Foraging modes in lacertid lizards from southern Africa

1999 ◽  
Vol 20 (3) ◽  
pp. 299-311 ◽  
Author(s):  
William E. Cooper ◽  
Martin J. Whiting

AbstractMost lacertids are active foragers, but intrafamilial variation in foraging mode is greater than in most lizard families. We collected data on eight species of African lacertids to assess this variation. Both active and ambush foraging occurred within Pedioplanis and Meroles. Meroles ctenodactylus had a proportion of time moving and proportion of attacked prey detected while moving intermediate to those for actively foraging and ambushing Pedioplanis, but its number of movements per minute was exceptionally high. This species has a unique mixed foraging mode. Like active foragers, it seeks food by tongue-flicking while moving and spends a high percentage of the time moving. Like ambush foragers, it searches visually for prey during pauses between movements. Our findings confirm published data on four Kalahari lacertids. We discuss the history of foraging modes in advanced lacertids.

1999 ◽  
Vol 20 (4) ◽  
pp. 391-399 ◽  
Author(s):  
Martin J. Whiting ◽  
P. le F.N. Mouton ◽  
Johannes H. Van Wyk ◽  
William E. Cooper

AbstractTwo lizard foraging modes, ambush and active foraging, are usually quantified by the variables MPM (movements per minute) and PTM (proportion of time spent moving), but both variables may be affected by behaviors other than foraging. We introduce PAM, the proportion of attacks on prey discovered while lizards are moving (in relation to total attacks). PAM focuses exclusively on foraging behavior. Preliminary data reveal a very high, significant rank correlation between PAM and PTM, and a fairly high, but nonsignificant correlation between PAM and MPM. Collection of PAM data can be very time-consuming. In the absence of PAM, PTM appears to be a superior index of foraging activity to MPM, but all three indices provide valuable information on different aspects of foraging. We additionally present data for four agamine and five gekkonid species from southern Africa. The first quantitative data for agamines (all for Agama) agree with previous qualitative assessments that members of several agamine genera are ambush foragers. All the gekkonids, including three species of Rhotropus and one each of Pachydactylus and Phyllodactylus, are ambush foragers, like most geckos studied to date.


1999 ◽  
Vol 20 (4) ◽  
pp. 391-399 ◽  
Author(s):  
William E. Cooper ◽  
Martin J. Whiting ◽  
Johannes H. Van Wyk ◽  
P. le F.N. Mouton

1999 ◽  
Vol 20 (3) ◽  
pp. 299-311 ◽  
Author(s):  
William E. Cooper ◽  
Martin J. Whiting

1996 ◽  
Vol 17 (3) ◽  
pp. 217-231 ◽  
Author(s):  
Christopher S. DePerno ◽  
William E. Cooper ◽  
Laura J. Steele

AbstractPoststrike elevation in tongue-flicking rate (PETF) and strike-induced chemosensory searching (SICS) were assessed experimentally in two species of gekkonoid lizards belonging to families differing in foraging mode. PETF is an increase in rate of lingual protrusions after a prey item has been bitten and escapes or is removed from the mouth of a squamate reptile, whereas SICS is PETF combined with locomotory searching behavior. Eublepharis mucularius, the leopard gecko, is an actively, albeit slowly, foraging eublepharid. This species exhibited PETF for a duration of about five minutes based on total lingual protrusions. Labial-licks were initially much more frequent than tongue-flicks. A substantial increase in movement occurred during minutes 5-8, hinting that SICS might be present, but was not quite significant. SICS is likely present, as in other actively foraging lizards, but was not conclusively demonstrated. Handling the lizards induced increased locomotion in both the experimental condition and a control condition, presumably accounting for the apparent delay in onset of increased movement. The tokay gecko, Gekko gecko, a gekkonid ambush forager, performed no tongue-flicks, but exhibited PETF based on labial-licks during the first minute. SICS was absent. These findings support the hypothesis that SICS is absent in ambush foraging lizards, which do not use the lingual-vomeronasal system to search for prey. They are suggestive, but equivocal regarding the hypothesis that SICS is present in actively foraging lizards that exhibit lingually mediated prey chemical discrimination. The finding of PETF in G. gecko suggests that this species and several iguanians previously found to increase rates of labial-licking after biting prey may be able to detect prey chemicals.


1990 ◽  
Vol 11 (4) ◽  
pp. 373-384 ◽  
Author(s):  
Y.L. Werner ◽  
I. Lampl ◽  
D. Rothenstein ◽  
G. Perry ◽  
N. Sivan ◽  
...  

AbstractForaging strategy was observed in five species of Israeli lacertid lizards in the field. Acanthodactylus scutellatus is a sit-and-wait strategist, whereas A. boskianus, A. schreiberi, Lacerta laevis and Mesalina guttulata forage widely. However, the actual values differed from those reported by Huey and Pianka (1981) for Kalahari lacertids, possibly indicating the existence of a continuum of foraging modes. Foraging intensity (proportion of time spent moving or frequency of moves) is positively correlated to relative tail length, and negatively correlated to relative clutch mass. Additional possible correlates are discussed, and some cautionary remarks added.


2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Takatso Mofokeng

Worthy of celebration is the contribution made by Itumeleng Mosala (hereafter Mosala) to the Black Methodist Consultation, the theological community in Southern Africa, and the Black Consciousness Movement. This article attempts to give theology its world, feet and hands in the person of Mosala. The article departs from the narration of the history of Mosala. It locates Mosala within township life and Old Testament scholarship. Furthermore, the article searches for suitable and effective weapons of intellectual struggle in light of Mosala’s life. The aim of this article is to celebrate the indelible footprints that Mosala made as he communed with black people.


2008 ◽  
Vol 42 ◽  
pp. 36-54
Author(s):  
M. S. Kulikovskiy

Main trends of diatom studies in Sphagnum bogs of Russia and adjacent countries are shown. On the basis of published data, making use of modern taxonomical changes, the taxonomical list of diatoms from the considered Sphagnum bogs is presented.


Author(s):  
L.V. Vetchinnikova ◽  
◽  
A.F. Titov ◽  
◽  

The article reports on the application of the best known principles for mapping natural populations of curly (Karelian) birch Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti – one of the most appealing representatives of the forest tree flora. Relying on the synthesis and analysis of the published data amassed over nearly 100 years and the data from own full-scale studies done in the past few decades almost throughout the area where curly birch has grown naturally, it is concluded that its range outlined in the middle of the 20th century and since then hardly revised is outdated. The key factors and reasons necessitating its revision are specified. Herewith it is suggested that the range is delineated using the population approach, and the key element will be the critical population size below which the population is no longer viable in the long term. This approach implies that the boundaries of the taxon range depend on the boundaries of local populations (rather than the locations of individual trees or small clumps of trees), the size of which should not be lower than the critical value, which is supposed to be around 100–500 trees for curly birch. A schematic map of the curly birch range delineated using this approach is provided. We specially address the problem of determining the minimum population size to secure genetic diversity maintenance. The advantages of the population approach to delineating the distribution range of curly birch with regard to its biological features are highlighted. The authors argue that it enables a more accurate delineation of the range; shows the natural evolutionary history of the taxon (although it is not yet officially recognized as a species) and its range; can be relatively easily updated (e.g. depending on the scope of reintroduction); should be taken into account when working on the strategy of conservation and other actions designed to maintain and regenerate this unique representative of the forest tree flora.


1998 ◽  
Vol 11 (1) ◽  
pp. 396-396
Author(s):  
I. Pustylnik

We study the short-time evolutionary history of the well-known contact binary VW Cep. Our analysis is based partly on the numerous UBV lightcurves obtained at Tartu Observatory, IUE spectra, and samples from the published data. Special attention is given to the effects of asymmetry of the light curves. A higher degree of asymmetry outside the eclipses along with the significant displacements of the brightness maxima in respect to the elongation phase is interpreted as evidence that a considerable portion of the flaring source is concentrated close to the neck connecting the components. We discuss the nature of asymmetry in terms of possible mass exchange and the flare activity and compare the results of our model computations with the record of orbital period variations over the last 60 years.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3712
Author(s):  
Ryan D. Rattray ◽  
Ben-Erik Van Wyk

The Lamiaceae is undoubtedly an important plant family, having a rich history of use that spans the globe with many species being used in folk medicine and modern industries alike. Their ability to produce aromatic volatile oils has made them valuable sources of materials in the cosmetic, culinary, and pharmaceutical industries. A thorough account of the taxonomic diversity, chemistry and ethnobotany is lacking for southern African Lamiaceae, which feature some of the region’s most notable medicinal and edible plant species. We provide a comprehensive insight into the Lamiaceae flora of southern Africa, comprising 297 species in 42 genera, 105 of which are endemic to the subcontinent. We further explore the medicinal and traditional uses, where all genera with documented uses are covered for the region. A broad review of the chemistry of southern African Lamiaceae is presented, noting that only 101 species (34%) have been investigated chemically (either their volatile oils or phytochemical characterization of secondary metabolites), thus presenting many and varied opportunities for further studies. The main aim of our study was therefore to present an up-to-date account of the botany, chemistry and traditional uses of the family in southern Africa, and to identify obvious knowledge gaps.


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