Distributions and Habitat Associations of Birds in Waikiki, Hawaii
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Pacific Science (1989), vol. 43, no . 2 © 1989 by University of Hawaii Press . All rights reserved Distributions and Habitat Associations of Birds in Waikiki, Hawaii RICHARD N. WILLIAMS 2 AND ROBERT C. FLEISCHER3 ABSTRACT: We conducted 57 transects along three routes in Waikiki from August through December 1986. Rock Doves, Zebra Doves, and House Sparrows, all alien species, accounted for approximately 80% of all birds ob served. All three species were most common near the Honolulu Zoo and Fort DeRussy Beach Park. Distributions of all three species were significantly cor related with decreasing distance from the Honolulu Zoo, increasing human densities, and parklike habitats. Effects of distance, human density, and habitat characteristics were separated using multiple regression analysis. Rock Dove distributions were primarily affected by distance from the Honolulu Zoo, a major feeding and roosting site for Rock Doves. House Sparrow distribu tions were primarily affected by human densities, and secondarily by habitat characteristics. Zebra Dove distributions were primarily related to habitat characteristics. ECONOMIC GROWTH and associated land de- Waikiki is regularly used by Hawaii resi velopment has accelerated dramatically in the dents, as well as visitors, for business and central Honolulu and Waikiki areas over the recreational pursuits. Because birds and hu past two decades. This has increased the mans are both concentrated in Waikiki, the amount of urban and suburban habitats in possibility exists for negative interactions southeastern Oahu, a factor that has been (e.g., transmission of disease, property dam implicated in an increase in the rate of natural age, etc.) to occur between them. However, ization and range expansion of several exotic basic ecological information on the distribu bird species during the 1970s(Williams 1987). tions and habitat associations of birds in Native bird species are absent from these Waikiki is required before any assessment of habitats (Pyle 1986)and many exotic or alien possible interactions can occur. bird species are either absent or occur in In this paper, we present ecological in frequently in urban environments. However, formation on the distributions of House several alien species that are recognized as Sparrows, Rock Doves, and Zebra Doves commensal with humans (Weber 1979), in throughout Waikiki and Kapiolani Park. cluding the Pigeon or Rock Dove (Columba These species have a long history of associa livia), Zebra Dove (Geopelia striata), and tion with humans and are generally recog House Sparrow (Passer domesticus), occur in nized as pests (Long 1981). We discuss asso their highest densities in Waikiki (Pyle 1986). ciations of these three species with human Indeed, these three species account for ap densities and habitat characteristics. Finally, proximately 80% of all birds occurring there we discuss the biological implications of at (Fleischer and Williams 1987). tempting to manage these alien bird popula tions. 1 The State of Hawaii, Department of Land and Natural Resources and the National Science Foundation History and Ecology ofBird Species (Grant BSR-85I6702)provided funding for this research. Manuscript accepted August 1988. ROCK DOVE. Rock Doves, native to the 2Department of Biology, Portland State University, P. O. Box 751, Portland, Oregon 97207. Mediterranean region of Europe, were in 3 Department of Biology, University of North Dakota, troduced to Hawaii in 1796 (Walker 1967), Grand Forks, North Dakota 58202. probably as an escape from domestication. 152 Habitat Associations ofWaikiki Birds-WILLIAMS AND FLEISCHER 153 Hawaii Audubon Society (1975) noted that human habitation and have not had the wide Rock Doves were found on all islands , with a spread success they have had elsewhere in the predominantly white form occurring through world . Nevertheless, House Sparrows are out Waikiki and Kapiolani Park. These white abundant in open-air restaurants throughout Rock Doves are apparently the descendents of Waikiki (Fleischer and Williams 1988). four pairs of "White Kings," a domesticated ZEBRA DOVE. Several races or subspecies of strain favored by pigeon fanciers, which were Zebra Doves, which are native to southeast released at the Honolulu Zoo (Go 1973). Asia and Australia, were introduced to Hawaii Our recent field work (Fleischer and in 1922. They are currently the most common Williams 1987) shows high levels of human bird on Oahu (Pyle 1986). Zebra Doves are Rock Dove interactions in the Waikiki not considered pests in Hawaii, with the Kapiolani Park area, especially at the possible exception of the Waikiki area where Honolulu Zoo , where many families picnic concentrations of them occur in association with small children. with humans at picnic areas and at open-air HOUSE SPARROW. The House Sparrow is restaurants (Fleischer and Williams 1988). native to Eurasia and North Africa and is probably the most widely and successfully MATERIALS AND METHODS introduced bird in the world (Long 1981). All House Sparrows in Hawaii are believed to We conducted 57 censuses along three tran have descended from nine sparrows imported sect routes in Waikiki from 5 August until 19 from New Zealand in 1871 (Caum 1933). December 1986. Transects were located along Although House Sparrows are found on all ·· AlaWaiand Kuhio avenues and along por major Hawaiian islands , they are restricted tions ofthe Waikiki beachfront and Kalakaua primarily to cities and rural areas around Avenue (Figure 1). Transects encompassed N 300m .. FIGURE 1. Map ofWaikiki study area noting transect stations along Ala Wai Boulevard, Kuhio Avenue, and the Waikiki beachfront. 154 PACIFIC SCIENCE, Volume 43, April 1989 Kapiolani Park, the edge of the Honolulu tional species made up the remaining 6.0% : Zoo, and both urban and beachfront areas of Red-crested Cardinal (Paroaria coronata), Waikiki. Each transect was 2.7 km in length Northern Cardinal (Cardinalis cardinalis), and had 10equally spaced (0.30 km) sampling Red-vented Bulbul (Pycnonotus cafer), Red stations. whiskered Bulbul (P. jocosus) , Japanese Transect censuses began at four different White-eye (Zosterops japonicus), Yellow times of the day: 0630, 1000, 1400, and 1630 fronted Canary (Serinus mozambicus), Java hours HST. Counts were randomized for Sparrow (Padda oryzivora) , Golden Plover date, time of day, direction along transect, (Pluvialisfulva), White Tern (Gygis alba roth and observer. Counts at each sampling station schildi), and Great Frigatebird (Fregata minor were conducted within the confines ofa 30-m palmerstoni). radius circle. A l-min initial count period was SPECIES DISTRIBUTIONS. Distributions of the used to assess human density in the sampling mean numbers for each speciesalong the three circle on a categorical scale (0 = 0 people, transects are presented in Figure 3. House 1 = 1-5, 2 = 6-10, 3 = 11-25, 4 = 26-100, Sparrows (Figure 3a) were common along the 5 = > 100). Birds were subsequently counted over a 5-min period. Each transect took ap beach transect and abundant in all three tran proximately 2 hr to census. sects near the Honolulu Zoo and adjacent areas of Kapiolani Park and Jefferson School. We also recorded habitat characteristics for House Sparrows were also concentrated on each transect and sampling station once dur ing the latter portion of the study. We used a the beach transect at the Fort DeRussy Beach Park (stations B and C). categorical relative abundance scale to esti mate the amount of grass, bushes, shrubs, Rock Doves (Figure 3b) had a similar dis tribution to that of House Sparrows, with trees, palms, sand/concrete, buildings (0 = 0 highest concentrations along the beach and 5%, 1 = 6-25%, 2 = 26-50%, 3 = 51-75%, near the Honolulu Zoo and Fort DeRussy 4 = 76-95%, 5 = 96-100%), and building Beach Park. Rock Doves were by far the most height (0 = none, 1 = 1-2 stories, 2 = 3-7, abundant bird near the Honolulu Zoo (Figure 3 = 8-15,4 = 16-30, 5 = >30) within each count circle. Categorical data values for each 3b, stations H and I) with feeding flocks of of the above parameters were assigned using a several hundred birds common in the zoo percentage cover estimate, where 100% repre interior and on the expansive lawn between sented the maximum density observed for that the Zoo and Waikiki Beach (corner of specific parameter along all three transects. Kapahulu and Kalakaua avenues). Although Transect census data were then used to widespread throughout Waikiki, Rock Doves determine avian community structure in occurred in low concentrations along the urban portions of the Ala Wai and Kuhio Waikiki and to compute correlations of bird densities with human densities and habitat transects , as compared to House Sparrows characteristics. (Figure 3a) and Zebra Doves (Figure 3c). Like House Sparrows and Rock Doves, Zebra Doves (Figure 3c) were most common near the Honolulu Zoo and Fort DeRussy RESULTS Beach Park; however, they were relatively more abundant and widespread throughout Transect Censuses the remainder of Waikiki than Rock Doves. Except for the parklike Zoo and Fort DeRussy SPECIES COMPOSITION. House Sparrows, Rock Doves, and Zebra Doves accounted for areas, Zebra Doves occurred in nearly equal 79.2% of all birds observed during transect numbers along the beach and Kuhio transects censuses in Waikiki (Figure 2). Inclusion of and in reduced numbers along the Ala Wai Common Mynas (Acridotheres tristis) and transect. Spotted Doves (Streptopelia chinensis) raised HABITAT CORRELATIONS. Principal compo the cumulative total to 94.0% . Eleven addi- nents analysis was performed on the eight Habitat Associations of Waikiki Birds- WILLIAMS AND FLEISCHER 155 100 • Zebra Dove iii Rock Dove ~ House Sparrow 80 r:a Common Myna lEI Spotted Dove Q) 0 o Others C Q) a- a- 60 :::] 0 0 0 C 40 -Q) 0 a- c..Q) 20 o Ala Wai Beach Kuhio To ta l Transect FIGURE 2. Species composition for birds along three transects in Waikiki and for combined dat a. habitat variables (Table 1) as a method of 3) negative relationship between mean num reducing them to a smaller number of sum bers of birds and positive PC-l scores (i.e., mary variables.