Prof. Sam Lawler
First #ALAN2023 talk today: M. Ditmer (US Forest Service) starting with lots of nighttime photos of big mammals!
Story 1: Lots of deer in well-lit areas, is it a shield against predators or a buffet? In very bright areas, cougars move to darker spots within, deer seek out brightest areas: "Limited predator buffet"
Story 2: Bears moving outside main forested area in Minnesota, citizen science project: where do people see bears? Very biased, people see bears where there is light
Prof. Sam Lawler
J. Heim talking about a topic near and dear (....well, hated) to my heart: satellite pollution! Satellite pollution is visible worldwide, affects astronomers, stargazers, and maybe affect migratory species.
8,600 active satellites now, estimate up to 100,000-500,000 could be in orbit in future. Huge impact to professional astronomers, but also to amateurs, photographers, and eveyrone who looks at the sky.
Collision risk increasing rapidly. Pollution to atmosphere too.
Prof. Sam Lawler
R. Evens: They put [cute little!] light sensor/locator backpacks on nightjars. Walking us through reading an actigram - can clearly see the influence of moon brightness (phase and sky altitude, clouds too) on their activity.
Birds have more activity during no moonlight period in light polluted place (Belgium) than in dark sites - clouds are bright rather than dark due to light pollution
More skyglow=more eating (behavioural change)
Prof. Sam Lawler
Good audience question: do the nightjars get fat because they're eating more often with light pollution? (and is this a good thing or bad thing? They need lots of extra fat to do their super long migration to Mongolia or Africa)
Answer: yes, good idea to measure that! Future study
Prof. Sam Lawler
S. Moaraf: studying zebra finches in the lab and their response to artificial light and also melatonin. Monitor behavior with cameras, gave melatonin as creme on neck of birds (noninvasive). Found more neuron growth with artificial light (counteracted effect with melatonin) - points out that more neuron growth isn't necessarily a good thing b/c taking resources from elsewhere.
Prof. Sam Lawler
C.A. Adams: nightjars are commonly seen foraging under lights at night, but is this normal behavior? Obs. bias? They nest on the ground and rely on camouflage [and being cute, probably], so might be very sensitive to artificial light.
It appears they avoid urban areas, lights don't seem to statistically help them forage and do make predators more effective against them.
Prof. Sam Lawler
Alberta follow-up to BC study (this one used many audio recorders in many habitats). In grasslands, nightjars avoid light, in boreal, don't seem to be as affected by it. Might be because there isn't true darkness in boreal forest in the summer b/c too far north.
Vocal pattern and temporal pattern isn't significantly affected by artificial light. But still need more investigation, back to BC or US?
Prof. Sam Lawler
@remiboucher talking about Mont Megantic dark sky preserve: greenhouses are a HUGE source of light pollution in Quebec now (One really big one near observatory for cannabis?! Went out of business)
Problem: regulation for outdoor lightning, greenhouses are lit up INSIDE. Can be 100x brighter than Montreal!
Blackout curtains are the best solution to greenhouse light pollution, but owners need to be educated - even better, need regulations, now adopted for new builds
Prof. Sam Lawler
A. Botte: looking at oysters! They have a daily cycle with their valve activity. When exposed to artificial light, their peak in activity shifts to night. All colours of light disrupt, blue is worst. Microbiota in gills is much lower with artificial light added
Prof. Sam Lawler
Removing observational biases do to reflected light!! I do this all the time with Kuiper Belt data, nice to see it in a totally different context
Story 3: mule deer spend less time in areas with good forage if there's artificial light.
Story 4: Deer prefer to cross roads at less well-lighted at night - darkness helps deer environment connectivity, but increases likelihood of being killed by cars
Prof. Sam Lawler
Story 5: sensory pollution (light and noise) decreases the fitness of birds, both together decrease fitness even more than one or the other.
Now looking at how animals respond to sensory pollution (mostly noise). Sets up noises to simulate human recreation, films animals' reactions: mostly run away. Uses anonymized cell phone data to see where people go inside parks/forests to look at how sensory pollution affects interactions
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