The Evening Grosbeak is a striking bird with bright yellow and black plumage. Once a common sight at backyard bird feeders across much of North America, this gregarious finch has declined precipitously over the past several decades. So what has happened to the Evening Grosbeak, and is it in danger of extinction?
What is an Evening Grosbeak?
The Evening Grosbeak (Coccothraustes vespertinus) is a large, stocky songbird in the finch family. It is named for its massive beak, which is adapted for crushing seeds. Males are a bright lemon-yellow with black wings, a white patch on the wings, and a dark tail. Females are more subdued gray-brown and yellow. Evening Grosbeaks are highly social and travel in flocks of up to several hundred birds. They breed in northern forests across Canada and the western United States. During winter, they may wander south in search of food.
Range and Habitat
Evening Grosbeaks breed across Canada and the western United States in coniferous and mixed forests. They are most abundant in mountainous areas. Their range extends from Alaska across Canada to Quebec and south to California, Arizona, and New Mexico. Outside the breeding season, Evening Grosbeaks may migrate short distances south if food is scarce. In some years, major influxes of Evening Grosbeaks occur as far south as the Gulf Coast states when populations in the north erupt.
Diet
Evening Grosbeaks have very large, powerful beaks suited for cracking hard seeds. Their diet is composed primarily of tree seeds such as maple, ash, and boxelder. They also eat buds, fruits, and some insects. At feeders, they prefer sunflower seeds, peanuts, and suet.
Evening Grosbeak Population Decline
Up until the 1980s, Evening Grosbeaks were a fairly common sight at backyard bird feeders during winter across much of the United States and southern Canada. However, beginning in the late 1980s, Christmas Bird Count data showed a precipitous decline in Evening Grosbeak numbers in the East. By the early 2000s, the decline encompassed the entire range of the Evening Grosbeak. Breeding Bird Survey data indicate a decline of over 90% between 1966 and 2015. What could have caused such a catastrophic collapse of this once abundant species?
Causes of Decline
The reasons for the Evening Grosbeak decline are not entirely clear, but several factors may be involved:
- Habitat loss: Logging of old-growth forests in Canada may have reduced nesting habitat.
- Climate change: Warmer winters mean fewer southward irruptions in search of food.
- West Nile Virus: First detected in North America in 1999, this disease may disproportionately affect Evening Grosbeaks.
- Reduction in spruce budworms: This key food source has declined due to pesticide use and changing forests.
The Evening Grosbeak population decline is likely due to a combination of some or all of these factors. More research is needed to determine the relative contribution of each one.
Current Conservation Status
The Evening Grosbeak is currently listed as a Species of Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). This means the species may become threatened if limiting factors are not reversed. It has a conservation ranking of 15 out of 20 on the Continental Concern Score by Partners in Flight. In the United States, it has no special conservation status or protections at the federal level.
Is the Evening Grosbeak Endangered?
While the Evening Grosbeak has clearly suffered a major population decline since the 1980s, there is no consensus on whether it warrants being listed as endangered at this time.
Arguments for Listing as Endangered
Some ornithologists argue that the Evening Grosbeak should be listed as endangered because:
- The population has declined by over 90% in just a few decades
- The causes of the decline are not fully understood or addressed
- Climate change may put additional pressure on populations
- Listing would provide protections for this vulnerable species
Arguments against Listing
Others argue against listing the Evening Grosbeak as endangered for several reasons:
- It still has a relatively large total population size in the millions.
- It has a vast breeding range across Canada and the western U.S.
- Population irruptions provide a buffer against extinction.
- More data is needed to justify listing it as endangered.
Given these differing viewpoints, there is debate around whether listing the Evening Grosbeak as endangered is warranted at this time.
Outlook and Conservation Recommendations
While not currently endangered, the Evening Grosbeak has suffered concerning declines and could become threatened without conservation action. Here are some recommended steps to aid Evening Grosbeak populations:
- Protect remaining old-growth forests on the breeding grounds
- Leave standing dead trees which provide nest cavities
- Monitor and control West Nile Virus outbreaks
- Provide ample, suitable food sources in wintering areas
Backyard bird enthusiasts can help by providing black oil sunflower seeds, suet, and peanut hearts at feeders during winter months. Reporting observations also aids monitoring of Evening Grosbeak population trends over time. With conservation action, hopefully, this distinctive northern finch can recover from its declines.
Conclusion
The Evening Grosbeak has undergone a steep population decline since the 1980s for reasons not entirely clear. While concerning, it remains fairly widespread across Canada and the western U.S. There is debate around whether to list it as endangered or not at this time. Increased habitat protection, disease monitoring, winter food provisioning, and long-term studies of population trends will help conserve the Evening Grosbeak. Backyard birders can aid by participating in citizen science efforts and making their feeders Evening Grosbeak friendly. With luck and concerted conservation action, the boisterous flocks of these striking yellow and black finches will once again return to backyards.