One of my new favorite activities is nighttime bird watching. Who knew you could spy on these little modern dinosaurs in the dark of night? The secret is BirdCast, and like most of our lives these days, it’s online.

The highest migration count this fall was 51,300 birds crossing Santa Barbara County on Sept. 30.

The highest migration count this fall was 51,300 birds crossing Santa Barbara County on Sept. 30. (Courtesy photo)

The website is powered by the Cornell Lab, Colorado State University, and UMass at Amherst.

When I discovered BirdCast last spring, I was astounded. It estimates the population, speed, direction and altitude of migrating birds on any given night. The number of birds crossing Santa Barbara County, headed for summer breeding and feeding grounds, was in the hundreds of thousands.

Through natural history and ground-checking, they even opine on which bird species are present. The most common species this fall have been Lincoln’s Sparrow, Pine Siskin, Pectoral Sandpiper, Vesper Sparrow, and Palm Warbler.

I have been an enthusiastic if not proficient birder for the last couple of decades, peering through my monocular in far-reaching habitats. I cheer when endangered species recover and suffer when they perish due to human perils like windows, lead bullets, and giant wind turbine blades.

I haven’t spent a lot of energy thinking about them at night.

My first birding instructor at the Santa Barbara Botanic Garden, Fred Emerson, shared his wife Nancy’s passion for the night sky. Local organizations such as Dark Sky and Save Our Stars are passionate about retrieving and preserving dark skies.

Amateur and professional astronomers need darkness to see the stars; nocturnal wildlife require darkness for cover. Darkness positively impacts human health by preserving circadian rhythms and allowing us to produce melatonin.

Migrating birds need darkness. Arctic terns travel more than 18,640 miles every year. They rarely stop to rest, which necessitates night flight

Hundreds of thousands of birds including herons, egrets, bald eagles, warblers, swallows, tanagers and flycatchers fly between Patagonia and Alaska on the Pacific Flyway: the avian equivalent of Highway 1.

These were all disconnected factoids in my brain. But BirdCast shows me in real time, which is richly different. If you’re reading this article at night, pause and check out BirdCast to see how many birds are flying over our county now (and then come back!).

Our fall migration is not as concentrated as the spring one, but if you haven’t contemplated these numbers before, I promise you’ll be amazed.

The highest migration count this fall was 51,300 birds crossing Santa Barbara County on Sept. 30. So far this season, more than 4,500,500 birds have crossed. When I checked on Oct. 24, the estimated number of birds in the air was 20,600. The birds peaked just before 8 p.m. at around 7,600 and tailed off about 3 a.m.

On Halloween night the count was down to about 7,100; perhaps they were avoiding all the ghosts and goblins.

The secrets to avian migration estimates are radar and big data.  Early in radar development days, unexplained dots on radar screens were called “angels.” In the mid-20th century, ornithologists Edward Gray and David Lack determined that huge flocks of birds were the transient “angels” gracing the screens.

NEXTRAD technology used for weather data provides sufficient detail for the estimates used by BirdCast.

Comparing the counts with what I recalled from the spring, I wondered why the fall migration nightly counts were only half as large as the spring one. An article in American Naturalist by Cecilia Nilsson, Raymond Klassen and Thomas Alerstam found that birds migrate faster in the spring (higher concentrations for shorter durations).

They posited the reasons for faster spring migrations could be competition for arrival order at breeding grounds and environmental factors such as increased daylight.

I worry about the historical average. The 4,500,500 total figure is about half the historic average. Is this an aberration or a trend? I’ll save that investigation for a later column. A more immediate question has been weighing on me lately.

Where does all the migrating bird poop go?

— Karen Telleen-Lawton serves seniors and pre-seniors as the principal of Decisive Path Fee-Only Financial Advisory in Santa Barbara. You can reach her with your financial planning questions at Click here to read previous columns. The opinions expressed are her own.

Karen Telleen-Lawton is an eco-writer, sharing information and insights about economics and ecology, finances and the environment. Having recently retired from financial planning and advising, she spends more time exploring the outdoors — and reading and writing about it. The opinions expressed are her own.