• Issue

    Journal of Animal Ecology: Volume 85, Issue 5

    1133-1422
    September 2016

In Focus

Free Access

It's only a matter of time: the altered role of subsidies in a warming world

  • Pages: 1133-1135
  • First Published: 11 August 2016
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Clockwise from left: an experimental stream reach from the study, highlighting the fences used to contain fish as the apex predator; a cutthroat trout from the experiment, the only fish species in the study streams; stomach contents from a fish, highlighting the major role of the terrestrial subsidy (mealworms) in the diet.

Community ecology

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A test of the effects of timing of a pulsed resource subsidy on stream ecosystems

  • Pages: 1136-1146
  • First Published: 12 March 2016
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While most of the spatial subsidies are temporally variable, less is known about how the timing of these subsidies affects communities and ecosystems. Here, the authors demonstrate that the timing of a pulsed subsidy can mediate stream community and ecosystem functions predominantly through a timing-dependent consumer response.

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The effects of food web structure on ecosystem function exceeds those of precipitation

  • Pages: 1147-1160
  • First Published: 27 April 2016
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The authors' results show stronger effects of food web structure than precipitation change on the functioning of bromeliad ecosystems. They predict that ecosystem function in bromeliads throughout the Americas will be more sensitive to changes in the distribution of species, rather than to the direct effects caused by changes in precipitation.

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Predator identity influences metacommunity assembly

  • Pages: 1161-1170
  • First Published: 14 May 2016
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Although predation plays a fundamental role in structuring natural communities, there remains only a basic understanding of its role in metacommunity assembly. This experiment examined the impact of two predators, one specialist and one generalist, on metacommunities to determine the role predator identity has on local and regional community structure.

Spatial ecology

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Allometric and temporal scaling of movement characteristics in Galapagos tortoises

  • Pages: 1171-1181
  • First Published: 23 June 2016
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Allometric scaling of home-range size has been much studied and is generally predictable but one-dimensional movement metrics scale more consistently with body size. Yet, evaluating movement parameters in one-dimensional space requires a priori definition of a temporal scale. The authors illustrate the importance of scale using movement of giant Galapagos tortoises.

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Simple settlement decisions explain common dispersal patterns in territorial species

  • Pages: 1182-1190
  • First Published: 07 May 2016
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Why do some animals wander far from their place of birth, while others stay put? The authors' models suggest that the answer may be beguilingly simple, lying a set of basic rules that individuals use to make movement and settlement decisions. These rules can help us understand population movement in space.

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Coupled range dynamics of brood parasites and their hosts responding to climate and vegetation changes

  • Pages: 1191-1199
  • First Published: 07 May 2016
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As populations shift their ranges in response to global change, local species assemblages can change, setting the stage for new ecological interactions, community equilibria and evolutionary responses. In South Africa, avian brood parasites did not hinder range expansion by their hosts, but range shifts are creating opportunities for new host–parasite and parasite–parasite interactions.

Parasite and disease ecology

Open Access

Trade-offs and mixed infections in an obligate-killing insect pathogen

  • Pages: 1200-1209
  • First Published: 07 May 2016
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Pathogens are often highly variable but what maintains this diversity is a key focus of disease ecology. In addition, within host pathogen dynamics can have a strong impact of infection outcome and the evolution of virulence. The authors compare eight genetically distinct strains with the mixed parent virus and show that a mixed strain insect virus kills more hosts than any of its component strains, but with a cost in terms of a reduction in the number of transmission stages. Theory suggests that their are likely to be trade-offs between virulence determinants. The authors also demonstrate a trade-off between the length of the infection period and the number of transmission stages produced (infections that kill faster produce less). However, there was no evidence for a trade-off between mortality and speed of kill or transmission potential.

Open Access

Slowing them down will make them lose: a role for attine ant crop fungus in defending pupae against infections?

  • Pages: 1210-1221
  • First Published: 02 May 2016
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Some fungus-growing ants have co-opted their symbiotic cultivar to create a cocoon-like mycelial matrix over their brood. The authors found that this cover suppresses the growth and subsequent spread of a fungal pathogen, buying the ants time to control disease and adding a novel layer of protection to ant defence portfolios. Photograph credit: David Nash.

Free Access

Experimental insight into the process of parasite community assembly

  • Pages: 1222-1233
  • First Published: 13 May 2016
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Community assembly processes shape the diversity and stability of biological assemblages, yet knowledge of assembly processes for parasites lags behind free-living communities. Taking a novel experimental removal approach, we show that both deterministic and stochastic processes contribute to parasite community assembly in wild hosts, but their importance shifts as communities reassemble.

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Parasite specialization in a unique habitat: hummingbirds as reservoirs of generalist blood parasites of Andean birds

  • Pages: 1234-1245
  • First Published: 13 May 2016

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Based on a comprehensive analysis of the process of colonization of unique hosts, this paper challenges our current concept of host specificity of avian blood parasites. Photo credit: Jaime Garcia Dominguez.

Free Access

Fitness costs of animal medication: antiparasitic plant chemicals reduce fitness of monarch butterfly hosts

  • Pages: 1246-1254
  • First Published: 10 June 2016
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The costs of non-immunological defences against parasites, such as behavioural defences, are not well characterized. Monarch butterflies can use cardenolides from their host plants as medication against their parasites. Here, the authors showed that while cardenolides increased both monarch tolerance and resistance to disease, they also reduced their survival and life spans.

Trophic interactions

Open Access

Phenological mismatch and ontogenetic diet shifts interactively affect offspring condition in a passerine

  • Pages: 1255-1264
  • First Published: 06 June 2016
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The authors studied prey switching and ontogenetic niche shifts in a woodland bird that was experimentally mismatched with its main prey. They show that alternative prey types that are rarely considered play a key role in offspring development and shed light on compensation mechanisms animals can use when faced with climate change.

Free Access

Alternative prey use affects helminth parasite infections in grey wolves

  • Pages: 1265-1274
  • First Published: 07 May 2016
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Wolves typically consume the most abundant ungulates, but this study suggests consuming alternative prey (beavers) can reduce wolf parasite loads. Long-term, increased use of alternative prey could interrupt parasite life cycles and influence parasite distributions on the landscape, ultimately benefiting ungulates that serve as intermediate hosts. Photo: Daniel Dupont

Free Access

The dominant detritus-feeding invertebrate in Arctic peat soils derives its essential amino acids from gut symbionts

  • Pages: 1275-1285
  • First Published: 20 June 2016
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For soil detritivores feeding on nutrient poor diets it may be challenging obtaining sufficient proteins and essential amino acids. To investigate how a bulk feeder of soil organic matter, the enchytraeid worm, make up for dietary deficiencies the authors employed isotope fingerprinting of amino acids. They found that worms feeding on high fibre diets received most of their essential amino acids from gut symbiotic bacteria.

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Hoverfly preference for high honeydew amounts creates enemy-free space for aphids colonizing novel host plants

  • Pages: 1286-1297
  • First Published: 22 June 2016
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The authors identify a mechanism that reduces the fitness disadvantages that aphids have to face when they colonize novel, less suitable hosts. The preference of hoverflies for plants with more aphid honeydew creates an enemy-free space on less suitable hosts that facilitates host race formation.

Demography

Open Access

Causes and consequences of spatial variation in sex ratios in a declining bird species

  • Pages: 1298-1306
  • First Published: 08 July 2016
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Small populations of migratory warblers are more likely to be male-biased and these small biased populations are increasingly widespread throughout Britain.

Free Access

Piscivorous fish exhibit temperature-influenced binge feeding during an annual prey pulse

  • Pages: 1307-1317
  • First Published: 26 July 2016
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Short-term binge-feeding by bull trout in the laboratory and in the field (during a prey pulse) were quantified and found to be extreme and largely not limited by low temperatures. Thus, the ability for predators to maximize short-term consumption when prey are available is greater than traditional bioenergetics models suggest.

Climate ecology

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Impact of changing wind conditions on foraging and incubation success in male and female wandering albatrosses

  • Pages: 1318-1327
  • First Published: 17 May 2016

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This study contributes to our understanding of the ecological impacts of climate change in the Subantarctic. Using tracking and demographic data from a long-term study on wandering albatrosses, the authors assessed the impact of wind on foraging success, morphology and reproductive performance of the wandering albatross, and predicted changes under future wind conditions.

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Field-based experimental acidification alters fouling community structure and reduces diversity

  • Pages: 1328-1339
  • First Published: 10 June 2016
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Ocean acidification is one of the primary threats to marine species and ecosystems. Most studies have focused on responses of individual species in laboratory settings, and there is a need for in situ community- and ecosystem-level experiments. The authors address this gap by studying the patterns of succession and community assembly under acidification.

Behavioural ecology

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The price of associating with breeders in the cooperatively breeding chestnut-crowned babbler: foraging constraints, survival and sociality

  • Pages: 1340-1351
  • First Published: 02 May 2016
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Using the cooperatively breeding chestnut-crowned babbler, the authors show that living in groups containing breeders may be costly and that such costs may increase with group size. The authors suggest that costs of associating with breeders may impede group living in species where constraints to independent breeding and costs of dispersal are not acute.

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Street lighting: sex-independent impacts on moth movement

  • Pages: 1352-1360
  • First Published: 04 May 2016
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The authors results provide evidence that street lights have a sex-independent impact on moth movement. Thus, public lighting is likely to divide suitable landscapes into many small habitats. Inevitably attracted insects are eliminated directly or temporarily from the mating pool possibly followed by a substantial impact on population dynamics.

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Kin effects on energy allocation in group-living ground squirrels

  • Pages: 1361-1369
  • First Published: 06 June 2016
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This study highlights the effects of the social environment (kin numbers) on a fundamental life history trade-off: the allocation of energy to reproductive or somatic functions.

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Contrasting patterns of short-term indirect seed–seed interactions mediated by scatter-hoarding rodents

  • Pages: 1370-1377
  • First Published: 02 May 2016
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Failure to consider scatter hoarding behavior strongly changed our impression of the indirect effects among animal-dispersed species and their consequences for plant demography and diversity. The framework established in this study contributes to measure and understand indirect effects between co-occurring seeds mediated by scatter-hoarding rodents as seed predators and dispersers.

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Diet preferences as the cause of individual differences rather than the consequence

  • Pages: 1378-1388
  • First Published: 16 June 2016
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Behavioural differences between animals are often explained by their physiology or morphology. The authors studied the causality between physiomorphic and behavioural differences in red knots, migratory shorebirds that feed on bivalves. They show that differences in gut size and movement patterns are likely caused by diet preferences, rather than vice versa. Photo credit: Jeroen Onrust.

Free Access

Thermal preference predicts animal personality in Nile tilapia Oreochromis niloticus

  • Pages: 1389-1400
  • First Published: 24 May 2016
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This study highlights the intimate connection between animal personality with firstly environmental temperature and secondly how thermal choice expressed as behavioural fever is used to combat infection and promote survival.

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Prey size and scramble vs. contest competition in a social spider: implications for population dynamics

  • Pages: 1401-1410
  • First Published: 14 June 2016
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When investigating foraging in social groups, it is rarely considered that the attributes of the shared resources themselves may influence the form of intraspecific competition and therefore potentially the groups’ population dynamics. This paper investigates this potential triple link between characteristics of the resources, individual behaviour and population dynamics.

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Evaluating random search strategies in three mammals from distinct feeding guilds

  • Pages: 1411-1421
  • First Published: 29 June 2016
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Searching allows animals to find food and mates. Recently developed methods to distinguish between movement patterns of search strategy models found stronger support for combined correlated random walks than Lévy walks in three species. However, these models were often inadequate, suggesting standard models do not represent search behaviour adequately. (Caribou photo by Craig DeMars. Bear photos by Andrew Derocher)