William Iko, Ph.D.
Science and Products
Prevalence and effects of West Nile virus on wild American kestrel (Falco sparverius) populations in Colorado
To assess the potential impacts of West Nile virus (WNV) on a wild population of free-ranging raptors, we investigated the prevalence and effects of WNV on American Kestrels (Falco sparverius) breeding along the Front Range of the Rocky Mountains in northern Colorado. We monitored kestrel nesting activity at 131 nest boxes from March to August...Paul, Ellen; Dusek, Robert J.; Iko, William M.; Hofmeister, Erik K.
Occurrence of West Nile virus infection in raptors at the Salton Sea, California
We investigated the prevalence of West Nile virus (WNV)-neutralizing antibodies and infectious virus, and the occurrence of overwinter transmission in two raptor species during January and March 2006 at the Salton Sea, Imperial County, California. We captured 208 American Kestrels (Falco sparverius) (January, n=100; March, n=108) and 116...Dusek, Robert J.; Iko, William M.; Hofmeister, Erik K.
Estimating the use of morphometric measurements from museum specimens for sex determination in Mountain Plovers (Charadrius montanus)
The Mountain Plover (Charadrius montanus) is a shorebird species endemic to the dry, terrestrial ecosystems of the Great Plains and southwestern United States. Breeding Bird Survey data suggest that Mountain Plover populations have declined by >60% in the last 30 years. A better understanding of the population dynamics of the Mountain Plover is...Iko, W.M.; Dinsmore, S.J.; Knopf, F.L.
Foraging ecology in White-tailed Kites (Elanus leucurus)
No abstract available.Mohan, H.M.
Isotope variations in white-tailed kites from various habitats in California: Possible limitations in assessing prey utilization and population dynamics
White-tailed kite (Elanus leucurus) populations in the 1930s were close to extirpation in the United States. But by the 1940s, an upward trend towards recovery was apparent and continued to their current stable population levels. These dramatic fluctuations in kite numbers may have been related to changes in rodent prey populations due to the...Iko, W.M.; Kester, C.L.; Bern, C.R.; Stendell, R.C.; Rye, R.O.
Plasma cholinesterase levels of mountain plovers (Charadrius montanus) wintering in central California, USA
Declines of over 60% in mountain plover (Charadrius montanus) populations over the past 30 years have made it a species of concern throughout its current range and a proposed species for listing under the U.S. Endangered Species Act. Wintering mountain plovers spend considerable time on freshly plowed agricultural fields where they may potentially...Iko, W.M.; Archuleta, A.S.; Knopf, F.L.
A comparison in Colorado of three methods to monitor breeding amphibians
We surveyed amphibians at 4 montane and 2 plains lentic sites in northern Colorado using 3 techniques: standardized call surveys, automated recording devices (frog-loggers), and intensive surveys including capture-recapture techniques. Amphibians were observed at 5 sites. Species richness varied from 0 to 4 species at each site. Richness scores,...Corn, P.S.; Muths, E.; Iko, W.M.
Pathogenicity of avian malaria in experimentally-infected Hawaii Amakihi
The introduction of avian malaria (Plasmodium relictum) and mosquitoes (Culex quinquefasciatus) to the Hawaiian Islands (USA) is believed to have played a major role in the decline and extinction of native Hawaiian honeycreepers (Drepanidinae). This introduced disease is thought to be one of the primary factors limiting recovery of honeycreepers...Atkinson, Carter T.; Dusek, Robert J.; Woods, K.L.; Iko, W.M.
Wildlife disease and conservation in Hawaii: pathogenicity of avian malaria (Plasmodium relictum) in experimentally infected Iiwi (Vestiaria coccinea)
Native Hawaiian forest birds are facing a major extinction crisis with more than 75% of species recorded in historical times either extinct or endangered. Reasons for this catastrophe include habitat destruction, competition with non-native species, and introduction of predators and avian diseases. We tested susceptibility of Iiwi (Vestiaria...Atkinson, C.T.; Woods, K.L.; Dusek, Robert J.; Sileo, L.S.; Iko, W.M.
Epidemic pox and malaria in native forest birds
Studies by Warner in the 1950’s and van Riper in the 1970’s identified disease as a potential limiting factor in the distribution and abundance of Hawaii’s native forest birds. Mosquito-transmitted protozoan and viral infections caused by malarial parasites and pox virus were especially significant. Both organisms were introduced to the islands...Atkinson, C. T.; Dusek, R. J.; Iko, W. M.
Avian malaria fatal to juvenile I'iwi
No abstract available.Atkinson, C. T.; Dusek, R. J.; Iko, W. M.
Non-random pairing in American kestrels: mate choice versus intra-sexual competition
Natural selection may influence the arrangement of individuals into mated pairs through either inter-sexual (mate choice) or intra-sexual selection (competition). A study of the American kestrel, Falco sparverius, in northern Saskatchewan distinguished between these two processes using size as a measure of the bird's competitive ability, and...Bortolotti, Gary R.; Iko, William M.