Tricolored Blackbirds of the Port of West Sacramento

The search for tricolored blackbirds (Agelaius tricolor) at the Port of West Sacramento along the Sacramento deep ship water channel started last year. A field biologist and I hiked out to the ship channel's levee access road via Carlin Drive in West Sacramento, hoping to detect a breeding colony across the channel in the Yolo Bypass Wildlife Area. We walked the levee road a bit to the south, and as we were about to give up, we saw a foraging flock of about 40 tricoloreds in the non-native grassland on our side of the channel. It was late April during the volunteer-based statewide survey organized by the Audubon Society and UC Davis. We tried a few other spots along the channel, as well as within the Yolo Bypass Wildlife Area, but had no further luck.

Tricolored blackbird is a species of special concern that may very soon become listed as endangered, pending on a decision by the California Fish and Game Commission. Nearly endemic to the State of California, the species has faced precipitous decline over the past several decades, declining 44% between 2011 and 2014. When a friend and colleague of mine suggested we go out this year and look for them, I was eager to go back and cover some of the spots at the Port of Sacramento that my former field partner a year ago was not willing to try to access. So exactly one year and one day later, my friend and I hiked out to the same levee access road from a dirt road off Ramos Drive.

This time we went north up the levee access road instead of south, along the ship channel towards the Port of Sacramento and Washington Lake. The road is owned by the Port of Sacramento; however, not just wildlife biologists looking for blackbirds use it. We saw others running, biking, driving, and fishing along it as well, so it is one of West Sacramento's hidden recreation spots for only those who know about it. We walked about 3 miles and didn't see the blackbirds, but enjoyed the exercise and some good conversation. Then we turned off the levee road and started heading back towards the street where we had parked, in the late part of the afternoon. Pausing for a quick pit stop, I spotted the foraging flock.

About a week later, I dragged my brother and husband out to the same spot along the ship channel so I could confirm the sighting and get GPS coordinates. It was earlier in the day, and this time I took some photographs of the deep ship water channel and the habitat. I did not get a shot of the blackbirds, however, as I had three years ago in the Livermore area.

Non-native, annual grass field where the tricolored blackbirds were seen foraging

We walked along the channel and again could not find the birds. Until once again, when we turned to leave and paused for another pit stop, I saw and confirmed the identity of the tricolored blackbirds. One way to distinguish foraging tricoloreds from their almost identical looking cousins, the red-winged blackbirds (A. phoeniceus), is their flocking behavior. The tricolored flock will suddenly emerge from where they are hidden in the grass, fly back and forth in a synchronous motion, and land again in another spot in the tall grass, where they disappear from sight until they emerge again. If I was quick enough to get a scope on them or close enough to get them in my binoculars, I might have been able to see the characteristic white patch on their wings that also distinguishes them from the other blackbirds. But I didn't.

Each time I saw this flock, I saw them fly off in the direction of the ship channel. It made my colleague and I wonder if there actually is a breeding colony on the other side, and if we could somehow get access to that levee and peer over the toe drain part of Prospect Slough that separates the ship channel from the wildlife area. There was also some really lovely looking freshwater marsh habitat in this area that was beckoning us to visit. We didn't get around to it this year. I am hoping next year to not only seek a new adventure along the ship channel, but to locate a breeding colony of tricolored blackbirds in an area where they seem to be rapidly disappearing from.