Measuring the trophic ecology of ants using stable isotopes

Tillberg, Chadwick V.; McCarthy, Daniel; Doležal, Adam; Suarez, Andrew V.

doi:10.1007/s00040-005-0836-7

Cited by 111 publications

(131 citation statements)

References 36 publications

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…In their native range, fire ant nests are highly variable in d 15 N ratios. This variance reflects an estimated span of two trophic levels (Tillberg et al 2006). Here we use the patch mean d 15 N, which estimates the average trophic position of fire ant colonies in a given patch, and patch range (maximum minus minimum) of In each peripheral patch (connected, rectangular, and winged) we collected fire ants using a stratified design.…”

Section: Study Sitementioning

confidence: 99%

“…Of these, we haphazardly selected 30-50 individuals for stable isotope analysis. To obtain an estimate from a relatively long time window of nitrogen assimilation and unbiased by the last meal ingested, we analyzed only heads and thoraxes (Tillberg et al 2006). Samples from a given nest were thoroughly mixed, weighed to the nearest 61 lg, and analyzed for d 15 N at the University of Georgia Savannah River Ecology Laboratory using continuous flow isotope ratio a mass spectrometer (Finnigan Delta plus XL; Finnigan-MAT, San Jose, CA).…”

Section: Study Sitementioning

confidence: 99%

See 1 more Smart Citation

Habitat corridors alter relative trophic position of fire ants

2012

View full text Add to dashboard Cite

Abstract. Habitat fragmentation disrupts species movement, leading to local extinctions and altered community structure. Habitat corridors, which connect isolated patches of habitat and facilitate movement between patches, provide a potential solution to these negative impacts. However, most studies to date have examined the movement of species alone without considering emergent effects on the community (e.g., altered trophic structure). We use large-scale, experimental landscapes and nitrogen stable isotopes ratios (d 15 N) of a common generalist consumer (the fire ant, Solenopsis invicta) to determine how corridors affect trophic structure. Thus, because the fire ant is a species whose trophic position is flexible and whose diet typically reflects local prey availability, we assume that shifts in fire ants' trophic position between connected and isolated patches are likely to reflect shifts in patch trophic structure. We found that colonies in isolated patches had lower means and ranges of d suggest that fragmentation may reduce trophic position and narrow trophic breadth of dietary generalists such as the fire ant. These shifts likely reflect an alteration of food webs in isolated patches. Our results suggest that corridors may be effective in preventing or reducing such alterations.

show abstract

Section: Study Sitementioning

confidence: 99%

Section: Study Sitementioning

confidence: 99%

Habitat corridors alter relative trophic position of fire ants

2012

View full text Add to dashboard Cite

show abstract

“…All specimens were conserved in a saturated NaCl solution and stored at À18 C until identification and further processing. Salted water preserves N and C isotopic ratios (unlike ethanol, which modifies the 13 C/ 12 C ratio) (Ponsard and Amlou, 1999;Tillberg et al, 2006).…”

Section: Sampling Designmentioning

confidence: 99%

Differential response of ants to nutrient addition in a tropical Brown Food Web

Jacquemin

Maraun

Roisin

et al. 2012

Soil Biology and Biochemistry

View full text Add to dashboard Cite

a b s t r a c tIn tropical ecosystems, access to nitrogen (N) and phosphorus (P) limits the decomposition rate of leaflitter. Leaf-litter ants are abundant in this microhabitat and present a wide variety of diets. Our aim was to study the response of various ant trophic groups to an increased nutrient availability which boosts the decomposition of their habitat and selectively affects the abundance of their prey.A 6-month nutrient addition experiment (CN, CNP) was performed in a tropical montane forest of the Ecuadorian Andes. The density of ants, of other predators (e.g. arachnids, beetles) and of their potential prey (mesofauna, ranging from 0.1 to 2 mm) was measured in treatments and control plots.The litter volume in fertilized plots decreased significantly. Collembola and total mesofauna density were enhanced by the CNP addition. Ants responded differentially according to their trophic group: despite increased prey availability, predatory species in general and collembolan hunters in particular were negatively affected by both treatments. Other ant trophic group densities did not change. By contrast, the density of Dermaptera increased with the treatments. A complementary isotopic approach allowed us to trace carbon fluxes through the food web.Our results suggest that the nutrient input enhanced the litter decomposition rate, leading to reduction of habitat size. They also suggest that predatory ants in tropical leaf-litter food webs are limited by habitat size rather than by prey availability, and that these ants are more affected by habitat loss than their prey, other ant trophic groups and other macrofauna taxa.

show abstract

“…Individual ant samples consisted of heads, thoraces, and legs of 10 -15 workers from the same colony, such that sample masses were Ϸ1,500 g. When possible, we sampled ants from at least five colonies per site per species to incorporate intercolony variation in trophic level (43). Individual samples of non-ant arthropods were homogenized and weighed to Ϸ1,500 g per sample.…”

Section: Biregional Comparisons Of Trophic Ecologymentioning

confidence: 99%

Trophic ecology of invasive Argentine ants in their native and introduced ranges

Tillberg

Holway

LeBrun

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

173

202

View full text Add to dashboard Cite

Although the ecological effects of invasions often become obvious soon after introduced species become established, more gradual effects may take years to manifest and can thus require long-term data for quantification. We analyzed an 8-year record of stable isotope data on Argentine ants ( biological invasions ͉ stable isotopes ͉ food webs B iological invasions threaten biodiversity and drain economic resources. Despite the importance of species introductions, the short-term and small-scale nature of most invasive species research is a recognized limitation of this field (1). Additionally, confounding environmental factors can obscure links between the spread of invasive species and decline of natives (2). Spatiotemporal fluctuations in the population sizes of introduced species (3) that result from changes in resource use or availability (4) can greatly alter the extent to which invaders disrupt ecosystems. Because a better understanding of such variation will inform both ecological theory and management strategies, there is an urgent need for long-term studies as well as for research that investigates ecological interactions in the native ranges of introduced species.One underappreciated source of variation regarding introduced species concerns dietary flexibility and shifts in trophic position between native and introduced populations. This form of ecological plasticity may enhance invasion success in a number of ways. Species capable of extracting required nutrients from multiple trophic levels might establish in a broader range of environments compared with more specialized consumers. Furthermore, theory predicts diminishing biomass at higher trophic levels, suggesting that species feeding at lower trophic levels might attain greater abundance (5).In this study we examine the direct effects of Argentine ant (Linepithema humile) invasions on native ant diversity and then quantify how dietary flexibility in this widespread invader affects spatiotemporal variation in its trophic position. Invasive ants provide an ideal system to test how trophic flexibility contributes to invasion success. With many species introductions, it can be difficult to separate the effects of the invader from covarying factors, such as habitat disturbance, that might also negatively affect natives (2, 6). Because Argentine ants aggressively displace above-ground foraging native ants (7), changes in the diet of L. humile that occur during and just after invasion can be linked to native ant displacement. Second, invasive ants, such as L. humile, are highly omnivorous and frequently form nonspecialized associations with honeydew-producing Hemiptera (7-10). Greater use of honeydew and other plant-based resources in introduced populations might result in a decrease in trophic position (relative to that of native populations), such that invasive ants would persist at higher densities than if they were acting as carnivores (7,11,12). Similar arguments have been proposed to explain the great abundance of ants in tropical rainforest canopies ...

show abstract

Measuring the trophic ecology of ants using stable isotopes

Cited by 111 publications

References 36 publications

Habitat corridors alter relative trophic position of fire ants

Habitat corridors alter relative trophic position of fire ants

Differential response of ants to nutrient addition in a tropical Brown Food Web

Trophic ecology of invasive Argentine ants in their native and introduced ranges

Contact Info

Product

Resources

About