Elusive and majestic, the Bittern’s booming call echoes across Minsmere’s reeds – a symbol of hope and conservation success

Egg abandonment leads to biased estimates of hatching failure in birds - Volume 35

Waterbirds Editor-in-Chief Job Description: We are seeking an Editor-in-Chief for our journal, Waterbirds, the International Journal of Waterbird Biology. The journal is published online four times a ...

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Journal of Ornithology - Migratory birds often traverse thousands of kilometers, yet some individuals may abandon migration and form sedentary populations—a process termed ‘migratory...

Bird collisions with power lines are a global conservation issue. This study examined the effects of wind farm construction and operation on seabird collisions with power lines in Galinhos, Northeastern Brazil. The research focused on a coastal area with 2.8 km of power lines across two beaches. Data on bird collisions, particularly involving Roseate Terns (Sterna dougallii) and Common Terns (Sterna hirundo), were collected from January 2010 to May 2020. The study aimed to assess collision impacts and the influence of wind farms. Results showed seasonal variation in collisions, peaking in March and declining in July. Wind farm construction correlated with a significant increase in collisions on the adjacent beach, suggesting disruption of migratory routes. Bird flight diverters installed on a power line segment did not significantly reduce collisions overall. These findings emphasize the need for thorough environmental impact assessments for power lines and wind farms to mitigate bird collision risks. The study underscores the complex causes of bird collisions with human-made structures and highlights the combined impacts of wind farms and power lines, calling for enhanced protective measures for vulnerable species.

The natural and anthropogenic wetlands of the Colorado River Delta are recognized as critical stopping and staging areas for migrating shorebirds. Given the importance of these wetlands and the uncertainty around their water sources, we conducted 9 paired, aerial and ground surveys between April 2021 and April 2023 to quantify migration season shorebird use across a study area of 486 km2 that covered the lower Colorado River estuary and the Ciénega de Santa Clara. We estimated that an average of 272,515 individual shorebirds occupy the study area at any given time during the active migration season. Shorebirds were most abundant in mudflats and flooded playas of the Ciénega de Santa Clara, followed by wetlands of the lower estuary. Shorebird abundance was positively related to the proportion of a count site covered by mudflats and flooded with surface water, and was positively related to the proportion of a year that a count site was flooded with surface water. While 21 shorebird species were recorded during ground surveys, 8 species made up more than 90% of the total birds counted. Estimated average abundances for these species were: 103,132 Western Sandpiper; 31,763 Red-necked Phalarope; 30,067 Long-billed Dowitcher; 23,527 American Avocet; 20,196 Least Sandpiper; 19,197 Black-necked Stilt; 10,901 Snowy Plover; and 8,993 Long-billed Curlew. We speculate that the study area hosts at least 1% of the North American population for 11 shorebird species during migration. Results confirm the importance of these wetlands for migrating shorebirds and highlight the need for securing water sources given increasing human water demands and decreased water availability due to climate change.

In order to understand causes of avian population declines and establish conservation strategies, we require knowledge of how changes to the environment are linked to changes in population abundance. Such linkages can be examined with large-scale, long-term databases, such as the North American Breeding Bird Survey (BBS). The BBS is generally under-utilized for waterbirds, in part due to the notion that it is unreliable; however, for some readily detectable species such as Black Terns (Chlidonias niger), this may be a valuable data source. We applied Bayesian hierarchical generalized additive models to BBS counts to examine population trends and drivers of abundance across the Black Tern range. We uncovered long-term declines and strong spatial variation in trends, with declines particularly prominent in peripheral areas at the edge of the species' range. There was a strong positive effect of spring moisture (measured via the Standardized Precipitation Evapotranspiration Index) on abundance, whereas moisture in the core of the species' range in the prairies had a negative effect on abundance in peripheral areas, suggesting birds are attracted to the core of the range in wet years, and vice versa. There was a weak and spatially varying effect of the North Atlantic Oscillation Index on annual abundance. Ongoing wetland loss coupled with climate extremes will become increasingly important for predicting population fluctuations in this and other waterbirds.