Brian Tanis - Academia.edu (original) (raw)
Papers by Brian Tanis
Scientific Reports, May 17, 2022
Endangered animals in captivity may display reduced brain sizes due to captive conditions and lim... more Endangered animals in captivity may display reduced brain sizes due to captive conditions and limited genetic diversity. Captive diets, for example, may differ in nutrition and texture, altering cranial musculature and alleviating constraints on cranial shape development. Changes in brain size are associated with biological fitness, which may limit reintroduction success. Little is known about how changes in brain size progress in highly managed carnivoran populations and whether such traits are retained among reintroduced populations. Here, we measured the endocranial volume of preserved Mexican wolf skulls across captive generations and between captive, wild, and reintroduced populations and assessed endocranial volume dependence on inbreeding and cranial musculature. Endocranial volume increased across captive generations. However, we did not detect a difference among captive, wild, and reintroduced groups, perhaps due to the variability across captive generations. We did not find a relationship between endocranial volume and either inbreeding or cranial musculature, although the captive population displayed an increase in the cross-sectional area of the masseter muscle. We hypothesize that the increase in endocranial volume observed across captive generations may be related to the high-quality nutrition provided in captivity. The relative endocranial volume of the vertebrate skull varies within and between populations of a species 1-3. Given its intricate relationship with brain size and structure, endocranial volume has been linked to differences in behavior, performance, and fitness 2,4. Changes in endocranial volume may have significant consequences for the viability of a population 1,5,6. Within captive populations, endocranial volumes have been documented to increase [e.g., 7 ], decrease [e.g., 7-9 ], and in some cases show no discernable difference [e.g., 10,11 ]. Most frequently, the reported changes occurring in captivity have been related to a reduction in endocranial volume [e.g., 7-9 ], which has been attributed to improper diets, socially and environmentally depauperate enclosures, or lack of stimulating enrichment activities 5,12,13. The nature of this relationship has been poorly documented in carnivoran species, particularly those that are intensively managed and bred for reintroduction initiatives. Measurements of endocranial volume provide a useful and widely used proxy for brain size 14,15. These measurements are often correlated with social behaviors and other traits related to learning, memory, problem-solving, and behavioral flexibility 1,4,16 and may also influence traits directly related to fitness, including longevity and fecundity 6,8. Changes in endocranial volume are not necessarily proportional across all brain structures 16,17. For example, domestic dogs show disproportionate decreases to the neocortex and olfactory bulb associated with a smaller endocranial volume (roughly 30%) compared to their wild counterparts [ 18 ; although see 19 ]. Disproportionate changes in endocranial volume may significantly influence cognition and important sensory functions 16,20. Within wild vertebrate populations, environmental variables have been linked to intraspecific variation in brain size, including seasonality, environmental severity, habitat complexity, and urbanization 3,15,21. However, brain tissue is metabolically expensive to maintain; therefore, intraspecific increases in brain size are primarily thought to occur under intense selection pressure or when ample resources are available, which can enable increased development without risking other aspects of fitness 3,5,8. Resource limitations are thought to constrain brain size in wild populations 3,8. However, in managed populations, where ample nutrient-rich diets may be readily and consistently available, and where energetically expensive activities are eliminated (e.g. foraging costs
1. Given the long and dynamic history of anthropogenic disturbances to ecosystems, it is difficul... more 1. Given the long and dynamic history of anthropogenic disturbances to ecosystems, it is difficult to determine the drivers of past population declines. These uncertainties dilute the efficacy of conservation efforts and might hinder species and ecosystem recovery. 2. Niche quantification can be a useful tool for understanding drivers of past population declines. Niche parameters reflect key resources used, providing insight into the conditions needed to achieve population stability. By reconstructing a population's niche position and space over a period of decline and comparing to historic baselines, shifts in the realized niche of a species can be assessed. Comparing shifts to historic information on resource availability and timing of declines can allow practitioners to identify probable drivers of species decline. 3. We demonstrated the utility of this technique by reconstructing parameters of isotopic dietary niche over a 130 year period and comparing isotopic niche reconst...
Southeastern Naturalist, 2021
Abstract Spilogale putorius (Eastern Spotted Skunk) experienced range-wide population declines be... more Abstract Spilogale putorius (Eastern Spotted Skunk) experienced range-wide population declines beginning in the mid-1900s with no clear understanding of the causal mechanism or whether such declines were associated with range contractions. Species-distribution models can provide a powerful framework to assess changes in landscape suitability in response to changing environmental conditions. Herein, we modeled time-stepped distributions of suitable environmental conditions for Eastern Spotted Skunks from 1938 to 2016 in Maxent, incorporating climate and land-cover predictors. Climate and land-cover variables reliably predicted landscape suitability of Eastern Spotted Skunks over time. We found a 37% decline in suitable area from historic predictions, consistent with reports of population declines in these areas. Our predicted landscape-suitability maps can be used to evaluate the current distribution of environmentally suitable conditions for the species as well as guide research and conservation efforts.
Wind energy is among the most rapidly growing energy industries in the United States, with suppor... more Wind energy is among the most rapidly growing energy industries in the United States, with support for development coming from both state and federal governments. While the industry depicts an environmentally friendly image, the addition of infrastructure associated with wind farms alters landscapes in novel ways. Numerous studies have documented impacts wind turbines have on bird and bat mortality; however, far less attention has been directed towards responses of non-volant, terrestrial organisms. Mammalian mesocarnivores are model organisms to assess the alteration of communities surrounding wind turbines as they respond to addition of turbines and human activity, addition and improvement of roadways, and increases in turbine-induced carrion. In September 2011, I established a yearlong study surrounding the Central Plains Wind Facility in western Kansas to document patterns associated with the occupancy of terrestrial mammals within turbine and turbine-free habitats. I placed 34 scent-baited trail cameras among turbine and control habitats, with a randomly placed subset along roadways. Detection histories during 28-day survey periods and habitat covariates were analyzed with PRESENCE 5.5. Canis latrans and Vulpes velox were the most abundant mesocarnivores detected. Canis latrans had a higher probability of occupancy at the control area, while V. velox had higher probabilities of occupancy at the turbine area. Detection probabilities were impacted strongly by mean precipitation as well as between field and roadway locations for V. velox. Vulpes velox detection probabilities were conditional on C. latrans presence and detection, although the two species occupied sites independently. iv ACKNOWLEDGMENTS There are numerous people who helped in the completion of this project. First I thank my advisor, Dr. Elmer J. Finck, without whose insight and assistance with the many questions, concerns, and problems I brought to him I would never have gotten off the ground. His constant support and belief in me was instrumental in all my work. I also thank my graduate committee, Dr. Rob Channell, Dr. Greg Farley, and Matt Peek. Their assistance with the direction of the project, finding funding sources, and statistical analysis was crucial in moving forward. A special thanks to Westar Energy and their Green Team including Brad Loveless, Chris Mammoliti, Rick Mastel, and Ken Smith. By recognizing the need for understanding their ecosystem interactions and community development they are moving the industry in a positive direction. I thank Eric Johnson from the Kansas Department of Wildlife, Parks, and Tourism, for his interest in my project and helping me contact the right people. I acknowledge my funding sources, the Kansas Department of Wildlife, Parks, and Tourism Chickadee Checkoff Program and the American Society of Mammalogists Grants-In-Aid of Research. I also thank the numerous landowners willing to allow a strange, east-coast student on their lands and in their crops to photograph mammals. I also thank Dr. Brett Sandercock for some key suggestions for analyzing my data. I thank everyone in the Department of Biological Sciences at Fort Hays State University, including the Sternberg Museum of Natural History and the Kansas Wetlands Education Center. The faculty and staff helped with teaching me all aspects of being a v professional biologist, to which I am sincerely appreciative. To all of my graduate student colleagues, especially Amanda Cheeseman, Brandon Calderon, and Brian Gaston, I thank for providing free labor, helpful insight, and open ears. I also thank my friends and family for all of their love and support during the good and difficult time alike. Finally, I thank my parents, Patricia Tanis and Leonard Tanis, without whom all this would never have been possible. They put up with my stubbornness, taught me the wonders of the world, and to follow my dreams relentlessly. I am eternally grateful. vi
eLife, 2021
March Mammal Madness is a science outreach project that, over the course of several weeks in Marc... more March Mammal Madness is a science outreach project that, over the course of several weeks in March, reaches hundreds of thousands of people in the United States every year. We combine four approaches to science outreach – gamification, social media platforms, community event(s), and creative products – to run a simulated tournament in which 64 animals compete to become the tournament champion. While the encounters between the animals are hypothetical, the outcomes rely on empirical evidence from the scientific literature. Players select their favored combatants beforehand, and during the tournament scientists translate the academic literature into gripping “play-by-play” narration on social media. To date ~1100 scholarly works, covering almost 400 taxa, have been transformed into science stories. March Mammal Madness is most typically used by high-school educators teaching life sciences, and we estimate that our materials reached ~1% of high-school students in the United States in 2...
Palaeogeography, Palaeoclimatology, Palaeoecology, 2018
Dental microwear textures across cheek teeth in canids: implications for dietary studies of
PeerJ
Anti-predator behaviors like vigilance or hiding come at the expense of other fitness increasing ... more Anti-predator behaviors like vigilance or hiding come at the expense of other fitness increasing behaviors such as foraging. To compensate for this trade-off, prey assess predation risk and modify the frequency of anti-predator behaviors according to the likelihood of the threat. In this study, we tested the ability of house crickets (Acheta domesticus) to indirectly assess predation risk via odors from a mammalian predator, Elliot’s short-tailed shrew (Blarina hylophaga). As natural differences in encounter rates and predation risk differs between sexes, we tested if male and female crickets perceive similar rates of predation risk from the presence of shrew odor measured via anti-predator behavioral response. Crickets were placed in enclosed, cardboard-lined chambers either treated with shrew odor or control, along with a food source. Time until foraging was measured for each individual and compared across treatment and sex. We found that in the presence of shrew odor, female cric...
Scientific Reports, May 17, 2022
Endangered animals in captivity may display reduced brain sizes due to captive conditions and lim... more Endangered animals in captivity may display reduced brain sizes due to captive conditions and limited genetic diversity. Captive diets, for example, may differ in nutrition and texture, altering cranial musculature and alleviating constraints on cranial shape development. Changes in brain size are associated with biological fitness, which may limit reintroduction success. Little is known about how changes in brain size progress in highly managed carnivoran populations and whether such traits are retained among reintroduced populations. Here, we measured the endocranial volume of preserved Mexican wolf skulls across captive generations and between captive, wild, and reintroduced populations and assessed endocranial volume dependence on inbreeding and cranial musculature. Endocranial volume increased across captive generations. However, we did not detect a difference among captive, wild, and reintroduced groups, perhaps due to the variability across captive generations. We did not find a relationship between endocranial volume and either inbreeding or cranial musculature, although the captive population displayed an increase in the cross-sectional area of the masseter muscle. We hypothesize that the increase in endocranial volume observed across captive generations may be related to the high-quality nutrition provided in captivity. The relative endocranial volume of the vertebrate skull varies within and between populations of a species 1-3. Given its intricate relationship with brain size and structure, endocranial volume has been linked to differences in behavior, performance, and fitness 2,4. Changes in endocranial volume may have significant consequences for the viability of a population 1,5,6. Within captive populations, endocranial volumes have been documented to increase [e.g., 7 ], decrease [e.g., 7-9 ], and in some cases show no discernable difference [e.g., 10,11 ]. Most frequently, the reported changes occurring in captivity have been related to a reduction in endocranial volume [e.g., 7-9 ], which has been attributed to improper diets, socially and environmentally depauperate enclosures, or lack of stimulating enrichment activities 5,12,13. The nature of this relationship has been poorly documented in carnivoran species, particularly those that are intensively managed and bred for reintroduction initiatives. Measurements of endocranial volume provide a useful and widely used proxy for brain size 14,15. These measurements are often correlated with social behaviors and other traits related to learning, memory, problem-solving, and behavioral flexibility 1,4,16 and may also influence traits directly related to fitness, including longevity and fecundity 6,8. Changes in endocranial volume are not necessarily proportional across all brain structures 16,17. For example, domestic dogs show disproportionate decreases to the neocortex and olfactory bulb associated with a smaller endocranial volume (roughly 30%) compared to their wild counterparts [ 18 ; although see 19 ]. Disproportionate changes in endocranial volume may significantly influence cognition and important sensory functions 16,20. Within wild vertebrate populations, environmental variables have been linked to intraspecific variation in brain size, including seasonality, environmental severity, habitat complexity, and urbanization 3,15,21. However, brain tissue is metabolically expensive to maintain; therefore, intraspecific increases in brain size are primarily thought to occur under intense selection pressure or when ample resources are available, which can enable increased development without risking other aspects of fitness 3,5,8. Resource limitations are thought to constrain brain size in wild populations 3,8. However, in managed populations, where ample nutrient-rich diets may be readily and consistently available, and where energetically expensive activities are eliminated (e.g. foraging costs
1. Given the long and dynamic history of anthropogenic disturbances to ecosystems, it is difficul... more 1. Given the long and dynamic history of anthropogenic disturbances to ecosystems, it is difficult to determine the drivers of past population declines. These uncertainties dilute the efficacy of conservation efforts and might hinder species and ecosystem recovery. 2. Niche quantification can be a useful tool for understanding drivers of past population declines. Niche parameters reflect key resources used, providing insight into the conditions needed to achieve population stability. By reconstructing a population's niche position and space over a period of decline and comparing to historic baselines, shifts in the realized niche of a species can be assessed. Comparing shifts to historic information on resource availability and timing of declines can allow practitioners to identify probable drivers of species decline. 3. We demonstrated the utility of this technique by reconstructing parameters of isotopic dietary niche over a 130 year period and comparing isotopic niche reconst...
Southeastern Naturalist, 2021
Abstract Spilogale putorius (Eastern Spotted Skunk) experienced range-wide population declines be... more Abstract Spilogale putorius (Eastern Spotted Skunk) experienced range-wide population declines beginning in the mid-1900s with no clear understanding of the causal mechanism or whether such declines were associated with range contractions. Species-distribution models can provide a powerful framework to assess changes in landscape suitability in response to changing environmental conditions. Herein, we modeled time-stepped distributions of suitable environmental conditions for Eastern Spotted Skunks from 1938 to 2016 in Maxent, incorporating climate and land-cover predictors. Climate and land-cover variables reliably predicted landscape suitability of Eastern Spotted Skunks over time. We found a 37% decline in suitable area from historic predictions, consistent with reports of population declines in these areas. Our predicted landscape-suitability maps can be used to evaluate the current distribution of environmentally suitable conditions for the species as well as guide research and conservation efforts.
Wind energy is among the most rapidly growing energy industries in the United States, with suppor... more Wind energy is among the most rapidly growing energy industries in the United States, with support for development coming from both state and federal governments. While the industry depicts an environmentally friendly image, the addition of infrastructure associated with wind farms alters landscapes in novel ways. Numerous studies have documented impacts wind turbines have on bird and bat mortality; however, far less attention has been directed towards responses of non-volant, terrestrial organisms. Mammalian mesocarnivores are model organisms to assess the alteration of communities surrounding wind turbines as they respond to addition of turbines and human activity, addition and improvement of roadways, and increases in turbine-induced carrion. In September 2011, I established a yearlong study surrounding the Central Plains Wind Facility in western Kansas to document patterns associated with the occupancy of terrestrial mammals within turbine and turbine-free habitats. I placed 34 scent-baited trail cameras among turbine and control habitats, with a randomly placed subset along roadways. Detection histories during 28-day survey periods and habitat covariates were analyzed with PRESENCE 5.5. Canis latrans and Vulpes velox were the most abundant mesocarnivores detected. Canis latrans had a higher probability of occupancy at the control area, while V. velox had higher probabilities of occupancy at the turbine area. Detection probabilities were impacted strongly by mean precipitation as well as between field and roadway locations for V. velox. Vulpes velox detection probabilities were conditional on C. latrans presence and detection, although the two species occupied sites independently. iv ACKNOWLEDGMENTS There are numerous people who helped in the completion of this project. First I thank my advisor, Dr. Elmer J. Finck, without whose insight and assistance with the many questions, concerns, and problems I brought to him I would never have gotten off the ground. His constant support and belief in me was instrumental in all my work. I also thank my graduate committee, Dr. Rob Channell, Dr. Greg Farley, and Matt Peek. Their assistance with the direction of the project, finding funding sources, and statistical analysis was crucial in moving forward. A special thanks to Westar Energy and their Green Team including Brad Loveless, Chris Mammoliti, Rick Mastel, and Ken Smith. By recognizing the need for understanding their ecosystem interactions and community development they are moving the industry in a positive direction. I thank Eric Johnson from the Kansas Department of Wildlife, Parks, and Tourism, for his interest in my project and helping me contact the right people. I acknowledge my funding sources, the Kansas Department of Wildlife, Parks, and Tourism Chickadee Checkoff Program and the American Society of Mammalogists Grants-In-Aid of Research. I also thank the numerous landowners willing to allow a strange, east-coast student on their lands and in their crops to photograph mammals. I also thank Dr. Brett Sandercock for some key suggestions for analyzing my data. I thank everyone in the Department of Biological Sciences at Fort Hays State University, including the Sternberg Museum of Natural History and the Kansas Wetlands Education Center. The faculty and staff helped with teaching me all aspects of being a v professional biologist, to which I am sincerely appreciative. To all of my graduate student colleagues, especially Amanda Cheeseman, Brandon Calderon, and Brian Gaston, I thank for providing free labor, helpful insight, and open ears. I also thank my friends and family for all of their love and support during the good and difficult time alike. Finally, I thank my parents, Patricia Tanis and Leonard Tanis, without whom all this would never have been possible. They put up with my stubbornness, taught me the wonders of the world, and to follow my dreams relentlessly. I am eternally grateful. vi
eLife, 2021
March Mammal Madness is a science outreach project that, over the course of several weeks in Marc... more March Mammal Madness is a science outreach project that, over the course of several weeks in March, reaches hundreds of thousands of people in the United States every year. We combine four approaches to science outreach – gamification, social media platforms, community event(s), and creative products – to run a simulated tournament in which 64 animals compete to become the tournament champion. While the encounters between the animals are hypothetical, the outcomes rely on empirical evidence from the scientific literature. Players select their favored combatants beforehand, and during the tournament scientists translate the academic literature into gripping “play-by-play” narration on social media. To date ~1100 scholarly works, covering almost 400 taxa, have been transformed into science stories. March Mammal Madness is most typically used by high-school educators teaching life sciences, and we estimate that our materials reached ~1% of high-school students in the United States in 2...
Palaeogeography, Palaeoclimatology, Palaeoecology, 2018
Dental microwear textures across cheek teeth in canids: implications for dietary studies of
PeerJ
Anti-predator behaviors like vigilance or hiding come at the expense of other fitness increasing ... more Anti-predator behaviors like vigilance or hiding come at the expense of other fitness increasing behaviors such as foraging. To compensate for this trade-off, prey assess predation risk and modify the frequency of anti-predator behaviors according to the likelihood of the threat. In this study, we tested the ability of house crickets (Acheta domesticus) to indirectly assess predation risk via odors from a mammalian predator, Elliot’s short-tailed shrew (Blarina hylophaga). As natural differences in encounter rates and predation risk differs between sexes, we tested if male and female crickets perceive similar rates of predation risk from the presence of shrew odor measured via anti-predator behavioral response. Crickets were placed in enclosed, cardboard-lined chambers either treated with shrew odor or control, along with a food source. Time until foraging was measured for each individual and compared across treatment and sex. We found that in the presence of shrew odor, female cric...