An introduced generalist parasite, the sticktight flea (Echidnophaga gallinacea), and its pathology in the threatened Florida scrub-jay (Aphelocoma coerulescens).
The sticktight flea, (Echidnophaga gallinacea), a major pest of the domestic chicken (Gallus gallus) that can cause severe pathology or death if untreated, is rarely recorded in free-living avian species. Sticktight fleas, however, were observed on the federally threatened Florida scrub-jay (Aphelocoma coerulescens) in February 2004, in south central Florida. Of the 81 Florida scrub-jays (FSJs) sampled before the 2004 breeding season, 12 were infested, with from 1 to as many as 57 fleas. Subsequent survivorship and variation in health indices led us to conclude that the sticktight flea caused the death of several jays. Within 4 mo, 46% of sticktight flea-infested (INF) jays died, whereas in the nonflea-infested (NINF) jays, only 5.9% died. Adult INF birds lost body mass in the time since a previous capture compared with NINF jays, and mass gain was slowed in 1-yr-old INF jays. Hematocrit of INF jays was dramatically impacted, as low as 17%, and was negatively correlated with the extent of infestation. Leukocyte counts were highest in INF jays; however, plasma immunoglobulin levels were lowest. Physiological stress levels, measured using plasma corticosterone, increased more rapidly in INF jays than NINF jays and were positively correlated with heterophil/lymphocyte ratios. The impact of the sticktight flea on the federally threatened FSJ negates previous findings that sticktight fleas are benign in wild avian hosts.
Boughton
R K
RK
Department of Biology University of Memphis Memphis Tennessee 38152, USA. rboughtn@memphis.edu
Atwell
J W
JW
Schoech
S J
SJ
D000818:Animals; D001715:Bird Diseases / Q000453:epidemiology / Q000469:parasitology* / Q000503:physiopathology; D001798:Blood Proteins / Q000032:analysis; D001835:Body Weight; D003345:Corticosterone / Q000097:blood; D004478:Ectoparasitic Infestations / Q000453:epidemiology / Q000503:physiopathology / Q000662:veterinary*; D005260:Female; D005431:Florida / Q000453:epidemiology; D006400:Hematocrit / Q000662:veterinary; D007074:Immunoglobulin G / Q000097:blood; D007958:Leukocyte Count / Q000662:veterinary; D008297:Male; D008842:Microfilariae / Q000302:isolation & purification; D046109:Passeriformes / Q000469:parasitology*; D005423:Siphonaptera / Q000472:pathogenicity*
D001798:Blood Proteins; D007074:Immunoglobulin G; D003345:Corticosterone