Parasites of the Hawaii Amakihi (Loxops virens virens)

Abstract

This paper deals with the parasites of the Hawaii Amakihi (Loxops virens virens). The study was undertaken in 1969 to determine the types of parasites present and what role they could play in regulating population numbers. Betaparasites and endoparasites were collected from as many birds as possible. A new form for the autopsy of passerine birds was developed and is included as Appendix I. Most of the external parasites I found on the Amakihi still await identification. The most commonly encountered feather louse seems to be Philopterus. Mites of the genus Rhinonyssus were found in the nasal passages of the Amakihi. I found Hippoboscid flies on Amakihi; blowflies often frequent active nests. Few parasites inhabit the nest of the Amakihi. Most of the nest fauna are nonparasitic arthropods associated with nests as saprophages or as predators on other nest arthropods. What appeared to be avian pox was found on five Amakihi. All were inflicted with the dry variety of pox. Four were infected on the head and one was infected on the leg. In two cases the infection was severe enough to cause death to the bird. Coccidia does not appear to be an important disease of wild Amakihi. I found two mild cases of this disease. In four of the 24 birds examined, smears of the heart, liver, spleen, and lungs were made; all were negative. I made 131 peripheral blood smears from 103 different Amakihi. Two slides were positive. Both contained protozoan parasites from the "Plasmodium relictum complex," being either F. giovannolai or P. matutinum. The birds that contracted malaria were caged individuals that had been moved from Puu Laau (7,500 feet) to Kamuela, Hawaii (2,500 feet). These birds died 32 and 45 days, respectively, after capture. Both exhibited ataxia, shivering, and weakness before death. Intestinal worms were the most frequently encountered parasites. Capillaria sp. ova were present in seven of the 24 fecal smears examined and adult worms were found in eight of the birds. Ova of Tetrameres sp. were detected in two individuals; adult worms were found in one bird. Tapeworm eggs were diagnosed in the feces of two birds. Both individuals contained large numbers of adults. Unidentified nematodes were found in three individuals. One bird had three worms in the left atrium and aorta. Puu Laau is a high, arid region. Many of the mosquito borne infections are not present there.