USGS2013
Haleakalā National Park (HALE) was surveyed for landbirds and habitat characteristics from March 20 through July 26, 2012. This information provides data in the time-series of landbird monitoring for long-term trends in forest bird distribution, density, and abundance. The Kīpahulu District of eastern Haleakalā Volcano was surveyed using point-transect distance sampling to estimate bird abundance. We surveyed 160 stations and detected a total of 2,830 birds from 12 species. Half of the species were native and half were non-native. Numbers of detections per species ranged from 1 to 849. There were sufficient detections of seven species to allow density estimation. Āpapane ( Himatione sanguinea ) was the most widely distributed and abundant native species detected in the survey. ‘Alauahio ( Paroreomyza montana newtoni ), Maui ‘Amakihi ( Hemignathus virens wilsoni ), and I‘iwi ( Vestiaria coccinea ) were widespread and occurred in relatively modest densities. Only eight Kiwikiu ( Pseudonestor xanthophrys ) and 20 ‘Ākohekohe ( Palmeria dolei ) were detected and were restricted to high elevation wet forest. We estimated an abundance of 495 ± 261individuals of Kiwikiu in a 2,036 ha inference area which likely includes the entire suitable habitat for this species in HALE. For ‘Ākohekohe, we estimated an abundance of 1,150 ± 389 individuals in the 1,458 ha inference area. There was a strong representation of non-native landbirds in the survey area. The Japanese White-eye ( Zosterops japonicus ), Japanese Bush-warbler ( Cettia diphone ), and Red-billed Leiothrix ( Leiothrix lutea ) accounted for nearly half of all landbird detections. Each species was common in predominantly native forests. Vegetation and topographic characteristics were recorded on 160 landbird monitoring stations. HALE canopy and understory composition was predominantly native, especially at elevations above 1,100 m. Much of the forest canopy was comprised of `ohi`a ( Metrosideros polymorpha ) interspersed with mature olapa ( Cheirodendron platyphyllum ). This canopy class occurred at 92.5% of the stations surveyed. More than three-quarters (77.5%) of the monitoring stations had a dense canopy with most crowns interlocking (> 60% cover). More than half (52%) of the stations surveyed had trees taller than 10 m, while almost a third (31%) had trees 5-10 m. Only 17% of the stations had a canopy shorter than 5 m. The native shrubs Vaccinium calycinum , Broussaisia arguta , and Leptecophylla tameiameae were the most common understory plants recorded, occurring at more than 30% of the stations sampled. Native mosses and ferns were also common at stations, occurring at more than 90% of the stations sampled. The invasive Psidium cattleainum , Clidemia hirta , and Hedychium gardnerianum occurred at approximately 14% of the stations sampled, predominantly at elevations below 1,100 m.