Resume

• 2000

  Cary Institute of Ecosystem Studies

  Southern Illinois University

  Urbana-Champaign

  Illinois Area

  Principal Research Scientist and Director

  Illinois Natural History Survey

  Carbondale

  IL

  My appointment was for 75% research

  25% teaching. I conducted research on population and community ecology

  disease processes

  and behavior of a variety of wildlife species. I taught Principles of Wildlife Biology

  Wildlife Diseases

  Population Ecology

  Zoological Literature (Scientific Writing)

  Wildlife Ecologist

  Associate Professor of Zoology

  Southern Illinois University

  Carbondale

  IL

  My appointment was for 75% research

  25% teaching. I conducted research on population and community ecology

  disease processes

  and behavior of a variety of wildlife species. I taught Principles of Wildlife Biology

  Wildlife Diseases

  Population Ecology

  Zoological Literature (Scientific Writing)

  Wildlife Ecologist

  Professor of Zoology

  Southern Illinois University

  Millbrook

  NY

  Postdoctoral Researcher

  Cary Institute of Ecosystem Studies

• 1996

  Ecological Society of America

• 1995

  Doctor of Philosophy (PhD)

  Ecology

  University of Connecticut

• 1994

  American Society of Mammalogists

• 1992

  Master of Science (MS)

  Wildlife Science

  Oregon State University

• 1989

  Illinois Chapter: President Elect

  President

  Past President

  The Wildlife Society

• 1988

  Bachelor of Science (BS)

  Wildlife Biology

  University of Massachusetts

  Amherst

• Prairie Research Institute News

  CHAMPAIGN – Eric Schauber

  an animal ecologist currently at Southern Illinois University Carbondale

  has been selected as the next director of the Prairie Research Institute’s Illinois Natural History Survey. Schauber will begin his appointment on...

  Prairie Research Institute News

  Statistical Data Analysis

  Environmental Science

  Field Work

  Population Ecology

  Wildlife

  Ecology

  Landscape Ecology

  Statistics

  Wildlife Biology

  Data Analysis

  Mathematical Modeling

  Teaching

  Grant Writing

  Animal Behavior

  Public Speaking

  University Teaching

  Scientific Writing

  Research

  Higher Education

  Science

  Localized Removal Affects White-Tailed Deer Space Use and Contacts

  Clayton Nielsen

  Social structure can influence transmission of disease agents both within and between social groups

  and that structure can be disrupted by within-group disease outbreaks or disease management efforts. This paper reports results of a controlled experiment designed to test whether separation from social group would lead remnant individual white-tailed deer to increase contacts with or even join other social groups nearby. This question is important in understanding how within-group disease outbreaks or lethal approaches to wildlife disease management could influence transmission of disease agents between groups. We found that adult female deer did not respond much to loss of social group

  while juvenile deer increased their home range size

  decreased their home range fidelity

  and may have joined up with individuals from outside their original group.

  Localized Removal Affects White-Tailed Deer Space Use and Contacts

  In Illinois

  Neotoma floridana (Eastern Woodrat) experienced range reductions\nand population bottlenecking over the past century. During the period 2004–2005

  the isolated\nremnant populations along the Mississippi bluffs in southwestern Illinois were genetically\naugmented with 47 Eastern Woodrats from Arkansas and Missouri

  resulting in 40%\nadmixture within the largest population. In 2009

  a strong windstorm created canopy gaps\nand woody debris throughout this area

  potentially improving habitat for Eastern Woodrats.\nWe investigated the status of Eastern Woodrat populations in southwestern Illinois by livetrapping\nremnant populations and conducting sign surveys from 2011 to 2015. We captured\n263 Eastern Woodrats; mean trapping success was 62.5% higher than trapping during the\n1990s

  and the number of individuals captured per trap-night was 3–6 times higher than\ntrapping events during the previous 18 years (all P <0.001). We also located sign of Eastern\nWoodrat 8.9 km east of the remnant populations. We recommend further genetic monitoring\nto evaluate whether population increases are coupled with increased admixture and\nrecommend forest-management actions that create habitat disturbance and resultant piles of\nwoody debris that increase woodrat habitat quality.

  Status of eastern woodrats in isolated remnant populations following genetic augmentation and habitat disturbance.

  Tyler Schartel

  PLoS ONE

  11(3): e0151483.

  A big pile of food (or even an empty trash can) can attract predators to a particular spot. So

  does that make it a terrible place to be if you are a prey? The answer depends on how tasty you are compared to the food drawing the predators in in the first place.

  Relative preference and localized food affect predator space use and consumption of incidental prey.

  Bob Bluett

  Joanne Crawford

  American Midland Naturalist

  Examining beaver pelts showed evidence of bites from other beavers. We tested the hypotheses that number of wounds would differ by sex and age and would be greater for beavers trapped on a large river. Aside from kits having fewer

  we found no evidence that wound frequency differed by sex and age

  which was surprising -- we expected subadults (which are typically dispersers) would show greater wounding as they moved through unfamiliar animals' territories. Wounds were substantially more prevalent in beavers from the main river. Therefore

  waterbody characteristics had a greater influence than demographic factors on aggression experienced by beavers.

  Conspecific Aggression by Beavers (Castor canadensis) in the Sangamon River Basin in Central Illinois: Correlates with Habitat

  Age

  Sex and Season

  Clayton K. Nielsen

  Dana J. Morin

  Humans alter landscapes and native species distributions in many ways

  including alterations\nmediated via domestic pets. While the negative impacts of domestic cats are well\ndocumented worldwide

  the ecological effects of domestic dogs have received less scientific\nattention

  particularly in the United States. Prevalence of free-ranging dogs may be\nespecially problematic in areas with low density

  but relatively ubiquitous human populations.\nWe used camera-trap data collected during a 2008e2010 landscape-scale study\nconsisting of 1181 camera stations (357 camera clusters) stratified over 16 counties in\nsouthern Illinois

  USA

  to estimate occupancy for domestic cats and dogs. We compared\nmodels of occupancy for three land cover types (forest

  grassland

  and wetland) in relation\nto anthropogenic features and estimated and compared the proportion of the region\noccupied by each species. Cats occurred across a moderate proportion of the landscape (j\n¼ 0.44 ± 0.13 SE) and were associated with anthropogenic features. Moreover

  we found\ndomestic dog occupancy was greater across the landscape (j ¼ 0.59 ± 0.09)

  influenced\nmore generally by land cover type

  and was highest on grasslands and privately owned\nland. Domestic cat occupancy was more localized than that of dogs and less influenced by\nland cover type compared to anthropogenic features. Model averaged probability of dog\noccupancy was >0.50 across 19

  049.39 km2 of the region (>99%)

  but only 2270.53 km2\n(11.8%) for cats. Thus

  while domestic cats may pose a more intensive threat to wildlife\nwithin the area they occupy

  the impact of domestic dogs is likely to be more geographically\nextensive. Predicting the potential effects of these non-native species is complicated\nby a nuanced interaction between landscape composition

  human density

  and human\nbehavior

  and upends simplistic perceptions of the relative threats posed by the two\nspecies.

  The truth about cats and dogs: landscape composition and human occupation mediate the distribution and potential impact of non-native carnivores

  Eric Hellgren

  Scott Cooney

  Journal of Mammalogy

  Marsh rice rats are a southeastern U.S. species that depends of wetlands

  so much of their habitat has been altered

  destroyed

  and fragmented over time. Here

  we provide the largest published dataset on movement and space use of marsh rice rats

  and show that although they select wetland habitats (as expected)

  they also spend a surprising amount of time traveling and nesting in upland grassy habitats. Further

  we present the largest published estimates of home range size for the species

  supporting the notion that they are highly mobile even through non-wetland habitat.

  Ranging behavior of marsh rice rats in a southern Illinois wetland complex

  Clayton Nielsen

  Preston Feltrop

  American Midland Naturalist

  We provide the first published documentation of Asian (silver and bighead) carp in the diet of river otters

  from scats collected in 2013-14. We also found that the relative importance of crayfish in their diet was higher during warmer months

  but broad diet categories (fish

  crayfish

  and other) did not appear to differ among streams based on landcover (e.g.

  agricultural vs. forested areas)

  Asian carp in the diet of river otters in Illinois

  Lagomorphs are important consumers and prey in ecosystems worldwide

  but have declined due to land use changes and habitat loss

  and such losses may be exacerbated for specialist species. We compared survival and habitat use of two closely related lagomorphs

  the swamp rabbit (Sylvilagus aquaticus (Bachman

  1837))

  a bottomland hardwood (BLH) forest specialist

  and the eastern cottontail (Sylvilagus floridanus (J. A. Allen

  1890))

  a habitat generalist. We tested whether survival and habitat use differed between radio-collared swamp rabbits (n = 129) and eastern cottontails (n = 72) monitored during December 2009 – December 2013 in southern Illinois. We found interactive effects of species and season on survival rates: swamp rabbits had higher annual survival (0.37 ± 0.05 (estimate ± SE)) than did cottontails (0.20 ± 0.05)

  but this difference occurred primarily during the growing season. Swamp rabbits were located closer to watercourses in areas characterized by higher basal area and more mature BLH forest cover compared with eastern cottontails. Our results suggest that BLH forests may be marginal habitat for cottontails and indicate predation as the primary cause of mortality for both species. Swamp rabbits use of early-successional BLH forest suggests that restoration efforts have been successful. However

  as specialists

  swamp rabbits remain restricted to a narrow band of bottomlands near watercourses and may benefit from improved upland cover that serves as refugia from flooding.

  Survival and habitat use of sympatric lagomorphs in bottomland hardwood forests

  Clayton K. Nielsen

  Allison C. Edmund

  In North America

  native lagomoprhs that are habitat specialist are of conservation concern due to loss\nof habitat and fragmentation

  population declines

  and their importance in food webs. Moreover

  lagomorphs\noccupying range edges are especially vulnerable to environmental conditions given changes in\nclimate. We evaluated the influence of snow cover on winter mortality for 136 swamp rabbits (Sylvilagus\naquaticus) monitored 2009–2016 in southern Illinois

  USA. Winter estimates of daily mortality rates\nwere at least five times higher (P = 0.03) on snow-covered days (x=0.033

  SE = 0.009) than snow-free days\n(x=0.004

  SE = 0.001). Winter estimates of daily mortality rates due to predation were at least twice as\nhigh (P = 0.08) on snow-covered days (x=0.027

  SE = 0.010) than snow-free days (x= 0.003

  SE = 0.000).\nSwamp rabbit mortality was higher on snow-covered days primarily via elevated levels of predation.\nSnow cover might limit the availability of hiding cover and food resources for swamp rabbits

  thereby\nincreasing their movements and vulnerability to predators

  especially given their pelage coloration.

  Winter snow cover increases swamp rabbit (Sylvilagus aquaticus) mortality at the northern extent of their range

  Clayton K. Nielsen

  Erin L. Koen

  Intraspecific social behavior can be influenced by both intrinsic and extrinsic factors. While\nmuch research has focused on how characteristics of individuals influence their roles in\nsocial networks

  we were interested in the role that landscape structure plays in animal sociality\nat both individual (local) and population (global) levels. We used female white-tailed\ndeer (Odocoileus virginianus) in Illinois

  USA

  to investigate the potential effect of landscape\non social network structure by weighting the edges of seasonal social networks with association\nrate (based on proximity inferred from GPS collar data). At the local level

  we found\nthat sociality among female deer in neighboring social groups (n = 36) was mainly explained\nby their home range overlap

  with two exceptions: 1) during fawning in an area of mixed forest\nand grassland

  deer whose home ranges had low forest connectivity were more social\nthan expected; and 2) during the rut in an area of intensive agriculture

  deer inhabiting home\nranges with high amount and connectedness of agriculture were more social than expected.\nAt the global scale

  we found that deer populations (n = 7) in areas with highly connected forest-\nagriculture edge

  a high proportion of agriculture

  and a low proportion of forest tended\nto have higher weighted network closeness

  although low sample size precluded statistical\nsignificance. This result implies that infectious disease could spread faster in deer populations\ninhabiting such landscapes. Our work advances the general understanding of animal\nsocial networks

  demonstrating how landscape features can underlie differences in social\nbehavior both within and among wildlife social networks.

  Does landscape connectivity shape local and global social network structure in white-tailed deer?

  Clayton K. Nielsen

  By deploying both GPS collars and proximity loggers on white-tailed deer

  we show that female deer in neighboring social groups often are found within 10 m of each other

  but very rarely approach within 1 m. In contrast

  females in the same social group have high contact rates at both 10 m and 1 m proximity levels. Finally

  we find suggestive evidence that deer that are unfamiliar with each other are much more likely than near neighbors to make close contact (1 m) on the rare occasions when they are within 10 m. These findings show that prior work using GPS locations with 10 m to infer contacts greatly underestimate the effect of social group membership on contact rates. They also suggest that home range overlap may not be a good predictor of potential direct disease transmission between groups.

  FAMILIARITY BREEDS CONTEMPT: COMBINING PROXIMITY LOGGERS AND GPS REVEALS FEMALE WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) AVOIDING CLOSE CONTACT WITH NEIGHBORS

  Raymond W. Moody

  To our knowledge

  hatchling over-wintering behavior has\nnot been documented for Phrynosoma

  and our data indicate\nkey differences in behavior between life stages. Hatchlings are\ngenerally understudied

  and our observations contribute to the\ngap in knowledge about their movements and behavior.

  Phrynosoma cornutum (Texas horned lizard) Behavior

  Clayton K. Nielsen

  Matthew Springer

  Mortality rates of white-tailed deer (Odocoileus virginianus (Zimmermann

  1780)) fawns have been quantified throughout North America. Few studies

  however

  have assessed cause-specific mortality of fawns after the first 3 months of life or during a severe weather event. During 2010–2014

  we captured and radio-tracked 93 fawns in southern and central Illinois and recorded 18 mortality events. In order of importance

  survival rates were affected by days since capture

  year of drought

  age at capture

  week after capture (1 or 0 indicator)

  and region. Estimated overwinter (fall through spring) survival rate (±SE) of fawns in both regions during 2010–2014 was 0.83 ± 0.04. However

  estimated overwinter survival rates were depressed during 2012–2013

  following the severe drought of 2012 (0.63 ± 0.11 or 0.66 ± 0.11 depending on the model). Main causes of mortality were capture-related and predation

  though some dead deer also showed signs of hemorrhagic disease. We suspect that the extreme drought of 2012 created favorable conditions for fall–spring mortality of fawns

  due to elevated disease transmission and lower forage quality and quantity for deer. In addition

  drought may have contributed to predation by reducing abundance of alternative prey. Our results suggest that severe weather conditions during summer can substantially impact overwinter fawn survival.

  Increased overwinter mortalities of white-tailed deer (Odocoileus virginianus) fawns during a drought year

  Clayton K. Nielsen

  Alex T. Hanrahan

  River otter (Lontra canadensis) populations in Illinois have rebounded\nconsiderably after .80 y of harvest protection and a successful re-introduction program.\nHowever

  few studies of river otter survival ecology exist in the Midwestern U.S. We estimated\nsurvival rates and mortality causes for river otters in southern Illinois during 2014–2016.\nThirty-four (16 F

  18 M) river otters were radio-marked and monitored for 8235 radio-days (¯x\ndays/river otter ¼ 242.2 6 20.6 [SE throughout]). Two males died (one trapped

  one\nunknown) during the period of radio-telemetry monitoring. Annual survival rates were 1.0 6\n0.00 (lower confidence bound ¼ 0.83) and 0.85 6 0.09 for females and males

  respectively

  \nand similar between sexes (P ¼ 0.19). Pooled-sex breeding season survival was 0.96 6 0.04.\nTrapping was the primary cause of mortality during our study

  and three river otters were\nkilled after radio-telemetry ended: two were harvested by recreational trappers and one by a\nvehicle collision. These primary mortality sources (i.e.

  trapping and vehicle collisions) for\nriver otters in southern Illinois were similar to those reported elsewhere

  but the high survival\nwe observed is similar to published estimates for unexploited populations. Our study provides\nuseful demographic information for river otter management in lightly harvested populations\nin the Midwest.

  Survival and cause-specific mortality of river otters in southern Illinois

  Eric Hellgren

  Jorista van der Merwe

  Ecosphere

  We used multi-season occupancy modeling to compare how marsh rice rat metapopulations in floodplain and upland wetland complexes respond to massive hydrological fluctuations (record breaking floods

  followed by record drought) over a 3 year span. Colonization and extinction rates were influenced by prior rainfall

  and extinction was more sensitive to hydrology in the floodplain complex. However

  rice rats were more abundant overall in the floodplain

  apparently benefiting from enhanced productivity in these dynamic floodplain habitats.

  Variation in metapopulation dynamics of a wetland mammal: The effect of hydrology.

  Eric C. Hellgren

  Scott Cooney

  Landscape Ecology

  The marsh rice rat is a wetland species that must cross uplands to disperse between habitats. By collectively marking rats within wetlands and trapping various distances int upland areas

  we found that marsh rice rats actually entered soybean fields more often and penetrated them to greater distances than was the case for wooded or grassland areas. This is the first documented use of crop fields or woodlands by this species

  and supports the hypothesis that areas that are less suitable as habitat may be more permeable to dispersing animals

  because animals move faster through such areas.

  Comparing permeability of matrix cover types for the marsh rice rat (Oryzomys palustris)

  Clayton Nielsen

  Brianna K. Tallitsch

  Jorista van der Merwe

  Justin Shew

  Behavioral Ecology and Sociobiology

  This study used repeated observations of red-winged blackbird nest defense behaviors to test 3 hypotheses to explain why they tend to become more aggressive later in the nesting season: 1) increased value of older offspring (nest age)

  2) reduced opportunity for renesting later in the nesting season (initiation date)

  and 3) reduced fear of human observers after repeated exposure (visit #). We used within-individual and between-individual centering to decompose differences between individuals observed at different times vs. the same individual observed multiple times. \n\nAggression by males was most strongly tied to nest age

  but the relationship with nest age was weaker later in the nesting season. Aggression by females was less predictable and showed evidence for all three competing hypotheses

  but nest age (as for males) was the strongest predictor. Additional factors

  such as clutch/brood size

  nest density

  and nest concealment

  appeared to have larger predictive roles in explaining female aggression relative to males.

  A classic question revisited in red-winged blackbirds: disentangling confounding hypotheses surrounding parental investment theory and nest defense intensity

  Raymond W. Moody

  Victor Bogosian III

  Brett DeGregorio

  Monika Burchett

  To our knowledge

  A. contortrix and L. holbrooki and have never\nbefore been confirmed as P. cornutum predators.

  Phrynosoma cornutum (Texas horned lizard) Predation

  Clayton Nielsen

  Lyann Corcoran

  Swamp rabbits in southern Illinois are at the northern limit of the species' geographic range

  and the bottomland hardwood forests they depend on have been greatly reduced and fragmented. We used up-to-date empirical estimates of swamp rabbit space use

  survival rates

  and movement potential to estimate their likelihood of persisting in the state. Fortunately

  our model suggests that the rabbits have a high likelihood of persisting

  unless survival and reproductive rates have been substantially overestimated.

  Metapopulation viability of swamp rabbits in southern Illinois: Potential impacts of habitat change

  Eric C. Hellgren

  Clayton K. Nielsen

  Angela Holland

  Streams and adjacent riparian habitats represent linked terrestrial and aquatic ecosystems\nthat exchange materials and energy. Recognized relationships among apex\npredators and ecosystem biodiversity led us to hypothesize that these predators in\nriparian-stream systems were more likely to be found in sites with high stream quality

  \ndefined as increased ecosystem function and integrity. In our freshwater study\nsystem

  river otter Lontra canadensis and mink Neovison vison play critical roles as apex\npredators. We used multi-season occupancy modelling across three sampling years\n(2012–2014) to compare aspects of the stream communities that explain occupancy\ndynamics of river otter and mink

  including their interactions with other semi-aquatic\nmammals. We surveyed for semi-aquatic mammals at 77 sites in 12 major watersheds\nin southern Illinois

  USA (44 526 km2). Naïve occupancy differed among years but\ngenerally increased for river otter

  and remained high (≥93.5%) for mink. Increasing\nsubstrate availability increased detectability of river otter

  whereas mink detection varied\nby survey period. Occupancy of river otter during the initial survey period was\nhigher in sites closer to reintroduction points. Probability of colonization of river\notter was positively associated with macroinvertebrate index of biotic integrity

  fish\nspecies richness

  and beaver presence. Sites with high species richness of fish families\npreferred by river otter also had increased river otter persistence. Mink occupied sites\nwith increased fish richness

  muskrat presence and mussel community index. Taken\ntogether

  our results show occupancy of both mink and river otter were predicted by\naspects of prey diversity and presence

  indicating the importance of community composition\nin occupancy dynamics of riparian predators.

  Stream quality and community richness predict apex predator occupancy in riparian systems

  Eric

  Schauber

  Illinois Natural History Survey