Wednesday, November 10, 2010

This Week in Nature:The 2nd week in November - Nene

What's Happening in Hawaii 
during the 2nd week in November:

Nēnē, the Hawaiian goose (Branta sandvicensis), begins nesting on the upper slopes of Haleakalā, Hualālai, and Mauna Loa. Historically, at least five species of geese (family: Anatidae) occurred in Hawai‘i; today, only the nēnē, or Hawaiian goose, survives. Adult males and females are mostly dark brown or sepia with a black face and crown, cream-colored cheeks, and a buff neck with black streaks. Females are smaller than males. Compared to other geese, nēnē are more terrestrial and have longer legs and less webbing between their toes; these differences likely facilitate nēnē walking on lava flows.

Nēnē, Haleakalā National Park, Maui.
Photo by Forest & Kim Starr

Nēnē pairs mate for life. Nēnē have an extended breeding season and eggs can be found all year except May-July, although the majority of birds nest between October and March, and most clutches are laid between October and December. Nēnē nests consist of a shallow scrape, moderately lined with plant materials and down. Pairs typically return to previous years’ nests sites, typically in dense vegetation; when available, kīpuka may be preferred. Females lay between two and five eggs which hatch after 30 days. Young are not fed by their parents; however, young remain with their parents for up to one year.

Nēnē, Haleakalā National Park, Maui.  
Photo by Forest & Kim Starr 

In 1951, the wild nēnē population was estimated at 30 individuals. Current population is estimated at between 1,300 and 1,500 individuals with 378 birds on the island of Hawai‘i, 295 to 325 birds on Maui, 720 birds on Kaua‘i, and 74 birds on Moloka‘i. All populations have been or are currently being supplemented by captive-bred birds.

Historical threats included habitat loss and degradation, hunting, and predation by rats (Rattus spp.), cats (Felis silvestris), dogs (Canis domesticus), and the small Indian mongoose (Herpestes auropunctatus). Current threats include predation by the non-native mammals listed above, exposure in high-elevation habitats, nutritional deficiency due to habitat degradation which may result in low productivity, a lack of lowland habitat, human-caused disturbance and mortality (e.g., road mortality, disturbance by hikers), behavioral problems related to captive propagation, and inbreeding depression.

Nēnē at Namana o ke Akua Haleakala National Park, Maui 
 Photo by Forest & Kim Starr

The goals of conservation actions are not only to protect current populations and key breeding habitats, but also to establish additional populations, thereby reducing the risk of extinction. Past and current actions include captive propagation and release of captive-bred individuals into the wild, predator control, habitat enhancement, research and monitoring, private conservation efforts, formation of the Nēnē Recovery Action Group, and public education.

For more details about the nēnē life cycle, and how DOFAW is working to protect the nēnē, visit the Hawaii Comprehensive Wildlife Conservation Strategy nēnē fact sheet.

Also, visit the nēnē page.

Check out Forest and Kim Starr's gallery for more beautiful images of nēnē and other native Hawaiian species. 

Drawn image from "Hawaii: A Calendar of Natural Events"
published by the Bishop Museum and Kamehameha Schools in 1989.

Text: Hawaii Comprehensive Wildlife Conservation Strategy, October 2005. 

No comments:

Post a Comment