4

1 2 3 4 5 6 7 8 9 10 11 12 13 14

may be found at the site the animal was found, e.g. disturbed soil or plants nearby, hairs or feathers and bloodstains in the vicinity etc. 3.1.5 Ingestion of toxic plants Studies have shown that, in herbivorous or omnivorous animals, ingestion of toxic plants and subsequent disease and even death is more widespread than previously thought. Although animals may have some kind of a natural avoidance of toxic plants, this does not rule out their ingestion, tentatively due to impairment of the animals’ senses or due to the plant being “unknown”, e.g. invasive alien plants. 18 3.1.6 Natural Disasters Many types of natural disasters like avalanches, landslides, flooding, thunderstorms, forest fires and lightning strikes may directly or indirectly (e.g. habitat loss) affect and kill wildlife. While some of these disasters may be obvious as causes of death, others may be more inconspicuous. For example, thunderstorms are known to have caused mass mortality events in birds due to the accompanying high winds and disorientation of the animals. Therefore, the recent environmental and weather conditions at the site one or more carcass was found should always be recorded. Further, inspection and documentation of the topographic characteristics of the site should be completed to rule out some of the natural disasters (e.g. avalanches and landslides will not occur in the plains). 3.2 Non-natural causes 3.2.1 Human induced „legal“ causes 3.2.1.1 Legal hunting Legal hunting of designated game species is common in the Alpine Region both for wildlife management as well as for recreational purposes. Although different hunting systems and hence hunting laws exist in the alpine countries, counties and regions, they all have in common a clear description of which species are huntable at what specific time of year and in which manner. All large carnivores and most(?) raptors are protected year round in the alpine countries, thus shooting them is invariably illicit. 3.2.1.2 Collisions The rapid growth of transport infrastructure like roads and railroads, negatively affect wildlife both in indirect ways - loss of connectivity, landscape degradation and fragmentation-, as well as directly via increased animal mortality by collisions. 19 Further, other infrastructure developments like wind farms and power lines that are built in or through wildlife habitats may endanger especially bird populations directly by increasing the threat of collisions, entanglement and electrocution. 3.2.1.2.1 Collisions with vehicles, trains and aircraft Wildlife-vehicle collisions are a very common, and probably underrated, cause of death in wildlife. For example, the numbers of game-animals killed on Austrian roads are as high as 100.000 individuals per year. Most of these accidents occur on secondary and tertiary roads since most of the highways and motorways are fenced in the Alpine Region, thus making these roads impermeable for most ground dwelling animals. However, bears, lynxes and wolves with their notable abilities to dig and/or jump may nevertheless enter these sorts of roads. Further, there is a risk for raptors (and of course other birds) being hit by vehicles (especially trucks) although this seems to happen only rarely. Deaths due to collisions with trains do occur, as happened for example in Grisons/Switzerland in 2012 and 2016 when brown bears M13 and M32 collided with local trains, with the latter bear succumbing to its injuries. Some aspects have to be obeyed in forensic investigations when vehicle collisions are suspected. Not all animals die on the spot and stricken animals may even survive if they received only slight injuries (e.g. in “near-misses”). Especially larger animals involved in vehicle collisions may cover some distance from the road until they succumb to their injuries, e.g. internal bleedings from ruptured organs or blood vessels may last for a while until the animal dies from the subsequent loss of blood. Consequently, victims of vehicle collisions may be found distant from nearby roads. Although there have been reports of ground-dwelling animals colliding with airplanes at airfields, cases of bird-strike are of much higher significance. While most of the cases with large passenger planes occur during the take-off and landing sequences (i.e. they happen rather close to an airport), military jets practising low-level flights and smaller sporting airplanes may also be involved. Though rather unlikely to be the cause of death in a raptor (or other birds) found dead, bird strike should at least be considered under special circumstances. For example, Vienna International Airport is located at closest proximity to Donau-Auen National Park harbouring several highly protected raptors. 20 3.2.1.2.2 Collisions with man-made structures Ground-dwelling animals may collide with and/or get entangled in (poorly perceivable wire-) fences that may cause significant injuries and even death. In smaller birds, collision with windows is the most significant anthropogenic cause of mortality while larger birds are especially endangered by collisions with windmills and entanglement in powerlines. The latter may also be the cause of electrocution. 3.2.1.3 Electrocution Especially larger birds are at risk of electrocution when using power lines and -poles as resting places. Electrocution occurs when the circuit between two different live-phase wires or between a live-phase wire and the ground-wire (or the insulators or poles) is completed by a bird. Normally this happens while spreading the wings during take-off from the resting place thereby completing the circuit with the wings and/or feet. While dry feathers provide some resistance, wet feathers have considerable less resistance, putting birds at higher risk in wet environmental conditions. 3.2.2 Human induced “illegal” causes Illegal killing of wildlife occurs for many reasons, e.g. because wildlife is seen as a competitor over resources (hunting, agriculture, livestock) or because of intentional animal abuse. For the most part, killing occurs by means of snaring/trapping, shooting or poisoning. 3.2.2.1 Snaring/Trapping Snaring or trapping of certain species of (game) animals is legal in some but not all countries. If not set and placed