© 2019 Copyright by P. K. H. Groth, Denver, Colorado, USA All rights reserved - See contact page for for permission to republish article excerpts.
Of Reindeer, Power Lines, the Soviet Iron Curtain, and Your Hunting Flashlight Selection The Sami (formerly called Laplander reindeer people) of Finland exist by reindeer herding. They experienced an increasing problem caused by electric transmission lines traversing their arctic pastures. The reindeer avoided and would not cross under them. Many forest animals will not cross under power lines or over pipelines. The clear-cutting necessary to keep vegetation away from the lines presents a dangerous open area lacking tree/brush cover. My son was an environmental geographic information specialist challenged with a similar trans-Andes pipeline planning problem. Monkeys would not cross the pipeline right-of-way. The monkeys travel through trees and only descended for short periods to defecate and obtain ground shrubs. My son's solution was to plan to intermittently leave large healthy trees on each side of the pipeline which had intergrown branches over the pipeline. He prescribed these to crossing sites to engineers using satellite imagery of the trees and topography. The monkeys then freely moved across the otherwise starkly barren pipeline right-of-way. The reindeer problem was vexing because arctic reindeer live in wide open spaces without any trees, so avoidance of open spaces was no the problem. An international team of scientists led by Dr. Nicholas Tyler studied the paradox. They approached the problem with curiosity - what are were the deer encountering near the power lines? Why do they refuse to go closer than a mile and a half from the cables? In early April 2014 the researchers reported discovering that static electricity was creating radiation in the ultraviolet light wavelengths on the lines, especially near towers and insulators. V. Gill (2014) and D. Cressey (2014) give a synopsis of Dr. Nicholas Tyler's team results. New imaging techniques disclosed the eerie pulsating UV light coronas on power lines. (You can view a helicopter video of the phenomenon at _________ .) It does not take much imagination to realize the reindeer will not approach the lines in either day or night because evolutionary and environmental factors have made it a NECESSITY for them to be extremely sensitive to UV radiation. Reindeer were the first large mammal recognized capable of seeing ultraviolet light. Now it appears almost all animals, birds, and insects can see in the UV range. They use extended light spectrum recognition not only for simple vision, but for navigation (birds) and hunting (pit vipers see in infrared). Only humans and a few species of apes are UV-detection deficient. Evolution gave us corneal filters to eliminate UV radiation and reduce eye damage. (Is this due to our historical habit of sleeping when it is dark and spending most of the days outside evolving in low latitudes where the sun intensely shines for consistently long days the entire year? Read on; maybe the reindeer give a clue to an answer.) Reindeer eyes change color with seasons. Maja Sojtaric (October 2013) disclosed another amazing reindeer revelation that is (in my opinion) is highly relevant to ungulate hunters. Mentally review your knowledge of the Arctic seasons. The summer sun never sets, the winter sun never rises. Much of the winter hardship season for reindeer must be lived in darkness, but survival is still successful. Norwegian researchers led by Professor Karl-Arne Stokkan at the Arctic University of Norway keyed into observations by herders that the deer eye colors seasonally change. In the summer the eyes are golden, and they progressively change to deep The HOW: Dr. Stokkan believes the reindeer eyes evolved because of the extreme sunlight variation. All deer have a membrane called the "tapetum lucidum" (Latin = bright carpet) behind the retina. This membrane reflects light multiple times to increase stimulation of light-recognizing rods at the eyes' rear. The tapetum is what changes color (and what you see when light reflects from animal eyes in the dark). During the long summers the eye pupil is very constricted. The pupils dilate with waning daylight. In winter the pupils dilate so much that they cover the drainage tubes that normally keep eye pressures normal. Rising pressure compacts the tapetum's fibers, changing their color. The WHY: Dr. Stokkan concluded the following annual scenario. Reindeer need to see far in the summer to detect predators, especially in misty and hazy landscapes. The yellow corneas filter out some of the blue haze and allow acute vision. Seeing distantly in the winter is not a needed asset, but having a greater visual sensitivity to close predator movement in low light is an asset. The blue tapetum scatters light to a greater degree than the yellow summer seasonal color. The greater scattering allows more rods to sense light. While winter vision is not acute, it gives reindeer a greater sensitivity to movement​ in the shadows. This is a distinct advantage in the dark for detecting predators. Dr. Stokkan illustrates this survival benefit: "Reindeer herders are very familiar with this phenomenon. They say that if you stand just a short distance from a herd of reindeer in the winter they will not see you, but as soon as you move the animals startle and run away." (As implored in my book, I once again advise hunters to explore the observations of people who had to understand prey to survive - the natives.) I am convinced that animals need to see in the ultraviolet spectrum. That certainly includes deer and elk. They have to in order to survive. The staple winter diet of reindeer is lichen in a land that is usually snow covered. Dr. Glen Jeffrey, neuroscientist at the Institute of Ophthalmology, University College London (in Cressey, 2014) found that lichens absorb UV light and appear dark against bright snow. This guides reindeer in locating food in a snowbound landscape. I theorize that deer and elk also use UV spectral identification abilities to locate the more nutritious new growth grass and forbs. I also speculate that elk bull dominance may be partly based on the older and lighter "silverback" bull's hide reflecting more UV light and thus appearing larger and more threatening. Perhaps the elk habit of urinating on its legs and in its wallow also has spectral connotations; it may fluoresce when chemmical hormones are present. Somewhere I read that plants change reflective and fluorescent wavelengths with the growing seasons. I also recall a researcher discovering how bees avoid wasting time going to flowers which have been previously visited by another bee. A flower senses pollination and immediately changes its spectral color (instrumentation can detect the change, but not human eyes). This benefits evolution. The strongest, brightest, sweetest smelling flowers get the first bees that bring pollen from similar prime flowers. Turn off the welcome light and pollen from inferior flowers will not contaminate the "Cookoo's nest", so to speak. Hovering kestrels use UV light to detect the urine of target rodents. {{Visit the Science Photolibrary's Animal Supersenses website for more enlightenment.}} Another interesting problem the Sami have is keeping their deer from being killed on highways. Finland has 200,000 farmed reindeer. Each year there are 3,000 - 5,000 vehicle/reindeer accidents. Losing that much stock crimps the bottom line of the marginal deer herding operations. Signs warning drivers of deer crossings do not work because tourists immediately steal them for souvenirs. Cooperatives and researchers are trying to find a solution. The photo shows how herders are experimenting by painting reindeer antlers with reflective paint to make them more visible to drivers (_______, 2013). Volvo used to equip some cars sold in Scandinavia with headlights which emitted UV light. The safety feature was intended to make roadside objects fluoresce and be observed at greater distances and sooner by the driver. We now have the high intensity blue headlamps on some cars. I have not yet tested these blue lamps, but strongly suspect they emit considerable light in the UV spectrum. I think having the blue headlights on when going on a deer/elk nature viewing drive (day or night) will alert the UV-seeing deer. How Does This Ultra Violet Discussion Relate to Hunting? Your hunting flashlights: In my book I stress that deer and elk can see and are sensitive to UV light. They have to be for night time navigation and grazing. Concentrated unnatural UV light is frightening to them. So why do many hunters walk around with a UV flashlight which startles the animals? Because they don't know the wavelengths which the flashlights emit. This photo shows an LED flashlight shining on untreated hunter orange material. Special light filters block visible spectrum light, but lets through the long UV ( on right) and short UV ( left). This illustrates that the LED lights are producing some light in the two UV wavelengths. I think some LED lights purposely emit UV light. It makes objects add fluorescence to normal light reflectance and makes them appear brighter to humans, while using less energy. Hunters using a common LED light while walking to their stands in the early morning darkness or towards camp at night are liable to alert deer and elk. Uncomfortable, the prey moves away silently and quickly before you get near it. So carry an old-fashioned incandescent flashlight or headlamp for dark-hour movement. Save the dollar LED wonders for camp chores. Blood revealing tracking flashlights should be shielded from forward direction to not startle away wounded animals. Your Outfitters Ramada: Some outfitters use ribbon electric fence corrals to allow their horses freedom to graze unfettered. I wonder if intermittent electrical shorting to waving tall grass could create sparking UV coronas along the fence line. This is only speculative, but I'd prefer not to experiment with the theory during hunting season. (I intend to field research this next summer.) There is a lot more I've learned about UV light and animal behavior, but that's for another story. Please see book for clothing UV discussions. Remember, it is not important to the hunter how he visualizes the world, but how the animals see. This might be how deer and elk see me - a body of contrasts instead of color.
Reindeer Sight and Behavior
© 2016 -2017 Copyright by P. K. H. Groth, Denver, Colorado, USA All rights reserved - See contact page for for permission to republish article excerpts.
Of Reindeer, Power Lines, the Soviet Iron Curtain, and Your Hunting Flashlight Selection The Sami (formerly called Laplander reindeer people) of Finland exist by reindeer herding. They experienced an increasing problem caused by electric transmission lines traversing their arctic pastures. The reindeer avoided and would not cross under them. Many forest animals will not cross under power lines or over pipelines. The clear-cutting necessary to keep vegetation away from the lines presents a dangerous open area lacking tree/brush cover. My son was an environmental geographic information specialist challenged with a similar trans-Andes pipeline planning problem. Monkeys would not cross the pipeline right-of-way. The monkeys travel through trees and only descended for short periods to defecate and obtain ground shrubs. My son's solution was to plan to intermittently leave large healthy trees on each side of the pipeline which had intergrown branches over the pipeline. He prescribed these to crossing sites to engineers using satellite imagery of the trees and topography. The monkeys then freely moved across the otherwise starkly barren pipeline right-of-way. The reindeer problem was vexing because arctic reindeer live in wide open spaces without any trees, so avoidance of open spaces was no the problem. An international team of scientists led by Dr. Nicholas Tyler studied the paradox. They approached the problem with curiosity - what are were the deer encountering near the power lines? Why do they refuse to go closer than a mile and a half from the cables? In early April 2014 the researchers reported discovering that static electricity was creating radiation in the ultraviolet light wavelengths on the lines, especially near towers and insulators. V. Gill (2014) and D. Cressey (2014) give a synopsis of Dr. Nicholas Tyler's team results. New imaging techniques disclosed the eerie pulsating UV light coronas on power lines. (You can view a helicopter video of the phenomenon at _________ .) It does not take much imagination to realize the reindeer will not approach the lines in either day or night because evolutionary and environmental factors have made it a NECESSITY for them to be extremely sensitive to UV radiation. Reindeer were the first large mammal recognized capable of seeing ultraviolet light. Now it appears almost all animals, birds, and insects can see in the UV range. They use extended light spectrum recognition not only for simple vision, but for navigation (birds) and hunting (pit vipers see in infrared). Only humans and a few species of apes are UV-detection deficient. Evolution gave us corneal filters to eliminate UV radiation and reduce eye damage. (Is this due to our historical habit of sleeping when it is dark and spending most of the days outside evolving in low latitudes where the sun intensely shines for consistently long days the entire year? Read on; maybe the reindeer give a clue to an answer.) Reindeer eyes change color with seasons. Maja Sojtaric (October 2013) disclosed another amazing reindeer revelation that is (in my opinion) is highly relevant to ungulate hunters. Mentally review your knowledge of the Arctic seasons. The summer sun never sets, the winter sun never rises. Much of the winter hardship season for reindeer must be lived in darkness, but survival is still successful. Norwegian researchers led by Professor Karl-Arne Stokkan at the Arctic University of Norway keyed into observations by herders that the deer eye colors seasonally change. In the summer the eyes are golden, and they progressively change to deep The HOW: Dr. Stokkan believes the reindeer eyes evolved because of the extreme sunlight variation. All deer have a membrane called the "tapetum lucidum" (Latin = bright carpet) behind the retina. This membrane reflects light multiple times to increase stimulation of light-recognizing rods at the eyes' rear. The tapetum is what changes color (and what you see when light reflects from animal eyes in the dark). During the long summers the eye pupil is very constricted. The pupils dilate with waning daylight. In winter the pupils dilate so much that they cover the drainage tubes that normally keep eye pressures normal. Rising pressure compacts the tapetum's fibers, changing their color. The WHY: Dr. Stokkan concluded the following annual scenario. Reindeer need to see far in the summer to detect predators, especially in misty and hazy landscapes. The yellow corneas filter out some of the blue haze and allow acute vision. Seeing distantly in the winter is not a needed asset, but having a greater visual sensitivity to close predator movement in low light is an asset. The blue tapetum scatters light to a greater degree than the yellow summer seasonal color. The greater scattering allows more rods to sense light. While winter vision is not acute, it gives reindeer a greater sensitivity to movement​ in the shadows. This is a distinct advantage in the dark for detecting predators. Dr. Stokkan illustrates this survival benefit: "Reindeer herders are very familiar with this phenomenon. They say that if you stand just a short distance from a herd of reindeer in the winter they will not see you, but as soon as you move the animals startle and run away." (As implored in my book, I once again advise hunters to explore the observations of people who had to understand prey to survive - the natives.) I am convinced that animals need to see in the ultraviolet spectrum. That certainly includes deer and elk. They have to in order to survive. The staple winter diet of reindeer is lichen in a land that is usually snow covered. Dr. Glen Jeffrey, neuroscientist at the Institute of Ophthalmology, University College London (in Cressey, 2014) found that lichens absorb UV light and appear dark against bright snow. This guides reindeer in locating food in a snowbound landscape. I theorize that deer and elk also use UV spectral identification abilities to locate the more nutritious new growth grass and forbs. I also speculate that elk bull dominance may be partly based on the older and lighter "silverback" bull's hide reflecting more UV light and thus appearing larger and more threatening. Perhaps the elk habit of urinating on its legs and in its wallow also has spectral connotations; it may fluoresce when chemmical hormones are present. Somewhere I read that plants change reflective and fluorescent wavelengths with the growing seasons. I also recall a researcher discovering how bees avoid wasting time going to flowers which have been previously visited by another bee. A flower senses pollination and immediately changes its spectral color (instrumentation can detect the change, but not human eyes). This benefits evolution. The strongest, brightest, sweetest smelling flowers get the first bees that bring pollen from similar prime flowers. Turn off the welcome light and pollen from inferior flowers will not contaminate the "Cookoo's nest", so to speak. Hovering kestrels use UV light to detect the urine of target rodents. {{Visit the Science Photolibrary's Animal Supersenses website for more enlightenment.}} Another interesting problem the Sami have is keeping their deer from being killed on highways. Finland has 200,000 farmed reindeer. Each year there are 3,000 - 5,000 vehicle/reindeer accidents. Losing that much stock crimps the bottom line of the marginal deer herding operations. Signs warning drivers of deer crossings do not work because tourists immediately steal them for souvenirs. Cooperatives and researchers are trying to find a solution. The photo shows how herders are experimenting by painting reindeer antlers with reflective paint to make them more visible to drivers (_______, 2013). Volvo used to equip some cars sold in Scandinavia with headlights which emitted UV light. The safety feature was intended to make roadside objects fluoresce and be observed at greater distances and sooner by the driver. We now have the high intensity blue headlamps on some cars. I have not yet tested these blue lamps, but strongly suspect they emit considerable light in the UV spectrum. I think having the blue headlights on when going on a deer/elk nature viewing drive (day or night) will alert the UV- seeing deer. How Does This Ultra Violet Discussion Relate to Hunting? Your hunting flashlights: In my book I stress that deer and elk can see and are sensitive to UV light. They have to be for night time navigation and grazing. Concentrated unnatural UV light is frightening to them. So why do many hunters walk around with a UV flashlight which startles the animals? Because they don't know the wavelengths which the flashlights emit. This photo shows an LED flashlight shining on untreated hunter orange material. Special light filters block visible spectrum light, but lets through the long UV ( on right) and short UV ( left). This illustrates that the LED lights are producing some light in the two UV wavelengths. I think some LED lights purposely emit UV light. It makes objects add fluorescence to normal light reflectance and makes them appear brighter to humans, while using less energy. Hunters using a common LED light while walking to their stands in the early morning darkness or towards camp at night are liable to alert deer and elk. Uncomfortable, the prey moves away silently and quickly before you get near it. So carry an old-fashioned incandescent flashlight or headlamp for dark-hour movement. Save the dollar LED wonders for camp chores. Blood revealing tracking flashlights should be shielded from forward direction to not startle away wounded animals. Your Outfitters Ramada: Some outfitters use ribbon electric fence corrals to allow their horses freedom to graze unfettered. I wonder if intermittent electrical shorting to waving tall grass could create sparking UV coronas along the fence line. This is only speculative, but I'd prefer not to experiment with the theory during hunting season. (I intend to field research this next summer.) There is a lot more I've learned about UV light and animal behavior, but that's for another story. Please see book for clothing UV discussions. Remember, it is not important to the hunter how he visualizes the world, but how the animals see. This might be how deer and elk see me - a body of contrasts instead of color.
Reindeer Sight and Behavior