El Hassan El Mouden

Sexual Dimorphism in the Greek Tortoise: A Test of the Body Shape Hypothesis

ABSTRACT In most animal species, it is expected that females should exhibit a greater abdominal volume than males to hold the progeny, when compared with females, males should exhibit more developed attributes that enhance mobility. We tested this hypothesis in the Greek tortoise. In chelonians, a reduction of the openings in the shell improves protection against predation but also constrains the abdominal volume and limits the space available to move the limbs. As expected, our data show that the shell provides a larger abdominal volume relative to tortoise size in females than in males. In males, deep notches in the shell and a reduction of several plastron plates offer more freedom to the limbs and to the tail; these characteristics presumably enhance mating success. Further studies are necessary to assess the applicability of these results in other chelonians, notably freshwater and marine turtles.

Long-term variation in reproductive traits of Bibron's Agama, Agama impalearis, in Western Morocco : original article

Abstract Female reproductive characteristics (clutch size [CS], egg volume [EV] and egg mass [EM]) of Agama impalearis and their annual variation were studied over a six‐year period (1993–1998) in the central Jbilet mountains, Western Morocco. Females produced one to two clutches per season and reproduced invariably from spring to late summer, irrespective of climatic conditions. Overall mean CS was 14 eggs per clutch (range: six to 23). CS was positively correlated with snout‐vent‐length (SVL), but not with relative laying date (RLD). There was no among year variation in CS within each age class with three‐year‐old females producing larger clutches over the studied period. Both SVL‐unadjusted and adjusted mean CSs varied significantly from year to year; the largest adjusted CS occurred in 1995 (14.6 + 0.6 eggs). A stepwise regression analysis using seasonal total precipitations and mean temperatures as independent variables indicated that clutch size is significantly related to spring precipitation, whereas it is not related to any other climatic variables tested, including all seasonal mean temperatures. Both EV and EM were not correlated with SVL, CS or RDL in any year, but they exhibit a significant annual variation with the smallest and lightest eggs produced in 1996 (1870.3 ± 372.4 mm3 and 1.05 ± 0.19 g, respectively) and the largest and heaviest ones in 1993 (2550.3 ± 647.7 mm3 and 1.16 ±0.27 g, respectively). Neither EV nor EM was related to precipitation or temperature. The results suggest that reproductive female A. impalearis are adapted to unpredictable proximate environmental factors, in particular spring precipitation which probably ensures sufficient resource levels for the long breeding season.

Does testosterone influence activity budget in the male Greek tortoise (Testudo graeca graeca)

The stimulatory effect of testosterone on male sexual activity is one of the clearest examples linking hormones and behaviors. However, this relationship is complex in Chelonians. We experimentally studied the influence of testosterone levels on the activity budget and space use in male Greek tortoises (Testudo graeca graeca) during the spring mating season. We first described the annual pattern of changes in plasma testosterone levels in free-ranging animals in Morocco. Two peaks, one in winter and one in summer, corresponded to periods of inactivity; whereas mating periods in spring and to a lesser extent in autumn were associated with low plasma testosterone levels. Second, we experimentally manipulated plasma testosterone levels in free-ranging males, and analyzed the behavioral consequences. The strong contrasts in plasma hormone levels induced by the experimental treatments did not result in changes in activity budget or space use, both in the short-term or more than one month after the beginning of the hormonal treatment. Our results suggest that testosterone levels did not influence directly behavioral activity in this species, either immediately or after a time delay of one month.

Species delimitation and digit number in a North African skink.

Delimitation of species is an important and controversial area within evolutionary biology. Many species boundaries have been defined using morphological data. New genetic approaches now offer more objective evaluation and assessment of the reliability of morphological variation as an indicator that speciation has occurred. We examined geographic variation in morphology of the continuously distributed skink Chalcides mionecton from Morocco and used Bayesian analyses of nuclear and mitochondrial DNA (mtDNA) loci to examine: (i) their concordance with morphological patterns, (ii) support for species delimitation, (iii) timing of speciation, and (iv) levels of gene flow between species. Four digit individuals were found at sites between Cap Rhir (in the south) and the northern extreme of the range, whereas five-digit individuals were found in two disjunct areas: (i) south of Cap Rhir and (ii) the north of the range where they were often syntopic with four-digit individuals. The pattern of variation in generalized body dimensions was largely concordant with that in digit number, suggesting two general morphotypes. Bayesian analyses of population structure showed that individuals from sites south of Cap Rhir formed one genetic cluster, but that northern four- and five-digit individuals clustered together. Statistical support for delimitation of these genetic clusters into two species was provided by a recent Bayesian method. Phylogenetic–coalescent dating with external time calibrations indicates that speciation was relatively recent, with a 95% posterior interval of 0.46–2.66 mya. This postdates equivalent phylogenetic dating estimates of sequence divergence by approximately 1 Ma. Statistical analyses of a small number of independent loci provide important insights into the history of the speciation process in C. mionecton and support delimitation of populations into two species with distributions that are spatially discordant with patterns of morphological variation.

Table de développement embryonnaire d'un lézard agamidé, Agama impalearis Boettger, 1874

Abstract This is the first description of the embryonic development of an agamid lizard from North Africa, Agama impalearis. The developmental stages of only one species of the same family, Calotes versicolor, had been described previously. Two complementary studies had been performed on this Asian species, one dealing with intra-oviductal development, the other with extra-oviductal development. Among other iguanians, several cameleonid species and only two American iguanid species had apparently been examined. The other previous studies dealt with some species among the Lacertidae (complete or partial embryonic development), Scincidae, Cordylidae and Anguidae (partial embryonic development). In the present table, 42 stages have been distinguished during the embryonic development of A. impalearis. Stages 1 to 27 correspond to intra-oviductal development including egg segmentation, gastrulation, neurulation and the beginning of organogenesis. Stages 28 to 42 describe morphological changes during extra-oviductal development, i.e. between egg-laying and hatching, and correspond to the continuation of the organogenesis. Although data in other groups are still incomplete, a comparison of the A. impalearis table with that of other lizards reveals a great homogeneity of embryonic development in these reptiles, except for the external ornamentation which is specific.

Shrewd shrikes and spiny shrubs: a calamity for hatchling Moorish tortoises (Testudo graeca graeca)

Cheloniansliveinasafe-boxthatoffersanef-Þcientprotectionagainstmostpredators,atleastin adults and sub-adults (Wilbur and Morin,1988). Nevertheless, in hatchlings, and to alesser extent, in juveniles the shell is soft and/ornot solid enough to resist to many predatorssuch as monitors, dogs, or birds for example(DouglasandWinegarner,1977;FitzpatrickandWoolfenden, 1978; Branch and Els, 1990; Gef-fen and Mendelssohn, 1997; Keller et al., 1998;Hill, 1999; Lagarde et al., 2001; Boarman,2002). In an open landscape, the predation onthese fragile tortoises can be severe; sometimesleaving strong marks on the population dynam-ics (Boarman, 2002). In April 2003, during aÞeld study on the ecology of Testudo graecagraeca in Morocco (Essaouira region, 31 23 N,9 42 W), we found several hatchling tortoisesimpaled on spiny shrubs ( Argania spinosa )ina typical shrike manner (Cramps and Perrins,1993). Therefore, several observations of shrike(Lanius excubitor ) were made in the study areaand even on the involved shrubs. We searchedintensively the study site and the surroundingarea (the total prospected area was 50 ha) anddiscovered a total of 25 impaled tortoises in 3spiny shrubs (respectively 17, 7 and 1 tortoisespershrub).WithanaverageShriketerritorysizeof 75 ha (Cramps and Perrins, 1993), such pre-dation may be due only to one Shrike breed-

Effects of temperature on the song parameters of the Moroccan bushcricket Eugaster spinulosa (Orthoptera, Tettigoniidae)

Acoustic signals are important for inter- and intraspecific interactions in many species. Their information potential depends largely on species characteristics. Here we describe quantitatively the song of Eugaster spinulosa (Johannson 1763), (Orthoptera, Tettigoniidae) and analyse the relationships of song parameters with temperature. To the best of our knowledge there are no previous descriptions available of the song of any species in the genus. Songs of seven males from the mountains of Jebilet, Marrakech (Morocco), were recorded in a semi-anechoic chamber for 105 days. Using automated thermal tables, individuals were exposed to a daily cycle of temperatures between 17.5 and 41.5°C. The calling song of Eugaster spinulosa is broader in frequency (2–28 kHz) than the song of other tettigoniids. It consists of extended series of separately audible echemes, which are polysyllabic and comprise a variable number of broadband syllables, usually between 5 and 10. The stridulatory activity of Eugaster spinulosa showed a wide thermal plasticity (ranging over 24°C between thermal thresholds). In addition to changes in temporal features, we found that an increase in temperature reduced the number of syllables per echeme.

Food choice of an Algerian population of the spur‐thighed tortoise, Testudo graeca

Abstract The diet of an Algerian population of spur‐thighed tortoise (Testudo graeca) was studied with the aims of exploring: (i) the variation in diet among males, females and juveniles, (ii) the relationships between consumption and relative availability of the plant species, and (iii) which plant tissues, vegetative or reproductive, are eaten by tortoises. We recorded more than forty plant species at the study area, with monocot species (n = 7) having a greater percent cover than that of dicot species (n = 31 species) or Gymnospermae (n = 2). Tortoise diet was studied by categorising 4422 plant and animal fragments in faecal pellets of 20 males, 16 females and eight juveniles. Tortoises ate a wide variety of plant species, including 13 dicots and three monocots, and occasionally invertebrates. The number of fragments for a plant species was correlated with plant species cover, and plant vegetative tissues exceeded plant reproductive tissues in the faeces. Dicots (Fabaceae, Composeae, Primulaceae, and Caryophyllaceae) accounted for over 70% of the diet (faecal fragments). The high dietary (niche) overlap, and null model analysis (RA3 algorithm with 30,000 Monte Carlo simulations), indicate that males, females and juveniles did not partition food resources; all three groups ate the same plant species.

Acaricidal properties of essential oils from Moroccan plants against immature ticks of Hyalomma aegyptium (Linnaeus, 1758); an external parasite of the spur-thighed tortoise (Testudo graeca)

ABSTRACT Hyalomma aegyptium (Linnaeus, 1758) is a hard-tick species of the Ixodidae family with the main adult hosts being Palearctic tortoises of the genus Testudo. In Morocco, it is commonly found infecting Testudo graeca that has a wide geographic distribution and is subject to protection through international illegal trade legislation. This tortoise tick has been reported as an important vector of various human and animal pathogens. Unfortunately, to date, there are no strategies to control this hematophagous ectoparasite. The present study was conducted in laboratory to evaluate the acaricidal activity of essential oils (EOs) extracted from six plants of Moroccan origin as an alternative against H. aegyptium. All EOs tested displayed toxic effects on different life stages of H. aegyptium. Mentha suaveolens subsp. timija (LC50 = 0.910 µL/mL and LC90 = 1.465 µL/mL) and Satureja calamintha EOs (LC50 = 0.927 µL/mL and LC90 = 1.347 µL/mL) exhibited higher activity against hatching eggs, whereas Chenopodium ambrosioides EO was comparatively more toxic to larvae (LC50 = 0.444 µL/mL and LC90 = 0.918 µL/mL). Juniperus thurifera var. africana (LC50 = 0.0045 mL/cm2 and LC90 = 0.0118 mL/cm2) and Lavandula pedunculata subsp. atlantica EOs (LC50 = 0.0036 mL/cm2 and LC90 = 0.0110 mL/cm2) caused high mortality in nymphs. The effect of different EOs is discussed according to their chemical composition and bioactive components.

Release calls of Moroccan spadefoot toad, Pelobates varaldii (Anura, Pelobatidae)

Release calls of Pelobates varaldii Pasteur and Bons (1959) are described quantitatively based on airborne recordings obtained from 4 males and 12 females from a population of the extreme north of its range. The calls are sequences of pulsed notes with a variable number of pulses per note. To the best of our knowledge this is the first report on the acoustic repertoire of this endemic endangered species from Morocco.