Avalanche probing re-visited

Avalanche probing is still required to search avalanche deposits when other rescue means such as transceivers are unavailable. For many years the most common method employed by organized rescue teams in western Canada has been the technique known as coarse probing. In coarse probing the rescuers line up elbow to elbow and probe the snowpack once per step as the line of probers advance. This technique produces a pattern of probe holes on a 75 x 70 cm grid. The probability of detection ranges from 20% for a vertically oriented victim to 95% for a prone or supine victim and is considered to average 76% The idea behind coarse probe spacing recognizes the need to sacrifice some thoroughness to improve the speed of probing and thus maximize the chances of recovering a victim alive. The decision to employ coarse probing reflects the sort of trade-offs or risk-management familiar to the modern incident commander. In avalanche searches requiring manual probing the problem, in simple terms, is how to get as many holes into the snow as fast as possible. This paper examines two possible means to improve the speed and efficiency of probing in rescues where there is still a possibility for live recovery. Limiting the depth of probing is discussed and several alternative probing techniques are compared. Limiting Depth of Probing The concept of restricting the depth of probing is not new. Lacking sufficient burial statistics, Perla (1967) assumed that avalanche victims were distributed uniformly in the top 3 m of an avalanche deposit, and concluded that limiting probing depth would not increase the probability of finding avalanche victims alive. However, recent Swiss and US statistics on burial depth It is clear that survival is related to depth of burial. Deeper burial likely means more restricted respiration and denser snow deposition containing less air. Deeper burial often results from larger and thus more violent events. Since deeper burial is more likely to mean the victim has already succumbed, it makes sense to consider limiting the depth of probing if it improves the odds of finding the victim who is more likely to still be alive because of shallower burial. If the depth of probing is limited, the speed of probing should increase because the probe does not travel as far. Speed is further improved if the probe itself can actually be shortened making it easier for the rescuer to manage

Behavioral responses of terrestrial mammals to COVID-19 lockdowns (code)

COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable, with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns, 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12%, and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide

Behavioral responses of terrestrial mammals to COVID-19 lockdowns

COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable, with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns, 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12%, and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide