July 2023
Bird of the Month
Ryan Crouse

Regional Cormorants

If you hang out around any of our lakes for just a bit, you’ll very likely observe a unique bird sitting atop a water-bound rock. It may have its wings outstretched in an effort to shed recently acquired water before it again slips below the surface in search of its next meal. This awkward-looking creature is one of our area’s cormorant species.

A local double-crested cormorant works to swallow a big channel catfish. (Everett Sanborn)

Cormorants and their close cousins, shags, are members of a group of birds that inhabit large parts of the globe. There are 42 different species worldwide and they all share a similar appearance, which includes a long neck, a slender hooked beak, short tail and generally a brightly colored eye and/or cere. The two species we can reliably observe in Prescott are the double-crested and neotropic cormorants.

Both are generally black or sooty grey, depending on age and gender. They both have a striking turquoise-colored eye and a bright orange gape and cere. While they are similar in appearance, they can be distinguished by size, the neotropic about half the weight of its larger cousin. This size difference is most obvious when you’re lucky enough to see them perched together. Otherwise relative abundance is a great clue, as the double-crested is much more common than the diminutive neotropic.

I should also note the feature that gives the double-crested cormorant its name. During breeding season the adults display plumes of feathers that extend horizontally from behind the eyes, used for courtship purposes. Neotropic cormorants display less prominent white tufts that rest lower on the sides of their heads.

Cormorants spend the vast majority of their days doing one of two things: fishing and resting on a prominent point. Similar to the common loon we recently highlighted, the cormorant hunts for its aquatic diet by diving below the surface and using its powerful webbed feet to propel itself at high speed. While the loon uses its lancelike beak to spear passing quarry, the cormorant uses its hooked beak to snare prey. Both cormorant varieties will troll the surface before abruptly diving when the moment is right. Unlike every other cormorant species, the neotropic is special in that it will drop from low altitude, plunging right on top of and snagging its next meal. This behavior is more generally associated with birds like terns, but the neotropic cormorant has added this effective method to its own arsenal.

Relative to ducks, cormorants possess significantly less water-repelling preening oil on their feathers. This means that they become water-logged much more easily than other aquatic birds do. This has it benefits, though. As they they take on water they become less buoyant, and don’t have to fight the tendency to float while they hunt. They can spend more time submerged, and they’re faster and more maneuverable, useful traits when trying to catch fish in their own element. While fish are fast, maneuverable and highly aware, cormorants simply can’t resist the challenge. Double-crested cormorants have been observed preying on over 250 fish species!

After a successful hunting trip, you’ll very likely find either of our region’s cormorants sitting on a whitewashed rock in the middle of a lake. Because of their tendency to get soggy, they have to spend time shedding that water using gravity and evaporation. They often spread their wings out to their sides, which amplifies their surface area, aiding the evaporative process. In a behavior similar to that of turkey vultures, this also helps regulate body temperature after an ice-cold dive. Taking flight from the water’s surface is often hard for a water-logged cormorant, so instead they must hop directly from the water onto their aquatic crag.

In this season it’s very easy to observe large numbers of cormorants roosting communally in what we call rookeries. They will nest together in the upper limbs of local cottonwood trees, often in and among neighboring heron rookeries. This can create a chaotic scene of awkward birds, guttural vocalizations and the ground beneath littered with leftover fish in varying states of decay. Despite that glowing review, it really is a sight to behold. For the sake of both your nose’s delicate sensibility and out of respect for the rearing process, always be sure to keep a respectful distance as you observe. Check out some of our local lakes for this unique opportunity. Get out there!

2023 Birding Challenge Update

In May I added several species to my 2023 The Lookout Birding Challenge list. These included a fleeting glimpse at a hepatic tanager, a juniper titmouse at my feeder, two peregrine falcons observed and identified from 2.5 miles away, several close looks at red-face warbler, a Townsend’s warbler, a surprise view of a Harris’ hawk as I drove to Phoenixn and several great flycatcher species, including the elusive greater pewee! Many of these birds were observed and shared with participants during one of our free weekly bird-walks. You should join us!

My year count now stands at 179 species!

Birds are still localizing like crazy, but they will soon fall into the late June into July breeding lull. This is when they move from the high-detection period of finding a mate into the low-detection period of raising and protecting their young. Get out in the woods for opportunities to see several fantastic warbler species, numerous and challenging flycatcher varieties, and even a recent influx in the area’s red crossbill population.

The Prescott Audubon Society is an official chapter of the National Audubon Society. Check it out online at PrescottAudubon.org.