, may be more exposed to anthropogenic activities and negative interactions with humans. If males are more vulnerable to such effects, this could decrease the survival of breeding males and potentially increase the recruitment of immature males to the breeding population. In this event, the ability of the inexperienced immature males that replace the adult eagles to cope with the food and care demands of the mate and offspring is critical for ensuring Chaco Eagle population maintenance. [ABSTRACT FROM AUTHOR]

In this article, the author discusses an observation of a Chaco Eagle nest on a human-made structure in central Argentina. Topics discussed include ability of the species to use artificial structures for breeding, using artificial platforms as a tool in habitat management for the Eagle and location of nest being in treeless sandy grasslands dominated by perennial grasses of Stipa.

Studies deploying Platform Transmitter Terminals (PTTs) or Global System for Mobile Communications-GPS (GSM) packages on Golden Eagles have typically used backpack harnesses for attachment despite evidence indicating potential significant negative effects on reproduction and survival. Retention, safety, and utility of tail-mounted PTTs were tested on a sample of Golden Eagles in southwestern Montana. Argos satellite-tracked PTTs of two configurations were attached dorsally or ventrally to the central rectrices of 27 Golden Eagles to study survival. Sixteen packages were known to have been molted or removed (i.e., shed) by the eagle and 13 recovered. Of recovered tail-mounts, six (46%) were forcibly removed by eagles; five by males and one by a female. All packages that were forcibly removed were 32-g ventral mounts. Females tended to retain tail-mounts longer than males and dorsally mounted PTTs tended to be retained longer than those mounted ventrally. Eagles tagged in winter retained PTTs the longest. The duration of tail-mounted PTT retention was adequate for analysis of survival and yielded an adult annual survival rate (86%) consistent with recent U.S. Fish and Wildlife Service estimates (87%). Eight of 13 (62%) territorial adults tagged with PTTs were known to attempt breeding the year they were tracked and six (46%) produced young, rates that did not differ ( P > 0.23) from those of a larger sample of the population surveyed during the same period. Logistic regression analysis of cumulative range size by monitoring duration of four territorial adult eagles with tail-mounted GPS indicated that 99% of total range was recorded within 140 d of tracking. Los estudios que utilizan Transmisores PTT o Sistemas Globales de Comunicación Móvil-GPS (GSM) montados en individuos de Aquila chrysaetos generalmente utilizan arneses tipo mochila para la instalación de los dispositivos, a pesar de la evidencia que indica posibles efectos negativos significativos en la reproducción y la supervivencia. La retención, la seguridad y la utilidad de los transmisores PTT montados sobre la cola de individuos de A. chrysaetos fueron probadas en una muestra de águilas de esta especie en el suroeste de Montana. Los transmisores PTT con seguimiento satelital Argos con dos configuraciones fueron montados dorsal o ventralmente en las plumas rectrices centrales de 27 individuos de A. chrysaetos para estudiar la supervivencia. Dieciséis emisores fueron mudados o quitados (i.e., desprendidos) por las águilas y 13 fueron recuperados. De los dispositivos recuperados, seis (46%) fueron quitados por la fuerza por las águilas; cinco por machos y uno por una hembra. Todos los dispositivos quitados por la fuerza fueron dispositivos de 32 gramos montados ventralmente. Las hembras tendieron a retener los dispositivos montados en la cola mayor tiempo que los machos y los transmisores PTT montados dorsalmente tendieron a ser retenidos mayor tiempo que los que fueron montados ventralmente. Las águilas marcadas en invierno retuvieron los transmisores PTT durante un mayor periodo de tiempo. La duración de la retención de los transmisores PTT fue adecuada para realizar un análisis de supervivencia y mostró una tasa de supervivencia anual de adultos (86%) consistente con las estimaciones del Servicio de Pesca y Vida Silvestre de los Estados Unidos (87%). Se supo que ocho de 13 (62%) adultos territoriales marcados con transmisores PTT intentaron reproducirse el año en el que fueron estudiados y seis (46%) sacaron adelante pollos, valores que no difirieron ( P > 0.23) de aquellos obtenidos en una muestra más grande de la población censada durante el mismo periodo. Los análisis de regresión logística del área acumulativa de campeo obtenida con GPS montados en la cola de cuatro águilas adultas territoriales indicaron que el 99% del área de campeo total fue registrada durante 140 días de seguimiento. [Traducción del equipo editorial] [ABSTRACT FROM AUTHOR]

The breeding success of raptors is strongly affected by food supply. We examined the reproductive success of Eurasian Eagle-Owls ( Bubo bubo) and assessed the effects of landscape and diet on reproductive success at 44 nest sites in wetland and non-wetland (mostly agricultural lands, forests, and human settlements) habitats in west-central Korea. We found that eagle-owl reproductive success was significantly higher in wetland than in non-wetland habitats (mean of 1.9 vs. 1.3 fledglings per breeding pair, respectively). Although the average number of fledglings per successful pair was similar in the two habitats (2.0 vs. 1.8), the average numbers of fledglings per hatchling (0.9 vs. 0.7) and per egg (0.8 vs. 0.5) were both higher in wetland habitats. Further, for the wetland habitats, birds (mostly Anatidae, Columbidae, and Phasianidae) were the most important prey group by both number and biomass (67% and 84%, respectively) in the breeding period. However, in non-wetland habitats, both mammals (59% by number) and birds (67% by biomass) were important prey in the breeding period. The amount of Phasianidae in the diet (by biomass) and the date of the onset of egg-laying were positively and negatively (respectively) significant determinants of the number of fledglings per egg, whereas the percentage of wetland in the habitat was the only significant determinant for the number of fledglings per hatchling. El éxito reproductivo de las aves rapaces está afectado fuertemente por la disponibilidad de alimento. Estudiamos el éxito reproductivo de Bubo bubo y evaluamos los efectos del paisaje y la dieta en su éxito reproductor en 44 sitios de cría en hábitats de humedales y de no humedales (principalmente tierras agrícolas, bosques y asentamientos humanos) en el centro oeste de Corea. Encontramos que el éxito reproductor de B. bubo fue significativamente mayor en hábitats de humedales que en no humedales (media de 1.9 versus 1.3 volantones por pareja reproductiva, respectivamente). Aunque el número promedio de volantones por pareja exitosa fue similar en los dos tipos de hábitat (2.0 versus 1.8), los promedios de volantones por pollo eclosionado (0.9 versus 0.7) y por huevo (0.8 versus 0.5) fueron ambos mayores en hábitats de humedales. Además, para los hábitats de humedales, las aves (principalmente Anatidae, Columbidae y Phasianidae) fueron el grupo más importante de presas tanto por la cantidad como por la biomasa (67% y 84%, respectivamente) en la época reproductiva. Sin embargo, en los hábitats de no humedales, tanto los mamíferos (59% en cantidad) como las aves (67% en biomasa) fueron presas importantes en la época reproductiva. La cantidad de Phasianidae en la dieta (en términos de biomasa) y la fecha de inicio de la puesta de huevos fueron determinantes significativos del número de volantones por huevo de forma positiva y negativa (respectivamente), mientras que el porcentaje de humedales en el hábitat fue el único determinante significativo con respecto al número de volantones por pollo eclosionado. [Traducción del equipo editorial] [ABSTRACT FROM AUTHOR]

The article presents a case study on the occurrence of two events of siblicide in Bonelli's Eagle (Aquila fasciata) which caused by its aggressive behavior. Topics discussed include decrease in the fertility rates and prey availability, increase in the mortality rates, resulting death of nestlings, impact of poor environmental conditions, removal of upper area skin and effect of aggression.

Buteogallus coronatus es un ave rapaz de gran tamaño y una de las especies de rapaces más amenazadas en el mundo, con una población máxima estimada de 1500 individuos. Las principales amenazas identificadas para esta especie son la pérdida y degradación de su hábitat y la mortalidad no natural por persecución directa y colisiones con infraestructuras humanas. Reportamos casos de persecución directa sobre esta especie en Argentina. Compilamos toda la información publicada disponible y también los casos de aves entregadas al centro de rehabilitación del Programa de Conservación y Rescate de Aves de Presa del Zoológico de Buenos Aires. Durante el periodo comprendido entre 1980 y 2014, encontramos 83 casos provenientes de casi todas las provincias argentinas en la que el águila está presente. Nuestros resultados evidencian que probablemente la persecución directa es una causa de mortalidad importante para las águilas en Argentina. [Traducción del equipo editorial] [ABSTRACT FROM AUTHOR]

The article presents research which examined the habitat use, home range as well as population density of crested serpent-eagles found in the Southern area of Taiwan. Topics covered include the lack of studies about the habitat use of many tropical raptors as well as the use of radio-tracking by researchers to observe the species. Also mentioned is the discovery of many perch sites of the eagles near a primary monsoon forest.

The article focuses on a study which investigates the diet of short-toed snake-eagles of all ages during the breeding season and autumn migration. It analyzes the stomach contents of the eagles, which were found to contain invertebrates such as centipedes and praying mantises. It suggests that the use of invertebrates as a food source from September onwards may be due to their abundance in late summer.

The article focuses on a study which summarizes documented cases of eagle mortality at wind energy facilities in the contiguous U.S., excluding Altamont Pass Wind Resource Area (APWRA), from 1997 to June 30, 2012, as starting point for future assessments. Information on eagle mortalities and injuries that occurred in the said period were retrieved using public-domain sources. Results revealed a minimum of 85 eagle mortalities at 32 wind energy facilities in 10 states during the said period.

The article offers the authors' insights on a study on the population trends of Bald Eagles at Besnard Lake in Saskatchewan, Canada between 1968-2012. The authors explain their investigation of the significance of population-size and climate factors in the explanation of population growth rate variation. They cite the statistical methods used in the study such as piecewise regression analysis, stepwise regression, and the Durbin-Watson test. Results show regular changes in mean productivity and nesting success.

The article presents a study which examined the effect of age at release and sex on the length of the dependence period of hacked captive-bred juvenile harpy eagles (Harpia harpyja) in Panama and Belize in 2002-2007. Based on the results, the survival or hacking success of the birds is greater at older release age compared to younger release age. The results showed that hacking can be employed for the successful release of captive-bred harpy eagles into the wild, but the method should be delayed until the bird's fledging age for better results.

The article presents a study on the communal roosting behavior of young Bonelli's Eagles in Spain. The researchers searched the areas with the largest concentration of young birds within the Guadal-canal and Cadiz-Sevilla dispersal areas to identify the sites chosen by eagles for roosting. They randomly selected a subset of three trees in each of the 10 different roosts in order to obtain an indication of the size of the trees used by eagles. They found that the communal roosting sites of the Bonelli's Eagles are entirely legally unprotected in Andalusia.

The article presents an observation study of the post-fledging behavior and prey of the Solitary Eagle or Harpyhaliaetus solitarius in the Cayo District of Belize near the Mountain Pine Ridge Forest Reserve. It mentions the interactions between juvenile and adult eagles that consisted of the juvenile food-soliciting and the adult vocalizing which consisted of long series of characteristic whistling before delivering the prey to the juvenile. The article also details the feeding habits and food exchange between the adult and juvenile hawks and concludes that Solitary Eagles have a specialized diet of reptiles, mainly snakes and lizards.

The article presents a study on the diet of the Crowned Eagle (Harpyhaliaetus coronatus) during the breeding season in the Monte Desert in Mendoza, Argentina. A group of researchers examined the diet of the eagle during the brood-rearing period with the use of direct observations of prey deliveries and through the collections of prey remains and pellets. They identified 330 prey items with mammals as the common prey in terms of number and biomass. They also reported the differences between diet as indicated by direct observations and prey remains.

The article presents a study on the characteristics of Mountain Hawk-Eagle, whose population reaches Japan, China and Taiwan. It is found that most of these species give time in their breeding season in a way that the greatest food demand period will correspond with the peak in the availability of food. Meanwhile, it is noted that the Mountain Hawk-Eagle's primary prey is the giant flying squirrel in which pregnancy takes place in the period ranging from December to February. Further, it is also observed that reptiles or birds that breed during the spring or summer are commonly fed by most of the forest raptors.

The article presents a study, which has used band recovery data for evaluating distances between locations of recovery for 154 nestling Florida Bald Eagles while discussing the understanding natal dispersal implications and the philopatry among the species. It has been observed that female and younger birds in particular, had longer distances for recovery among the 21 mature eagles of known banding and sex. The study suggests that the records being examined show higher level of philopatry as well as short distances for natal dispersal specifically in male Bald Eagles.

The article presents a study which aims to determine the direction as well as extent of Bald Eagles' post-fledging migration after placing colored identification bands and transmitters. Observation shows that there were 13 of the juveniles that successfully fledged while one transmitter failed. Further, 11 eagles which survived the post-fledging and one eagle was lost through trackers following the departure. It is also noted that habitats are varying on stopping locations as well as the involved interior lakes and reservoirs.

The article presents efforts to conserve Bonelli's eagles which are rescued through the Corpo Forestale dello Stato, Divisione Investigativa in Rome, Italy and in compliance with the Convention on International Trade in Endangered Species (CITES). The volunteers of the group considered the technique of readoption of the eagles by the natural parents in their natural habitat in Sicily, and the health of the eagles were monitored because of telemetry attached to them.

The article focuses on the cannibalist behavior of Bonelli's eagle. Topics covered include the way scientists view cannibalism as the process of eating conspecifics at any stage of the life cycles of species as well as the threat posed by parental cannibalism to offsprings of animal species. Also mentioned is the observation of cannibalism among some species of bird such as Aquila fasciata in the Iberian Peninsula.

Corrections to the articles "Diurnal Raptors in Los Tuxtlas Biosphere Reserve, Mexico: Current Presence and Relative Abundance" and "Natal Dispersal Distance of Bald and Golden Eagles Originating in the Coterminous United States As Inferred from Band Encounters," published in previous issues are presented.