About

Donovan Davis is an Instructional Professor in the Department of Biological and Agricultural Engineering at Texas A&M University. He holds a Bachelor of Science degree in Agricultural Systems Management from Texas A&M University. His professional role involves teaching and contributing to the academic programs within the department, which is part of the College of Agriculture & Life Sciences and the College of Engineering. The department offers undergraduate and graduate degrees in biological and agricultural engineering, with Davis being a key faculty member supporting these educational initiatives. His work is focused on advancing education in biological and agricultural engineering, supporting student development, and contributing to the department's mission of research, extension, and education in agricultural systems management.

Research topics

• Computer Science
• Biology
• Demography
• Agronomy
• Zoology
• Ecology
• Remote sensing
• Geology
• Fishery
• Human–computer interaction

Selected publications

• LightSound: A Sonification Tool for Observing Solar Eclipses

  American Astronomical Society Meeting Abstracts #235 · 2020 · 1 citations

  Senior authorCorresponding
  • Computer Science
  • Computer Science
  • Remote sensing
  Publisher

• Florida Key Deer Abundance and Recovery Following New World Screwworm Infestation

  Southeastern Naturalist · 2020 · 11 citations

  • Biology
  • Ecology
  • Fishery

  An infestation of Cochliomyia hominivorax (New World Screwworm, hereafter Screwworm) was detected in the endangered Odocoileus virginianus clavium (Florida Key Deer) population in July 2016. We assessed the impact of this infestation on Florida Key Deer population abundance and recovery potential. We synthesized historical mortality and population data with new analyses including monitoring of Florida Key Deer mortalities and estimation of abundance on Big Pine Key and No Name Key (islands that support 75% of the Florida Key Deer population). We documented 135 Screwworm-related Florida Key Deer mortalities (∼9–20% of the total population) during the Screwworm outbreak (July 2016–January 2017). Most mortalities occurred in the adult male population, as Screwworm flies laid eggs on open wounds sustained from sparring during mating season. The Screwworm incident was contained prior to the 2017 fawning season, which prevented substantial negative impacts on females or fawns. Historical growth rates at similar population levels and sex ratios indicated that, absent other external variables (e.g., Hurricane Irma in September 2017), the population was likely to recover.

  PublisherDOI

• Ranges and Movements of Montezuma Quail in Southeast Arizona

  National Quail Symposium Proceedings · 2017-01-01 · 5 citations

  articleOpen access

  Historical assumptions about Montezuma quail movements and home ranges at the population level are limited due to the lack of markrecapture studies on this species from which solid conclusions can be derived. Such information is crucial for estimating population sizes, densities, and rate of emigration and immigration throughout the landscape. Our study examined home range size of 29 Montezuma quail and movements of 65 quail in southeast Arizona from 2008–2010. We used radio telemetry to follow radio-tagged birds in 3 study sites that varied in vegetation composition and topography. Mean home range size (MCP) was about was similar (51 ha) to the largest use area (50 ha) described in the literature for this species. The largest MCP home range estimate (206.7 ha) was far larger than what has been reported in the literature. Within a season, the largest mean maximum distance moved between 2 locations was 1,128.4 ± 619.5 m and the largest maximum linear distance between 2 locations for an individual was 2,375.5 m. Results from our research should help to address knowledge gaps about Montezuma quail home ranges and movements and provide a baseline to assist management of this species in the future.

  PublisherOA PDFDOI

• Survival Demographics of Montezuma Quail in Southeast Arizona

  National Quail Symposium Proceedings · 2017-01-01

  articleOpen access

  Many facets of Montezuma quail (Cyrtonyx montezumae mearnsi) population dynamics, such as survival and causes of mortality, are unknown because of limited or lack of mark–recapture studies on wild populations of this species. Much of what is known about this species comes from casual observations in the field or from dog-assisted flush-count surveys. Further insight into rate and causes of mortality for this species is necessary to ensure proper conservation measures. We evaluated survival and causes of mortality of Montezuma quail in southeastern Arizona from winter 2007 to spring 2010. Survival was determined from quail captured, radiotagged, and monitored among 3 separate study sites. In 2 of these sites hunting was permitted; and in 1 site (the control) hunting was not permitted. Estimation of accurate mortality rates in hunted sites was complicated by large quantities of censored data, some of which was attributable to lack of reported mortalities from hunting. Mortality in the control site may have been compounded by a combination of stochastic events (i.e., wildfire, freezing) occurring during the study. Mortality rate for all sites were higher than any estimates reported or hypothesized in known scientific literature. The estimated rate of survival, combined among the 3 sites, was 21.9% from autumn 2008 to autumn 2009.

  PublisherOA PDFDOI

• <i>TRYPANOSOMA CRUZI</i>IN FREE-RANGING MAMMALIAN POPULATIONS IN SOUTH TEXAS, USA

  Journal of Wildlife Diseases · 2017-05-17 · 10 citations

  article

  Chagas disease, also known as American trypanosomiasis, is caused by the flagellate protozoan Trypanosoma cruzi. It is a significant health concern in South and Central America, where millions of people are infected or at risk of infection, and is an emerging health concern in the US. The occurrence of Chagas disease in natural environments is supported by mammal host species, but those primary species may vary based on geographic location. In South Texas, the primary host species for the disease is poorly understood, and required a field study to determine the spatial distribution of T. cruzi prevalence in free-ranging mammals. Our study objectives were to determine the spatial distribution and prevalence of T. cruzi parasites in free-ranging mammals. We compared T. cruzi prevalence among species, among vegetative communities, and among different topographies (i.e., floodplain versus upland). From December 2011 through December 2013, 450 blood and tissue samples from geolocated free-ranging wildlife mammal species were analyzed with the use of polymerase chain reaction to detect protozoan T. cruzi DNA. We also calculated mammal abundance with the use of mark-recapture methodology and recorded capture-site characteristics such as vegetation structure. We found that animals in grasslands had a significantly lower infection rate when summed across all species compared with animals in dense hardwoods and semi-improved woodlands (P=0.001). A higher percentage of infections were found in the lower-elevation floodplain-65% (28/43) of animals sampled, compared to upland areas-25% (9/36) of animals sampled. Our study suggested that common free-ranging meso-mammals supported T. cruzi in natural environments and are of public health concern in South Texas. Mitigation strategies should consider a range of management activities to include vegetation management, selective application of insecticides, and changes in human behavior in high-risk areas.

  PublisherDOI

• A model for assessing mammal contribution of Escherichia coli to a Texas floodplain

  Wildlife Research · 2015-06-09 · 1 citations

  article

  Context Free-ranging mammals contribute to faecal pollution in United States water bodies. However, research into wildlife impact on water quality is dependent upon unreliable data (e.g. data uncertainty, unknown importance of parameters). Aims Our goal was to determine the potential impacts of common free-ranging mammal species and their management on Escherichia coli in the study floodplain. Our objectives for this research were to construct a model from study area- and literature-derived data, determine important species for E. coli deposition, and conduct sensitivity analyses on model parameters to focus future research efforts. Methods We constructed a model that incorporated parameters for four wildlife species known to contribute E. coli in central Texas: raccoons (Procyon lotor), white-tailed deer (Odocoileus virginianus), Virginia opossums (Didelphis virginiana), and wild pigs (Sus scrofa). These parameters were (1) population density estimates, (2) defaecation rates, (3) defaecation areas, (4) E. coli concentration in faecal material estimates, and (5) E. coli survival. We conducted sensitivity analyses on the model parameters to determine relative importance of each parameter and areas for additional study. Key results We found that adjustment of raccoon and Virginia opossum population densities had higher impacts on E. coli in the floodplain than similar changes in other species across all spatial and seasonal variations. We also found that the changes in E. coli survival, E. coli concentration in raccoon faecal material, and defaecation rates had the highest impacts on E. coli in the floodplain. Conclusions Our sensitivity analyses indicated that the largest impacts to projected E. coli loads were from changes in defaecation rates followed by E. coli concentration in faecal material and E. coli survival. Watershed planners, ranchers, and regulators must be cautioned that faecal deposition patterns are location specific and could significantly impact which species are considered the most important contributors. Implications Although all parameters require more research, we recommend that researchers determine defaecation rates for contributing species due to their relatively large impacts on E. coli in comparison to the other parameters. We also suggest additional research in free-ranging wildlife faecal morphology (form and structure) and area of deposition. Finally, species-specific E. coli survival studies for free-ranging wildlife should be conducted.

  PublisherDOI

• Impact of gate width of corral traps in potential wild pig trapping success

  Wildlife Society Bulletin · 2014-11-03 · 9 citations

  article

  ABSTRACT Wild pig ( Sus scrofa ) populations do considerable environmental damage throughout much of the United States and have prompted varied capture and control efforts. Corral traps are a popular wild pig trapping tool. However, the impact of gate width on the effectiveness of corral traps has not been tested. This information could increase efficacy of capture and is important for future population‐control efforts. We hypothesized that wild pigs would habituate better to corral traps with wider gate openings. We used remote game cameras to monitor the willingness of wild pigs to enter baited corral traps through 4 common gate widths (0.9 m, 1.2 m, 1.5 m, 1.8 m; no doors on any gates). We found no significant differences in gate‐width selection for total wild pigs, sex‐based selection, or number of piglets. Land managers should feel comfortable using gate sizes as small as 0.9 m when constructing corral traps. © 2014 The Wildlife Society.

  PublisherDOI

• The genus Erechthias Meyrick of Ascension Island, including discovery of a new brachypterous species (Lepidoptera, Tineidae)

  ZooKeys · 2013-10-07 · 8 citations

  articleOpen access1st authorCorresponding

  One previously named and two new species of the tineid genus Erechthias Meyrick are described and illustrated from the small, remote, mid-Atlantic Ascension Island. With these additions the Lepidoptera fauna of Ascension now totals 38 known species. Little is known regarding the biology of the two new species of Erechthias, and none of the species has been reared from larvae from Ascension. Erechthias minuscula (Walsingham) is a widespread, largely pantropical species first described from the West Indies. Larvae of Erechthias minuscula are known to be scavengers on a wide variety of dead plant material. Erechthias ascensionae,new species, is one of two species of Erechthias now known to be endemic to the island. The other endemic species, Erechthias grayi, new species, is further remarkable in having wing reduction occurring in both sexes. It is one of the few species of Lepidoptera known where this extreme of brachyptery involving both sexes has evolved. The larvae of Erechthias grayi are believed to be lichenivorous, and larval cases suspected to represent this species are illustrated.

  PublisherDOI

• Role of free-ranging mammals in the deposition of Escherichia coli into a Texas floodplain

  Wildlife Research · 2013-12-15 · 7 citations

  articleSenior author

  Context The role of wildlife in faecal pollution of water bodies (deposition of Escherichia coli (E. coli)) is not well understood. Current water-quality and land-use planning research largely relies on unreliable wildlife data (e.g. poor sourcing of abundance estimates, population density estimates applied to multiple fundamentally different areas, suspect or insufficiently described data collection techniques) Aims Our goal for the present research was to investigate deposition of E. coli into a floodplain by free-ranging mammals. Objectives of the research were to determine the density of important free-ranging meso- and large mammals in the study area, determine faecal E. coli loads for each species, and evaluate spatial data on species-specific faecal deposition. Methods We conducted our research in south-eastern Texas, USA, on two cattle ranches bisected by Cedar Creek (44-km long). Cedar Creek has elevated E. coli concentrations. We conducted mark–recapture and mark–resight population density estimates (2008/09) for meso- and large mammals in the study areas. We collected faecal samples from all captured wildlife. We also conducted transects through the study area to determine faecal-deposition patterns. Key results We found that raccoons (Procyon lotor), wild pigs (Sus scrofa), Virginia opossums (Didelphis virginiana) and white-tailed deer (Odocoileus virginianus) all had substantial faecal E. coli loads and population densities, thus implying an important role in E. coli deposition into the study floodplain. All species were widely distributed through the floodplain. Conclusions Free-ranging mammals contribute E. coli to floodplains and potentially affect water quality. We determined that four species commonly found in floodplains throughout North America all contributed E. coli to the study floodplain, thus implying mammal E. coli contributions in many locations and this is potentially important for E. coli management. Implications Improved locally specific mammal population estimates and estimates of locally derived E. coli concentration will improve floodplain and water-quality models that often depend on data of various quality. Additionally, our analyses demonstrated the need for continued research into the role of wildlife in E. coli deposition.

  PublisherDOI

• An annotated catalog of fossil and subfossil Lepidoptera (Insecta: Holometabola) of the world

  Zootaxa · 2012-04-30 · 119 citations

  articleOpen access

  In this catalog, we attempt to assemble all fossil records of Lepidoptera described formally or informally in the worldliterature. A total of 667 records dealing with at least 4,568 specimens have been compiled. They include descriptions of131 fossil genera and 229 fossil species, as well as 72 extant genera and 21 extant species to which some of these fossilssupposedly belong or show superficial similarity. Replacement names of two fossil genera are proposed to avoidhomonymy: Baltopsyche Sohn, gen. nov. for Palaeopsyche Sobczyk and Kobbert, 2009 and Netoxena Sohn, gen. nov. forXena Martins-Neto, 1999. New generic combinations are proposed for: Tortrix? destructus Cockerell, 1916, Tortrixflorissantanus Cockerell, 1907, and Tortrix sp. sensu Gravenhorst (1835), all three to Tortricites Kozlov, 1988;Pterophorus oligocenicus Bigot, Nel and Nel, 1986, to Merrifieldia Tutt, 1905; Aporia sp. sensu Branscheid (1969) toPierites Heer, 1849; Noctua spp. sensu Hope (1836) and Lomnicki (1894), both to Noctuites Heer, 1849. Eleven namesimproperly proposed for lepidopteran fossils are invalidated: Baltonides roeselliformis Skalski in Kosmowska-Ceranowicz and Popiolek, 1981; Baltodines Kupryjanowicz, 2001; Barbarothea Scudder, 1890; Lepidopterites Piton,1936; Palaeozygaena Reiss, 1936; Psamateia calipsa Martins-Neto, 2002; Saxibatinca meyi Skalski in Kristensen andSkalski, 1998; Spatalistiforma submerga Skalski, 1976; Thanatites juvenalis Scudder, 1875; Tortricibaltia diakonoffiSkalski, 1976; and Zygaenites Reiss, 1936. An unnecessary subsequent type designation for Pierites Heer, 1849, isdiscussed. A total of 129 records include lepidopteran fossils which cannot be placed in any taxonomic rank. There alsoexist at least 25 fossil records which lack any evidence of the supposed lepidopteran association. Misidentified specimens,including 18 fossil genera, 29 fossil species and 12 unnamed fossils, are excluded from Lepidoptera. All the knownlepidopteran fossils are annotated by fossil type, specimen deposition, excavation locality, association with plants when present, and geological age. A bibliographic list of lepidopteran fossils is provided.

  PublisherOA PDFDOI

Frequent coauthors

• Roel R. Lopez

  30 shared

• Nova J. Silvy

  Texas A&M University

  29 shared

• Israel D. Parker

  Texas A&M University

  14 shared

• Pedro M. Chavarria

  10 shared

• Philip H. Elzer

  Louisiana State University Agricultural Center

  10 shared

• L. Garry Adams

  10 shared

• Angel B. Montoya

  Lasen (United States)

  10 shared

• Tariq R. Qureshi

  9 shared

Education

• B.S., Agricultural Systems Management

  Texas A&M University