Kim Jensen

Kim Jensen
Aarhus University | AU · Department of Animal Science

Ph.D

About

43
Publications
9,337
Reads
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868
Citations
Additional affiliations
April 2017 - June 2019
Aarhus University
Position
  • PostDoc Position
April 2016 - March 2017
Aalborg University
Position
  • PostDoc Position
December 2013 - March 2016
North Carolina State University
Position
  • PostDoc Position
Education
October 2005 - June 2010
University of Oxford
Field of study
  • Zoology
September 1998 - June 2005
Aarhus University
Field of study
  • Biology

Publications

Publications (43)
Article
Full-text available
Evolutionary theory predicts that animals should forage to maximize their fitness, which in predators is traditionally assumed equivalent to maximizing energy intake rather than balancing the intake of specific nutrients. We restricted female predatory ground beetles (Anchomenus dorsalis) to one of a range of diets varying in lipid and protein cont...
Article
Full-text available
Modest dietary restriction extends lifespan (LS) in a diverse range of taxa and typically has a larger effect in females than males. Traditionally, this has been attributed to a stronger trade-off between LS and reproduction in females than in males that is mediated by the intake of calories. Recent studies, however, suggest that it is the intake o...
Article
Full-text available
1.Temperature influences biological processes of ectotherms including ecological interactions, but interaction strengths may depend on species‐specific traits. Furthermore, ectotherms acclimate to prevailing thermal conditions by adjusting physiological parameters, which often implies costs to other fitness‐related parameters. Both predators and pr...
Article
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Understanding how diet affects reproduction and survival is a central aim in evolutionary biology. Although this relationship is likely to differ between the sexes, we lack data relating diet to male reproductive traits. One exception to this general pattern is Drosophila melanogaster, where male dietary intake was quantified using the CA pillary F...
Article
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The food and feed sector requires new sustainable sources of protein and innovative solutions for upcycling of food waste (former foodstuffs), which today is downcycled into energy or even wasted. This study aimed at evaluating the use of former foodstuff waste streams as feed substrate for Hermetia illucens (L.) larvae (black soldier fly larvae, B...
Article
1. Despite widespread variation in lifespan across species, three clear patterns exist: sex differences in lifespan are ubiquitous, lifespan is commonly traded against reproduction, and nutrition has a major influence on these traits and how they trade-off. One process that potentially unites these patterns is intralocus sexual conflict over the op...
Article
The quality of biological control agents used in augmentative releases may be affected by rearing conditions due to inbreeding or laboratory adaptation, or to phenotypic effects of the rearing environment. We hypothesized that individuals from a wild population would be in better body condition and kill more prey than individuals from a commerciall...
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Understanding the factors that control the growth of heterotrophic organisms is central to predicting food web interactions and biogeochemical cycling within ecosystems. We present a new framework, Geometric Stoichiometry (GS), that unifies the disciplines of Nutritional Geometry (NG) and Ecological Stoichiometry (ES) by extending the equations of...
Article
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1. The presence of predators is known to suppress prey populations not only by consumptive but also by non‐consumptive effects, as it stresses the prey inducing costly changes to behaviour and physiology. However, there is recent evidence that disturbance from non‐predacious, non‐competing commensals can also negatively affect herbivore performance...
Article
We studied the food quality of the aphid Rhopalosiphum padi to the pirate bug Orius majusculus using Ephestia eggs as high‐quality comparison prey. Several performance parameters were tested on individuals that had been reared and maintained on each of the two single‐prey diets or on a mixed diet. All fitness parameters were lower in individuals fe...
Article
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Generalist predators potentially have access to a wide array of prey, but it is little studied how experience with specific prey affects preference for this prey. In particular, it is unknown how experience with pest prey affects predator foraging decisions in cases where the pest is nutritious but protected by a repelling, potentially deadly defen...
Article
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Habitats vary in food resources with carnivores often being prey limited, but it is unclear whether habitats facilitate a nutritionally balanced diet. Two paradigms in nutritional ecology, ecological stoichiometry and nutritional geometry, predict that carnivores are limited mainly by protein or lipid, respectively. Using the carabid beetle Anchome...
Article
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Soil living mites have large potential as biocontrol agents against soil-dwelling pests, but little is known about their ecological and ecophysiological responses to cold. We investigated the interactive effects of acclimation temperature and time on cold tolerance in the laelapid mite Gaeolaelaps aculeifer Canestrini after exposure to 5, 10, 15, o...
Article
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Predatory arthropods are used for biological control in greenhouses, but there is increasing interest to extend their use to the outdoor environment where temperatures are typically lower. Acclimation at low temperature increases the ability of ectotherms to cope with subsequent more extreme cold, but may involve costs or benefits to other performa...
Article
Full-text available
Changes in feeding behaviour, especially the overconsumption of calories, has led to a rise in the rates of obesity, diabetes, and other associated disorders in humans and a range of animals inhabiting human-influenced environments. However, understanding the relative contribution of genes, the nutritional environment, and their interaction to diet...
Article
Predatory arthropods are increasingly used in biological control of insect pests. For this purpose, control agents are produced commercially in large quantities for release in crops. The production stocks, however, may have undergone numerous population bottlenecks and may have been exposed to artificial selection pressures in the production facili...
Article
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Protein is an abundant nutrient in sperm, and males therefore expend protein every time they mate. In addition, many males provide the female with a nitrogen-rich nuptial gift during mating, which often increases female fertility by supplementing her pool of limiting nutrients. However, it is unknown whether males compensate for the nitrogen cost o...
Article
Full-text available
Life-history theory assumes that traits compete for limited resources, resulting in trade-offs. The most commonly manipulated resource in empirical studies is the quantity or quality of diet. Recent studies using the geometric framework for nutrition, however, suggest that trade-offs are often regulated by the intake of specific nutrients, but a fo...
Article
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Environmental conditions during sexual maturation impact sexual signal expression, but little is known about how individual histories of changing environmental conditions affect the intensity of male sexual advertisement. We investigated the effects of shifting dietary nutrient composition (protein vs. carbohydrates) in male Nauphoeta cinerea cockr...
Article
Full-text available
Ectotherms respond to their thermal environments by physiological acclimation, which increases tolerance to thermal extremes and may increase field performance. However, acclimation often has costs, and increased performance in some traits may be associated with reduced performance in other traits due to trade-offs. We investigated effects of therm...
Article
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There is often large divergence in the effects of key nutrients on lifespan and reproduction in the sexes, yet nutrient intake is regulated in the same way in males and females given dietary choice. This suggests that the sexes are constrained from feeding to their sex-specific nutritional optima for these traits. Here we examine the potential for...
Article
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Glucose-aversion is a heritable trait that evolved in a number of German cockroach (Blattella germanica L.) populations in response to strong selection with glucose-containing insecticide baits. However, in the absence of glucose-containing bait, glucose-averse (GA) cockroaches have lower performance than wild-type (WT) cockroaches in several fitne...
Article
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The condition dependence of male sexual traits plays a central role in sexual selection theory. Relatively little, however, is known about the condition dependence of chemical signals used in mate choice and their subsequent effects on male mating success. Furthermore, few studies have isolated the specific nutrients responsible for condition-depen...
Article
Full-text available
The German cockroach (Blattella germanica L.) is an excellent model omnivore for studying the effect of foraging effort on nutrient balancing behavior and physiology, and its consequences for performance. We investigated the effect of foraging distance on individual German cockroaches by providing two foods differing in protein-to-carbohydrate rati...
Article
Full-text available
Fitness-related costs of evolving insecticide resistance have been reported in a number of insect species, but the interplay between evolutionary adaptation to insecticide pressure and variable environmental conditions has received little attention. We provisioned nymphs from three German cockroach (Blattella germanica L.) populations, which differ...
Article
Full-text available
Sexual selection may cause dietary requirements for reproduction to diverge across the sexes and promote the evolution of different foraging strategies in males and females. However, our understanding of how the sexes regulate their nutrition and the effects that this has on sex-specific fitness is limited. We quantified how protein (P) and carbohy...
Article
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1. Condition is defined as the pool of resources available to an individual that can be allocated to fitness-enhancing traits. Consequently, condition could influence developmental trade-offs if any occur. Although many studies have manipulated diet to demonstrate condition-dependent trait expression, few studies have determined the contribution of...
Article
Full-text available
Adaptations to hazardous environmental factors are essential for survival, although they may be maladaptive in conditions where the hazard is absent. In German cockroach (Blattella germanica L.) populations, glucose aversion has evolved rapidly in response to glucose-containing insecticidal baits, but little is known about the consequences of this...
Article
Full-text available
Carnivorous animals are known to balance their consumption of lipid and protein, and recent studies indicate that some mammalian carnivores also regulate their intake of carbohydrate. We investigated macronutrient balancing and lipid restoration following hibernation in the ground beetle Anchomenus dorsalis, hypothesizing that carbohydrates might b...
Article
Full-text available
Sexual conflict results in a diversity of sex-specific adaptations, including chemical additions to ejaculates. Male decorated crickets (Gryllodes sigillatus) produce a gelatinous nuptial gift (the spermatophylax) that varies in size and free amino acid composition, which influences a female’s willingness to fully consume this gift. Complete consum...
Article
Full-text available
It is commonly assumed that because males produce many, tiny sperm, they are cheap to produce. Recent work, however, suggests that sperm production is not cost-free. If sperm are costly to produce, sperm number and/or viability should be influenced by diet, and this has been documented in numerous species. Yet few studies have examined the exact nu...
Article
Animals balance their intake of specific nutrients, but little is known about how they do so when foraging in an environment with toxic resources and whether toxic foods promote adaptations that affect life history traits. In German cockroach (Blattella germanica) populations, glucose aversion has evolved in response to glucose-containing insectici...
Article
Full-text available
Balancing of macronutrient intake has only recently been demonstrated in predators. In particular, the ability to regulate carbohydrate intake is little studied in obligate carnivores, as carbohydrate is present at very low concentrations in prey animal tissue. In the present study, we determined whether American mink (Neovison vison) would compens...
Article
Full-text available
The nutritional composition of prey is known to influence predator life histories, but how the life history strategies of predators affect their susceptibility to nutrient imbalance is less investigated. We used two wolf spider species with different life histories as model predators: Pardosa amentata, which have a fixed annual life cycle, and Pard...
Article
Full-text available
Nutrient balancing is well known in herbivores and omnivores, but has only recently been demonstrated in predators. To test how a predator might regulate nutrients when the prey varies in nutrient composition, we restricted juvenile Pardosa prativaga wolf spiders to diets of one of six fruit fly, Drosophila melanogaster, prey types varying in lipid...
Data
Data for Jensen, K., Mayntz, D., Toft, S., Raubenheimer, D., and Simpson, S.J. 2011. Nutrient balancing in a predator, the wolf spider Pardosa prativaga. Animal Behaviour 81, 993-999
Article
Full-text available
We investigated whether spiders fed lipid-rich rather than protein-rich prey elevate metabolism to avoid carrying excessive lipid deposits, or whether they store ingested lipids as a buffer against possible future starvation. We fed wolf spiders (Pardosa prativaga) prey of different lipid:protein compositions and measured the metabolic rate of spid...

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Projects

Projects (2)
Project
The project aims at finding methods to acclimate predatory arthropods so they perform better under field conditions and consume more of the prey they are released to target.