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Full-Text Articles in Ecology and Evolutionary Biology

Electrophysiological Studies Of Olfaction In The Whip Spider Phrynus Parvulus (Arachnida, Amblypygi), Eileen Hebets, Reginald F. Chapman Nov 2000

Electrophysiological Studies Of Olfaction In The Whip Spider Phrynus Parvulus (Arachnida, Amblypygi), Eileen Hebets, Reginald F. Chapman

Eileen Hebets Publications

The olfactory response of the whip spider Phrynus parvulus from Costa Rica was examined using a technique analogous to that used for insect electroantennograms on the tarsi of the antenniform legs which bear multiporous sensilla. Responses to 42 chemicals representing different chain lengths of alkanes, carboxylic acids, alcohols, aldehydes, and ketones, as well as some esters, monoterpenes, and phenolics were examined. Fifty-four percent of the chemicals tested elicited responses. Concentration–response curves were generated for guaiacol, hexanal, methyl salicylate, benzaldehyde, octanoic acid, and linalool. Guaiacol, benzaldehyde, and hexanol elicited the greatest responses and no differences were detected between the sexes. Compounds …


An Analysis Of Migratory Behavior Physiological Condition And Life History Strategy In The Salamanders Ambystoma Mabeei And A. Opacum In Southeastern Virginia, Michael W. Mccoy Oct 2000

An Analysis Of Migratory Behavior Physiological Condition And Life History Strategy In The Salamanders Ambystoma Mabeei And A. Opacum In Southeastern Virginia, Michael W. Mccoy

Biological Sciences Theses & Dissertations

Ambystoma mabeei is listed as threatened in Virginia due to its rarity and susceptibility to urbanization and poor forestry practices. The goal of this study was to identify factors that may affect the persistence of A. mabeei in Virginia by studying the life history and ecology of A. mabeei and its syntopic congener A. opacum. This information will contribute to the knowledge of life history variation within Ambystomatidae and will be critical for the development of a comprehensive management plan for A. mabeei. Population sizes of the two species and the proximate factors responsible for initiating breeding migrations were determined …


Mixing At Young Ages Reduces Fighting In Unacquainted Domestic Pigs, Anton D. Pitts, Daniel M. Weary, Edmond A. Pajor, David Fraser Jun 2000

Mixing At Young Ages Reduces Fighting In Unacquainted Domestic Pigs, Anton D. Pitts, Daniel M. Weary, Edmond A. Pajor, David Fraser

Agonistic Behavior Collection

Under normal farming practices, piglets from different litters are often mixed around the time of weaning, and a high incidence of fighting and minor injuries often occur. The aim of this experiment was to determine the effect of age on the incidence of fighting in piglets mixed before weaning, at different ages between 5 and 26 days. We found no significant relationship between age and the likelihood that a pair of piglets would fight during the first 75 min after mixing. However, the duration of the first fight observed increased from 101±38 s at 5 days to 621±278 s at …


Bubble Ring Play Of Bottlenose Dolphins (Tursiops Truncatus): Implications For Cognition, Brenda Mccowan, Lori Marino, Erik Vance, Leah Walke, Diana Reiss Mar 2000

Bubble Ring Play Of Bottlenose Dolphins (Tursiops Truncatus): Implications For Cognition, Brenda Mccowan, Lori Marino, Erik Vance, Leah Walke, Diana Reiss

Sentience Collection

Research on the cognitive capacities of dolphins and other cetaceans (whales and porpoises) has importance for the study of comparative cognition, particularly with other large-brained social mammals, such as primates. One of the areas in which cetaceans can be compared with primates is that of object manipulation and physical causality, for which there is an abundant body of literature in primates. The authors supplemented qualitative observations with statistical methods to examine playful bouts of underwater bubble ring production and manipulation in 4 juvenile male captive bottlenose dolphins (Tursiops truncatus). The results are consistent with the hypothesis that dolphins monitor the …


Surviving The Flood: Plastron Respiration In The Non-Tracheate Arthropod Phrynus Marginemaculatus (Amblypygi: Arachnida), Eileen Hebets, Reginald F. Chapman Jan 2000

Surviving The Flood: Plastron Respiration In The Non-Tracheate Arthropod Phrynus Marginemaculatus (Amblypygi: Arachnida), Eileen Hebets, Reginald F. Chapman

Eileen Hebets Publications

Specimens of Phrynus marginemaculatus can remain responsive when submerged in water for more than 24 hours. Behavioral data indicate that P. marginemaculatus utilizes dissolved oxygen from the surrounding water. Scanning electron miscroscopy and light microscope sections show cuticular modifications for plastron respiration. All previous examples of plastron respiration have involved animals with tracheal systems, but amblypygids respire through the use of two pairs of book lungs. This study provides the first example of plastron respiration not only in the order Amblypygi, but also, in any non-tracheate arthropod.


Salinity And Shade Preferences Result In Ovipositional Differences Between Sympatric Tiger Beetle Species, W. Wyatt Hoback, Douglas A. Golick, Tina Marie Svatos, Stephen M. Spomer, Leon G. Higley Jan 2000

Salinity And Shade Preferences Result In Ovipositional Differences Between Sympatric Tiger Beetle Species, W. Wyatt Hoback, Douglas A. Golick, Tina Marie Svatos, Stephen M. Spomer, Leon G. Higley

Department of Entomology: Faculty Publications

1. Adult tiger beetles of the genus Cicindela often co-occur within a habitat but larvae do not. Larvae are sedentary and form usually permanent burrows at the site of oviposition where they require 1-3 years for development.

2. To test niche partitioning based on ovipositional preference, the behavior of two sympatric salt marsh tiger beetles, Cicindela circumpicta and C. togata (Coleoptera: Cicindelidae), were examined.

3. In laboratory studies, female C. circumpicta and C. togata distinguished between experimental salinities, with the former preferring 4 parts per thousand (ppt) and the latter preferring 12 ppt. In the field, C. circumpicta larvae were …


The Male-Male Tandem: A Novel Form Of Mate Guarding In Perithemis Tenera, Paul V. Switzer, Jaime K. Schultz Jan 2000

The Male-Male Tandem: A Novel Form Of Mate Guarding In Perithemis Tenera, Paul V. Switzer, Jaime K. Schultz

Paul V. Switzer

No abstract provided.


Proximate Constraints On Intruder Detection In The Dragonfly Perithemis Tenera (Odonata: Libellulidae): Effects Of Angle Of Approach And Background, Paul V. Switzer, Perri K. Eason Jan 2000

Proximate Constraints On Intruder Detection In The Dragonfly Perithemis Tenera (Odonata: Libellulidae): Effects Of Angle Of Approach And Background, Paul V. Switzer, Perri K. Eason

Paul V. Switzer

The implications of insects’ vision for territorial defense have been relatively little studied in the field. In the dragonfly Perithemis tenera Say we investigated whether either the angle at which an intruder was viewed by a territorial resident or the background against which it was viewed affected the detection of that intruder. Residents detected intruders at a greater distance if the intruders were directly in front of them; they also detected more intruders in front of them than from other angles. Intruders viewed against distant vegetation were detected more readily than were intruders against near vegetation. Residents detected more intruders …


Regulation Of Contact With Offspring By Domestic Sows: Temporal Patterns And Individual Variation, E. A. Pajor, D. L. Kramer, D. Fraser Jan 2000

Regulation Of Contact With Offspring By Domestic Sows: Temporal Patterns And Individual Variation, E. A. Pajor, D. L. Kramer, D. Fraser

Rearing Behavior Collection

We used a sow-controlled housing system to examine temporal and individual variation in the tendency of sows to associate with young. During a 5-week lactation, 22 sows and litters were housed in a pen where the sow could freely leave and re-enter the piglets' area by stepping over a barrier that the piglets could not cross. Despite this option, the sows remained with the piglets almost constantly during the 1st day after birth. Nineteen sows ('leavers') changed to spending most of their time away from the litter at some point in the lactation. The change was rapid, often within a …


Lack Of Reproduction In Muskoxen And Arctic Hares Caused By Early Winter?, L. David Mech Jan 2000

Lack Of Reproduction In Muskoxen And Arctic Hares Caused By Early Winter?, L. David Mech

USGS Northern Prairie Wildlife Research Center

A lack of young muskoxen (Ovibos moschatus) and arctic hares (Lepus arcticus) in the Eureka area of Ellesmere Island, Northwest Territories (now Nunavut), Canada, was observed during summer 1998, in contrast to most other years since 1986. Evidence of malnourished muskoxen was also found. Early winter weather and a consequent 50% reduction of the 1997 summer replenishment period appeared to be the most likely cause, giving rise to a new hypothesis about conditions that might cause adverse demographic effects in arctic herbivores.

Durant l’été 1998, et ce, à la différence de la plupart des années depuis …


Do Wolves Affect White-Tailed Buck Harvest In Northeastern Minnesota?, L. David Mech, Michael E. Nelson Jan 2000

Do Wolves Affect White-Tailed Buck Harvest In Northeastern Minnesota?, L. David Mech, Michael E. Nelson

USGS Northern Prairie Wildlife Research Center

We used simple linear regression to analyze 8-23 years of data on a wolf (Canis lupus) population and human harvest of white-tailed deer (Odocoileus virginianus) bucks in northeastern Minnesota to determine any effects of wolves on buck harvesting. Over the long term, wolves accounted for at least 14-22% inter-year variation in buck harvest in the region, but an unknown amount of variation in hunter effort have obscured any more precise estimate. For part of the area with poorest habitat, we found strong relationships (r2 = 0.66-0.84) between annual wolf numbers and buck harvests from 1988 …


Proximity Of White-Tailed Deer, Odocoileus Virginianus, Ranges To Wolf, Canis Lupus, Pack Homesites, Michael E. Nelson, L. David Mech Jan 2000

Proximity Of White-Tailed Deer, Odocoileus Virginianus, Ranges To Wolf, Canis Lupus, Pack Homesites, Michael E. Nelson, L. David Mech

USGS Northern Prairie Wildlife Research Center

Seven adult female White-tailed Deer (Odocoileus virginianus) in northeastern Minnesota lived within 1.8 km of Wolf pack (Canis lupus) homesites without vacating their home ranges. Six of these deer and at least three of their fawns survived through the Wolf homesite period.


Prolonged Winter Undernutrition And The Interpretation Of Urinary Allantoin:Creatinine Ratios In White-Tailed Deer, Glenn D. Delgiudice, Ken D. Kerr, L. David Mech, Ulysses S. Seal Jan 2000

Prolonged Winter Undernutrition And The Interpretation Of Urinary Allantoin:Creatinine Ratios In White-Tailed Deer, Glenn D. Delgiudice, Ken D. Kerr, L. David Mech, Ulysses S. Seal

USGS Northern Prairie Wildlife Research Center

The urinary allantoin:creatinine (A:C) ratio (expressed in micromoles of allantoin to micromoles of creatinine) has shown potential as an index of recent winter energy intake in preliminary controlled studies of elk (Cervus elaphus) involving mild condition deterioration (up to 11% loss of body mass). To ensure reliable nutritional assessments of free-ranging cervids by measuring A:C ratios of urine in snow, it is essential to extend this work. We assessed the effect of moderate and severe winter nutritional restriction on urinary A:C ratios of captive white-tailed deer (Odocoileus virginianus) that lost up to 32% body mass and …


Accuracy And Precision Of Estimating Age Of Gray Wolves By Tooth Wear, Philip S. Gipson, Warren B. Ballard, Ronald M. Nowak, L. David Mech Jan 2000

Accuracy And Precision Of Estimating Age Of Gray Wolves By Tooth Wear, Philip S. Gipson, Warren B. Ballard, Ronald M. Nowak, L. David Mech

USGS Northern Prairie Wildlife Research Center

We evaluated the accuracy and precision of tooth wear for aging gray wolves (Canis lupus) from Alaska, Minnesota, and Ontario based on 47 known-age or known-minimum-age skuIIs. Estimates of age using tooth wear and a commercial cementum annuli-aging service were useful for wolves up to 14 years old. The precision of estimates from cementum annuli was greater than estimates from tooth wear, but tooth wear estimates are more applicable in the field. We tended to overestimate age by 1-2 years and occasionaIIy by 3 or 4 years. The commercial service aged young wolves with cementum annuli to within …


Habitat Utilization Of Fish Species On The Ohio River: Preliminary Development Of A Multi-Metric Habitat Index, James P. Hawkes Jan 2000

Habitat Utilization Of Fish Species On The Ohio River: Preliminary Development Of A Multi-Metric Habitat Index, James P. Hawkes

Theses, Dissertations and Capstones

Development of a habitat index requires an understanding of the longitudinal distribution of habitat, fish assemblages, and how the two interact. Because of the complexity and size of the Ohio River, this understanding has not been reached. Habitat analysis has long been considered, and is essential, in assigning impaired and reference condition of habitat quality. The Ohio River is diverse in the distribution of its habitat within pool and river-wide. An Analysis of Variance (ANOVA) was used to analyze these distributions. Within pool assessment of % habitat composition revealed woody cover and vegetation types were significantly greater in the lowest …


Leg Ornamentation And The Efficacy Of Courtship Display In Four Species Of Wolf Spider (Araneae: Lycosidae), Eileen Hebets, George W. Uetz Jan 2000

Leg Ornamentation And The Efficacy Of Courtship Display In Four Species Of Wolf Spider (Araneae: Lycosidae), Eileen Hebets, George W. Uetz

Eileen Hebets Publications

This study used both correlative and experimental video playback methods to test the hypothesis that the secondary sexual traits of male wolf spiders act to increase the efficacy of visual courtship displays. Direct observations of courtship of several lycosid genera and a review of the literature revealed a significant association between ornamentation and visual courtship displays. This suggests that the ornamentation may be playing the role of amplifier for a visual display. To test this hypothesis, male courtship behaviors of four Schizocosa species were experimentally manipulated using video-imaging techniques. Females of species with non-visually displaying, non-ornamented males (Schizocosa duplex …


Proximate Constraints On Intruder Detection In The Dragonfly Perithemis Tenera (Odonata: Libellulidae): Effects Of Angle Of Approach And Background, Paul Switzer, Perri Eason Jan 2000

Proximate Constraints On Intruder Detection In The Dragonfly Perithemis Tenera (Odonata: Libellulidae): Effects Of Angle Of Approach And Background, Paul Switzer, Perri Eason

Faculty Research & Creative Activity

The implications of insects’ vision for territorial defense have been relatively little studied in the field. In the dragonfly Perithemis tenera Say we investigated whether either the angle at which an intruder was viewed by a territorial resident or the background against which it was viewed affected the detection of that intruder. Residents detected intruders at a greater distance if the intruders were directly in front of them; they also detected more intruders in front of them than from other angles. Intruders viewed against distant vegetation were detected more readily than were intruders against near vegetation. Residents detected more intruders …


A Record Large Wolf, Canis Lupus, Pack In Minnesota, L. David Mech Jan 2000

A Record Large Wolf, Canis Lupus, Pack In Minnesota, L. David Mech

USGS Northern Prairie Wildlife Research Center

This report documents a pack of 22-23 Wolves (Canis lupus) in central Minnesota. This is larger than the largest pack previously observed on the mainland in the midwestern U.s. during 650 wolf pack-years. Because this record-large pack preyed on White-tailed Deer (Odocoileus virginianus), one of the Wolfs smaller prey, it is evidence that pack size and prey size are not tightly related. It also indicates the size that Wolf packs can attain in the area if fully protected from human persecution.


Leadership In Wolf, Canis Lupus, Packs, L. David Mech Jan 2000

Leadership In Wolf, Canis Lupus, Packs, L. David Mech

USGS Northern Prairie Wildlife Research Center

I examine leadership in Wolf (Callis lupus) packs based on published observations and data gathered during summers from 1986 to 1998 studying a free-ranging pack of Wolves on Ellesmere Island that were habituated to my presence. The breeding male tended to initiate activities associated with foraging and travel, and the breeding female to initiate, and predominate in, pup care and protection. However, there was considerable overlap and interaction during these activities such that leadership could be considered a joint function. In packs with multiple breeders, quantitative information about leadership is needed.


Assessing Factors That May Predispose Minnesota Farms To Wolf Depredations On Cattle, L. David Mech, Elizabeth K. Harper, Thomas J. Meier, William J. Paul Jan 2000

Assessing Factors That May Predispose Minnesota Farms To Wolf Depredations On Cattle, L. David Mech, Elizabeth K. Harper, Thomas J. Meier, William J. Paul

USGS Northern Prairie Wildlife Research Center

Wolf (Canis lupus) depredations on livestock cause considerable conflict and expense in Minnesota. Furthermore, claims are made that such depredations are fostered by the type of animal husbandry practiced. Thus, we tried to detect factors that might predispose farms in Minnesota to wolf depredations. We compared results of interviews with 41 cattle farmers experiencing chronic cattle losses to wolves (chronic farms) with results from 41 nearby "matched" farms with no wolf losses to determine farm characteristics or husbandry practices that differed and that therefore might have affected wolf depredations. We also used a Geographic Information System (GIS) to …


Geometric Rule Learning By Clark’S Nutcrackers (Nucifraga Columbiana), Alan Kamil, Juli E. Jones Jan 2000

Geometric Rule Learning By Clark’S Nutcrackers (Nucifraga Columbiana), Alan Kamil, Juli E. Jones

Papers in Behavior in Biological Sciences

Clark’s nutcrackers (Nucifraga columbiana) were trained to search in a location defined by its geometric relationship to 2 landmarks. Two groups were trained to search at different points along the line connecting the landmarks, and 2 groups were trained to find the 3rd point of a triangle, on the basis of either direction or distance from the landmarks. All groups learned and transferred to new interlandmark distances. However, the constant-distance group learned more slowly, searched less accurately, and showed less transfer than the other 3 groups. When tested with new orientations of the landmarks, the birds tended to …


The Cost Of Limited Attention In Blue Jays, Reuven Dukas, Alan Kamil Jan 2000

The Cost Of Limited Attention In Blue Jays, Reuven Dukas, Alan Kamil

Papers in Behavior in Biological Sciences

Experiments with fish and birds suggest that animals are unable to simultaneously allocate sufficient attention to tasks such as the detection of an approaching predator while searching for cryptic prey. We quantified the effects of limited attention on performance in controlled laboratory settings and report here the first direct evidence that attending to a difficult central task simulating foraging deters a bird’s ability to detect a peripheral target, which could be a predator. Our results fill a gap between ecological and neurobiological studies by illustrating that, although attention is an efficient filtering mechanism, limited attention may be a major cause …


Low Reproductive Success Of Black Skimmers Associated With Low Food Availability, Christopher A. Gordon, Daniel A. Cristol, Ruth A. Beck Jan 2000

Low Reproductive Success Of Black Skimmers Associated With Low Food Availability, Christopher A. Gordon, Daniel A. Cristol, Ruth A. Beck

Arts & Sciences Articles

No abstract provided.


The Male-Male Tandem: A Novel Form Of Mate Guarding In Perithemis Tenera, Paul Switzer, Jaime Schultz Jan 2000

The Male-Male Tandem: A Novel Form Of Mate Guarding In Perithemis Tenera, Paul Switzer, Jaime Schultz

Faculty Research & Creative Activity

No abstract provided.


The Male-Male Tandem: A Novel Form Of Mate Guarding In Perithemis Tenera, Paul V. Switzer, Jaime K. Schultz Jan 2000

The Male-Male Tandem: A Novel Form Of Mate Guarding In Perithemis Tenera, Paul V. Switzer, Jaime K. Schultz

Faculty Research & Creative Activity

No abstract provided.


Proximate Constraints On Intruder Detection In The Dragonfly Perithemis Tenera (Odonata: Libellulidae): Effects Of Angle Of Approach And Background, Paul V. Switzer, Perri K. Eason Jan 2000

Proximate Constraints On Intruder Detection In The Dragonfly Perithemis Tenera (Odonata: Libellulidae): Effects Of Angle Of Approach And Background, Paul V. Switzer, Perri K. Eason

Faculty Research & Creative Activity

The implications of insects’ vision for territorial defense have been relatively little studied in the field. In the dragonfly Perithemis tenera Say we investigated whether either the angle at which an intruder was viewed by a territorial resident or the background against which it was viewed affected the detection of that intruder. Residents detected intruders at a greater distance if the intruders were directly in front of them; they also detected more intruders in front of them than from other angles. Intruders viewed against distant vegetation were detected more readily than were intruders against near vegetation. Residents detected more intruders …


Temperature-Dependent Parental Investment In The Giant Waterbug Belostoma Flumineum (Heteroptera: Belostomatidae), Scott Kight Dec 1999

Temperature-Dependent Parental Investment In The Giant Waterbug Belostoma Flumineum (Heteroptera: Belostomatidae), Scott Kight

Scott Kight

We examined the effects of ambient temperature on the brooding behavior of male waterbugs, Belostoma flumineum Say. Male waterbugs are more likely to prematurely terminate care for small egg-pads than for larger egg-pads. Because embryogenesis and breeding season are both associated with ambient temperature, males in warmer environments may respond differently than those in cooler conditions. We studied the effects of temperature on male parental behavior by housing groups of completely and partially egg-encumbered males under different thermal regimes. Completely encumbered males rarely discarded egg-pads, regardless of ambient temperature. Partially encumbered males housed under warm ambient temperatures, however, were signiÞcantly …