Egg-secution

Well, it’s another year without a successful Northern Flicker brood so I’ve turned off the nest cam stream. I’m not sure what went wrong. As I posted, the Northern Flicker pair laid their first egg on June 13th. A mid-June nest attempt is late, but from what I’ve read, flickers will nest anytime between March and June.

At first, things seemed to be going well. The female flicker did skip a day laying after the first egg, which can happen when there’s bad weather (usually if it’s cold and/or rainy/snowy, which wasn’t the case here), but then she reliably laid another 3 eggs over the next 3 mornings. Below is a video of her laying the second egg. The interesting thing with this female is that it was so obvious when she was laying her eggs. With the successful pair from 2016, I could only tell an egg had been laid when she got up off of them.

Then, the same day the female laid her 4th egg, the male ended up crushing 3 of the 4 eggs. I don’t know if he did it on purpose or if he was just clumsy. He certainly seemed not to be taking too much care jumping into the box! But he was also very vigilant about keeping the eggs moving rather than sitting in one spot, which keeps them viable. After the eggs were destroyed, I saw him eat bits of the remaining shells. Birds sometimes eat their eggs if they have a vitamin deficiency. Is this a clue to what happened?

After the big mishap, the female laid a new second egg, but later that same day either she or the male destroyed that egg and the remaining egg. Here’s video of one of the flickers removing the final egg after the female leaves the box.

I have a couple of hypotheses about why the birds destroyed/removed the eggs, but nothing solid. Perhaps it was too late and too hot in the season for the eggs to be viable, which the birds recognized. Or maybe one or both of the birds were sick or too inexperienced to be fit parents. Whatever the reason, there are no new flicker babies this year.

Advertisements

Egg-cellent

The past week, the female Northern Flicker has been hanging out in and around the flicker box regularly. Since female birds of many (most?) bird species are the ones to choose the nesting spot, this was a great sign. Well, what do my eyes see this morning but a tiny little egg in the bottom of the box!

Northern Flickers nest anytime between March and June so this pair is a little on the later end of nesting, but still within the usual time frame. I have no concrete idea why they are nesting so late, but it’s possible it could have something to do with pressure from European Starlings or maybe their previous nest attempt earlier in the season failed. Whatever the reason, hopefully, despite the hot temperatures we’ve been getting, and and will no doubt continue to see moving into full-bore summer, the nest will do all right.

Now that the nesting has truly started, I’m starting a new nest attempt at Cornell Lab of Ornithology’s NestWatch site. NestWatch is a great resource for researchers to learn more about breeding birds from citizen science data. Citizen science is immeasurably important because it would be impossible for scientists to collect as much data as the average person can provide on their own.

If you find a nest this season, you can record it on NestWatch too. Just remember to follow the nestwatching code of conduct to make sure you’re not doing any harm to the birds.

Butcher Bird

Did you know that some song birds are carnivores and that their prey, including amphibians, reptiles, mammals, and other birds, may be the same size or bigger than them? If you watched the tv show Hannibal or read the book Red Dragon, you may already be familiar with the shrike.

There are over 30 species of shrike around the world, with most occurring in grasslands. They are generally dull-colored with hooked beaks suitable for snapping necks, which makes their family name Laniidae extremely appropriate (Laniidae is Latin for “butcher”). But while they’re active during the day and eat meat, shrikes lack the strong, grasping talons of raptors like hawks, eagles, and falcons. Therefore, shrikes employ an ingenious method to hold onto their prey as they eat.

Shrike larder. Remains of a Western Meadowlark. Photo by Jamie Simo.

If you’re traversing a farm field in Colorado, you may have come across a shrike cache. Perhaps it was a moth or the skull of a lizard festooning a fence-line or a sparrow hanging from the branch of a wild plum. After killing, the shrike will impale its prey on a thorn or a piece of barbed wire. This holds the food in place so that the shrike can rip off chunks at its leisure. The shrike can also return to the impaled food item later, like accessing a pantry. Caching food may allow it to survive in times of scarcity.

Northern Shrike. Photo by Jamie Simo.

Colorado is home to 2 shrike species, the Loggerhead Shrike (Lanius ludovicianus) and the Northern Shrike (Lanius borealis). The Loggerhead Shrike can be found year-round in southern Colorado, but along most of the Front Range they’re present only in the spring and summer. They can be distinguished from the Northern Shrike, which is only found in Colorado during the winter, by a broader black mask, less hooked bill, and clean breast lacking the faint barring seen on the Northern Shrike.

Loggerhead Shrike. Photo by Jamie Simo.

Unfortunately, because of the loss of grassland and pasturage in much of the United States, as well as the decline in prey species, particularly insects, the Loggerhead Shrike is imperiled. Less is known about population trends of the Northern Shrike since it breeds far north in the tundra, but likely it too is in decline as it loses wintering habitat. This is in line with the overall decline in numbers of grassland birds across North America.

To protect these bizarre song birds and their neighbors, we must come up with more creative ways to protect their habitat.