Nest-site selection by the white-tailed eagle and black stork – implications for conservation practice

Abstract

Background Nesting trees and habitat represent the key factor underpinning stand selection by forest-dwelling birds. While two large European species – the black stork (Ciconia nigra L.) and white-tailed eagle (Haliaaetus albicilla L.) – are known to require old, large trees for nesting, we sought to investigate further by comparing species requirements at the levels of the nesting tree, nesting stand, and landscape. This entailed a detailed examination of forest features within circles of radius 15 m surrounding 16 and 19 trees holding the nests of storks and eagles respectively. The same parameters were also checked in the vicinity of 50 randomly-selected mature trees. Results Our results indicate different nesting preferences, with the eagles entirely confining themselves to Scots pine (Pinus sylvestris L.) – a species also chosen by black storks, which nevertheless regularly favour pedunculate oak (Quercus robur L.). Both species select trees of greater girth than the random ones, but white-tailed eagles choose to nest in the vicinity of patches of mature old stands with a loose canopy, to the extent that nesting trees and surrounding trees are of similar ages. In contrast, black storks prefer “veteran” trees with low-set crowns that are much older than any others in their vicinity. Nesting trees of the eagles are away from roads and close to lakes, while black storks do not avoid roads. Conclusions As the ages of nesting trees of both species are greater than ages at final cutting in this region’s managed forest, silvicultural measures will need to be adjusted, with small patches of forest spared, or larger areas as “islands” of old-growth. Likewise, as tending and thinning are engaged in, certain trees with horizontal branches will need to remain, with relict trees also left untouched. As it happens, all of these recommendations are anyway key elements of close-to nature silviculture and multifunctional forestry.

Identification of spatial data and ecology of Javan hawk-eagle's nest (Nisaetus bartelsi) in the Kondang Merak Coastal, South Malang, East Java, Indonesia

“…Effective nest positioning reduces the threat of predation upon nests. In addition, a necessity to minimize the risks of predator attacks is the most influential factor to determine the nests' location as well as its physical structure (Mundahl et al 2013;Phillips and Hatten 2013;Mainwaring et al 2014;Lopez-Lopez et al 2016;Khaleghizadeh and Anuar 2017;Zawadzki et al 2020). According to Azmi et al (2016), the Javan hawk-eagle prefers to occupy primary and secondary tropical rainforest habitats with fairly high rainfall characteristics.…”

Anthropogenic noise and habitat structure shaping dominant frequency of bird sounds along urban gradients

“… 63 The segmentation of individual trees within the nine recording plots was performed using Lidar 360, followed by the calculation of single-number tree attributes from the quantitative structure models using TreeQSM software in MATLAB. 64 Previous findings suggest that individual tree parameters, such as tree height and crown base height, may be key factors influencing bird diversity 65 , 66 and noise propagation. 67 , 68 Therefore, the aforementioned method primarily focuses on extracting individual tree height data, including tree height and crown base height.…”

White-Tailed Eagles’ (Haliaeetus albicilla) Exposure to Anticoagulant Rodenticides and Causes of Poisoning in Poland (2018–2020)

“…The white-tailed eagle (Haliaeetus albicilla) is the largest predatory and scavenging free-living species of bird in Poland, also generally widely distributed across Eurasia [30][31][32]. The body mass of adult individuals reaches 4 to 5 kg, and their wingspan up to 2.5 m [32].…”

“…The white-tailed eagle (Haliaeetus albicilla) is the largest predatory and scavenging free-living species of bird in Poland, also generally widely distributed across Eurasia [30][31][32]. The body mass of adult individuals reaches 4 to 5 kg, and their wingspan up to 2.5 m [32]. In recent decades, the population of the white-tailed eagle in Poland has shown a growing trend, which also results in a larger area of occurrence.…”

“…In recent decades, the population of the white-tailed eagle in Poland has shown a growing trend, which also results in a larger area of occurrence. It is most likely to nest in older forests on large trees, near feeding grounds that are rich in fish and waterbirds [30,32]. The diet of the white-tailed eagle is mainly fish, but also includes animals such as birds, mammals (including red fox Vulpes vulpes), and occasionally carrion [30,33].…”