Cormorants

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Credit: Chad King /
Monterey Bay National Marine Sanctuary

I’ve started this bestiary with cormorants, which might seem odd given all of the amazing animals in Monterey Bay, but they’re ever-present and, for me, disconcerting.

I kayak to relax and reflect. Bustling cormorants interrupt my attempts at calm. They’re constantly, energetically engaged in some must-do-now task.

Cormorants are most noticeable in late winter (February/ March) when males start collecting marine algae and plants for nests. I usually see them flying by (laboriously) with a wad of material stuffed in the bill. Mating pairs are easy to watch atop Monterey’s Coast Guard breakwater courting, building nests and defending territory against sea lions. The females continuously repair nests with materials supplied by their mates shuttling to and fro.

Both parents keep busy during the summer feeding their brood of youngsters. That means diving for fish nearby or far afield. According to White et al. (2007), great cormorants (not a local species) don’t see very well under water — more like our unaided underwater vision (hard to believe!). They’re best at short distances, hence all the diving, and nabbing what gets flushed or pursuing what they see.

Cormorants are elegant divers, but the flying seems hard. And, they squeak when they fly! I can tell a flying cormorant is approaching by the slight squeak of the feathers.

Credit: Josh Pederson / Monterey Bay National Marine Sanctuary

Credit: Josh Pederson /
Monterey Bay National Marine Sanctuary

In the fall, after the young have fledged (they hang in groups that appear lost), adults get a break — there’s less flying, but they’re not inactive. Those I encounter are in perpetual motion diving-surfacing-diving (in contrast to the still stance of egrets on the kelp canopy). Or, they’re flapping wings to wash them in the water or to dry them when perched on rocks. (I seldom see them standing with wings spread like photos show.) Loafing cormorants are a rare siting where I kayak. They’re the hardest working birds I know.

In our area there are three species: Brandt’s (Phalacrocorax penicillatus), pelagic (P. pelagicus) and double-crested (P. auritus). In a 2012 PLoSOne paper — A Climate Change Vulnerability Assessment of California’s At-Risk Birds — Brandt’s and pelagic made it to a Level 2, or moderate, vulnerability risk status for climate change. But more concerning was that the highest percentage of the list’s vulnerable species are California’s wetlands and coastal birds. Not unexpected, but when a list includes oystercatchers, terns, pelicans, turnstones and others I commonly see around Monterey’s breakwater, it’s attention-getting.

The authors conducted the vulnerability study to help inform a future update of the California Wildlife Action Plan. The 2007 version didn’t fully address climate change impacts and management solutions.

Note: For updates on nesting cormorants, visit my Cormorant Hatchlings post. CP

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Sources
White, C.R., Day, N., Butler, P.J. & Martin, G.R. (2007). Vision and Foraging in Cormorants: More like Herons than Hawks? PLoS ONE 2(7): e639. doi:10.1371/journal.pone.0000639
Gardali, T., Seavy, N.E., DiGaudio R.T. & Comrack, L.A. (2012). A Climate Change Vulnerability Assessment of California’s At-Risk Birds. PLoS ONE 7(3): e29507. doi:10.1371/journal.pone.0029507
Resources
Don Roberson’s Creagrus website: Cormorants
NOAA National Marine Sanctuaries SIMoN (Sanctuary Integrated Monitoring Network) website: Cormorants