Helminths and the northern bobwhite population decline: A review

Olsen, Andrew C.; Brennan, Leonard A.; Fedynich, Alan M.

doi:10.1002/wsb.660

Cited by 13 publications

(12 citation statements)

References 27 publications

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“…pennula is so successful in Texas quail populations. Aulonocephalus pennula is an imbiber (Inglis, 1958) and does not seem to attach to host caecal tissues (Olsen et al ., 2016; personal observations by authors), which could limit host immune response. Second, the intermediate host is presently thought to be an insect (Henry et al ., 2018; Peterson & Fedynich, in press) that is likely abundant, comprises a major portion of the bobwhite's insect diet (insects represent 8–23% of the total diet; Larson et al ., 2010) and is a highly suitable host for the larval stages of this helminth.…”

Section: Discussionmentioning

confidence: 99%

Assessment of the helminth fauna in northern bobwhites (Colinus virginianus) occurring within South Texas

2021

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Populations of northern bobwhites (Colinus virginianus; hereafter bobwhite) have been declining across their geographic range in North America, prompting consideration of the role parasites may play. We conducted this study to learn about the helminth fauna in South Texas, a region that supports a sustainable bobwhite population. Helminths were examined from 356 bobwhites collected during the 2014–2015 (n = 124) and 2015–2016 (n = 232) hunting seasons, when increasing trends in precipitation were observed in comparison with the previous two years. Ten helminth species were found, consisting of 14,127 individuals. Of these, all are heteroxenous parasites and three are pathogenic (Dispharynx nasuta, Tetrameres pattersoni and Oxyspirura petrowi). Aulonocephalus pennula numerically dominated the component community (81% prevalence, 99% of the total helminths found), whereas each of the remaining species occurred rarely (≤9% prevalence) and contributed few individuals (≤0.4%) to the helminth community. Prevalence and abundance of A. pennula were not influenced by host age, sex or body mass, but abundance was higher during the 2014–2015 than the 2015–2016 hunting season. Our findings indicate that the helminth community in bobwhites from South Texas can vary during long-term, highly variable precipitation conditions and these communities are more similar to those found in the Rolling Plains of Texas than those found in the eastern part of the bobwhite's geographic range in the US.

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Section: Discussionmentioning

confidence: 99%

Assessment of the helminth fauna in northern bobwhites (Colinus virginianus) occurring within South Texas

2021

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“…It is important to emphasize that the owls in this study were seemingly normal at the time of harvest, without any overt clinical signs or behavioral abnormalities. Olsen et al (2016) emphasized that experimental studies are the preferred method to study the potential health effects of orbital helminths in quail. Similar to others (Bruno et al 2015; Dunham et al 2016b), a relationship between histologic lesions and individual bird fitness was not clearly defined in our study because visual acuity was not explicitly evaluated, and inflammation appeared too mild to have affected vision.…”

Section: Discussionmentioning

confidence: 99%

“…Most ocular nematode infections are considered incidental or a rare cause of morbidity in isolated cases (Beckmann et al 2014). Since 2010, increasing reports have implicated infection by the nematode Oxyspirura petrowi in Northern Bobwhite Quail ( Colinus virginianus ) and Lesser Prairie Chickens ( Tympanuchus pallidicinctus ) affecting host fitness, although the effects of periorbital nematodes are not completely understood at the individual or population level (Dunham et al 2014a, b; Olsen et al 2016; Henry et al 2017). Recently, a human was infected by a nematode closely related to O. petrowi , further emphasizing the increasing importance of studying periorbital nematodes (Dung et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Apparent Prevalence, Diversity, and Associated Lesions of Periorbital Nematodes in a Population of Barred Owls (Strix Varia) From Northern California, Usa

Niedringhaus

Dumbacher

Dunker

et al. 2023

Journal of Wildlife Diseases

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Over the last four decades, Barred Owls (Strix varia) have expanded their range to include much of western North America, including California. This expansion is suspected to have contributed to declining populations of a closely related species, the federally threatened Northern Spotted Owl (Strix occidentalis caurina). As a result, understanding potential health threats to Barred Owls has implications for Spotted Owl health and recovery. From 2016 to 2020, 69 Barred Owls were collected to determine the apparent prevalence of periorbital nematode infection, to identify the parasite species present, and to investigate the potential pathologic effects on their hosts. The nematodes were morphologically identified as Oxyspirura and Aprocta spp. On the basis of phylogenetic analyses, they were clearly divergent from published sequences of other species within these genera. Overall, 34 (49%) Barred Owls were infected with periorbital nematodes, with Oxyspirura sp. infections being much more common (94%) than Aprocta sp. (18%). Histopathology revealed varying severity of conjunctivitis in infected owls. Despite the frequency of infection and subsequent inflammation, parasite burden was not associated with reduced body weight in these owls. As a result, the potential health effect of these nematodes is unclear. Further taxonomic characterization is needed to determine potential novelty of these nematodes.

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“…Northern bobwhite quail ( Colinus virginianus ; hereafter, bobwhite) is an upland game bird in North America that is both a species of conservation concern (BirdLife International, 2021) and the focus of intense land management for government agencies and private landowners interested in increasing hunting opportunities. Bobwhite populations have declined approximately 80% over the last 50 years (Sauer et al, 2020), predominantly due to habitat loss and fragmentation (Brennan, 1991; Droege & Sauer, 1990; Robbins et al, 1986). Bobwhite is a ground‐nesting bird that in the US Great Plains seeks nesting cover consisting primarily of bunchgrasses, such as cheatgrass ( Bromus tectorum ) (Klimstra & Roseberry, 1975) or little bluestem ( Schizachyrium scoparium ) (Townsend et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Mesopredator predation risk limits northern bobwhite nesting habitat

Harris

O’Connell

2023

Ecosphere

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Predators can significantly limit the amount of available habitat for vulnerable prey. Encouraging spatial segregation of predators and prey through habitat management prescriptions may be a useful tool to increase productivity and abundances of prey species of conservation concern. We estimated the total area of low‐risk nesting habitat by interacting predator habitat selection models with northern bobwhite (Colinus virginianus) nest‐site selection models. We used trail cameras, transect sampling, spotlighting transects, and incidental tracking to survey and map occurrences of mesopredators at a site in western Oklahoma, USA. We created broad‐scale resource selection function models for bobwhite nest‐site and mesopredator habitat selection using generalized linear models to create maps of occurrence probability in ArcGIS. Bobwhite nests were more likely to be depredated in areas of high selection by coyotes (Canis latrans) and striped skunks (Mephitis mephitis) compared to areas with low mesopredator selection. Approximately 392 ha of bobwhite nesting habitat (17%) had low probabilities of selection by both coyotes and striped skunks. Our results demonstrate the need for incorporating species' interactions into estimations of available habitat. Based on the total area of highly selected cover by northern bobwhite, approximately 29% of the study area would have been deemed suitable for nesting. However, only 5% of that area is predicted to have a low predation risk.

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Helminths and the northern bobwhite population decline: A review

Cited by 13 publications

References 27 publications

Assessment of the helminth fauna in northern bobwhites (Colinus virginianus) occurring within South Texas

Assessment of the helminth fauna in northern bobwhites (Colinus virginianus) occurring within South Texas

Apparent Prevalence, Diversity, and Associated Lesions of Periorbital Nematodes in a Population of Barred Owls (Strix Varia) From Northern California, Usa

Mesopredator predation risk limits northern bobwhite nesting habitat

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