Technical Report No. 11' BIRDS OF THE KILAUEA FOREST RESERVE, A PROGRESS REPORT Andrew J. Berger Department of Zoology University of Hawaii Honolulu, Hawaii ISLAND ECOSYSTEMS IRP U. S. International Biological Program September 1972 TABLE OF CONTENTS Page Abstract ••••••••••••••••••••••• *................... 1 IntroducU.on .......•...•.•......•.••..••........... 1 Boney ereepe rs ...•...•..•.....•.••..........•.•.•... 4 Hawa.iian l'h.rush ...................... e.............. 6 Elepaio •••••••••••••••••••••••••••••••••••••••••••• 9 Introduced species ••••••••••••••••••••••••••••••••• 10 Cardinal ••••••••• ,. II • ., ......................... 10 Olinese Thrush ................................. 10 White-eye and Red-billed Le10thrix ........... u ... ~~~~ If P'orilgiJ,1g<he1:i'~J,I);£oriof the birds ..................... 11 Nestina data ••••••••••••••••••••••••••••••••••••••• 15 Adaptability of five species ••••••••••••••••••••••• 18 Literature cited ••••••••••••••••••••••••••••••••••• 22 ABSTRACT The. Kilauea Forest Reserve is notable for the island of &'l1aii because it provides habitat for at least nine species of endemic birds, of which six species are members of the Hawaiian Honeycreeper f!l1llily (Drepanididae): Amakihi, Akepa, Creeper, J&iapolaau, Apapane, and Iiwi. The other endemic species are the Hawaiian Hawk, the Elepaio, and the Hawaiian Thrush. The thrush is abundant throughout the forest, and is common even in areas that have been disturbed by cattle and by logging operations. Two species of introduced birds occur in relatively large numbers: Japanese White-eye and Red-billed Leiothrix. Other species of introduced birds are found in the pasture land adjacent to the forest but have not been seen within the forest itself. The foragins behavior of endemic and introduced species is discussed. No data are available to suggest that introduced species compete with endemic birds for food or for nesting sites. Nesting data are presented. An apparently unusual feature about the Apapane i3 that this species not uncommonly builds its nest on the tops of tree fern fronds, rather than in ohia trees, which ie the typical site for nests of this species in ohia-tree fern foresta. The adaptability of three endemic species (£lepaio, Aaakihi, ~ciapolaau) and two introduced species (Japanese White-eye, Red-billed Leiothrix) to wide vegetational and climatic conditions is discussed. Physiological data obtained by Dr. Richard E. MaCMillen on captive Amakihi from Mawaii and Kauai are presented. - i - Birds of the Kilauea Forest Reserve, A Progress Report Andrew J. Berger The Kilauea Forest Reserve is owned by the Bernice P. Bishop Estate; IBP personnel were invited to conduct studies in the Reserve by Mr. Norman K. Carlson, the manager of agricultural and forestry lands of the Estate. Dr. Dieter Mueller-Dombola ~e1ected a 20o-acre portion of the forest for study, and R. S. Oooray end Jean Craine laid out four 1,OOo-meter transects (figs. 1, 2) within the study plot and analyzed the vegetation found there. It. cliwltie atation at the northwestern comer of the study plot has been in operation since August 1, 1970. The rainfall for 1971 totalled 112 inches (2810 mm) under the trees, and 94 inches (2342 mm) under open skies. The study plot fall. vithin segment 11 of figure 31 in the work of Doty and Mu.~er-Doabo18 (1966: 418-419), which corresponds to segment 11 of figure 3 in lIP Tectmieal hpol't No. 2 (January 1972). The IllaDe. 'or.at· las.rv~ is an excellent example of a near-virgin, llawaiianll -.:mta. rain fOl'e,stj) and very few such forut.e l'eetUn on the island of Bawai1a It consiBte of a mixed ohis ~2troa1deros'col1ina var polymC?reha), koa (Ae8,;Ci,! ~f). and tree fern (Cibotium spp.) forest at an elevation (about 5,400 feat at the climatic station) that is intermediate between that of a typical ~acia forest (found, in general, between 5,000 and 6,000 feet) Dud a typical ~tr~sideros rain forest that is characteristic of elevations below app~oxtmate1y 4,500 feet (Doty and Muel1er-Dombois, 1966: 418-419) • In addition to the dominant tree species (Hetrosideros and AcaCia), several others were found IIscattered throughout the forest": olapa, SC~LE 1:24000 .' ...... Fig. 1. Map of 200 acre study site (5ectio~ of Ku1~ni, Hawaii Topcgr. sheet). N I!lBPAToltlUH ROAD .,,~ pA~C.M ____ -t""- ------ 1'ft I I I I I I I I GTAIlT _11 .&11 iS6 ~ · 'LOT.. ·'a-· :Z •• ....· ~!! · -· -· 'N"O~ · · ""oT- I t t Ix I I ,:- I I ~! ~t2. 111 · • · · ...· · :.. -· · -· · · · ·• t T· t ? I I I I I • I I E 125 1 8 , 13 118 0 • ·• • • 0 ·• • ·• 0 -· · .:. -· · · · 1 t t T· I I I I I I I I I ~4 ~ :Sf '19 +9 • · :..· .:. -· · -· · · · T· T· ,· T I I I I I I I m 15 +10 ~15 :~ZO • · . .;..· -. -· · -· · · 800M -- ---- --------- -- --- Kilauea Forest Reserve IBP study site orientation map for partici~nt8. outline of study site. --------- base line (S50 NE) white flags every 5 meters • • --- -. blue flags every 5 m from base line to start of plots 1,6,11 & 16 and between plots on transectS. (l450 SE) ••••••••• orange flags every 5 m in plots on transects.{1450 SE) IV IV "" blue flags froill logging road to base line. starting points of transects marked with tag & blue & white flags. !±j~ starting & end points of plots marked with tag, blue & orange flags. ~ 50 m point in plots marked with tag, blue & orange flag. _2_ (Cheirodendron trigynum), kawau (Ilex ~!!)t and alan! (Pelea spp.). The olapa is of special importance. for the Omao or Hawaiian Thrush (?~aeornis £. obscurus), because the birds eat large quantities of the fruit of this tree. A third group of plants vas described as being rare--"less than 5 individuals per species were enumerated in the entire sample" (lBP Technical Report No.2, pel. 51). Examples are: oha-kepau (Clermontia hawaiiensis), kue-~ul (~x.ne! spp.) kalea-Iaulii (Myrsine !!ndwiCensis), and mamaki (P12turus hawallensis). A simple llstln& of tbe plants within the 200-acre (800 x 1,000 m) study plot, bowever. in no sense gives a true picture of the nature of the Kilauea Foreat, nor does the statement that the plot contains four I,OOO-_ter transects extending from the basel ine road to the lower end of the' plot. 1be ba ••Une road runs at an elevation of approximately 5,400 feet; the tranaects descend to an elevation of approximately 5.200 feet. Althouah Doty and HUeller-Dombois (1966: 419) refer to certain areas in the obla-koa-tree fern ecosystem that cent.lft "relatively deep, well-weathered BOil." the substrate is aa lava 1n the atudyplot, and there are many aree8 Where the angular lava blocks occur at Burface level. In general. the lava, crevices. and holes are more or less covered and concealed by mo •••a. ferns. and other ground-cover plants. This makes hiking both difficult and haz4rdous, so that one has to look at the ground before taking al.ost every step. Moreover, there obviously was a series of prehtstot'ic lava floW's in this region, because there are several places on the transects where there Is a steep drop of 20 or more feet. suggesting the line at which a particular flow stopped. In addition to this great irregularity in the ground. there are many fallen trees in the forest, Some of which exceed five feet in d~ameter. Hence. one either haa to crawl under or climb over these fallen giants. which typically are mcss~eover.d and slippery. Seedlings of many species of planta (lncl~dina tree ferns) find eonditlons suitable for germinating and growin, on the upper .u~f.c.. of .these dead tree trunks • The ground usually 'a wet. and. where there are accumulations of soil in low areas, It ,a not uncommon to sink 8 foot or more into the mud while follovln, • transect. Areas, and there are many, where pigs wallow are .apeclally difficult to crosa. (1 have seen one or mere pigS every tl.. I have walked 8 transect.) At several sites, there are larger boa areas that support asSocIations of farex aad acattered trees; these souaetl.- boleS as much as 8 foot of mud and water. All of these features of the Kilauea Forest make ordinary hiking hard work and bird study very difficult. Gaps in the crown canopy occur primar1l,y only in two situation,,: where there are bogs, and where large koa trees have fallen to the around. Throughout the rest of the forest, there is ! II complete crown cover at heights of 70 to 80 teet. i Transects 1 and 2 were "flagged out" during January 1971; transects ) and 4 were completed durIng late June. I made my first trip to the . -~Kil~l.te~F()r_e.!Ot Reserve in company wi th Norman Carlson, Dieter Mueller- DomboiS, and other IBP personnel on July 23, 1970. I visited the area again on November 20 that year. and on January 11. and June 24, 1971. netalled census counts along the transects were first made on January 11 -4- and 12, 1972. Tables 1 through 4 show the results of census trips through July 1972. Only two transects were covered on anyone day. Cross trai,ls (flagged by P. Quentin Tomich). near the lower ends of the transects, interconnect transects 1 and 2 and transects 3 and 4. The cross trails make it possible to cover the pairs of transects in from 2.4 (July only) to 4.15 hours. depeQdtna upon ~Ather conditions and the amount of bird activity at the tt.. of the census. the average time for five census trips on tranaecta l.eul 2 .. 3.6 hours. the average time for six census trip. on t~cee l an4 4 va. 3.9 hour•• I. Honeycreepers The Kilauea 'or.at Is notable because it provide. habitat for at least six species of Hawaiian honeycreepers (family Drepanididae), three of vhi ch are rare and endangered: Creeper (l:-Oxops maculata mana).