Bullock’s Oriole (Icterus bullockii) Foraging For Insects

This lovely male Bullock’s oriole (Icterus bullockii) spent some time foraging for insects in a catclaw acacia tree (Acacia greggii) outside my kitchen window a couple of weeks ago. He was cocking his head and performing acrobatics in search of small bits of edible protein amongst the foliage. Now that it has rained a decent amount and various things are leafing out that were formerly dormant due to drought, that should provide a food source for various insects, which will in turn provide food for various birds, lizards, and mammals. The food chain is all interconnected and life goes on.

The bright orange-gold frontal color is the most striking feature of these birds.

These photos were taken July 14, 2021, the day after a good 1.15 inches (29 mm) of rain fell in the first decent summer monsoonal storm since 2019. The monsoon failed entirely in 2020 and brought my region zero rainfall all summer, which has been enormously stressful on the native plants and animals. Fortunately July 2021 has so far seen a good monsoon over much of Arizona, including me near Yucca AZ – I have received 3.45 inches (87 mm) of rain since July 13. Some regions of southeastern and central Arizona have gotten over 10 inches (300 mm) of rainfall this month!
The contrasting black hood and back with white wing bars provides a colorful counterpoint, as the birds seeks bugs to eat on the underside of some of the catclaw’s developing seed pods.
This catclaw acacia also hosts clumps of desert mistletoe (Phoradendron californicum), which grow mostly upon members of the legume family. The mistletoes themselves can provide a useful source of nectar, berries, and nesting shelter for desert critters. They also support insects that birds and more can eat as well. Some people dislike mistletoe but it is an important and natural part of the desert ecosystem, so I tend to leave them in the trees where they occur.
A photo showing the oriole in the wider context of the catclaw acacia tree, with developing bean pods which are called legumes in botany. This is why members of the Fabaceae are commonly referred to as legumes – for the specific type of seed pods they form, which are anatomically useful as an identifier of the entire family.
I hope these photos illustrate the activity level of the bird. I took slightly over 300 photos over the course of a few minutes using my camera’s burst mode, most of which were either blurry, poorly composed, or half-hidden by obscuring tree foliage. I had to spend a couple of hours culling the substandard photos and editing to show the best ones I captured. This is par for the course with active subjects that do not sit still for long.
A final shot of the bird’s plumage, showing the colors and patterns of the back and upper wings.

Two weeks prior to the photos of the acacia-feeding Bullock’s oriole, I was able to photograph two different oriole species found here in the Sonoran-Mojave Desert transitional ecozone of southern Mohave County, Arizona, feeding upon the exact same saguaro cactus (Carnegiea gigantea) fruits within minutes of one-another. First was a Scott’s oriole (Icterus parisorum) seen at a particular saguaro I planted years ago about 20 feet away from my front door and entry walkway. Then came the Bullock’s oriole, not more than three minutes later, visiting the same fruits on the same cactus. These images were snapped on July 2, 2021 at about 8 AM.

Scott’s orioles (Icterus parisorum) are quite a bit more yellow and black than the orange-yellow and black of the other two species found in the southwestern deserts. All three are spring and early summer residents, and breed in the region, although they may vacate for higher, cooler, or more northerly locales during the worst summer heat. All migrate to Mexico for the winter months.
The cactus fruits are larger and heavier than the birds themselves are. Imagine if you were a human being feeding upon a giant fruit larger than you. Aside from perhaps a few varieties of squash, melon, or pumpkin (all cucurbits) this isn’t really a thing that is possible for us.
Just after the Scott’s oriole departed, it was replaced by a Bullock’s oriole feeding upon the exact same fruits. It would have been great to see the hooded oriole (Icterus cucullatus) also show up. That would have made a unique trifecta!
The Bullock’s oriole takes his turn to feed. This is one of the primary ways by which saguaro cactus seeds are dispersed – via the feeding of various birds, but also via airborne bats and even ground-based mammals, which also consume the fruits. All of these creatures are highly mobile and can readily disperse seeds post-digestion to locales far away from the original parent plant.

2 thoughts on “Bullock’s Oriole (Icterus bullockii) Foraging For Insects

  1. I enjoyed seeing this on my computer. I’ve seen these Orioles as well right here in my little yard. Southern Nevada, Las Vegas, but not on the strip! Thanks

  2. Such beautiful photo’s, thank you! I was just looking for some clear pics of Saguaro flowers for a craft project and stumbled upon your site. Aren’t those birds stunning… I often heard a Black-headed oriole near my house in South Africa, but rarely saw it. Check out its sound on wikipedia, if you like. “a liquid-sounding warble”. Once you know it, you can’t miss it!

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