Bend, Oregon

Central Oregon GrosbeaksEvening Grosbeak

     Two Grosbeak species occur regularly in Central Oregon, the Evening Grosbeak and the Black-headed Grosbeak.

     The Evening Grosbeak is slightly smaller than a Robin, with a massive lightly colored bill. The male has a dark head with a bright yellow eyebrow, yellow lower breast and belly, and black wings with a large white patch. The female is more gray overall and lacks the bright yellow plummage above the eye and on the breast. Evening Grosbeaks are very social and are typically seen in large flocks.

     Like the Evening Grosbeak, the Black-headed Grosbeak also has a large thick bill, although it is more darkly colored. As the name suggests, the male Black-headed Grosbeak has a black head. Most striking though is their bright orange breast, neck, and rump. The back is black and the wings are dark with small white patches. Female Black-headed Grosbeaks do not have the solid black head of the male, rather they have a dark brown head with a prominent white stripe above the eye and another lower on the face.  Instead of the orange breast of the males, the females are more muted with a buffy breast with faint brown streBlack-headed Grosbeakaks.

     While both species consume insects, their diet consists predominantly of seeds. These Grosbeaks visit feeders regularly for their favorite food, black oil sunflower seeds either in or out of the shell. 

     Although similar in diet, size, and beak structure, these two Grosbeak species are not closely related. The Evening Grosbeak is closely related to finches and is in the Finch family (Fringillidae), while the Black-headed Grosbeak is in the Cardinal family (Cardinalidae). The similarities between these distant cousins is a great example of convergent evolution; disimilar species that evolve similar traits because of common selective pressures. In this case, it is presumed that the large beak that both species possess is an adaptation for eating large seeds, nuts, and insects with strong exoskeletons.

     While both the Evening Grosbeak and the Black-headed Grosbeak visit Central Oregon, they are not usually here at the same time of year. Flocks of Evening Grosbeaks are typcially seen in the spring and the fall. While not as common, they will occasionally be seen throughout the winter.  They tend to move further north and into higher elevation areas to nest, and are uncommon here during the summer.

     About the time the Evening Grosbeaks are leaving the area, the Black-headed Grosbeaks are beginning to return. Black-headed Grosbeak are neotropical migrants, spending the winters in Central and South America and returning to our area in early May.  Once here, they will nest and raise their young, and then begin their return journey south in September.

     This spring has been somewhat unusual because the Evening Grosbeaks have been very numerous late in the season, and a still present in large numbers when the Black-headed Grosbeaks are arriving.  Enjoy being able to see these two beautiful species in your yard at the same time, it does not happen too often!

Grosbeak Fun Facts

  • Black-headed Grosbeaks are one of the few birds capable of eating toxic monarch butterflies. They discard the wings before eating the butterfly in an apparent attempt to reduce the amount of toxins they ingest.
  • The Black-headed Grosbeak, along with the Black-backed Oriole are the two primary avian predators of the over-winter populations of Monarch Butterflies found in Mexico. Combined they are responsible for more than 60% of Monarch mortality at many of the Mexican roosting sites.
  • These two species feed twice daily at the roosts in mixed flocks of five to at least 60 birds and annually consume several million Monarchs in the Mexican roosts.
  • At one 5.5 acre Monarch butterfly colony, Black-headed Grosbeaks, along with the Black-backed Orioles ate an average of 15,000 butterflies a day. It is estimated that over 2 million butterflies were consumed during the entire winter resulting in almost a 10 % reduction of the roost's entire population.
  • Evening Grosbeaks can break open seeds that require up to 125 pounds of pressure to crush.
  • Black-headed Grosbeaks have been known to feed at oriole nectar feeders.
  • Other birds like to eat wild cherries, but only Evening Grosbeaks target the pits. The slippery seeds are held firmly with special pads on the “gross beak” and are simply crushed. So favored are cherry pits that Evening Grosbeaks sometimes seek out the pits voided by American Robins.
  • Evening Grosbeaks manipulate cherries in their beak to remove the outer skin and flesh, the remaining seed is then swallowed after it is cracked open with their beak.
  • Evening Grosbeaks can break open food items that require up to 125 pounds of force to fracture apart in testing devices.
  • As with many finches whose diet is primarily vegetarian, Evening Grosbeaks are attracted to natural salt and mineral sources.
  • The Evening Grosbeak was not commonly found east of the Rocky Mountains before the 1850’s. Winter irruptions now occur in all of the 48 contiguous states. This expansion may be attributed to widespread planting of box elder trees in landscapes across the east. Its seeds persist on the tree throughout the winter and provided flocks with a reliable source of food.
  • The Evening Grosbeak was named in 1825 based on erroneous accounts that they became vocal and active only “at the approach of night.” This erroneous belief persisted for years, and the name is still a misnomer.