geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Can you dig it? Use of excavation, a risky foraging tactic, by dugongs is sensitive to predation danger


, : Can you dig it? Use of excavation, a risky foraging tactic, by dugongs is sensitive to predation danger. Animal Behaviour 74(Part 4): 1085-1091

Foraging and vigilance are mutually exclusive for some foraging tactics but not others. Thus, in response to changes in predation danger, prey species with multiple foraging tactics may switch facultatively between them, allowing for differential levels of vigilance. Using data from focal observations collected over 4 years ( 2002-2004, 2006) in Shark Bay, Western Australia, we explored the use of two tactics, cropping and excavation, by dugongs, Dugong dugon, foraging under risk of predation by tiger sharks, Galeocerdo cuvier. Overall, dugongs predominantly used the cropping tactic, which allows for regular visual scans, to harvest temperate sea grass species. Dugongs only used the excavation tactic, which precludes regular visual scans but allows individuals to access the nutritious rhizomes of preferred tropical sea grass species, in months when tropical species were most available ( February-May). However, during these months the time dugongs allocated to excavation was inversely related to shark abundance rather than the availability of these sea grass species. We conclude that use of foraging tactics by dugongs is sensitive to predation danger, and that individuals manage their risk of mortality via reduced use of a pro. table but potentially hazardous tactic when the likelihood of encountering predators is high. Excavating dugongs are more likely to disrupt sea grass meadow structure and promote succession than are those engaged in cropping. Thus, by altering the time dugongs devote to these alternative tactics, tiger sharks may exert an indirect effect on sea grass patch composition and structure and, ultimately, benthic communities.

US$19.90

DOI: 10.1016/j.anbehav.2007.02.009


Other references

Lacroix, J.C.; Loones, M.T., 1974: Selection, by lampbrush chromosomes, of strains carrying chromosomal mutations inPleurodeles poireti. Chromosoma 48(3): 297-326

Karcioglu Z.A.; Debartolo D.; Conway M., 1986: Tumor seeding in ocular fine needle biopsy an animal model. Investigative Ophthalmology & Visual Science 27(3 SUPPL): 86

Anonymous, 1960: Use of Funds from Sales of Surplus Foods for Science and Education Is Not up to Expectations. Science 132(3426): 534-535

Kopachevs'ka Y.H., 1973: New for the flora of the ussr ochrolechia balcanica new record. Ukrayins'Kyi Botanichnyi Zhurnal: 241-243

Chaurasia, P.; Berenzon, D.; Hoffman, R., 2011: Chromatin-modifying agents promote the ex vivo production of functional human erythroid progenitor cells. Presently, blood transfusion products (TPs) are composed of terminally differentiated cells with a finite life span. We have developed an ex vivo–generated TP composed of erythroid progenitor cells (EPCs) and precursors cells. Several histon...

Kim, L.S.; Koch, J.; Yee, J.; Halvorsen, R.; Cello, J.P.; Rockey, D.C., 2001: Comparison of patients' experiences during imaging tests of the colon. Physical discomfort, anxiety, embarrassment, and other aspects of patient experience impact on future compliance for colonic imaging tests. Therefore, a prospective study was performed comparing patient experiences during air contrast barium enema...

Thielges, B.A., 1971: Genetically improved northern red oak. The work of selection and progeny testing with Quercus rubra carried out since 1967 as part of a long-term improvement programme is described.

Tsuji, K.; Takayama, N., 2002: A study of the layered structure of physical characteristics in connection with discernment of a forest scene. Descriptions of forest scenes were used to investigate the importance of physical characteristics in the formation of forest scenery. The experience and knowledge of the viewer were important in the appreciation of the scene. The form of the tree...

Skinner H.A., 1979: A multi variate evaluation of the michigan alcoholism screening test. A self-administered format of the Michigan Alcoholism Screening Test (MAST) was completed by 418 inpatient alcoholics; half of the responses were used to examine internal properties of the MAST and half to determine external correlates. The 2 grou...

Carroll, T.S.; Liang, Z.; Salama, R.; Stark, R.; de Santiago, I., 2014: Impact of artifact removal on ChIP quality metrics in ChIP-seq and ChIP-exo data. With the advent of ChIP-seq multiplexing technologies and the subsequent increase in ChIP-seq throughput, the development of working standards for the quality assessment of ChIP-seq studies has received significant attention. The ENCODE consortium...