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The Ferruginous Hawk (Buteo regalis) is a raptor of conservation concern in much of its range. Population trend estimates from Breeding Bird Surveys and migration counts for this species are often contradictory and of low credibility. Therefore, we used Christmas Bird Count data to assess population trends for Ferruginous Hawks that winter in California, USA. Evidence suggests that the birds breeding in southeastern Washington and northeastern Oregon may represent a metapopulation that winters almost exclusively in California. Data for the 25-yr period from Count Year 98 (winter 1997–1998) to Count Year 122 (winter 2021–2022) from 22 California Christmas Bird Count circles in the core winter range of Ferruginous Hawks showed a significant positive trend. This positive trend contrasts with the continent-wide negative trends observed for most grassland/open country bird species and is surprising given ongoing declines of this species' preferred winter habitat in California during this same period. We discuss potential explanations that may account for these differences, including the possibility that the California-wintering Ferruginous Hawks include a large proportion of birds breeding outside of southeastern Washington and northeastern Oregon. [ABSTRACT FROM AUTHOR]

We conducted an annual late-summer raptor survey along a 53-km route around Henrys Lake Flats, Idaho, from 1994 to 2022, and pooled the resulting data with similar published information collected from 1974 to 1993. A mean of 36 Red-tailed Hawks (Buteo jamaicensis), 13 Ferruginous Hawks (Buteo regalis), and 16 Swainson's Hawks (Buteo swainsoni) were observed each year along this route. The counts of Ferruginous Hawks declined significantly (P < 0.001) over the combined study period and were almost 10 times lower from 2013–2022 compared to 1974–1983. The counts of Red-tailed Hawks also declined significantly (P = 0.04), whereas no significant variation was evident for Swainson's Hawks over the combined 49-yr study period. Summer precipitation levels and hawk numbers were not correlated. The observed numbers of Ferruginous Hawks and Red-tailed Hawks were correlated throughout the study period, suggesting similar responses to local environmental and/or land-use factors. Obvious changes in the study area during the corresponding 49 yr include conversion of some pastures to center-pivot-irrigated agriculture and a substantial expansion of all-terrain vehicle trails and recreational activity. Because 88% of Ferruginous Hawks breeding in the Columbia Basin funnel through the upper Snake River Plain and adjacent areas on their way to post-breeding ranges in the Great Plains, expanded surveys in these areas in late August/early September could effectively monitor this intermountain population. Realizamos un censo anual de rapaces en el final del verano a lo largo de una ruta de 53 km alrededor de las planicies del Lago Henrys, Idaho, desde 1994 hasta 2022, y combinamos los datos obtenidos con información similar publicada colectada entre 1974 y 1993. Se observó un promedio de 36 individuos de Buteo jamaicensis, 13 de B. regalis y 16 de B. swainsoni cada año a lo largo de esta ruta. Los conteos de B. regalis disminuyeron significativamente (P < 0.001) durante el período de estudio combinado y fueron casi 10 veces más bajos entre 2013–2022 en comparación con 1974–1983. Los conteos de B. jamaicensis también disminuyeron significativamente (P = 0.04), mientras que no se observó variación significativa en el caso de B. swainsoni durante el período de estudio combinado de 49 años. Los niveles de precipitación en verano y el número de individuos de Buteo no estuvieron correlacionados. Los números observados de B. regalis y B. jamaicensis estuvieron correlacionados durante todo el período de estudio, lo que sugiere respuestas similares a factores locales ambientales y/o de uso del suelo. Los cambios evidentes en el área de estudio durante los 49 años analizados incluyen la conversión de algunos pastizales a agricultura con sistemas de riego de pivote central y una expansión sustancial de caminos para vehículos todo terreno y actividad recreativa. Dado que el 88% de los individuos de B. regalis que se reproducen en la Cuenca de Columbia pasan por la parte alta de la planicie del Río Snake y áreas adyacentes en su camino a las áreas post reproductivas en las Grandes Llanuras, la ampliación de los censos en estas áreas a finales de agosto/principios de septiembre podrían permitir un seguimiento efectivo de esta población inter-montana. [Traducción del equipo editorial] [ABSTRACT FROM AUTHOR]

Using fall migration trend data from the Raptor Population Index analyses (n = 59 count sites) paired with winter Christmas Bird Count trend data at the USA state and Canadian province level, we evaluated continental and regional patterns in trends of American Kestrels (Falco sparverius) over the last 30 yr. Long-term trends at the continental and regional level showed widespread declines in the number of kestrels counted during both fall migration and winter. The lone exception was in western North America where declining migration counts were evident, but could at least partly be explained by increasing winter counts. These results suggest that western kestrels are shifting migratory tendencies, migrating shorter distances (short-stopping), or are not migrating at all. This contrasts with patterns in central and eastern North America where kestrel counts declined in both fall and winter over the last 20- and 30-yr periods. Recent trends (2009–2019) showed less widespread declines in both fall and winter across North America and for most regions, suggesting kestrel declines might have moderated in the past decade. However, the species remains at significantly reduced abundance levels compared to the recent past and has not rebounded. [ABSTRACT FROM AUTHOR]

We analyzed counts from the annual Midwinter Bald Eagle Survey to examine state, regional, and national trends in counts of wintering Bald Eagles ( Haliaeetus leucocephalus) within the conterminous 48 United States from 1986 to 2010. Using hierarchical mixed model methods, we report trends in counts from 11 729 surveys along 844 routes in 44 states. Nationwide Bald Eagle counts increased 0.6% per yr over the 25-yr period, compared to an estimate of 1.9% per yr from 1986 to 2000. Trend estimates for Bald Eagles were significant ( P ≤ 0.05) and positive in the northeastern and northwestern U.S. (3.9% and 1.1%, respectively), while trend estimates for Bald Eagles were negative ( P ≤ 0.05) in the southwestern U.S. (−2.2%). After accounting for potential biases resulting from temporal and regional differences in surveys, we believe trends reflect post-DDT recovery and subsequent early effects of density-dependent population regulation. [ABSTRACT FROM AUTHOR]

En Australia, la mayoría de las poblaciones de Australasia de Pandion haliaetus cristatus se encuentran en hábitats costeros y de estuario a lo largo de las regiones subtropicales y templadas del norte. En las líneas de costa del sur, la especie se distribuye de modo más disperso y existe un ancho vacío en la distribución reproductiva en la esquina sureste del continente por debajo de los 36° de latitud sur, incluyendo Tasmania. La población es fundamentalmente sedentaria y se la considera como estable a lo largo de la mayor parte de su rango de distribución. Sin embargo, existen reportes de que la población se encuentra en disminución en el borde sur de su distribución en el sur de Australia, pero que está aumentando y extendiendo su área de distribución reproductiva hacia el sur en New South Wales. Las tasas reproductivas y las densidades poblacionales para las poblaciones en expansión en la costa este son equivalentes a las registradas para las poblaciones en recuperación de P. haliaetus luego de las disminuciones causadas por pesticidas en el hemisferio norte. A la inversa, la densidad poblacional es significativamente más baja en el sur de Australia donde, comparativamente, una baja productividad más el aislamiento geográfico sugieren que P. haliaetus podría estar en riesgo en el extremo sur de su distribución reproductiva en Australia. [ABSTRACT FROM AUTHOR]

The article discusses a study on the colonization of Cooper's Hawks or Accipiter cooperii in the Milwaukee, Wisconsin area in 1988-2008. It documents the natural colonization of the landscape by Cooper's Hawks population and its growth from 1993 to 2008. It notes that the population was possibly increasing at a rapid rate during the 1990s and continued to increase throughout the remainder of the study. An analysis of how reproduction of Cooper's Hawks varied with time and density is also offered.

The article presents an analysis of American Kestrels migration counts in 20 autumn hawkwatch sites in North America to estimate the population trends. It states that in the eastern part, significant declines was noted from 1974-2004, which was along the Appalachian Mountains and the Atlantic Coast, while stable numbers in eastern Great Lakes, and a noteworthy increase in western Great Lakes regions. It mentions that the study indicates population decline along the Pacific Northwest and the western interior of North America. Migration counts across the Gulf of Mexico were also included, which shows no significant population changes. The study suggests that kestrel populations had a long-term decline along the northeastern, western, and midwestern parts of North America.