Crossbills are unique finches found across North America and Eurasia. Their crossed mandibles allow them to efficiently extract seeds from conifer cones. While crossbills can be challenging to find due to their nomadic nature, there are strategies birders can use to increase their chances of observing these remarkable birds. In this article, we will discuss how to find crossbills by understanding their biology, behavior, habitat preferences, seasonal movements, vocalizations, and utilizing tools like eBird alerts. With persistence and the right approach, you can add these irregular winter finches to your life list!
Understanding Crossbill Biology and Behavior
Crossbills are specialist feeders, using their unique crossed bills to pry open conifer cones and extract the seeds inside. Their distinctive mandibles cross at the tips, enabling them to grip cones and leverage them apart. This gives crossbills access to an abundant but tough-to-reach food source that most other birds cannot exploit.
There are 10 recognized species of crossbill worldwide, including the Red Crossbill and White-winged Crossbill in North America. Crossbills are sexually dimorphic, meaning males and females differ in appearance. Males tend to be red or orange while females are yellow or green.
Crossbills are highly gregarious and social, traveling in flocks numbering from just a few individuals to hundreds of birds. They can breed at any time of year, with breeding activity tied to food availability instead of season. Nesting begins when a bumper crop of cones appears, triggering crossbills to settle in an area and breed.
Key Facts about Crossbill Biology and Behavior:
– Specialized bill shape allows access to seeds in conifer cones |
– Males are red, females are yellow/green |
– Highly social, travel in nomadic flocks |
– Can breed any time ample food is present |
Understanding these aspects of crossbill biology and behavior provides insights into where and when we may encounter them. Next, we’ll look at their preferred habitat and foods.
Crossbill Habitat Preferences and Diet
Crossbills are found wherever their preferred conifer foods occur. This includes mature conifer forests across the northern and western United States, Canada, and Alaska. In eastern North America, they occur in areas with spruces and hemlock. Western birds rely more on pines.
The seeds extracted from conifer cones make up over 90% of the crossbill diet. Their favorite conifer foods include:
– Spruces (white, black, Engelmann, etc.) |
– Pines (lodgepole, ponderosa, Jeffrey, pinyon, etc.) |
– Hemlock |
– Douglas-fir |
– True firs |
Crossbills also occasionally consume tree seeds, buds, fruits, and insects, especially when feeding young. But mature conifer seeds are their dietary mainstay.
Knowing which conifers occur in your area helps pinpoint where to search for crossbills. Focus on stands of mature spruce, pine, hemlock, fir, and other cone-bearing trees. Next, let’s examine crossbill movements throughout the year.
Crossbill Movements and Seasonality
Crossbills are nomadic, wandering widely in search of bumper cone crops. This makes their movements somewhat unpredictable compared to other birds. Still, some seasonal patterns emerge:
Winter
In winter, crossbills irrupt southward in variable numbers. This coincides with scarcer food in their northern breeding locales and the maturation of southern cone crops. They can appear anywhere from Canada to the southern U.S. Listen for their distinctive flight call when near conifers.
Spring
Spring migration is less pronounced. Some crossbills remain in wintering areas if adequate food is present. Others head northward to breed as northern cones mature. Nesting activity begins once a suitable cone crop is found.
Summer
Through summer, crossbills nest at various latitudes following cone crops. They can breed successfully anywhere from Alaska to Newfoundland to high-elevation forests in the western mountains.
Fall
Like spring, fall movements are irregular. Some crossbills remain nested in summer areas into fall if cones persist. Others form large nomadic flocks that roam regionally in search of food.
While hardly predictable, understanding these seasonal movement patterns can help you know when crossbills are more likely to occur in your area. Late fall through winter are the best times to find them in southern locations.
Tuning in to Crossbill Vocalizations
Crossbill vocalizations provide excellent clues for locating these sociable but nomadic birds. Here are some of their primary calls to listen for:
Flight Call
The bold, rolling flight call is given frequently when crossbills are on the move. It’s a loud “chip-chip-chip-chip” that carries far and betrays the presence of a flock. Listen for flight calls when near areas of conifer forest, especially in fall and winter.
Excitement Calls
Crossbills have a chattery series of notes given when excited or alarmed. These buzzing “brrrdit, brrrdit” calls signify agitated or concerned birds. If you hear excitement calls, stay still and you may see crossbills appear.
Male Songs
Singing males give rapid trills and warbles that sound reminiscent of a Red-winged Blackbird. These songs are associated with breeding activity when crossbills settle in one area.
– Flight call: Loud, rolling “chip-chip-chip” heard during flight. |
– Excitement call: Chattery “brrrdt” notes given when agitated. |
– Male song: Trills and warbles like a Red-winged Blackbird. |
By learning these vocalizations, you can detect the presence of crossbills even when they remain hidden in the trees. Next, let’s examine some tools that can further help pinpoint crossbill locations.
Using eBird and Alerts to Locate Crossbills
eBird, an online database sponsored by the Cornell Lab of Ornithology, provides real-time information on bird distribution. Checking eBird can reveal recent crossbill sightings, which may indicate where flocks are currently wandering.
You can also set up email alerts through eBird to receive notifications anytime crossbills are reported in your county or region. This allows you to rapidly respond to local crossbill activity.
Some key ways to utilize eBird for crossbill finding:
– Check recent crossbill sightings in your area |
– Set up county or regional alerts to receive crossbill notices |
– Note any patterns in movements, habitat, or flock size |
– Connect with eBird users who report crossbills for tips |
Combining eBird information with your knowledge of crossbill biology will boost your chances of a successful crossbill quest.
Tips for Finding Crossbills
Here are some key tips for locating nomadic crossbill flocks:
Seek mature conifer stands
Focus on finding areas of mature spruce, pine, hemlock, fir, or other cone-bearing trees. Crossbills rely on these food sources.
Listen for flight calls
Frequently stop to listen for the loud, rolling flight call of traveling crossbills. Following vocalizing flocks often leads to discovery.
Be patient and still
Crossbills can be frustratingly tough to spot as they sit silently feeding in treetops. Sitting quietly in one spot improves odds over moving around.
Try using playback
Broadcasting a recording of crossbill flight or excitement calls may attract birds to your location if used sparingly. Just be sure not to overdo playback.
Follow eBird reports
Check eBird regularly for recent crossbill sightings and set up alerts. Then visit those same areas when possible.
Persistence is key to finding crossbills. Their movements can seem haphazard and random. But by applying the right techniques at the right times in the right habitat, you’ll eventually be rewarded with sightings of these fascinating finches.
Ideal Locations for Finding Crossbills
While crossbills can turn up almost anywhere with adequate cone crops, these areas hold reliably good populations:
Western Mountains
High-elevation pine forests in the Sierra Nevada, Cascades, and Northern Rockies host dependable numbers of Red Crossbills and other species. Try campgrounds, lakes, and backcountry trails.
Eastern Canada
Newfoundland, Quebec, Nova Scotia, New Brunswick, and Ontario get regular irruptions of crossbills in spruce and fir forests, especially along the boreal zone.
Alaska
Vast subarctic and boreal forests make Alaska a crossbill bastion. Red and White-winged Crossbills occur statewide wherever conifers grow.
Great Lakes Region
Containing a mix of conifer habitats, states bordering the Great Lakes see frequent winter finch irruptions when northern seed crops fail. Watch for crossbills at feeders here.
Pacific Northwest
Diverse conifer forests spanning Oregon and Washington make this region a crossbill hotspot. Pine-dominated areas east of the Cascades are particularly productive.
Focus your efforts in these conifer strongholds, especially during winter months, and you’ll have an excellent chance of crossing crossbills off your birding bucket list.
Conclusion
Crossbills can be reliably found by learning their habitat preferences, seasonal movements, vocalizations, and utilizing tools like eBird alerts. Focus on mature conifer forests, frequently stop to listen for flight calls, and be patient. Crossbill nomadism makes predicting their occurrence challenging, but with persistence and the right strategies you can be rewarded with sightings of these unique finches. Their specialized bills and complex nomadic ecology make crossbills a fascinating bird to find and observe. So sharpen your search image, tune your ears to their calls, monitor recent reports, and head out to search those conifer treetops. Before long you’ll pick up the sounds, sights, and pleasures of encountering North America’s wandering pine seed specialists.