female societies

After a three weeks break we have a new suggestion by Tsuji:

Pazol K. and Cords M. 2005. Seasonal variation in feeding behavior, competition and female social relationships in a forest dwelling guenon, the blue monkey (Cercopithecus mitis stuhlmanni), in the Kakamega Forest, Kenya. Behavioral Ecology and Sociobiology 58, 566-577.

I have not read it... so no comment for this time.

Enjoy!


Image: Blue Monkey Friday, by Marsha Heatwole

Ecosystem engineering

Beavers do modify the phisical conditions of the habitats they inhabit. For that reason they qualify as ecosystem engineers.

Wright et al. (2002) showed how beaver dams increase habitat heterogeneity at landscape level, which permits a higher number of herbaceous plants to be present. Ecosystem engineering by beavers results thus into higher species richness.

This week's paper has been suggested by Yu Yoshihara:

Wright JP, CG Jones & AS Flecker. 2002. An ecosystem engineer, the beaver, increases species richness at landscape level. Oecologia 132, 96-101.


Image: Bever pond, oil by Frank Larson.

Jordano in Niigata

I'm just back from Niigata, where I attended the joint meeting of the Japanese Ecological Society (JES) and the East Asian Federation of Ecological Societies (EAFES).

One of the most interesting presentations was the one by Pedro Jordano, a Spanish researcher working on plant-animal interactions. For this week I suggest his paper:

Godoy, JA & Jordano, P. 2001. Seed dispersal by animals: exact identification of source trees with endocarp DNA microsatellites. Molecular Ecology 10, 2275-2283.

Godoy and Jordano noticed that they could use DNA fingerprinting of a seed's endocarp to identify its mother plant (the endocapr is a tissue entirely of maternal origin!) in seeds dispersed by vertebrates.

Enjoy!


Image: Sierra Cazorla, oil by Kiko Plaza.

Stable isotopes

In 1999 Oecologia published a special issue dedicated to the analysis of stable isotope ratios in ecology. We have previously posted a paper by Cerling et al., in which they used these analyses to identify crop-raider and migrant individuals in an elephant population. Afterwards, Mugino Ozaki and Udayani Weeransinghe have respectively proposed the following papers:

Cerling, T.E. & Harris J.M. 1999. Carbon isotopes between diet and bioapatite in ungulate mammals and implications for ecological and paleontological studies. Oecologia 120, 347-363, and

Cerling, T.E., Harris, J.M. & Leakey, M.G. 1999. Browsing and grazing in elephants: the isotope record of modern and fossil proboscideans. Oecologia 120, 364-374.

The first paper is somewhat arid, but provides very important information on the enrichment factor of 13C for tooth enamel of ungulates and their diet accross a number of world's biomes.

In the second paper, Cerling et al. present an easier to read work in which they use 13C isotope ratios to show how the diet of current elephants is predominantely browse (rather than graze how it has been sometimes inferred from direct observation studies in savannah environs!). Subsequently they show that, however, the diet of proboscideans has been C4-dominated for most of their history until very recently (1 Ma) when they shifted towards C3 food items. Why this change?

Read the beautiful paper!

Photo: young male of Asian elephant grazing at Uda Walawa NP, Sri Lanka (by Oliphas)