Parasites of the American White Pelican Robin M
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Gulf and Caribbean Research Volume 17 | Issue 1 January 2005 Parasites of the American White Pelican Robin M. Overstreet University of Southern Mississippi, [email protected] Stephen S. Curran University of Southern Mississippi DOI: 10.18785/gcr.1701.04 Follow this and additional works at: http://aquila.usm.edu/gcr Part of the Marine Biology Commons Recommended Citation Overstreet, R. M. and S. S. Curran. 2005. Parasites of the American White Pelican. Gulf and Caribbean Research 17 (1): 31-48. Retrieved from http://aquila.usm.edu/gcr/vol17/iss1/4 This Article is brought to you for free and open access by The Aquila Digital Community. It has been accepted for inclusion in Gulf and Caribbean Research by an authorized editor of The Aquila Digital Community. For more information, please contact [email protected]. Book for Press.qxp 2/28/05 3:29 PM Page 31 Gulf and Caribbean Research Vol 17, 31–48, 2005 Manuscript received November 3, 2004; accepted January 7, 2005 PARASITES OF THE AMERICAN WHITE PELICAN Robin M. Overstreet and Stephen S. Curran Department of Coastal Sciences, The University of Southern Mississippi, PO Box 7000, Ocean Springs, Mississippi 39566 USA, E-mail [email protected] ABSTRACT Metazoan symbionts, including parasites, infecting the American white pelican (AWP) Pelecanus ery- throrhynchos comprise a list of 75 species, 7 of which are new host records. Several new geographic records are also presented, but generally these have a low value because of the migratory nature of the bird. Evidence suggests that some parasites, mostly flies and other arthropods but also nematodes and digeneans, produce detrimental behavioral or pathologic changes in the AWP. Some of the arthropods transmit microbial agents to the pelican. Two digeneans that have the AWP as a definitive host harm and even kill their catfish intermediate host, especially in aquaculture, and another causes abnormalities and mortality in amphibians. Some of the arthropods with low host- specificity can potentially transmit harmful microbial agents to humans and domestic animals. A few avian blood- flukes, intestinal flukes, and nematodes can potentially cause “swimmers itch,” gastroenteritis, and “anisakiasis,” respectively, in humans. Because of the life cycles of some helminths, presence of those worms can provide an indi- cation as to the dietary items of a specific pelican individual, where the individual has been, and how long it has been present in an area. Feather mites, lice, and diplostomoid digeneans serve as good parasites to indicate phylo- genetic relationships among different pelican species as well as relationships among the Pelecanidae and other fam- ilies such as the Sulidae. INTRODUCTION other host groups (e.g., Nadler and Hafner 1993) have strengthened our understanding of phylogeny by taking The American white pelican (AWP) Pelecanus ery- advantage of a variety of molecular approaches rather than throrhynchos serves as a host for numerous parasites, sev- performing strictly morphological analyses. Molecular eral of them recently or not previously reported. It serves techniques now provide additional useful tools to investi- as an acceptable host for many parasites because it gate a variety of parasitological problems. migrates over an extensive, defined, geographic range, all This article intends to provide a preliminary foray into the while feeding on a large variety of prey items. Those many of the AWP’s symbionts. “Symbiont” is a general prey species in turn serve as intermediate hosts for numer- term used here to encompass organisms that cover a com- ous parasites of the AWP, and many of those parasites as plete range of benefit and harm to a “host,” whether com- well as other symbionts without such complicated life monly referred to as a “parasite” or not (Overstreet 1978). cycles have co-evolved with the pelican. Consequently, They include organisms ranging from those with only a knowledge about the symbionts, especially the truly para- loose bond, such as a stable fly, to those “true” parasites sitic fauna, provides knowledge about the dynamics of the like the digenean Bolbophorus damnificus, which is spe- bird host during certain seasons, in certain regions, or cific to pelicans and exhibits a complicated life cycle in through time. Further, the AWP nests in groups, allowing which the intermediate hosts but not the pelican host are for easy transference of certain parasites among flock harmed. For purposes of this study, we usually refer to cohorts. each of the symbionts, regardless of the degree of host- Parasites of birds have been used before by several specificity, ability to harm a host, or other aspects of its researchers as indicators of the bird’s biology. For exam- association with the host, as a parasite. Some of these neg- ple, digeneans (Bartoli 1989) have indicated host diets, atively influence the bird, pose a potential public health prey preference, habitat where prey was eaten, and host risk, or provide useful biological information about the migration, even though digeneans and other parasites of pelican or its associates. The focus of this article is not fishes have been used more often than those of birds as meant to emphasize disease in the AWP resulting from par- well as used for additional categories of biological indica- asites but rather to show how parasites may play an impor- tions (e.g., Kabata 1963, Margolis 1963, MacKenzie 1983, tant role in understanding the biology of the bird. Lester 1990, Overstreet 1993, 1997). These articles cite criteria one should meet, which vary considerably, MATERIALS AND METHODS depending on the type of question the biological indicator should answer. Analysis of the phylogeny of bird parasites Data for this article have been gathered from prior col- as well as the co-evolution or host-switching with their lections made by the authors, specimens borrowed from hosts also have concerned lice (e.g., Page et al. 2004) and museums, and the literature. Collections consist of para- other parasites. That recent study and others involving sites from a relatively small number of the AWP. Those 31 Book for Press.qxp 2/28/05 3:29 PM Page 32 OVERSTREET AND CURRAN birds from the Mississippi-Louisiana region were shot or examined for parasites. And from these few individuals, died during their migration in conjunction with the often the site of infection has not been recorded. As a USDA/APHIS/ Wildlife Services, provided by the Wildlife result, we predict that many additional parasites infect the Rehabilitation & Nature Preservation Society, or collected AWP. For example, the brown pelican hosts the eimerian from aquaculture facilities. A single specimen was shot at coccidian protozoan Eimeria pelecani, but no protozoan the Summer Lake Wildlife Area, Oregon. We compare our other than a record of the coccidian Sarcocystis sp. in cysts data on the AWP with that collected or described from the in the pectoral muscle (Forrester and Spalding 2003) is brown pelican (Pelecanus occidentalis) in Mississippi or known yet from the AWP. elsewhere. Parasites were removed from birds that were either freshly killed or birds that had been collected earli- DISCUSSION er and their alimentary tract frozen or fixed in alcohol or formalin. A few birds were examined thoroughly for para- Because some parasite identifications were based on sites in general, and specific organs of others were exam- single, few, or incomplete specimens and because some ined for certain species of parasites. Parasites were pre- identifications or infections required annotation, we men- pared using a variety of methods common in our laborato- tion a few relevant points. For the cestodes, no scolex was ry, including some described by Cable (1977), Crites and found among our tapeworm material of Paradilepis cf. Overstreet (1991), and Overstreet and Curran (2005). In caballeroi, so the species could not be identified, but, the most recent collections, we placed representative spec- based on the diagnosis by Forrester and Spalding (2002), imens in refrigerated 95% molecular grade ethanol or we assume P. caballeroi is probably correct. There exists directly into a –70 °C freezer for molecular studies. some debate about the status of species in Paradilepis and related genera. Parvitaenia heardi (= Glossocercus carib- RESULTS aensis by Scholz et al. 2002a) was described from the great blue heron (Ardea herodias) in South Carolina by Schmidt Appendix 1 lists most of the parasites about which we and Courtney (1973), with the brown pelican listed as an have knowledge and provides the site in the bird, the geo- accidental host. Rysavy and Macko (1971) reported graphic location of the infection, and principal references, Parvitaenia eudocimi (= Cyclustera ibisae by Scholz et al. when applicable. When we considered recorded parasite 2002a) from the brown pelican in Cuba as well as from the names to represent junior synonyms, we usually included white ibis (Eudocimus albus), for which it was named. the accepted names only. We also include in the table They described P. caballeroi from the double-crested cor- infections of parasites that we encountered for this study. morant (Phalacrocorax auritus). Additional well-fixed The list, plus a single unidentified coccidian protozoan, material of dilepidids from the AWP should allow exact contains 75 species, 9 of which are flies and 1 a flea with identifications and perhaps reveal the presence of several very little specificity toward the AWP but important to the additional species. For example, Scholz et al. (2002b) bird’s health. About three of the reports represent syn- found five different dilepidid species in “Phalacrocorax onyms or misidentifications of binomial species already on olivaceus” (= the neotropic cormorant, P. brasilianus) in the list. That leaves about 62 listed species, not counting Mexico. the flies and flea, even though some unidentified species For the digeneans, Bolbophorus confusus has been probably represent a complex of species. Of the 62, about reported by several authors as one of a few diplosto- 24 have not been reported from the brown pelican (e.g., moideans infecting the brown pelican and AWP.