Black chinned hummingbirds (Archilochus alexandri) and broad-tailed hummingbirds (Selasphorus platycercus) are two similar looking hummingbird species found in the western United States. While they may appear identical at first glance, there are some key differences between these two hummingbirds in terms of physical features, habitat, diet, and behavior. Understanding the distinctions can help birders properly identify them.
Physical Features
In terms of physical appearance, black chinned hummingbirds are darker and have more vibrant iridescent throats. The males have a dark, purple-black chin and throat feathers that appear black unless struck by sunlight at the proper angle. Females and juveniles have light gray chins and white throats with some dark spotting.
Broad-tailed hummingbirds, on the other hand, have brighter green backs and crowns. Males have a pinkish-red throat with a small black spot in the center, while females have whitish throats with black speckles. In flight, broad-tailed hummingbirds’ tail feathers are noticeably broader and more rounded compared to the black chinned’s more pointed tails.
Size
The birds are very similar in size, with black chinned hummingbirds measuring 3-3.5 inches on average and broad-tailed hummingbirds measuring 3.1-4 inches. As you can see, their sizes overlap significantly.
Bill Shape
Looking at bill shape can also help distinguish the two. Black chinned hummingbirds have short, straight bills less than an inch long. Broad-tailed hummingbirds have slightly longer bills (over an inch) that curve slightly downward.
Habitat
These two hummingbirds occupy different primary habitats. Black chinned hummingbirds are more common in lower elevation valleys, canyons, and along water sources like streams and irrigated fields. Broad-tailed hummingbirds prefer higher elevations and are commonly found in mountain meadows, pine forests, and aspen groves above 5000 feet. However, some habitat overlap may occur.
Backyard Feeders
In backyards, black chins are the most likely hummingbird visitors to feeders east of the Rockies while broad-tails commonly visit feeders west of the Continental Divide. So if you live in New Mexico, Colorado, Wyoming etc. and see hummingbirds at your feeder, chances are they are broad-tailed.
Diet
The two species have similar nectar-based diets. They use their long tongues to slurp nectar from tube-shaped flowers. Some favorite nectar sources include columbine, trumpet vine, bee balm, and salvia.
However, broad-tailed hummingbirds are more specialized on nectar while black chins have a more varied diet. Black chinned hummingbirds get a larger share of their calories from eating small insects and spiders. So in terms of diet composition, black chins rely more heavily on insects to meet their nutritional needs.
Sap Feeders
An interesting difference is that broad-tailed hummingbirds readily feed from sap wells created by sapsuckers. Black chinned hummingbirds do not demonstrate this sap-feeding behavior as commonly. So if you see a hummingbird drinking from sap wells, it’s likely a broad-tail.
Breeding and Nesting
In the breeding season, male black chinned hummingbirds perform elaborate courtship displays to impress females. They climb high in the air and then dive sharply, producing a loud chirping sound with their tail feathers. This is called a “J-dive display.” Broad-tailed hummingbird males do not perform the same display.
For nesting, black chinned hummingbirds often nest in trees along riparian corridors. Broad-tailed hummingbirds nest farther from water sources and prefer small conifers, low branches, or shrubs for nest sites. The nests themselves are compact, cup-shaped, and made of plant down, spider webs, and lichen bound with silk.
Migration
Black chins and broad-tails have slightly different migration timing. Black chins arrive earlier on breeding grounds, usually by early May. Most broad-tailed hummingbirds don’t arrive to breed until late May or early June. In the fall, broad-tails depart earlier for their wintering grounds in Mexico by July while black chins linger longer into late summer or early fall.
Range
The range also differs between the species. Black chinned hummingbirds are widespread across the western United States and Mexico. Broad-tailed hummingbirds occupy a smaller range primarily across the Rocky Mountain region from Mexico to Wyoming and Idaho. Some limited overlap occurs, but broad-tailed hummingbirds are generally found at higher elevations.
Rarity
Within their resident ranges, black chinned hummingbirds are common and broad-tailed are relatively uncommon in number of individuals. But in areas where their ranges overlap, broad-tails become much rarer compared to the more numerous black chins.
Behavior
Some subtle behavioral differences exist:
- Black chins are more likely to hover quietly beneath feeders, while broad-tails have more aggressive darting movements.
- Broad-tailed hummingbirds have high-pitched twittering calls compared to black chins.
- Black chins sometimes nest semi-colonially with multiple nests in one tree, while broad-tails are strictly solitary nesters.
However, in general behaviors are quite similar between the species when it comes to feeding, migrating, defending territories, etc. The differences mentioned above are more nuanced.
Identification Tips
Here are some quick identification tips:
- Location – If west of the Rockies, especially at higher elevations, more likely broad-tailed. East of the Rockies, more likely black chinned.
- Chin – Black chin means black chinned hummingbird.
- Throat – Pink throat with black spot is broad-tailed, while solid purple-black throat is black chinned.
- Tail shape – Rounded is broad-tailed, pointed is black chinned.
- Habitat – Near water favors black chinned, while high mountain areas indicate broad-tailed.
Conclusion
While black chinned and broad-tailed hummingbirds appear very similar at first glance, careful observation of key identification points like chin color, tail shape, habitat, and geographic location can help distinguish these two western hummingbird species. Understanding their differences in physical features, diet, nesting behaviors, range, and migration patterns provides a richer appreciation of their biological uniqueness. So next time you see a hummingbird zipping by, take a closer look to determine if its a black chin or a broad-tail!
