Rufous-tailed Hummingbird

IMG_8361.JPG
A male rufous-tailed hummingbird



Common name: Rufous-tailed hummingbird
Latin name: Amazilia tzacatl
Family: Trochilidae

Range and abundance:
Widely found from east-central Mexico, through Central America and into northwestern South America; most common hummingbird in Costa Rica

Coloration and morphology:
Length of 8 to 11 cm, wingspan of 2 to 2.4 cm and mass of 5.2-5.5 g; green body, straight, medium-sized, reddish bill with a dark tip and a blackish upper mandible and forked, rufous tail with a dark tip; slight differences between males, females and juveniles
male—larger with longer body and wingspan; more golden green body; grayish belly
female—smaller with shorter body and wingspan; more black upper mandible; paler belly; throat edged with whitish feathers for a more scalloped appearance
juvenile—more black upper mandible like females; darker grayish belly; face and crown edged with bronzy feathers



IMG_8344.JPG
A male
7D_Tuesday_Morning_Bird_Walk_0016.jpg
A female


Reproduction:
During mating season, males claim areas of flowers as their territory and sing to attract females. Mating season varies from region to region: it peaks from January through May in Costa Rica, coinciding with the dry season. Rufous-tailed hummingbirds are polygynous, and males are only involved in fertilization. Females typically select horizontal branches in smaller trees and bushes 2 to 5 m above the ground as nesting sites. They build compact cup nests from plant fibers, cobwebs and dead leaves; lichens and mosses cover the outer surfaces. Females usually lay 2 eggs per season and incubate them for 15 to 16 days until they hatch. The young leave the nests when they are around 18 to 22 days old, but their mothers continue to feed them until they are around 58 days old.

Habitat:
Low thickets in tropical to subtropical rain forests, mountains and coastal areas at low to middle elevations; prefers semi-open areas to dense forests, including disturbed forests, forest edges, secondary forests, banana and coffee plantations and gardens.

Songs:
male’s song—shrill notes that rise and accelerate; repeated in bursts
call—low note; repeated in a sputtering series

Ecology:
The rufous-tailed hummingbird has co-evolved with the flowers on which it feeds. The flowers have distinct characteristics that attract the birds and maximize the chances that the birds will transfer their pollen so that they can reproduce. In addition, the hummingbirds’ beaks are specialized for feeding from these flowers. Many plants rely on the birds for pollination because their tubular-shaped flowers prevent bees and butterflies from feeding on and pollinating them: these plants would be unable to survive without pollination by the rufous-tailed hummingbird. Rufous-tailed hummingbirds provide ecosystem services for humans by pollinating important crops such as bananas and coffee. They offer pest control by eating insects. Furthermore, they promote ecotourism by attracting birdwatchers. Due to their agility in flight, adult rufous-tailed hummingbirds have few predators. However, eggs and chicks in the nest are susceptible to predation. The birds are predators themselves for the small insects and spiders that they eat as a source of protein. Rufous-tailed hummingbirds compete with other birds and large insects for nectar. They aggressively defend their feeding territories with intimidating displays and diving flights, and they are dominant over most other hummingbirds and smaller competitors.

Behavior:
Males aggressively defend their territories against other males of their species. They sometimes sing in small, loosely-assembled groups. Rufous-tailed hummingbirds occasionally form loose nesting colonies.

Diet:
Rufous-tailed hummingbirds feed primarily on nectar from a variety of small, brightly-colored, scented flowers of trees, shrubs and epiphytes, favoring heliconias and bananas. They use their hollow, extendible, forked tongues to retrieve nectar, typically while hovering in the air with their tails cocked upward. Alternatively, they may perch on a flower to feed. Rufous-tailed hummingbirds also eat some small insects and spiders for protein, often catching them in flight, snatching them off leaves and branches, or taking them from spider webs. As a result of their high metabolism, rufous-tailed hummingbirds feed frequently—every 10 to 15 minutes. They can visit up to 1,000 flowers a day and lap up nectar at a rate of 13 licks per second.




IMG_8664.JPG
Feeding from Heliconia
019_6.JPG
Feeding from Stachytarpheta


Personal experience:
During my trip to Costa Rica, I was only able to catch a few glimpses of rufous-tailed hummingbirds feeding from the flowers of shrubs located in clearings in the rain forest.

IMG_8362.JPG
In flight

References:
Borchardt H. 2004. Amazilia tzacatl. Animal Diversity Web [Internet]. [cited April 28, 2012]. Available from: http://animaldiversity.ummz.umich.edu/site/accounts/information/Amazilia_tzacatl.html
Henderson CL. 2010. Birds of Costa Rica: A field guide. Austin: Univ of Texas Pr. p. 156.
Reich SK. 2010. Rufous-tailed Hummingbird (Amazilia tzacatl). Neotropical Birds Online [Internet]. Ithaca: Cornell Lab of Ornithology; [cited April 28, 2012]. Available from: http://neotropical.birds.cornell.edu/portal/species/lifehistory?p_p_spp=255416
2010. Rufous-tailed hummingbirds. AvianWeb [Internet]. [cited April 28, 2012]. Available from: http://www.avianweb.com/rufoustailedhummingbirds.html