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13 Blue-Throated Mountain Gem Facts

The Blue-throated Mountain Gem is a larger hummingbird found mainly in Mexico, but makes annual visits to the United States. Named for males’ blue throat and their preference for high altitude living, these hummingbirds have plenty of unique behaviors. From singing duets with their mates to building intricate nests in difficult locations, these remarkable little birds never cease to amaze. Let’s learn 13 Blue-Throated Mountain Gem facts. 

13 Blue-Throated Mountain Gem Facts

1. The male and female have different color patterns

Blue throated mountain gem perching
Blue throated mountain gem perching | image by Bettina Arrigoni via Wikimedia Commons | CC BY 2.0

The Blue-throated Mountain Gem is a species that exhibits sexual dimorphism, meaning that the males and females have different color patterns.

For this species, adults of both sexes have a bronzy green back, a gray chest and belly, and a white stripe behind the eye. They also have large white spots on their tail feathers, mainly only visible in flight. The main difference between them is males have a glittering blue throat, known as a gorget. This patch may appear dark in poor light. 

2. They are high-altitude specialists

This bird species can be found in various high-altitude moist forest landscapes in northern Mexico, including riparian, pine-oak, and mixed coniferous forests. In Arizona, you’ll typically find the blue-throated mountain gem in the “sky island” mountain ranges that are above 4,300 ft. 

In the central and southern regions of Mexico, they prefer coniferous forests. Moving southward, near Mexico City, they can be found in elevations between 11,800 and 12,800 ft and in Oaxaca between 8,200 and 9,800 ft.

3. Male blue-throated mountain gems are territorial

Blue-throated mountain gem on branch
Blue-throated mountain gem on branch | image by Ryan Mandelbaum via Flickr | CC BY 2.0

Male blue-throated mountain gems are territorial creatures, particularly during the breeding season. To establish and protect their territories, they will aggressively chase away rivals.

They use their large bill to attack potential intruders and employ a variety of displays, including expanding their plumage and fanning and flicking their large tails to make themselves appear larger and more intimidating to potential rivals. Males may strike their beaks together making a loud cracking noise. This territorial behavior is not limited to adult males, as young males may also attempt to establish territories shortly after fledging. 

4. They are capable of producing ultrasonic vibrations

Ultrasonic vibrations are sounds emitted at frequencies higher than the human ear can detect. While this has not been widely studied, it is thought the Blue-throated Mountain Gem hummingbird uses them for hunting. By producing ultrasonic vibrations, the hummingbird can disorient and confuse its insect prey, making them easier to capture and consume.

5. They have interesting courtship and mating rituals

Rather than using an aerial display to attract mates, these hummingbirds prefer to perch and sing while flashing their blue throat feathers and the white of their tail feathers. This intricate song can last for several days and is far softer than the usual chip-note songs produced by males. For this reason it is sometimes referred to as their “whisper song.”

Interested females may join the males in song and create a duet. After some days of courtship, male Mountain Gems will mate with the female but provide no further assistance with breeding activities.

6. Males and females do not pair for long periods

Although males and females may pair for a few days or weeks, they generally do not remain together for extended periods and don’t form pair bonds. After successful mating, the male will typically move on to other territories while the female is left to incubate the eggs.

It takes about 19 days for the eggs to hatch and for the female to incubate and feed her young. The chicks are usually ready to fledge by day 26 and will leave the nest shortly afterward.

Blue-throated mountain gem on flight
Blue-throated mountain gem on flight | image by ALAN SCHMIERER via Flickr

7. Some migrate for the Winter

Most populations in central and southern Mexico stay put year-round, however they often move locally from areas of higher elevation to lower elevation during the winter. They are only present in the U.S. during the spring and summer breeding season. You can find them in higher elevation areas just over the southern border, mainly in the Sky Island mountain range of southeastern Arizona and the Chisos Mountains in Big Bend Texas. Most that summer in the U.S. head back south into Mexico for the winter. 

8. They love feeding on nectar

Blue throated mountain gem feeding on nectar
Blue throated mountain gem feeding on nectar

The Blue-throated hummingbirds mainly consume nectar from tubular-shaped, brightly colored flowers with high sugar content. This can include plants such as Nicotiana, Penstemon, Salvia species, Mountain Sage, Desert Honeysuckle, Coral Bells, Agave and Golden Columbine.

They are incredibly fast feeders, using their extendible straw-like tongues to lick the nectar as much as 13 times every second. Furthermore, these birds are also known for aggressively protecting the flowers they feed on. As a result, many native and cultivated plants rely heavily on hummingbirds for pollination.

9. Insects make up a large part of their diet

Insects are an important source of protein for the Blue-throated Mountain Gem, and they form a large part of their diet. During the breeding season, a nesting female will capture many insects per day to feed her young either by hawking, snatching from leaves or branches, or taking them from spider webs.

Insects such as spiders, aphids, flies, and beetles can be an important food source during the dry season, when flowers are more scarce.

10. Females build nests

Female blue-throated mountain gem on nest
Female blue-throated mountain gem on nest | image by Bettina Arrigoni via Wikimedia Commons | CC BY 2.0

Females construct cup-shaped nests made from various materials, including spider silk, plant fibers, animal hair, and feathers. These nests are typically 6 feet off the ground and may be found on tree branches, rock ledges, houses, and sheds. Nests are about 2 inches wide. Sometimes they will build right on top of an old nest.

Females often use materials from old nests to build new ones, making them extra sturdy and well-camouflaged. In drier areas, the nests may not be as camouflaged due to a lack of moss in the building material. Unlike many hummingbird species, they do not use lichens in their nests. 

11. They can raise more than one brood every year

The Blue-throated mountain gem can raise multiple broods in one year, though this usually depends on the availability of food and other resources. If conditions are suitable, they can raise up to three broods per year, with a clutch size of 1-2 eggs per brood. To do this, they will begin building a nest soon after their first brood has left the nest

12. They are the largest hummingbird found in the U.S.

Blue-throated hummingbirds are fairly large in the hummingbird world, with a length of about 4.4 – 5.0 inches. Compare that with a ruby-throated hummingbird which is about 2.8-3.5 inches. Because of this size, they will win out if there is a territory dispute over coveted flowers with smaller hummingbird species. While their range is pretty small in the U.S., they are still currently the largest species to regularly visit. 

13. They only beat their wings half as fast as other hummingbirds

Blue throated hummingbird in action
Blue throated hummingbird in action

While some of the smaller hummingbirds, such as the rufous hummingbird, can beat their wings up to 62 times a second, the Blue-throated Mountain Gem beats its wings up to 23 times per second while hovering. This is due to its relatively large body size and wingspan, making it more difficult for the bird to achieve higher wing beats.

Nevertheless, this hummingbird species is still an adept flier that can produce a wide range of flight maneuvers, including hovering, diving, as well as backward and lateral movements.