Under a full moon

Crested_butte_winter_2008

The moon was bright and full last night brightening the sky and even making the snow sparkle with color. Seeing the bright moonlight got us to wondering how moonlight nights might effect animal behavior.

There have been many studies effects so we thought it might be interesting to pass along just a few more recent observations we are aware of.

Several phenomenon related to animal behavior have been attributed to the full moon including increased spawning of corals and other reproductive behavior.

The Barau’s petrel, a tropical seabird species, uses the lunar cycle., unlike many other birds with use the sun or length of day, to time mating.

A recent study by Norevik et al. describes how the full moon synchronizes the initiation of the fall migration in the European Nightjar. The abstracts states:

We found that the daily foraging activity more than doubled during moonlit nights, likely driven by an increase in light-dependent fuelling opportunities. This resulted in a clear cyclicity also in the intensity of migratory movements, with occasionally up to 100% of the birds migrating simultaneously following periods of full moon. We conclude that cyclic influences on migrants can act as an important regulator of the progression of individuals and synchronize pulses of migratory populations, with possible downstream effects on associated communities and ecosystems.1

So as we enjoy another night of moonlight skies we can all ponder what other effects the lunar cycles have on the other inhabitants we share the planet with. So much to study and so much still unknown. Do we need to expand our ecosystem to include the moon? the show universe?

1) Norevik G, Åkesson S, Andersson A, Bäckman J, Hedenström A (2019) The lunar cycle drives migration of a nocturnal bird. PLoS Biol 17(10): e3000456. https://doi.org/10.1371/journal.pbio.3000456

Three Billion Birds: follow-up.

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We recently linked to a study finding that over 3 billion birds have been lost from the ecosystem in North America as well as a study indicating that perhaps 66% of North American Birds are threatened with extinction resulting form anthropogenic climate change.

For those who are interested we just received an email informing us of an online presentation this Monday evening Nov, 4th at 7pm EST by Dr. Ken Rosenberg of the Cornell Laboratory of Orinthology titled “3 Billion Birds Gone: The Bird Crisis and What We Can Do About It“. Importantly it looks like this presentation will focus on the broader implication of the results of these findings beyond birds.

Looks to be an interesting presentation.

American Kestrel

An American Kestrel sat quietly surveying the field on a late November day out in the Rocky Mountain Arsenal National Wildlife Refuge near Denver, CO.

We watched as the Kestrel quickly swooped down into the dried brown fall grass and pulled up small juicy meals which looked to be caterpillars easily held in their toe.

After a few successful hunts from this one fence post the Kestrel glanced back to see how we had liked the show and then flew off down the road to find another hunting spot.

Swimming through air

An interesting new study by V. B. Baliga, I. Szabo, D. L. Altshuler entitled Range of motion in the avian wing is strongly associated with flight behavior and body mass suggests that rather than the shape of a birds wing per se it is the range of motion in the elbow and wrist joints that determine how a bird swims though the air. Some birds glide smoothly like a bald eagle while other can hover like a hummingbird and this paper suggest range of motion in the joint is the key. A interesting read for those who are interested both in biomechanics and evolutionary biology.

You can find a short summary in Science Daily here.

Green Tailed Towhee

The Green Tailed Towhee spends most of its time in dense low thickets, where it forages on the ground. Like other towhees, it scratches in the leaf-litter with both feet as it searches for food. It is somewhat secretive and difficult to see so we were thrilled to get a quick glimpse at this bird when it quickly flew from a berry thicket and landed on this tree for a few seconds.

https://www.allaboutbirds.org/guide/Green-tailed_Towhee/id
http://www.audubon.org/field-guide/bird/green-tailed-towhee