Tracing the diet of the monitor lizard Varanus mabitang by stable isotope analyses (δ15N, δ13C)

  title={Tracing the diet of the monitor lizard Varanus mabitang by stable isotope analyses ($\delta$15N, $\delta$13C)},
  author={Ulrich Struck and Alexander Volker Altenbach and Maren Gaulke and Frank Glaw},
Abstract. In this study, we used analyses of stable isotopes of nitrogen (δ15N) and carbon (δ13C) to determine the trophic ecology of the monitor lizard Varanus mabitang. Stable isotopes from claws, gut contents, and soft tissues were measured from the type specimen. Samples from Varanus olivaceus, Varanus prasinus, Varanus salvator, the herbivorous agamid lizard Hydrosaurus pustulatus, and some plant matter were included for comparison. Our data show a rapid decrease in δ13C (about10‰) from… 

Diet and Habitat Requirements of the Philippine Endemic Frugivorous Monitor Lizard Varanus bitatawa

Data is presented that show that Varanus bitatawa has a seasonal omnivorous diet comparable to its southern congener Varanus olivaceus, a recently discovered monitor lizard endemic to the Sierra Madre Mountains of Northern Luzon.

Tissue‐Carbon Incorporation Rates in Lizards: Implications for Ecological Studies Using Stable Isotopes in Terrestrial Ectotherms

This study highlights the lack of experimental data for isotope dynamics in ectotherms across a range of temperatures, body sizes, and developmental stages and determined carbon incorporation rates and Δ13C in tissues of prairie lizards and collared lizards.

A trophic study of the sympatric Amazonian freshwater turtles Podocnemis unifilis and Podocnemis expansa (Testudines, Podocnemidae) using carbon and nitrogen stable isotope analyses

The trophic level and the primary carbon source from the diets of both species in Baixo Araguaia, Tocantins, Brazil, were analyzed using stable isotope analyses of carbon (δ13C) and nitrogen ( δ15N) and possible intraspecific variations (related to sex and body mass) were verified.

Stable carbon and nitrogen isotope discrimination and turnover in a small-bodied insectivorous lizard

Estimates of carbon and nitrogen isotope discrimination factors and turnover for the tree lizard (Urosaurus ornatus) using a diet-switch experiment are estimated and should be appropriate for use in trophic studies of U. ornatus, and possibly other related small-bodied insectivorous lizards.

Stable C and N isotope concentration in several tissues of the loggerhead sea turtle Caretta caretta from the western Mediterranean and dietary implications

Comparison of the concentration of stable isotopes in the turtles with that of other species from several areas of the Algerian Basin revealed that they consumed planktonic prey and that the trophic level of the sea turtles was higher than that of carnivorous cnidarians but lower than those of zooplanktophagous fish and crustaceans.

Regional, seasonal and interspecific variation in 15N and 13C in sympatric mouse lemurs

Food composition of two identical sized omnivorous mouse lemur species, Microcebus griseorufus and M. murinus, is studied with the help of stable isotope analyses to understand the mechanisms that allow coexistence of sympatric congeneric species without obvious niche differentiation.

Giant lizards occupied herbivorous mammalian ecospace during the Paleogene greenhouse in Southeast Asia

The results indicate that competitive exclusion and predation by mammals did not restrict body size evolution in these herbivorous squamates, and elevated temperatures relative to modern climates during the Paleogene greenhouse may have resulted in the evolution of gigantism through elevated poikilothermic metabolic rates and in response to increases in floral productivity.

Applications of stable isotopes to study plant-animal relationships in terrestrial ecosystems

Stable isotope technique can continuously measure animal trophic position in a foodweb, which can eventually reveal the predator-prey relationship and its role in determining matter balance and energy flow in the entire ecosystem.



Stable isotope ratios indicate diet and habitat use in New World monkeys.

The use of stable isotope ratios of carbon and nitrogen in animal tissue for indicating aspects of species behavioral strategy is demonstrated and museum-curated primate material can be analyzed to yield information on forest cover and diet in populations and species lacking behavioral data.

Using stable carbon (δ13C) and nitrogen (δ15N) isotopes to infer trophic relationships among black and grizzly bears in the upper Columbia River basin, British Columbia

Female grizzly bears, however, had lower δ15N values in their hair than the other groups of bears, indicating either less animal protein in their diet or a reliance on foods more depleted in 15N, possibly related to altitude.

Stable Isotopes of Nitrogen in Fossil Cladoceran Exoskeletons: Implications for Nitrogen Sources in the Central Baltic Sea During the Past Century

It is postulate that nitrogen fixation by diazotrophic bacteria has been one of the larger sources of nitrogen in the Baltic Sea, as it is today.

Stable isotopes of carbon and nitrogen in the study of avian and mammalian trophic ecology

  • J. Kelly
  • Environmental Science, Geography
  • 2000
Differences in stable-isotope composition among trophic groups were detected despite variation attributable to geographic location, climate, and analytical techniques, indicating that these effects are large and pervasive.

15N‐enrichment of plant tissue to mark phytophagous insects, associated parasitoids, and flower‐visiting entomophaga

New techniques are presented on the use of 15N to mark insects to help establish whether agriculturally important entomophaga visiting 15N‐enriched flowers or parasitizing enriched sentinel larvae in the field can be effectively marked with 15N.

Food web structure on Georges Bank from stable C, N, and S isotopic compositions

  • B. Fry
  • Environmental Science
  • 1988
A combination of stable isotopic measurements was used to study food web structure of Georges Bank, an important northwestern Atlantic fishing ground. Particulate, invertebrate, and fish samples were

Atmospheric nitrogen is a reliable standard for natural 15N abundance measurements

Research based on 15N stable isotope variations in natural compounds is expanding in scientific fields such as biogeochemistry (isotope fractionation effects measurements1–7), metabolic studies8,9,