Mortality of birds associated with power line infrastructure has emerged as an important conservation issue, revealing substantial and frequently underestimated threats to avian populations at a global scale (Lehman et al. 2007; Jenkins et al. 2010; Bernardino et al. 2018). With the rapid expansion of electrical infrastructure, including power lines and poles, birds are increasingly exposed to fatal encounters. Globally, millions of birds are estimated to die each year due to interactions with power lines, particularly large-bodied, slow-reproducing species such as raptors and waterfowl. These losses pose serious conservation challenges, as even modest increases in adult mortality can affect long-term population viability (Loss et al. 2014; Singh et al. 2024).

Among the main mechanisms of bird mortality associated with power lines is electrocution, which typically occurs on low- to medium-voltage distribution lines where insufficient separation between energized components or between an energized conductor and grounded hardware (e.g., metal crossarms) enables birds to bridge contacts and complete an electrical circuit, often while perching or taking off (Demerdzhiev 2014; Biasotto et al. 2022). These interactions represent a distinctive form of human–wildlife conflict. Unlike direct conflicts such as crop depredation or livestock predation (Nyhus 2016; Mekonen 2020), the impacts here are indirect, with essential energy networks that sustain economic growth, electrification, and renewable energy deployment simultaneously imposing hidden costs on biodiversity (Burdett et al. 2022; Singh et al. 2024). At the same time, power lines may create ecological opportunities for species, offering perches or nesting substrates in landscapes lacking tall natural structures. This dual role, as both hazard and habitat surrogate, complicates management, requiring a balance between energy security and ecological sustainability (D’Amico et al. 2018; Bennett et al. 2025).

Mitigation measures are well established, and engineering interventions such as insulating energized components, reconfiguring cross-arms, or installing perch deterrents can substantially reduce electrocution risk (Bevanger 1994; Dixon et al. 2019). When combined with strategic routing, micro-siting, and rigorous environmental assessment, these measures demonstrate that bird mortality can be significantly reduced without compromising energy delivery (Dwyer et al. 2014; D’Amico et al. 2018). Despite this research and the proven solutions, implementation remain patchy.

The majority of electrocution studies have been conducted in developed regions, leaving major knowledge gaps in biodiversity-rich but under-studied regions (Bernardino et al. 2018; Guil and Pérez-García 2022). One such under-represented region is the South Caucasus, where diverse topography, high avian richness, and growing energy infrastructure coverage converge. While a study from Azerbaijan’s Nakhchivan Autonomous Republic has documented substantial mortality on distribution lines (Mammadov and Matsyura 2020), information from other territories in the region remains scarce, confined to NGO reports or general information from raptor research (Abuladze 2013; Abuladze 2023; Mammadov et al. 2025), rather than systematic scientific analyses. This evidence gap is particularly concerning in a region that lies along important migratory corridors for raptors and other large birds (Verhelst et al. 2011; Heiss 2013). The ecological implications of bird electrocution and collision extend beyond individual mortality to broader ecosystem functions, as many avian species act as scavengers, dispersers, or predators (Sekercioglu 2006; Loss et al. 2015).

Against this backdrop, the present case study provides the first assessment of avian mortality from power lines in several territories of Armenia. The primary objective of this study was to assess the extent of bird electrocution in the study areas (mainly concentrating on birds of prey), with particular focus on identifying the most affected species and high-risk hotspots. The analysis further examines incident distribution, sex and age composition of victims, and the influence of different pole types and on electrocution risk.

Our results show that bird electrocution affects a diverse group of species, with 15 species identified and 4 additional specimens recorded to the genus level (Figure 4). The dataset (Table 1) includes detailed information on sex, life stages, and pole types. The summary includes 252 electrocution records, with the highest numbers recorded for Eurasian magpie (n = 49), common kestrel (n = 34), rook (n = 34), western jackdaw (n = 33), and common buzzard (n = 31), together comprising 71.8% of all records. Raptors accounted for 97 individuals (38.5%). Sex could rarely be determined (250 of 252 records were classified as NA sex), precluding sex-based comparisons. Age was determined for 53 individuals, of which 44 (83.0%) were classified as juvenile/immature and 9 (17.0%) as adult. In the raptor subset, 31 of 34 age-determined individuals (91.2%) were juvenile/immature. Most records occurred on concrete poles (239/252; 94.8%), whereas only a small proportion were found on wooden poles (13/252; 5.2%). Most carcasses were recorded on intermediate poles (216/252; 85.7%), while fewer cases were associated with anchor poles (27/252; 10.7%) and poles with switches (9/252; 3.6%). A more detailed breakdown of pole types and materials is provided in the following sections.

This study provides one of the first assessments of bird-power line interactions in the Republic of Armenia and suggests that electrocution on medium-voltage OPLs may represent an important source of avian mortality in the country, with patterns broadly consistent with global findings.

Overall, corvids and raptors comprised the majority of records. Within corvids, Eurasian magpie was the most frequently recorded victim, followed by rook and western jackdaw, reflecting their relative abundance in steppe and agricultural landscapes and their communal perching behaviour. Among raptors, common buzzard, long-legged buzzard, and common kestrel were most frequently recorded, consistent with their regular use of poles as hunting and resting perches. These findings suggest that areas with flat terrain, limited natural perches, extensive uninsulated power lines, and key migratory habitats may concentrate electrocution risk, particularly for medium and large species that rely on elevated structures for hunting and roosting.

Among the 97 recorded raptor individuals (38.5% of all recorded carcasses), age could not be determined for many individuals due to carcass condition. Juvenile/immature accounted for about 32% of all recorded raptors, indicating that younger birds were also susceptible to electrocution. Although less frequent, large raptors of local conservation concern were also affected, including a juvenile golden eagle and a Eurasian eagle-owl, both listed as Vulnerable in the Red Book of Animals of Armenia. Additionally, four gull carcasses were found, presumably Armenian gulls breeding at Lake Arpi, a species also classified as Vulnerable in the Red Book listings for the country, although species identification could not be confirmed with certainty.

The majority of recorded fatalities were associated with concrete poles, particularly intermediate types. This pattern reflects both the higher inherent hazard associated with certain concrete pole configurations and the survey design, which prioritized concrete lines. Wooden poles yielded fewer incidents in the surveyed sections, probably due to their structural characteristics, including comparatively wide spacing between wires, moreover, most of the examined wooden poles were not grounded. However, it should be emphasized that wooden-only lines were under-sampled (and excluded in the second survey phase), so their relative risk cannot be directly compared with that of concrete poles. In Shirak province, particularly in the northern regions such as Ashotsk, Amasia, and Maralik, most poles were wooden. These poles, built in the 1960s during the Soviet era, remain widely used and, according to the engineer of the “Ashotsk” network, are better suited to Shirak’s harsh climate, where prolonged severe frosts can cause concrete poles to break at their base. Another contributing factor is that wooden poles are comparatively easier to transport and install in mountainous terrain or remote areas lacking vehicle access, which explains their continued use and replacement to this day in Armenia (L. Harutyunyan pers. comm.).

Among pole types, most electrocution cases occurred on intermediate poles, primarily concrete poles, with only one case recorded on wooden pole. This was followed by anchor poles, which included three wooden poles. Poles with switches were rarely involved; however, of the nine such poles recorded, seven were wooden and grounded.

In some cases, particularly in Ararat and Armavir provinces, surveyed power lines were short and terminated abruptly, requiring the team to relocation to survey other potentially hazardous lines. In addition, access to certain poles within populated areas was occasionally restricted due to private property boundaries and barriers. In Armavir, although the surveyed lines were relatively short, they represented potential hazards because they were often the only elevated structures in otherwise open landscapes. They were mostly constructed of concrete poles with metal cross-arms, however, no bird casualties were recorded during their inspection, possibly because many of these lines were located near settlements, highways, and agricultural fields, where scavenging by dogs and other carnivores may have reduced carcass detectability. Following preliminary assessments, surveys in Armavir were later discontinued for several reasons, including the fact that most power lines traversed settlements and active roads, where the risk to large birds appeared relatively low, and frequent accessibility constraints. Nevertheless, incidents of collision and electrocution involving white storks (Ciconia ciconia) were reported in villages by local residents, governmental bodies and Armenian Electric Networks (pers. comm.).

Although quantifying insulated versus non-insulated OPLs was not a primary goal on this study, it is interesting to note, some newly constructed lines in Ararat, Armavir, and Kotayk provinces were fully equipped with closed cable wires, potentially reducing electrocution risk. Approximately 7 km of relatively insulated lines (closed cable wires) have been erected near Lanjanist, Lanjazat, and Lusashogh villages in Ararat province and no casualties were recorded on this section.

Spatial analyses identified key “hotspots”. During the breeding season, the highest concentration of cases occurred around Hatsavan and Garni villages in Kotayk province. Raptors were relatively few in this season, with only four common kestrels recorded, but they were clustered in the same locations. During the autumn migration season in Shirak, the highest concentration of electrocution incidents was recorded around Lake Arpi National Park, particularly at locations where parallel, uninsulated 10 kV lines ran approximately 20 m apart along the lakeshore. Additional hotspots included the regions between Zorakert and Paghakn villages, from Paghakn to Ardenis village, and along the Bavra–Tavshut highway. Other hazardous sections included the Hartashen–Tashir line, where casualties included a golden eagle, buzzards, and kestrels, and the Karaberd–Maralik section, which caused multiple raptor deaths. These patterns suggest that open steppe and agricultural areas with few natural perches and extensive uninsulated infrastructure are especially dangerous, particularly in key migratory habitats.

Several unique or unexpected cases further illustrate the diversity of risks. In Ararat province, a greater flamingo collision was documented, with photographic evidence provided by a fishpond owner. White storks were also reported dying from both electrocution and collisions near their nests. One young long-legged buzzard showed signs of captivity, including cut tail feathers and cords on its legs, suggesting that compromised survival skills may have contributed to its mortality.

Electrocution effects varied widely. Only nine carcasses bore visible burn marks, ranging from localised burns on toes or bills, to a magpie with full-body burns and scorched ground around the carcass, however, most carcasses lacked external signs of electrocution. This indicates that the absence of burns should not be used to rule out electrocution as a cause of death.

Unfortunately, due to resource limitations, we were unable to conduct systematic carcass removal trials, which prevented a robust estimation of true mortality in the surveyed area after accounting for scavenger activity and carcass disappearance due to environmental exposure. The absence of formal carcass persistence (including scavenger removal and decomposition) trials and observer-detection trials represents an important source of uncertainty in mortality surveys under power lines. Previous studies have shown that a substantial proportion of bird carcasses may disappear before scheduled searches, while others may remain undetected because detection probability varies with carcass size, season, habitat structure, ground visibility, and observer performance. As these biases are site and method specific, failure to quantify them can lead to a substantial underestimation of true mortality (Loss et al. 2014; Borner et al. 2017; Bernardino et al. 2022). Therefore, the numbers reported in the present study should be interpreted as minimum observed mortality rather than absolute mortality estimates. However, to obtain at least an approximate indication of carcass persistence for birds of prey, we marked several fresh carcasses that had probably been electrocuted within the previous 1–2 days. During subsequent visits, we found that marked buzzard and kestrel carcasses persisted for more than a month in some cases, even in open grassland with low vegetation, and one Golden Eagle carcass remained on a pole for at least 301 days (from 27 September 2024 to 25 July 2025; rechecked in 2025). Although some carcasses did show signs of scavenging or displacement, many remained intact for extended periods, suggesting that detection probability for large raptors may be relatively high in the studied area.

Although the surveyed areas were relatively limited, the results indicate that bird electrocution on medium-voltage power lines is an existing conservation problem in Armenia and underline the need for targeted mitigation. Retrofitting hazardous concrete poles with insulation of energized components, perch deterrents, or other bird-safe designs would reduce mortality substantially and should be prioritized by the national electricity distribution company and its regional branches and OPL owners. This is especially important in open landscapes with few natural perches, key biodiversity areas such as Lake Arpi National Park, and migration corridors in Shirak marz. The mortality of Red Book species further emphasizes the conservation urgency of this mitigation. More broadly, these results show that power infrastructure impacts may represent a form of human–wildlife conflict, in which essential development creates severe but preventable biodiversity losses. Integrating bird-safe standards into national energy planning, technical regulations and legislation, and environmental assessment procedures should therefore be considered by the relevant governmental bodies, while systematic monitoring could be supported jointly by state institutions, the energy sector, and conservation organizations to reduce avian mortality and better safeguard bird populations.