COOPERATIVE NATIONAL PARK RESOURCES S T U D I E S U N I T

U N I V E R S I T Y OF HAWAII A T MANOA

D e p a r t m e n t of B o t a n y

H o n o l u l u , H a w a i i 9 6 8 2 2

( 8 0 8 ) 9 4 8 - 8 2 1 8

C l i f f o r d W. S m i t h , U n i t D i r e c t o r A s s o c i a t e Professor of B o t a n y

T e c h n i c a l R e p o r t s 4 2 & 4 3

B r e e d i n g E c o l o g y of P a l i l a and

' A m a k i h i Parasites

C h a r l e s van R i p e r I11

4 2 . A BREEDING ECOLOGY OF THE ENDANGERED P A L I L A ( P S I T T I R O S T R A B A I L L E U I ) ON MAUNA KEA, H A W A I ' I

4 3 . A SURVEY SHOWING THE E F F E C T OF ENVIRONMENT AND BEHAVIOR UPON P A R A S I T E LEVELS I N THE H A W A I ' I 'AMAKIHI (LOXOPS V I R E N S ) (AVES: DREPANIDIDAE)

S e p t e m b e r 1 9 8 1

U N I V E R S I T Y OF HAWAII AT MANOA

NATIONAL PARK S E R V I C E C o n t r a c t N o . CX 8 0 0 0 7 0 0 0 9

C o n t r i b u t i o n Number CPSU/UH 0 2 2 / - 1 : ,;\ \ 0 2 2 / 1 2

v i i

A SURVEY SHOWING THE EFFECT OF ENVIRONMENT AND BEHAVIOR UPON PARASITE LEVELS I N THE H A W A I ' I ' A M A K I H I (LOXOPS VIRENS)

(AVES: DREPANIDIDAE)

ABSTRACT

From 1972 t h r o u g h 1979 a f i e l d s u r v e y was conduc ted t o d e t e r m i n e what p a r a s i t e s were p r e s e n t i n an 'Amakihi (Loxops v i r e n s ) p o p u l a t i o n from a d r y f o r e s t on t h e i s l a n d of Hawai' i . Fauna were c o l l e c t e d from r e c e n t l y used n e s t s and few a v i a n p a r a s i t e s were found ; most were n o n p a r a s i t i c a r t h r o p o d s a s s o - c i a t e d w i t h n e s t s a s s a p r o p h a g e s , o r a s p r e d a t o r s o n o t h e r n e s t a r t h r o p o d s . Mites o f t h e g e n u s P t i l o n y s s u s were found i n t h e n a s a l c a v i t y and s e v e n o t h e r g e n e r a were i d e n t i f i e d from body washes . Avian pox l e s i o n s were found on f i v e 'Amakih i , and i n two i n s t a n c e s t h e i n f e c t i o n s a p p e a r e d s e v e r e enough t o have c a u s e d d e a t h . C o c c i d i a ( I s o s p o r a s p . ) were r e c o r d e d from f o u r b i r d s , and a l l b lood s m e a r s f rom 107 b i r d s were n e g a t i v e f o r haematozoans .

Complete pos tmor tems were c a r r i e d o u t on 4 4 'Amakihi . I n t e s t i n a l h e l m i n t h s were t h e mos t f r e q u e n t l y e n c o u n t e r e d p a r a - s i t e s , and t h e i r abundance v a r i e d s i g n i f i c a n t l y be tween h o s t a g e c l a s s e s . From 1972 t h r o u g h 1979 c a p i l l a r i d s were p r e s e n t i n n i n e o f 20 postmortemed a d u l t s , b u t were n o t found i n any j u v e n i l e b i r d s . Four c a s e s o f c e s t o d e p a r a s i t i s m were a l l from a d u l t spec imens . E c o l o g i c a l f a c t o r s a r e g i v e n which p o s s i b l y e x p l a i n t h e d i f f e r i n g l e v e l s o f p a r a s i t e i n f e c t i o n be tween young and a d u l t b i r d s .

TABLE OF CONTENTS

ABSTRACT . . . . . . . . . . . . . L I S T O F T A B L E S . . . . . . . . . L I S T OF F I G U R E S . . . . . . . . INTRODUCTION . . . . . . . . . .

. . . . . MATERIALS AND METHODS

S t u d y A r e a . . . . . . . . . . . . . . . . . . . T h e B i r d

C o l l e c t i o n T e c h n i q u e s . . . RESULTS . . . . . . . . . . . .

N i d i c o l e s and E c t o p a r a s i t e s

. . . . . . . . . A v i a n P o x

. . . . . . B l o o d P a r a s i t e s

G a s t r o i n t e s t i n a l P a r a s i t e s . D I S C U S S I O N . . m e . . . . . . .

v

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . LITERATURE C I T E D

GLOSSARY . . . . . . . . . . . .

LIST OF TABLES

T a b l e

1 P a r a s i t e s c o l l e c t e d from 'Amakihi n e s t s , body washes , and n a s a l c a v i F i e s . . . . . . . . . . . . 52

2 Numbers o f 'Amakihi found w i t h g a s t r o i n t e s t i n a l h e l m i n t h p a r a s i t e s o n t h e i s l a n d o f Hawait i from 1 9 7 2 t h r o u g h 1979 . . . . . . . . . . . . . . . . 53

LIST OF FIGURES

F i g u r e

1 The s t u d y a r e a on Mauna Kea, H a w a i ' i . . . . . . . . . 54

2 He lmin th i n f e c t i o n l e v e l s and y e a r l y r a i n f a l l on Mauna Kea, H a w a i ' i . . . . . . . . . . . . 55

INTRODUCTION

P a r a s i t e s and d i s e a s e can a c t i n d i v e r s e ways upon a g r o u p o f o r g a n i s m s , and i n many i n s t a n c e s t h e e f f e c t s a r e s u b t l e and d i f f i c u l t t o i n t e r p r e t b e c a u s e , among o t h e r f a c t o r s , chang ing e n v i r o n m e n t a l c o n d i t i o n s and d i v e r s e b e h a v i o r a l p a t t e r n s o f d i f - f e r e n t h o s t a g e c l a s s e s have a p ro found i n f l u e n c e upon p a r a s i t e l e v e l s (Dog ie1 1961; B u l l 1964; Kennedy 1975; Holmes e t a l . 1 9 7 7 ) . D i s e a s e can be a p r i m a r y f a c t o r o f p o p u l a t i o n r e g u l a t i o n , a 1 though t h e o v e r a l l impor t ance is p r o b a b l y more c l o s e l y r e l a t e d t o i t s r o l e i n i n c r e a s i n g t h e s u s c e p t i b i l i t y o f t h e h o s t t o o t h e r m o r t a l i t y f a c t o r s ( B r a d l e y 1972; Esch 1977; F o r r e s t e r e t a l . 1 9 7 8 ) . T h i s v i ew i s o f t e n e x t e n d e d t o p r e d i c t t h a t i n times when food s u p p l i e s a r e r e d u c e d , l e v e l s o f p a r a s i t e i n f e c t i o n a r e g r e a t e r ( E s c h e t a l . 1 9 7 5 ) . T h e r e a r e , however , few examples i n which e n v i r o n m e n t a l p r o d u c t i v i t y , i n f o r m a t i o n on h o s t d i e t , and p a r a s i t e l e v e l s have been mon i to red s o a s t o document t h e i n t e r - r e l a t i o n s h i p o f t h e chang ing env i ronmen t upon l e v e l s o f p a r a s i t e s and d i s e a s e s .

T h i s p r e s e n t s t u d y was conce rned w i t h t h e e f f e c t o f e n v i r o n - m e n t a l and b e h a v i o r a l f a c t o r s upon p a r a s i t e s and d i s e a s e s i n an endemic Hawai' i 'Amakihi (Loxops v i r e n s ) p o p u l a t i o n o n Mauna Kea, Hawai' i . Al though some a t t e n t i o n h a s b e e n g i v e n t o t h e d i s e a s e s o f p o u l t r y and i n t r o d u c e d b i r d s i n H a w a i ' i ( A l i c a t a 1969; Navvab G o j r a t i 1970; Lewin 6 Holmes 1971; Smi th & Gues t l 9 7 4 ) , l i t t l e work h a s been done on t h e n a t i v e b i r d s . Warner ( 1 9 6 8 ) s t u d i e d t h e presumed r o l e t h a t i n t r o d u c e d a v i a n m a l a r i a a n d ' p o x p l a y e d i n t h e e x t i n c t i o n o f t h e Hawaiian a v i f a u n a . b u t no o t h e r i n f o r m a t i o n e x i s t s on l e v e l s of p a r a s i t e s i n any n a t i v e b i r d p o p u l a t i o n . The q u e s t i o n s t o be answered j.n t h i s s t u d y were: (1) what d i s e a s e s and p a r a s i t e s were p r e s e n t i n t h i s b i r d p o p u l a t i o n ? and ( 2 ) what were p o s s i b l e e x p l a n a t i o n s f o r d i f f e r e n t p a r a s i t e l e v e l s between y e a r s and among d i f f e r e n t a g e g r o u p s ? I n t h i s p a p e r t h e pa ra - s i t i c f a u n a o f 'Amakihi a r e d e s c r i b e d . I t is a l s o shown t h a t p a r a s i t e l e v e l s a r e n o t i n c r e a s e d i n y e a r s o f low food r e s o u r c e s , and d i f f e r e n t f o r a g i n g s t t a t e g i e s a r e c o r r e l a t e d w i t h d i f f e r i n g l e v e l s o f h e l m i n t h i n f e c t i o n .

MATERIALS AND METHODS

S t u d y Area

T h i s s t u d y was c a r r i e d o u t on t h e i s l a n d o f ~ a w a i ' i , w i t h t h e m a j o r i t y o f work done on t h e s o u t h w e s t e r n s l o p e o f Mauna Kea; t h r e e i n t e n s i v e s t u d y s i t e s were e s t a b l i s h e d a t 1980 , 2130, and 2290 m e l e v a t i o n s ( F i g . 1 ) . The Mauna Kea s t u d y a r e a i s l o c a t e d i n o n e o f t h e l a s t e x t e n s i v e d r y - f o r e s t e c o s y s t e m s i n t h e Hawaiian a r c h i p e l a g o , and is e s s e n t i a l l y a s a v a n n a , i n t e r r u p t e d

i n p l a c e s by b a r e l a v a , q r a s s l a n d , and s c r u b . The h a b i t a t i s - . -

domina ted by two t r ee s p e c i e s , mzmane ( Sophora c h r y s o p h y l l a ( S a l i s b . ) Seem.) and n a i o (Myogorurn sandwicense Gray) , and h a s a v a r i e t y o f s h r u b and ground cove r p l a n t s ( v a n R i p e r 1 9 7 8 ) . The main camp, a t 2290 m e l e v a t i o n , was 6.6 km f rom t h e n e a r e s t paved r o a d , and a 4-wheel d r i v e v e h i c l e was needed t o r e a c h i t . T h e r e was no a c c e s s i b l e hous ing o r e l e c t r i c i t y and b e c a u s e o f t h e r e m o t e n e s s , most b a c t e r i a l and v i r a l a n a l y s e s were n o t f e a s i b l e . The Mauna Loa s t u d y s i t e s were a l l above 1500 m on t h e S t r i p Road o f Hawaii Vo lcanoes N a t i o n a l Pa rk .

The B i r d

The 'Amakihi is o n e o f t h e mos t common b i r d s o n Mauna Kea and h a s been t h e s u b j e c t o f r e c e n t i n v e s t i g a t i o n s c o n c e r n i n g i t s b r e e d i n g , e c o l o g y , and b e h a v i o r (Ba ldwin 1953; B e r g e r 1969; van R i p e r 19752, 1975b, 1976a , 1977 , 1978; Kamil 1978; Kamil h van R i p e r , i n p r e s s ) . T E ~ b i r d - i s a s m a l l ( a p p r o x . 1 5 g ) pas - s e r i n e o f t h e endemic h o n e y c r e e p e r f a m i l y D r e p a n i d i d a e . A d u l t ' Amakihi u t i l i z e c o n s i d e r a b l e n e c t a r d u r i n g t h e b r e e d i n g s e a s o n and t h r o u g h t e r r i t o r i a l i t y d e f e n d t h i s r e s o u r c e ; t h e i r d i e t a l s o i n c l u d e s i n s e c t s and v a r i o u s f r u i t s ( v a n R ipe r 1 9 7 8 ) . N e s t l i n g s and r e c e n t l y f l e d g e d young a r e f e d r e g u r g i t a t e d i n s e c t s and n e c t a r by p a r e n t b i r d s ; however , i n d e p e n d e n t young s u b s i s t . c h i e f l y upon n e c t a r ( v a n R ipe r & Evenson, i n p r e p . ) . Because o f t h e ' Amakihi ' s abundance , i t s d i e t a r y r e q u i r e m e n t s , and i ts s e n s i t i v i t y t o l e v e l s o f food a v a i l a b i l i t y , t h e s p e c i e s i s i d e a l f o r s t u d y o f t h e compar i son o f p a r a s i t e l e v e l s i n r e l a t i o n t o c h a n g i n g b e h a v i o r a l and e n v i r o n m e n t a l c o n d i t i o n s .

C o l l e c t i o n Techn iques

'Amakihi p a r a s i t e s were c o l l e c t e d from 1972 t h r o u g h 1979 o n Mauna Kea and d u r i n g 1978-1979 on Mauna Loa. Nests from which young had r e c e n t l y f l e d g e d were p l a c e d i n B e r l e s e - T u l l g r e n fun- n e l s f o r 48 t o 60 h o u r s , and t h e f a u n a c o l l e c t e d i n 70% e t h a n o l w i t h g l y c e r i n e . From m i s t - n e t t e d 'Amakihi t o e c l i p s were made and t h i n b lood smear s t a k e n ; s l i d e s were f i x e d f o r 3 0 sec i n a b s o l u t e me thy l a l c o h o l t h e n s t a i n e d w i t h Giemsa. F e c a l m a t e r i a l c o l l e c t e d from l i v e - c a u g h t b i r d s was t r a n s p o r t e d i n s a l i n e w a t e r .

Dead 'Amakihi were e i t h e r postmortemed i m m e d i a t e l y o r p r e s e r v e d i n 70% e t h a n o l w i t h g l y c e r i n e . E c t o p a r a s i t e s were c o l l e c t e d by s h a k i n g t h e b i r d i n d e t e r g e n t and w a t e r f o r 2 m i n t removing t h e h o s t , p e r m i t t i n g t h e wash t o s t a n d f o r 1 h r , b r e a k - i n g t h e s u r f a c e t e n s i o n w i t h 95% a l c o h o l , t h e n d e c a n t i n g ; e c t o - p a r a s i t e s were p r e s e r v e d i n 70% a l c o h o l . A l l pos tmor temed ' Amakihi were n e c r o p s i e d a c c o r d i n g t o t h e t e c h n i q u e o u t 1 ined by van Riper and van R ipe r ( 1 9 8 0 ) . F e e t and f a c i a l l e s i o n s were e x c i s e d , p r e s e r v e d i n 10% f o r m a l i n , and l a t e r examined f o r mites a s w e l l a s a v i a n pox i n c l u s i o n b o d i e s . ~ m p r e s s i o n s m e a r s o f o r g a n s were f i x e d i n a b s o l u t e me thy l a l c o h o l and s t a i n e d w i t h Giemsa. I n t e s t i n a l c o c c i d i a were s p o r u l a t e d i n 1% f o r m a l i n . The l o c a t i o n and numbers o f a l l i n t e s t i n a l h e l m i n t h s were n o t e d .

C e s t o d e s were f i x e d i n FAA and nematodes i n a l c o h o l ; b o t h were p r e s e r v e d i n 7 0 % e t h a n o l w i t h g l y c e r i n e .

RESULTS

N i d i c o l e s and E c t o p a r a s i t e s

Fauna from 4 6 'Amakihi n e s t s were a n a l y z e d and few p a r a - s i t i c g r o u p s were found; most were a s s o c i a t e d w i t h t h e n e s t a s s a p r o p h a g e s , o r a s p r e d a t o r s on o t h e r n e s t a r t h r o p o d s . Only O r n i t h o n y s s u s s y l v i a r u m ( ~ a r a s i t i f o r m e s : Mac r o n y s s i d a e ) was p a r a s i t i c t o b i r d s . The re were , however , s e v e n g e n e r a o f pa ra - s i t i c A c a r i n a c o l l e c t e d from body washes , and n a s a l m i t e s o f t h e g e n u s P t i l o n y s s u s were found i n two b i r d s ( T a b l e 1 ) . I n one n a s a l f l u s h t h e f i r s t nymphal i n s t a r o f a s c a l e i n s e c t ( C o c c i d a e : Homoptera) was found . I t was no d o u b t an a c c i d e n t a l v i s i t o r i n t h e n a r e s .

Avian Pox

Avian pox l e s i o n s were o b s e r v e d on o n l y f i v e o f o v e r 900 m i s t - n e t t e d 'Amakihi . The l e s i o n s o f f o u r b i r d s were l o c a t e d on t h e f a c e , w h i l e t h e o t h e r had s w e l l i n g s on t h e l e g and t o e s . H i s t o p a t h o l o g y o f t h e l e s i o n s r e v e a l e d i n c l u s i o n b o d i e s . Two of t h e s e b i r d s a p p a r e n t l y d i e d o f a v i a n pox , b e c a u s e e y e s and n a r e s were c o m p l e t e l y cove red w i t h l e s i o n s . One o f t h e b i r d s was a f e m a l e c o l l e c t e d from t h e 2290 m s t u d y s i t e on 27 March 1974. The b i r d was f i r s t o b s e r v e d i n t a l l wet g r a s s ; i t s f e a t h e r s were s a t u r a t e d a n d , a s a r e s u l t , i t c o u l d n o t f l y . The b i r d , c o l - l e c t e d from t h e ground by hand , had a p r o m i n e n t k e e l ; i t d i e d s h o r t l y t h e r e a f t e r . Both o p e r c u l a were o c c l u d e d by s c a b s a s was t h e l e f t e y e . L e s i o n s ex t ended i n t o t h e o r a l c a v i t y and t h e b i r d b r e a t h e d w i t h i t s beak open . T h i s was d u r i n g t h e h e i g h t o f t h e b r e e d i n g s e a s o n , y e t no brood p a t c h was e v i d e n t and t h e gonads were r e g r e s s e d .

Blood P a r a s i t e s

From l i v e b i r d s t h a t were m i s t - n e t t e d , 1 3 1 p e r i p h e r a l b lood smear s from 107 i n d i v i d u a l s were t a k e n . A l l were n e g a t i v e f o r haematozoans . H e a r t , l i v e r , s p l e e n , and l u n g i m p r e s s i o n smear s

- were made o n postmortemed b i r d s and none c o n t a i n e d b lood pa ra - s i t e s . I t a p p e a r s t h a t haematozoa a r e a b s e n t from t h e h i g h a l t i t u d e ' Amakihi p o p u l a t i o n on Mauna Kea.

B Two c a s e s o f a v i a n m a l a r i a deve loped i n 'Amakihi t h a t were t a k e n t o a lower e l e v a t i o n f o r b e h a v i o r a l s t u d i e s . T h r e e b i r d s were removed from t h e 2290 m s t u d y a r e a on Mauna Kea t o Kamuela, H a w a i ' i , a t a p p r o x i m a t e l y 760 m e l e v a t i o n on t h e s o u t h e r n s l o p e o f t h e Kohala Mounta ins , and were m a i n t a i n e d i n an i n d o o r a v i a r y . The f i r s t b i r d d i e d a f t e r 18 days w i t h no s i g n s o f m a l a r i a ; t h e

second died a f t e r 32 days; and the l a s t died 45 days a f t e r expo- su re t o mosquitoes a t lower e l eva t ions . The l a s t two t h a t died had acute i n f e c t i o n s of ~lasmodium, which had b i z a r r e f e a t u r e s i n t h a t the blood was obviously abnormal and contained numerous microcytes and o ther immature c e l l s , which, i n t u r n , exhib i ted unusually small and otherwise odd p a r a s i t e s . Laird ( p e r s . comm.) found t h a t the p a r a s i t e resembled Plasmodium e l o n g a t u ~ , but he believed the organism i n quest ion n e r of the 'Plasmodium re l ic tum complex."

G a s t r o i n t e s t i n a l P a r a s i t e s

I n December 1973 and January 1974 f e c a l samples were co l - l e c t e d from 1 4 mist-netted 'Amakihi. While t h i s mater ia l does no t g ive an accurate p i c t u r e of a l l the i n t e s t i n a l p a r a s i t e s p resen t , the more prevalent spec ies a r e de tec ted . Nine of the b i r d s showed no s i g n s of being p a r a s i t i z e d , t h r e e had c a p i l l a r i d eggs (one sample contained both c a p i l l a r i d s and c o c c i d i a ) , while two had only coccid ia .

During postmortem examinations a number of g a s t r o i n t e s t i n a l p a r a s i t e s were found (Table 2 ) . The helminth i n f e c t i o n r a t e was 75% fo r a l l b i r d s examined i n 1972, 33% i n 1973, and 4 4 % i n 1974. The most f requent ly encountered p a r a s i t e was C a p i l l a r i a sp . , which was present i n 33% of the examined b i r d s . The i n f e c t i o n r a t e of t h i s p a r a s i t e f e l l from 58% i n 1 9 7 2 t o 33% i n 1973, and was not de tec ted in any of the 1974 b i rds .

Juveni le b i r d s had a s i g n i f i c a n t l y lower i n f e c t i o n l e v e l than did a d u l t s (Chi-squared = 7 . 7 7 ; degrees of freedom = 1; p r o b a b i l i t y is l e s s than 1%). Coccidia were found i n four of the postmortemed ' ~ m a k i h i , but none were heavy i n f e c t i o n s . Sporu- l a t e d oocys ts , of the genus Isospora, ranged from 1 8 t o 2 4 microns.

DISCUSSION

Malaria p a r a s i t e s a r e sometimes very l o c a l i z e d (Sarnham 1 9 6 6 ) , and t h i s appears t o be the case i n Hawai'i. None of the 'Amakihi on the higher s lopes of Mauna Kea, t h e Kohala Mountains, or Mauna Loa were found t o harbor blood p a r a s i t e s . B u t the b i r d s a r e suscep t ib le a s shown by the two indiv iduals t h a t contracted malaria when t r ans fe r red t o lower e l eva t ions . Warner ( l 9 6 8 ) , a f t e r moving na t ive b i r d s t o lower e l eva t ions on Kaua' i t a l s o found t h a t the b i r d s became infec ted with malar ia l p a r a s i t e s . There a r e , however, n a t i v e Amakihi populations t h a t do surv ive a t lower e levat ions . Indiv iduals have been r e g u l a r l y observed i n Mznoa Valley and Makiki-Heights (0' ahu) below 200 m e l e v a t i o n , and on Hawai' i i n the Kiholo and lower Hi l ina P a l i areas, Berger ( 1 9 7 2 ) found 'Amakihi a t 76 m e l eva t ion in the Malamaki Fores t Reserve on ~ a w a i ' i . Work is c u r r e n t l y i n p rogress t o determine i f t h e ex tan t 'Amakihi populations t h a t e x i s t wi th in vector range

have deve loped r e s i s t a n c e t o t h e i n t r o d u c e d m a l a r i a l p a r a s i t e i n Hawai' i .

One d i s e a s e which i s p r e s e n t i n t h e upper f o r e s t s o f Mauna Kea i s a v i a n pox. ~ e s c r i p t i o n s o f a v i a n pox i n endemic a v i f a u n a o f Hawai' i a r e found i n t h e e a r l y l i t e r a t u r e ( P e r k i n s 1893; Henshaw 1902; Munro 1944; Amadon 1 9 5 0 ) . More r e c e n t l y Warner ( 1 9 6 8 ) a p p e a r s t o have shown t h e s u s c e p t i b i l i t y o f some n a t i v e and i n t r o d u c e d b i r d s t o t h i s v i r u s . The d i s e a s e h a s p r o b a b l y been i n t r o d u c e d by b i r d s , such a s t h e House F i n c h ( ~ a i p o d a c u s m e x i c a n u s ) , which e a c h y e a r move t o t h i s h i g h f o r e s t t o b r e e d ( v a n R ipe r 1 9 7 6 b ) ; I h a v e found s e v e r a l House F inch w i t h l e s i o n s o n f a c e and f e e x . Mosqu i toes have been i m p l i c a t e d a s t h e p r i m a r y m e c h a n i c a l c a r r i e r o f pox i n f e c t i o n s , b u t t h e v i r u s may a l s o b e s p r e a d d i r e c t l y by c o n t a c t o f s u s c e p t i b l e b i r d s w i t h i n f e c t e d o n e s , by c o n t a c t w i t h c o n t a m i n a t e d o b j e c t s , o r by b i r d mites ( K a r s t a d 1 9 7 1 ) . The l a c k o f m o s q u i t o e s i n t h e h i g h e r f o r e s t s o f Mauna Kea may b e why t h e i n c i d e n c e o f a v i a n pox ( 3 % ) r e c o r d e d was s o low. I t would a p p e a r t h a t i n t h e a b s e n c e o f m o s q u i t o e s , a v i a n pox is p r o b a b l y s p r e a d t o t h e endemic b i r d s o f Mauna Kea e i t h e r b y d i r e c t c o n t a c t w i t h c o n t a m i n a t e d o b j e c t s , o r p o s s i b l y by t r a n s o v a r i a l t r a n s m i s s i o n ( t r a n s m i s s i o n from p a r e n t t o o f f s p r i n g i n t h e mite) o f t h e v i r u s by O r n i t h o n y s s u s s y l v i a r u m .

The most f r e q u e n t l y e n c o u n t e r e d 'Amakihi p a r a s i t e s were found i n t h e g a s t r o i n t e s t i n a l t r a c t . C o c c i d i a ( I s o s p o r a s p . ) were found i n f o u r b i r d s , t h i s b e i n g t h e f i r s t r e p o r t i n any n a t i v e Hawaiian b i r d . A l i c a t a ( 1 9 6 9 ) r e p o r t e d c o c c i d i a i n domes- t i c c h i c k e n s , Gues t ( 1 9 7 3 ) i n J a p a n e s e Whi te -eyes ( Z o s t e r o p s i a p o n i c u s ) from O'ahu , and Smith and Gues t ( 1 9 7 4 ) i n 15 .7% o f a l l t h e i n t r o d u c e d b i r d s t h e y examined i n Honolu lu . None o f t h e 'Amakihi found i n t h i s s t u d y had heavy c o c c i d i a i n f e c t i o n s . Because c o c c i d i a a r e u s u a l l y t r a n s m i t t e d from one i n d i v i d u a l t o a n o t h e r i n food o r w a t e r c o n t a m i n a t e d w i t h f e c e s (Todd & Hammond 1971 ) , t h i s p a r a s i t e would p r o b a b l y n o t b e found t h a t f r e q u e n t l y i n w i ld -caugh t ' Amakihi .

The most a b u n d a n t g a s t r o i n t e s t i n a l p a r a s i t e s o f t h e ' Amakihi were h e l m i n t h s . The o v e r a l l h e l m i n t h i n f e c t i o n r a t e was p o s i - t i v e l y c o r r e l a t e d ( r = 0.425) w i t h t h e Mauna Kea r a i n f a l l p a t t e r n ( F i g . 2 ) . The amount o f mzmane f l o w e r i n g ( t h e r e f o r e n e c t a r p ro- d u c t i o n ) was r e l a t e d t o t h e r a i n f a l l p a t t e r n , i n t h a t g r e a t e r f l o w e r i n g o c c u r r e d i n y e a r s o f h i g h e r p r e c i p i t a t i o n ( v a n R ipe r l 9 7 5 b ) . The p a r a s i t i c h e l m i n t h l e v e l s a l s o i n c r e a s e d i n y e a r s o f i n c r e a s e d n e c t a r ( i . e . , f o o d ) s u p p l i e s ( F i g . 2 ) .

The re a r e two p o s s i b l e e x p l a n a t i o n s f o r t h e s e i n c r e a s e d p a r a s i t e l o a d s i n t h e ' ~ m a k i h i . The f i r s t is t h a t w i t h i n c r e a s e d food r e s o u r c e s , t h e b i r d s a r e a b l e t o p h y s i c a l l y c a r r y h e a v i e r p a r a s i t e l o a d s . I f t h i s i s t h e c a s e , i t would s u g g e s t t h a t t h e 'Amakihi h o s t - p a r a s i t e sys t em is f i n e l y tuned and i n dynamic e q u i l i b r i u m , b e i n g a b l e t o respond r a p i d l y t o c h a n g i n g e n v i r o n - m e n t a l c o n d i t i o n s . The s e c o n d , and p r o b a b l y more l i k e l y , e x p l a - n a t i o n i s t h a t i n y e a r s o f h i g h r a i n f a l l t h e r e is a g r e a t e r p r o d u c t i o n o f i n s e c t s which a c t a s i n t e r m e d i a t e h o s t s ; a n d ,

b e c a u s e o f t h e i n c r e a s e d p r o b a b i l i t y o f e n c o u n t e r i n g t h e s e i n t e ' r - . m e d i a t e h o s t s , p a r a s i t e l o a d i n g i n t h e ' ~ m a k i h i i n c r e a s e s . Both s u g g e s t i o n s a r e o n l y f i e l d h y p o t h e s e s and need t o b e t e s t e d i n a c o n t r o l l e d l a b o r a t o r y s i t u a t i o n .

R e s e a r c h on c h a n g i n g p a r a s i t e f a u n a w i t h a g e s u g g e s t s t h a t d i f f e r e n t age -g roups c a r r y h e a v i e r p a r a s i t e l o a d s b e c a u s e o f d i f f e r e n c e s i n immunologica l r e s p o n s e ( B u l l l 9 7 4 ) , c h a n g e s i n s t r u c t u r e (Kennedy 1 9 7 5 ) , b e h a v i o r o r d i e t (Dog ie1 1 9 6 1 ) , and So a l s o a c h a n g e i n t h e p r o b a b i l i t y o f i n f e c t i o n . I n t h e 'Arnakihi a un ique s i t u a t i o n a p p e a r s t o e x i s t i n which young b i r d s a r e b e h a v i o r a l l y e x c l u d e d from c o n t a c t w i t h i n t e r m e d i a t e p a r a s i t e h o s t s , t h e r e b y p r e v e n t i n g h i g h l e v e l s o f g a s t r o i n t e s t i n a l h e l - m i n t h i n f e c t i o n s u n t i l l a t e r i n l i f e . T h i s is b r o u g h t a b o u t by t h e f a c t t h a t b r e e d i n g b i r d s a r e h i g h l y t e r r i t o r i a l and e x c l u d e c o n s p e c i f i c s from t h e i r t e r r i t o r i e s ( v a n R ipe r 1 9 7 8 ) . Because o f t h i s , t h e young a r e f o r c e d t o c o n t i n u a l l y move i n o r d e r t o pro- c u r e f o o d , and a r e , t h e r e f o r e , f o r c e d t o s u b s i s t a l m o s t t o t a l l y upon t h e h i g h e r e n e r g y s o u r c e o f mgmane n e c t a r ( v a n R i p e r & Evenson, i n p r e p . ) . A s a r e s u l t , t h e young b i r d s t a k e few i n s e c t s ( w h i c h a c t a s nematode i n t e r m e d i a t e h o s t s ) , and t h u s g a s t r o i n t e s t i n a l p a r a s i t e l e v e l s may b e k e p t a t a minimum.

Where s e v e r a l p a r a s i t i c s p e c i e s o c c u r w i t h i n t h e same h o s t , t h e i r d i s t r i b u t i o n may b e r e s t r i c t e d by c o m p e t i t i o n w i t h o t h e r s p e c i e s (Holmes 1961; MacKenzie & Gibson 1 9 7 0 ) . ~ i f f e r e n c e s i n t h e s p e c i e s c o m p o s i t i o n o f h e l m i n t h p a r a s i t e s i n t h e ' Arnakihi m i g h t s u g g e s t t h a t i n t e r s p e c i f i c c o m p e t i t i o n is o c c u r r i n g . The d e c r e a s e d C a p i l l a r i a s p . i n f e c t i o n l e v e l s o v e r t h e 3-year s t u d y p e r i o d , complemented by i n c r e a s e d c e s t o d e numbers , i s s u g g e s t i v e o f t h i s ( F i g . 2 ) . F u r t h e r m o r e , a l l b i r d s i n which c e s t o d e s were found d i d n o t h a r b o r c a p i l l a r i d s . I n t h e one i n d i v i d u a l t h a t d i d have a mixed i n f e c t i o n , t h e c e s t o d e s o c c u p i e d t h e g u t w h i l e nematodes were found o n l y i n t h e g i z z a r d . However, a s Kennedy ( 1975 ) h a s p o i n t e d o u t , c o n c l u s i v e e v i d e n c e f o r i n t e r s p e c i f i c c o m p e t i t i o n f o r s i t e s c a n o n l y b e p roven by a compar i son o f t h e d i s t r i b u t i o n o f t h e s p e c i e s when t h e y o c c u r a l o n e and t o g e t h e r .

ACKNOWLEDGMENTS

I am g r a t e f u l t o M. L. G o f f , M. L a i r d , R. S t r a n d t m a n n , and T. Ateyo f o r i d e n t i f i c a t i o n o f p a r a s i t e s . The u n p u b l i s h e d n o t e s and a s s i s t a n c e o f A. Miyahara and E. Chang have been i n v a l u a b l e t o t h i s work. I t h a n k J. A l i c a t a , A. J. B e r g e r , M. L. G o f f , M . L a i r d , and e s p e c i a l l y S. G. van R ipe r f o r t h e i r comments o n v a r i o u s d r a f t s o f t h i s p a p e r . F i n a n c i a l s u p p o r t was p r o v i d e d by t h e World W i l d l i f e Fund G r a n t US-35, The Frank M . Chapman Memorial Fund, and C o n t r a c t CX 8000 7 0009 from t h e N a t i o n a l P a r k S e r v i c e t o t h e C o o p e r a t i v e N a t i o n a l Pa rk R e s o u r c e s S t u d i e s U n i t a t t h e U n i v e r s i t y o f Hawaii .

LITERATURE CITED

A l i c a t a , J. E. 1969 . P a r a s i t e s o f man and a n i m a l s i n Hawai i . S. Ka rge r , B a s e l , S w i t z e r l a n d .

Amadon, D. 1950. The Hawai ian h o n e y c r e e p e r s ( A v e s , Dre- p a n i i d a e ) . B u l l . Amer. Mus. N a t . H i s t . 95: 151-262.

Ba ldwin , P. H. 1953 . Annual c y c l e , e n v i r o n m e n t and e v o l u t i o n i n t h e Hawa i i an h o n e y c r e e p e r s (Aves : D r e p a n i i d a e ) . Univ. C a l i f . P u b l . Zool . 52: 285-398.

B e r g e r , A. J. 1969 . The b r e e d i n g s e a s o n o f t h e Hawai i Amakihi . Occas. Pap . B. P. B i s h o p Museum 24: 1-8.

. 1972. Hawai ian b i r d l i f e . Hono lu lu : U n i v e r s i t y P r e s s o f Hawa i i . x i v + 270 pp .

B r a d l e y , D. J. 1972. R e g u l a t i o n o f p a r a s i t e p o p u l a t i o n s : A g e n e r a l t h e o r y o f t h e e p i d e m i o l o g y and c o n t r o l o f p a r a s i t e i n f e c t i o n s . T r a n s . Roy. Soc . T rop . Med. Hyg. 66: 697-708.

B u l l , P. C . 1964. Eco logy o f h e l m i n t h p a r a s i t e s o f t h e w i l d r a b b i t ( O r y c t o l a g u s c u n i c u l u s ) i n N e w Zea l and . B u l l . New Zea l and Dept . S c i . and I n d u s t . R e s e a r c h 158: 1-147.

D o g i e l , V. A. 1961 . Eco logy o f t h e p a r a s i t e s o f f r e s h w a t e r f i s h e s . P a g e s 1-47 i n V. A. D o g i e l , G. K . P e t r u s h e v s k i , and Y. I . P o l y a n s k i . ~ a r a s i t o l o ~ ~ o f f i s h e s . Ed inbu rgh and London: O l i v e r and Boyd.

E s c h , G. W . 1977 . R e g u l a t i o n o f p a r a s i t e p o p u l a t i o n s . New York: Academic P r e s s , I n c .

Esch G . W . , J. W . G i b b o n s , and J . E . Bourque. 1975 . An a n a l - y s i s o f t h e r e l a t i o n s h i p be tween s t r e s s and p a r a s i t i s m . Am. Mid l . Na t . 93: 339-353.

F o r r e s t e r , D. J . , J . W . C a r p e n t e r , and D. R. B l a n k i n s h i p . 1978 . C o c c i d i a o f Whooping Cranes . J . W i l d l . D i s . 1 4 : 24-27.

Garnham, I?. C . C . 1966 . M a l a r i a p a r a s i t e s and o t h e r haemo- s p o r i d i a . O x f o r d , Eng land : B l a c k w e l l S c i e n t i f i c P u b l .

G u e s t , S. J . 1973 . A r e p r o d u c t i v e b i o l o g y and n a t u r a l h i s t o r y o f t h e J a p a n e s e Whi t e - eye ( Z o s t e r o p s j a p o n i c a j a p o n i c a ) i n u r b a n Oahu. I s l a n d Ecosys t ems IRP, US/IBP Tech . Rep. 29.

Henshaw, H . W . 1902. B i r d s o f t h e Hawai ian P o s s e s s i o n s w i t h n o t e s on t h e i r h a b i t s . Honolu lu : T. G . Thrum.

Holmes, J. C. 1961. E f f e c t s o f c o n c u r r e n t i n f e c t i o n s on Hymenolep is d i m i n u t a ( C e s t o d a ) and M o n i l i f o r m i s d u b i s ( A c a n t h o c e p h a l a ) . I . G e n e r a l e f f e c t s and compar i son w i t h c rowd ing . J . P a r a s i t . 47: 209-216.

Holmes, J. C., R. P. Hobbs, and T. S. Leong. 1977. P o p u l a t i o n s i n p e r s p e c t i v e : Community o r g a n i z a t i o n and r e g u l a t i o h o f p a r a s i t e p o p u l a t i o n s . P a g e s 209-245 i n G. W . ~ s c h . ~ e g u l a - t i o n o f p a r a s i t e p o p u l a t i o n s . N e w k : ~ c a d e m i c P r e s s , I n c .

K a m i l , A. C. 1978 . S y s t e m a t i c f o r a g i n g by a n e c t a r - f e e d i n g b i r d , t h e Amakihi (Loxops v i r e n s ) . J . Comp. and P h y s i o l . P s y c h . 92: 388-396.

Kami l , A. C. , and C. v a n R i p e r 111. ( I n P r e s s ) . T e r r i t o r i a l d i v i s i o n by b r e e d i n g p a i r s o f t h e Hawai i Amakihi (Loxops v i r e n s ) . Condor .

K a r s t a d , L. 1971 . Pox. P a g e s 3 4 - 4 1 i n J. W. D a v i s , R. C. Ande r son , L. K a r s t a d , and D. ~ T ~ r a i n e r . I n f e c t i o u s and p a r a s i t i c d i s e a s e s o f w i l d b i r d s . A m e s : Iowa S t a t e Univer - s i t y P r e s s .

Kennedy, C. R. 1975 . E c o l o g i c a l a n i m a l p a r a s i t o l o g y . New York: J o h n Wi l ey & S o n s , I n c .

Lewin, V . , and J . C . Holmes. 1971 . H e l m i n t h s f rom t h e e x o t i c game b i r d s o f t h e Puuwaawaa Ranch, Hawai i . Pac . S c i . 25: 372-381.

MacKenzie, K . , a nd D. G ib son . 1970 . E c o l o g i c a l s t u d i e s o n some p a r a s i t e s o f p la ice ( P l e u r o n e c t e s p l a t e s s a L.) and f l o u n d e r ( P l a t i c h t h y s f l e s u s L. ) Symp. B r i t i s h Soc . P a r a s i t . 8 : 1-42.

Munro, G . C. 1 9 4 4 . B i r d s o f Hawa i i , R u t l a n d , Vermont: B r i d g e - way P r e s s , I n c .

Navvab G o j r a t i , H . A. 1970 . E p i z o o t i o l o g i c a l s u r v e y o f a v i a n m a l a r i a i n t h e Hawa i i an ~ s l a n d s . Ph.D. ~ i s s e r t a t i o n i n En tomology , U n i v e r s i t y o f H a w a i i , H o n o l u l u .

P e r k i n s , R. C. L. 1893 . N o t e s o n c o l l e c t i n g i n Kona, Hawai i . I b i s 1893: 101-114.

S m i t h , H . E . , and S. J . G u e s t . 1974 . A s u r v e y o f t h e i n t e r n a l p a r a s i t e s o f b i r d s o n t h e w e s t e r n s l o p e s o f Diamond Head, Oahu, Hawai i 1972-1973. I s l a n d Ecosys t ems IRP, US/IBP Tech . Rep. 37.

Todd, K . S . , J r . , a n d D. M. Hammond, 1971 . C o c c i d i a o f A n s e r i - f o r m e s , G a l l i f o r m e s , and P a s s e r i f o r m e s . P a g e s 234-281 J . W . D a v i s , R. C. Ande r son , L. K a r s t a d , and D. 0. T r a i n e r . I n f e c t i o u s and p a r a s i t i c d i s e a s e s o f w i l d b i r d s . Ames: Iowa S t a t e U n i v e r s i t y P r e s s .

van R i p e r , C., 111. 1975a . P a r a s i t e s o f t h e Hawai i Amakihi (Loxops S r e n s v i r e n s ) . I s l a n d Ecosys t ems IRP, US/IBP Tech . Rep. 62.

van R i p e r , C . , 111. 1975b . c h r y s o p h y l l a ) and n a i o Hawa i i , a s r e l a t e d t o

The p h e n o l o g y o f mamane ( S o p h o r a (Myoporum s a n d w i c e n s e ) o n Mauna Kea, t h e a n n u a l c y c l e o f t h e Amakihi

(Loxops v i r e n s ) and t h e P a l i l a ( P s i t t i r o s t r a b a i l l e u i ) . -- I s l a n d ~ c o s y s t & r ~ s IRP, US/IBP Tech . Rep. 51.

. 1976a . S u p e r i m p o s i t i o n o f Amakihi n e s t o n o n e o f an ~ l e p a i o : Condor 78: 267-269.

. 197613. - A s p e c t s o f House F i n c h b r e e d i n g b i o l o g y i n Hawa i i . Condor 78: 224-229.

. 1977 . The u s e o f s h e e p wool i n t h e n e s t s of ~ a w a i i a n b i r d s . Auk 94: 646-651.

. 1978 . The b r e e d i n g e c o l o g y o f t h e Amakihi (Loxops v i r e n s ) and ~ a l i l a ( P s i t t i r o s t r a b a i l l e u i ) on Mauna Kea, Hawa i i . Ph.D. D i s s e r t a t i o n i n Zoology, U n i v e r s i t y o f Hawa i i , Hono lu lu .

van R i p e r , C . , 111, and W, E. Evenson. A c o m p a r i s o n o f p a s s e r i n e f o r a g i n g n i c h e s o n Mauna Kea, Hawai i . ( I n p r e p a r a t i o n ) .

van R i p e r , C . , 111, and S. G . van R i p e r . 1980 . A n e c r o p s y p r o c e d u r e f o r s a m p l i n g d i s e a s e i n w i l d b i r d s . Condor 82 : 85-98.

Warner , R. E. 1968 . The r o l e o f i n t r o d u c e d d i s e a s e s i n t h e e x t i n c t i o n o f t h e endemic Hawa i i an a v i a f a u n a . Condor 70: 101-120.

TABLE 1. Parasites collected from 'Amakihi nests, body washes, and nasal cavities,

NIDICOLES PARASITES

ORDER PARASITIFORNES

COHORT GAMASINA

ORDER PARASITIFORMES

COHORT GAMASINA

RHODACARIDAE - sp. MACRONYSSIDAE - Ornithonyssus sylviarum PHYTOSEIIDAE - Amblyseius ovatus RHINONYSSIDAE - Ptilonyssus sp.

ORDER ACARIFORMES ORDER ACARIFORMES

SUBORDER ACTINEDIDA SUBORDER ACTINEDIDA

BDELLIDAE - Spinibdella sp. nr. depressa HARPYRHYNCHLDAE - Har pyr hynchus sp.

CUNAXIDAE - Sp,

ANYSTIDAE - Sp.

ERYTHREIDAE - Erythrites sp.

SUBORDER ACARIDIDA

SUPERFAMILY ANALGOIDEA

ANALGIDAE - Analqes sp. SUBORDER ACARIDIDA PROCTOPHYLLODIDAE - Proctophyllodes sp. ACARIDAE - Tyrophaqus putrescentiae Pterodectes sp,

SUBORDER ORISATIDA

CYMBAEREMAEIDAE - Scapheremaeus sp.

TROUESSARTIIDAE - Trouessar tia sp. XOLALGIDAE - gen. & sp.

TABLE 2. Numbers o f 'Amakihi found w i t h g a s t r o i n t e s t i n a l h e l m i n t h p a r a s i t e s on t h e i s l a n d o f Hawai' i from 1972 t h r o u g h 1979. A t o t a l o f 4 4 b i r d s was n e c r o p s i e d .

Age C l a s s No I n f e c t i o n s S i n g l e I n £ e c t i o n s Mixed I n f e c t i o n s Only C e s t o d e s Only Nematodes C e s t o d e s and C e s t o d e s i n

Nematodes t h e Gut and O c c u r r i n g Nematodes i n Toge the r t h e G i z z a r d

ADULT

JUVENILE -:+ .a? ..

P A R K E R R A N C H

2290 METER STUDY

/ ,.. ,.,.-----/ WPHENOLW ',// ,. ", PLOT .

2 130 METER STUDY

METER STUDY

'- . KAOHE GAME MANAGEMENT AREA

FIGURE 1. The study area on Mauna Kea, Hawai'i.

-

TOTAL HELMINTH INFECTION RATE

CAPILLARIA INFECTION RATE 0 RAINFALL n = NUMBER OF BIRDS EXAMINED

FIGURE 2. Helminth infection levels and yearly rainfall on Mauna Kea, Hawai'i.

GLOSSARY

Acar ina Spiders and mites .

arthropods I n s e c t s , s p i d e r s , and mites . /

c a p i l l a r id ~ n t e s t i n a l p a r a s i t i c roundworm.

cestode Tapeworm.

coccid ia I n t e s t i n a l protozoan p a r a s i t e s .

e c t o p a r a s i t e External p a r a s i t e .

i n s t a r Developmental s t age ( e . g . , f i r s t nymphal i n s t a r ) .

FAA Formal in/Acetic Acid/Alcohol . haematozoan ~ l o o d protozoan p a r a s i t e .

helminth P a r a s i t i c gut flatworm.

his topathology Tissue damage.

microcyte Immature blood c e l l .

nematode Roundworm.

n id ico le Nest-inhabiting organism.

operculum Opening ( a s of the ear c a v i t y ) .

passer ine Perching song b i rd .

sapr ophag e Organism which feeds on dead or decaying mat ter .