Mohammed Znari - Academia.edu (original) (raw)
Papers by Mohammed Znari
Russian journal of herpetology, Feb 29, 2024
Research Square (Research Square), May 24, 2023
Population characteristics of Atlas Barbary sheep (Ammotragus lervia) were investigated 17 years ... more Population characteristics of Atlas Barbary sheep (Ammotragus lervia) were investigated 17 years following the 1999 introduction of 10 individuals into the fenced nature reserve of Amassine, High Atlas range, Morocco, for promoting wildlife watching and tourism. Population age-sex structure and density were determinate in late winter early spring during four consecutive years (2016-2019) by direct observation before dispersal of the herd. During 2017 the population age-sex structure and density were also investigated and determinate in mid-late spring while the herd is dispersed using the line transect-distance sampling method to have a comparison between the two methods (direct and indirect). Population size increased from 37 to 62 animals during the four-year study period; the maximal population size being 82 individuals recorded in 2006. An estimated population density ranged from 0.25 to 0.41 Barbary sheep/ha. The adult sex ratio varied from 91 to 67 per 100 ewes. The apparent birth rate was of 14 to 73/100 ewes. Juveniles and subadults comprised 27-43% of the population, adult rams 26-31% and, adult ewes 29-45%. The survival rate from birth to 1 year of age approximated 35%. For adult rams was estimated to average 69%/year. The obtained results would be helpful for developing a sustainable population management and habitat restoration plan, and assessing the feasibility of potential reintroduction/restocking in other areas of the Atlas range.
The 87th Annual Meeting of the American Association of Physical Anthropologists, Austin, TX, 2018
International journal of avian & wildlife biology, Aug 8, 2017
Amphibia-reptilia, Mar 1, 2023
A previous study on the feeding habits of Moorish tortoises in west-central Morocco suggests that... more A previous study on the feeding habits of Moorish tortoises in west-central Morocco suggests that these animals are selective herbivores, but the nutritional consequences have not been examined. Because of the potassium excretion load, which requires water and/or nitrogen loss, we predicted that tortoises do not have salt glands. Moorish tortoises prefer plants rich in water and protein but low in potassium (PEP index). To this end, we studied the spring diet of adult tortoises in an arid steppe in west-central Morocco during two seasons of relatively dry years (2011-2012) using feces analyses. We also estimated the relative abundance of potential food plants by stratified sampling under the canopy of jujube bushes Ziziphus lotus. We statistically compared diet to plant abundance. Finally, we assessed plant species' nutritional composition (water, crude protein, and potassium) available to tortoises. Results showed that species assemblages differed significantly between the two plant communities in both years. Nevertheless, tortoises consumed only about 5-6 and nearly the same species at the study site in 2011 and 2012, respectively. The plants consumed by the tortoises had the highest positive PEP index values indicating that there was more water and nitrogen in the food than is needed to excrete potassium.
Amphibia-reptilia, Oct 8, 2021
Animals inhabiting arid environments use a variety of behavioural and physiological strategies to... more Animals inhabiting arid environments use a variety of behavioural and physiological strategies to balance their water and salt budgets. We studied the effects of dehydration and salt loading on osmoregulatory capacities in a large herbivorous desert lizard, the Moroccan Spiny-tailed lizard Uromastyx nigriventris, the family Agamidae. These lizards select plants with a high K+ to Na+ ratio of 15 to 20, and like other herbivorous lizards, effectively eliminate the extra electrolyte load, mainly via a pair of active nasal salt glands, which exude the extra ions from blood. Here we present results of a series of laboratory experiments, which tested a five-week food and water deprivation and the excretory response of nasal salt glands, during a short period of five days, following salt loading by two separated injections of KCl or NaCl at a 5-day interval (4th and 9th days). During food-water deprivation, hypohydrated lizards lost 32% of their initial body mass with a substantial decrease of their Body Condition Index and the tail volume as an index of energy (fat and then potential metabolic water) storage. Plasma osmolality significantly increased by 20%. There were also significantly increased plasma sodium, chloride, and total protein concentrations. On the other hand, there was no significant decrease in the plasma glucose level. Most of the salt loaded lizards secreted far more K+ than Na+ via the nasal glands, even after NaCl loading. The K+/Na+ ratio decreased only after two to three repetitive NaCl injections but insufficient Na+ was eliminated. Two successive KCl injections were successfully eliminated, but daily natural average K+ administration induced progressive hyperkaliemia. These experimental data agreed with previous observations showing variations of plasma Na+ and K+ concentrations in free-living lizards. The nasal gland constitutes the main route of Cl− excretion but the Cl−/(Na+ + K+) ratio may vary according to observations in other herbivorous species.
Biological Journal of the Linnean Society, 2016
Quaternary climatic oscillations and geographic barriers have strongly influenced the distributio... more Quaternary climatic oscillations and geographic barriers have strongly influenced the distribution and diversification of thermophilic species occurring in the Mediterranean Basin. The Western Mediterranean pond turtle, Mauremys leprosa, is widely distributed throughout the Iberian Peninsula, southern France and most of the Maghreb region, with two subspecies currently recognized. In this work, we used 566 samples, including 259 new individuals, across the species range, and sequenced two mitochondrial markers (cytochrome b gene and control region; 163 samples in a concatenated mtDNA dataset) and one nuclear intron (R35; 23 samples representing all identified sublineages) to study the evolutionary history of M. leprosa. We combined phylogenetic methods and phylogeographic continuous diffusion models with spatial analysis. Our results (1) show a high level of genetic structure in Morocco originated during the Pleistocene; (2) reveal two independent population expansion waves from Morocco to Tunisia and to southern Europe, which later expanded throughout the Iberian Peninsula, and (3) identify several secondary contact zones in Morocco. Our study also sheds new light on the role of geographical features (Moroccan mountains ranges and the Strait of Gibraltar) and Pleistocene climatic oscillations in shaping genetic diversity and structure of M. leprosa, and underlines the importance of the Maghreb as a differentiation centre harbouring distinct glacial refugia.
HAL (Le Centre pour la Communication Scientifique Directe), 2001
The social and sexual behaviour of a marked group of Agama impalearis was observed under natural ... more The social and sexual behaviour of a marked group of Agama impalearis was observed under natural conditions in an arid area of the central Jbilet mountains (Western Morocco) during spring 1995. Supplementary observations were made either in Iaboratory or in the field on unmarked individuals at different periods of the year from 1993 to 1996. We examined the behavioural repertoire of adults. A quantitative analysis of field data allowed to assess relative time proportions and frequencies of the main behavioural categories. The diurnal emergence of animais from their refuges appears to be greatly influenced by temperature as agamas were observed to emerge in the field at different times of the day but at closely similar thermal conditions. The Iizards are highly heliophilous and predominantly sit-and-wait foragers. Feeding behaviour, escape from ennemies, courtship, oviposition and other behaviours were described. Adult males are strongly territorial and have specifie display action-patterns of aggressive behaviour. The displays involve postural change, pushups and head nodds. They were able to rapidly change their colours. The two sexes showed differences in nuptial colours and behavioural attitudes. Contrary to males, females exhibited neither pushup nor head nodds but a specifie display with mouth-gaping when males are courting them. Monogamy is the predominant mating system and there is no real social hierarchy. Home ranges were larger in males and showed low overlaps. Basking and alert postures are predominant through activity time and pushups are the most frequent display.
HAL (Le Centre pour la Communication Scientifique Directe), 1998
Spatial and trophic resource partitioning among seven sympatric insectivorous !izard species was ... more Spatial and trophic resource partitioning among seven sympatric insectivorous !izard species was investigated in arid area in the central Jbilet mountains (Western Morocco) during spring 1995. Two foraging guilds are apparent: a specialist sit-and-wait (Agama impalearis, Ta rentola mauritanica et Saurodactylus brosseti) and a generalist one (Eumeces algeriensis, Chalcides polylepis, Acanthodactylus erythrurus and Mesa/ina simoni). The studied !izard species differentiate from each other in substrate use relatively to their respective adaptive morphological traits. A. impalearis and T. mauritanica occur mainly in rocky areas, E. al geriensis and M. simoni appear mostly on rocky and pebbly-bare ground substrates, A. erythrurus and C. po/y/epis are found on sandy-pebbly substrates while S. brosseti occurs in pebbly soils. By contrast, there were large overlaps in the taxonomie composition of their diets which are numerically dominated by Formicidae, lsoptera, Coleoptera and Araneidae with different proportions according to !izard species. However, important prey-size differ ences between species allowed to reduce trophic overlap. A selectivity analysis of !izard diet revealed patterns of prey selection based on criteria inherent either to predator (foraging behaviour, morphological constraints) or prey (size, abundance and activity). Results suggest that spatial and trophic segregation along with taxonomie divergence make possible the coexistence of these !izard species.
![Research paper thumbnail of The Last-Surviving Moroccan Dorcas Gazelle (Gazella dorcas massaesyla) Viability Analysis [M’Sabih Talaa Reserve, Morocco]](https://attachments.academia-assets.com/109947093/thumbnails/1.jpg)
](International Journal of Zoological Investigations, 2021
The single remnant Moroccan dorcas gazelle (Gazella dorcas massaesyla) has been isolated for more... more The single remnant Moroccan dorcas gazelle (Gazella dorcas massaesyla) has been isolated for more than five decades in the M’Sabih Talaa reserve, an arid area of west-central Morocco. This population has been subject to different disturbances, especially poaching and depredation by feral dogs. A five-season line transect survey revealed that the population size has been halved in less than 15 years with a lower apparent fecundity rate. In the present work, we carried out a population viability analysis simulating different scenarios using VORTEX software based on available demographic and life-history data from captive populations,. A sensitivity analysis revealed that inbreeding depression and possible catastrophic events could have a considerable impact on the population’s prospects. Scenarios of splitting population into two subpopulations with different management measures reducing/deleting mortality sources, is proposed. Such scenarios resulted in reducing the consequences of c...
![Research paper thumbnail of [Effect of prolonged water deprivation on weight gain and water metabolism in a gerbillid rodent (Meriones shawi shawi)]](https://attachments.academia-assets.com/106051419/thumbnails/1.jpg)
](PubMed, 1987
The effect of prolonged water deprivation, applied progressively since weaning, was studied on bo... more The effect of prolonged water deprivation, applied progressively since weaning, was studied on body weight in growing sub-desert rodents (Meriones shawi). Then, water metabolism, food consumption and kidney weight were measured in these adults animals. During partial water deprivation the weight curve was similar to that of controls, whereas with total water deprivation three different stages were noticed: a decrease, a stabilization and an increase in body weight as a function of age. At the end of the experiment, the body water volume was similar in dehydrated and in control animals. However, in water deprived animals, there was a lower rate of water influx and efflux compared to controls. Their food consumption was two-fold that of controls. Dehydrated meriones showed a significant increase in kidney weight as compared to controls.
Zoo Biology, Jul 1, 2008
Flock breeders of black-bellied sandgrouse originated from wild-laid eggs collected in west centr... more Flock breeders of black-bellied sandgrouse originated from wild-laid eggs collected in west central Morocco in 2003 and 2004, were hatched, and handreared in captivity in the framework of a reinforcement population program. Three to five pairs of different ages were housed in an aviary. Egg-pulling procedure was used and eggs incubated artificially. Breeding parameters, hatchability, and posthatching mortality were recorded. The black-bellied sandgrouse showed a seasonal breeding pattern with a laying period extending from 7 to12 weeks. The clutch frequency varied from 3 to 7 clutches per female per season. The mean clutch size was 2.6670.47 eggs, and the mean interclutch interval was 1072.7 days. The average total egg production was 1275.83 eggs per female varying with age from 8 to18 eggs per female. Egg hatchability of incubated eggs increased with age and varied from 37.5 to 72.2%. Chick mortality occurred only in the first week after hatching, averaging 60.5%. The obtained results showed that black-bellied sandgrouse can be successfully bred in captivity and opened the possibility of controlling, managing, and maximizing their production for the reinforcement of the local declining wild populations. Zoo Biol 27:269-281, 2008.
African Journal of Marine Science, 2019
Morphometric variation can be very useful for discriminating 'phenotypic stocks' as groups with s... more Morphometric variation can be very useful for discriminating 'phenotypic stocks' as groups with similar life-history traits. Such groups are of great importance for accurate population-dynamics modelling for purposes of fishery stock assessment and management, independent of their genetic differences or similarities. This study is a contribution to the stock identification of the sardine Sardina pilchardus off the Moroccan Atlantic coast. The objectives were to (i) assess whether specimens from stocks defined by the FAO correspond to different morphotypes, and (ii) compare the obtained results with those recently published on the genetic variability of the studied populations. Morphometric analyses, using truss variables and landmarks data from sardine sampled from four widely spaced ports of landing along the Moroccan Atlantic coast (from north to south: Larache, Safi, Tantan and Dakhla), were carried out using multivariate and geometric approaches. Principal components analysis of truss variables and cluster analysis of the average shape of the sardine revealed the existence of three distinct morphotypes: 'Larache,' 'Safi-Tantan' and 'Dakhla.' These correspond well with the FAO's stock subdivision. The morphometric variation might be related to the mesoscale hydrodynamic characteristics of the study area. However, these morphometric results do not fully accord with recently published data on genetic variability of the species. Those data indicated the genetic singularity of the Safi population, which could have led to the historical collapse of that sardine stock in the 1970s. Additional work is needed to validate the obtained results by taking into account seasonal variations and transitional areas between stocks.
Mammalia, 2021
Atlas Barbary sheep, Ammotragus lervia lervia, are the only wild caprinid of Northwest Africa. So... more Atlas Barbary sheep, Ammotragus lervia lervia, are the only wild caprinid of Northwest Africa. Some studies have investigated their feeding ecology, but there is no information on intraspecific dietary variation. Therefore, we determined the spring diet and its variation between age-sex classes in Atlas Barbary sheep within a fenced nature reserve in the Western High Atlas mountain range, Morocco. We used faecal microhistological analysis to assess diet composition based on a reference epidermis catalogue. The habitat was a highly diversified open mixed forest with 61 identified species (55 genera; 24 families). The herbaceous layer was dominated by grasses, mainly Stipa capensis. Atlas Barbary sheep revealed to be opportunistic grazers, consuming 44 forage species; grasses and forbs constituted 87% of the overall diet. There were significant intraspecific dietary differences. Rams showed a more diverse (42 species) and distinct diet compared to those of ewes (22 species) and juveni...
Revue d'Écologie (La Terre et La Vie)
Spatial and trophic resource partitioning among seven sympatric insectivorous lizard species was ... more Spatial and trophic resource partitioning among seven sympatric insectivorous lizard species was investigated in arid area in the central Jbilet mountains (Western Morocco) during spring 1995. Two foraging guilds are apparent : a specialist sit-and-wait (Agama impalearis, Tarentola mauritanica et Saurodaclylus brosseti) and a generalist one (Eumeces algeriensis, Chalcides polylepis, Acanthodaclylus erythrurus and Mesalina simoni). The studied lizard species differentiate from each other in substrate use relatively to their respective adaptive morphological traits. A impalearis and T. mauritanica occur mainly in rocky areas, K algeriensis and M. simoni appear mostly on rocky and pebbly-bare ground substrates, A. erythrurus and C. polylepis are found on sandy-pebbly substrates while S. brosseti occurs in pebbly soils. By contrast, there were large overlaps in the taxonomic composition of their diets which are numerically dominated by Formicidae, Isoptera, Coleoptera and Araneidae with...
Revue d'Écologie (La Terre et La Vie)
SSRN Electronic Journal, 2022
Sustainable Marine Structures, 2021
This article summarizes the state of stocks of sardine, sardina pilchardus in Moroccan waters at ... more This article summarizes the state of stocks of sardine, sardina pilchardus in Moroccan waters at the end of 2016 and 2018. These stocks varies according to the region,They are now in a sustainable exploitation situation:Atlantic sardine, but also stocks that have reached or are still in over-exploitation levels: Mediterranean sardine. The fi shing pressure exerted on the sardine stock exceeds the optimal level by 40%. Due to the degradation of the fragile marine environment of the Mediterranean region, generated by pollution of various origins, the overexploitation of juveniles in the coastal strip, non-responsible practices and the use of non-fi shing gearselective, it is imperative to take the necessary measures to protect the marine environment and ensure rational and sustainable exploitation of the resource. (High commission plan 2006 report).
Russian journal of herpetology, Feb 29, 2024
Research Square (Research Square), May 24, 2023
Population characteristics of Atlas Barbary sheep (Ammotragus lervia) were investigated 17 years ... more Population characteristics of Atlas Barbary sheep (Ammotragus lervia) were investigated 17 years following the 1999 introduction of 10 individuals into the fenced nature reserve of Amassine, High Atlas range, Morocco, for promoting wildlife watching and tourism. Population age-sex structure and density were determinate in late winter early spring during four consecutive years (2016-2019) by direct observation before dispersal of the herd. During 2017 the population age-sex structure and density were also investigated and determinate in mid-late spring while the herd is dispersed using the line transect-distance sampling method to have a comparison between the two methods (direct and indirect). Population size increased from 37 to 62 animals during the four-year study period; the maximal population size being 82 individuals recorded in 2006. An estimated population density ranged from 0.25 to 0.41 Barbary sheep/ha. The adult sex ratio varied from 91 to 67 per 100 ewes. The apparent birth rate was of 14 to 73/100 ewes. Juveniles and subadults comprised 27-43% of the population, adult rams 26-31% and, adult ewes 29-45%. The survival rate from birth to 1 year of age approximated 35%. For adult rams was estimated to average 69%/year. The obtained results would be helpful for developing a sustainable population management and habitat restoration plan, and assessing the feasibility of potential reintroduction/restocking in other areas of the Atlas range.
The 87th Annual Meeting of the American Association of Physical Anthropologists, Austin, TX, 2018
International journal of avian & wildlife biology, Aug 8, 2017
Amphibia-reptilia, Mar 1, 2023
A previous study on the feeding habits of Moorish tortoises in west-central Morocco suggests that... more A previous study on the feeding habits of Moorish tortoises in west-central Morocco suggests that these animals are selective herbivores, but the nutritional consequences have not been examined. Because of the potassium excretion load, which requires water and/or nitrogen loss, we predicted that tortoises do not have salt glands. Moorish tortoises prefer plants rich in water and protein but low in potassium (PEP index). To this end, we studied the spring diet of adult tortoises in an arid steppe in west-central Morocco during two seasons of relatively dry years (2011-2012) using feces analyses. We also estimated the relative abundance of potential food plants by stratified sampling under the canopy of jujube bushes Ziziphus lotus. We statistically compared diet to plant abundance. Finally, we assessed plant species' nutritional composition (water, crude protein, and potassium) available to tortoises. Results showed that species assemblages differed significantly between the two plant communities in both years. Nevertheless, tortoises consumed only about 5-6 and nearly the same species at the study site in 2011 and 2012, respectively. The plants consumed by the tortoises had the highest positive PEP index values indicating that there was more water and nitrogen in the food than is needed to excrete potassium.
Amphibia-reptilia, Oct 8, 2021
Animals inhabiting arid environments use a variety of behavioural and physiological strategies to... more Animals inhabiting arid environments use a variety of behavioural and physiological strategies to balance their water and salt budgets. We studied the effects of dehydration and salt loading on osmoregulatory capacities in a large herbivorous desert lizard, the Moroccan Spiny-tailed lizard Uromastyx nigriventris, the family Agamidae. These lizards select plants with a high K+ to Na+ ratio of 15 to 20, and like other herbivorous lizards, effectively eliminate the extra electrolyte load, mainly via a pair of active nasal salt glands, which exude the extra ions from blood. Here we present results of a series of laboratory experiments, which tested a five-week food and water deprivation and the excretory response of nasal salt glands, during a short period of five days, following salt loading by two separated injections of KCl or NaCl at a 5-day interval (4th and 9th days). During food-water deprivation, hypohydrated lizards lost 32% of their initial body mass with a substantial decrease of their Body Condition Index and the tail volume as an index of energy (fat and then potential metabolic water) storage. Plasma osmolality significantly increased by 20%. There were also significantly increased plasma sodium, chloride, and total protein concentrations. On the other hand, there was no significant decrease in the plasma glucose level. Most of the salt loaded lizards secreted far more K+ than Na+ via the nasal glands, even after NaCl loading. The K+/Na+ ratio decreased only after two to three repetitive NaCl injections but insufficient Na+ was eliminated. Two successive KCl injections were successfully eliminated, but daily natural average K+ administration induced progressive hyperkaliemia. These experimental data agreed with previous observations showing variations of plasma Na+ and K+ concentrations in free-living lizards. The nasal gland constitutes the main route of Cl− excretion but the Cl−/(Na+ + K+) ratio may vary according to observations in other herbivorous species.
Biological Journal of the Linnean Society, 2016
Quaternary climatic oscillations and geographic barriers have strongly influenced the distributio... more Quaternary climatic oscillations and geographic barriers have strongly influenced the distribution and diversification of thermophilic species occurring in the Mediterranean Basin. The Western Mediterranean pond turtle, Mauremys leprosa, is widely distributed throughout the Iberian Peninsula, southern France and most of the Maghreb region, with two subspecies currently recognized. In this work, we used 566 samples, including 259 new individuals, across the species range, and sequenced two mitochondrial markers (cytochrome b gene and control region; 163 samples in a concatenated mtDNA dataset) and one nuclear intron (R35; 23 samples representing all identified sublineages) to study the evolutionary history of M. leprosa. We combined phylogenetic methods and phylogeographic continuous diffusion models with spatial analysis. Our results (1) show a high level of genetic structure in Morocco originated during the Pleistocene; (2) reveal two independent population expansion waves from Morocco to Tunisia and to southern Europe, which later expanded throughout the Iberian Peninsula, and (3) identify several secondary contact zones in Morocco. Our study also sheds new light on the role of geographical features (Moroccan mountains ranges and the Strait of Gibraltar) and Pleistocene climatic oscillations in shaping genetic diversity and structure of M. leprosa, and underlines the importance of the Maghreb as a differentiation centre harbouring distinct glacial refugia.
HAL (Le Centre pour la Communication Scientifique Directe), 2001
The social and sexual behaviour of a marked group of Agama impalearis was observed under natural ... more The social and sexual behaviour of a marked group of Agama impalearis was observed under natural conditions in an arid area of the central Jbilet mountains (Western Morocco) during spring 1995. Supplementary observations were made either in Iaboratory or in the field on unmarked individuals at different periods of the year from 1993 to 1996. We examined the behavioural repertoire of adults. A quantitative analysis of field data allowed to assess relative time proportions and frequencies of the main behavioural categories. The diurnal emergence of animais from their refuges appears to be greatly influenced by temperature as agamas were observed to emerge in the field at different times of the day but at closely similar thermal conditions. The Iizards are highly heliophilous and predominantly sit-and-wait foragers. Feeding behaviour, escape from ennemies, courtship, oviposition and other behaviours were described. Adult males are strongly territorial and have specifie display action-patterns of aggressive behaviour. The displays involve postural change, pushups and head nodds. They were able to rapidly change their colours. The two sexes showed differences in nuptial colours and behavioural attitudes. Contrary to males, females exhibited neither pushup nor head nodds but a specifie display with mouth-gaping when males are courting them. Monogamy is the predominant mating system and there is no real social hierarchy. Home ranges were larger in males and showed low overlaps. Basking and alert postures are predominant through activity time and pushups are the most frequent display.
HAL (Le Centre pour la Communication Scientifique Directe), 1998
Spatial and trophic resource partitioning among seven sympatric insectivorous !izard species was ... more Spatial and trophic resource partitioning among seven sympatric insectivorous !izard species was investigated in arid area in the central Jbilet mountains (Western Morocco) during spring 1995. Two foraging guilds are apparent: a specialist sit-and-wait (Agama impalearis, Ta rentola mauritanica et Saurodactylus brosseti) and a generalist one (Eumeces algeriensis, Chalcides polylepis, Acanthodactylus erythrurus and Mesa/ina simoni). The studied !izard species differentiate from each other in substrate use relatively to their respective adaptive morphological traits. A. impalearis and T. mauritanica occur mainly in rocky areas, E. al geriensis and M. simoni appear mostly on rocky and pebbly-bare ground substrates, A. erythrurus and C. po/y/epis are found on sandy-pebbly substrates while S. brosseti occurs in pebbly soils. By contrast, there were large overlaps in the taxonomie composition of their diets which are numerically dominated by Formicidae, lsoptera, Coleoptera and Araneidae with different proportions according to !izard species. However, important prey-size differ ences between species allowed to reduce trophic overlap. A selectivity analysis of !izard diet revealed patterns of prey selection based on criteria inherent either to predator (foraging behaviour, morphological constraints) or prey (size, abundance and activity). Results suggest that spatial and trophic segregation along with taxonomie divergence make possible the coexistence of these !izard species.
International Journal of Zoological Investigations, 2021
The single remnant Moroccan dorcas gazelle (Gazella dorcas massaesyla) has been isolated for more... more The single remnant Moroccan dorcas gazelle (Gazella dorcas massaesyla) has been isolated for more than five decades in the M’Sabih Talaa reserve, an arid area of west-central Morocco. This population has been subject to different disturbances, especially poaching and depredation by feral dogs. A five-season line transect survey revealed that the population size has been halved in less than 15 years with a lower apparent fecundity rate. In the present work, we carried out a population viability analysis simulating different scenarios using VORTEX software based on available demographic and life-history data from captive populations,. A sensitivity analysis revealed that inbreeding depression and possible catastrophic events could have a considerable impact on the population’s prospects. Scenarios of splitting population into two subpopulations with different management measures reducing/deleting mortality sources, is proposed. Such scenarios resulted in reducing the consequences of c...
PubMed, 1987
The effect of prolonged water deprivation, applied progressively since weaning, was studied on bo... more The effect of prolonged water deprivation, applied progressively since weaning, was studied on body weight in growing sub-desert rodents (Meriones shawi). Then, water metabolism, food consumption and kidney weight were measured in these adults animals. During partial water deprivation the weight curve was similar to that of controls, whereas with total water deprivation three different stages were noticed: a decrease, a stabilization and an increase in body weight as a function of age. At the end of the experiment, the body water volume was similar in dehydrated and in control animals. However, in water deprived animals, there was a lower rate of water influx and efflux compared to controls. Their food consumption was two-fold that of controls. Dehydrated meriones showed a significant increase in kidney weight as compared to controls.
Zoo Biology, Jul 1, 2008
Flock breeders of black-bellied sandgrouse originated from wild-laid eggs collected in west centr... more Flock breeders of black-bellied sandgrouse originated from wild-laid eggs collected in west central Morocco in 2003 and 2004, were hatched, and handreared in captivity in the framework of a reinforcement population program. Three to five pairs of different ages were housed in an aviary. Egg-pulling procedure was used and eggs incubated artificially. Breeding parameters, hatchability, and posthatching mortality were recorded. The black-bellied sandgrouse showed a seasonal breeding pattern with a laying period extending from 7 to12 weeks. The clutch frequency varied from 3 to 7 clutches per female per season. The mean clutch size was 2.6670.47 eggs, and the mean interclutch interval was 1072.7 days. The average total egg production was 1275.83 eggs per female varying with age from 8 to18 eggs per female. Egg hatchability of incubated eggs increased with age and varied from 37.5 to 72.2%. Chick mortality occurred only in the first week after hatching, averaging 60.5%. The obtained results showed that black-bellied sandgrouse can be successfully bred in captivity and opened the possibility of controlling, managing, and maximizing their production for the reinforcement of the local declining wild populations. Zoo Biol 27:269-281, 2008.
African Journal of Marine Science, 2019
Morphometric variation can be very useful for discriminating 'phenotypic stocks' as groups with s... more Morphometric variation can be very useful for discriminating 'phenotypic stocks' as groups with similar life-history traits. Such groups are of great importance for accurate population-dynamics modelling for purposes of fishery stock assessment and management, independent of their genetic differences or similarities. This study is a contribution to the stock identification of the sardine Sardina pilchardus off the Moroccan Atlantic coast. The objectives were to (i) assess whether specimens from stocks defined by the FAO correspond to different morphotypes, and (ii) compare the obtained results with those recently published on the genetic variability of the studied populations. Morphometric analyses, using truss variables and landmarks data from sardine sampled from four widely spaced ports of landing along the Moroccan Atlantic coast (from north to south: Larache, Safi, Tantan and Dakhla), were carried out using multivariate and geometric approaches. Principal components analysis of truss variables and cluster analysis of the average shape of the sardine revealed the existence of three distinct morphotypes: 'Larache,' 'Safi-Tantan' and 'Dakhla.' These correspond well with the FAO's stock subdivision. The morphometric variation might be related to the mesoscale hydrodynamic characteristics of the study area. However, these morphometric results do not fully accord with recently published data on genetic variability of the species. Those data indicated the genetic singularity of the Safi population, which could have led to the historical collapse of that sardine stock in the 1970s. Additional work is needed to validate the obtained results by taking into account seasonal variations and transitional areas between stocks.
Mammalia, 2021
Atlas Barbary sheep, Ammotragus lervia lervia, are the only wild caprinid of Northwest Africa. So... more Atlas Barbary sheep, Ammotragus lervia lervia, are the only wild caprinid of Northwest Africa. Some studies have investigated their feeding ecology, but there is no information on intraspecific dietary variation. Therefore, we determined the spring diet and its variation between age-sex classes in Atlas Barbary sheep within a fenced nature reserve in the Western High Atlas mountain range, Morocco. We used faecal microhistological analysis to assess diet composition based on a reference epidermis catalogue. The habitat was a highly diversified open mixed forest with 61 identified species (55 genera; 24 families). The herbaceous layer was dominated by grasses, mainly Stipa capensis. Atlas Barbary sheep revealed to be opportunistic grazers, consuming 44 forage species; grasses and forbs constituted 87% of the overall diet. There were significant intraspecific dietary differences. Rams showed a more diverse (42 species) and distinct diet compared to those of ewes (22 species) and juveni...
Revue d'Écologie (La Terre et La Vie)
Spatial and trophic resource partitioning among seven sympatric insectivorous lizard species was ... more Spatial and trophic resource partitioning among seven sympatric insectivorous lizard species was investigated in arid area in the central Jbilet mountains (Western Morocco) during spring 1995. Two foraging guilds are apparent : a specialist sit-and-wait (Agama impalearis, Tarentola mauritanica et Saurodaclylus brosseti) and a generalist one (Eumeces algeriensis, Chalcides polylepis, Acanthodaclylus erythrurus and Mesalina simoni). The studied lizard species differentiate from each other in substrate use relatively to their respective adaptive morphological traits. A impalearis and T. mauritanica occur mainly in rocky areas, K algeriensis and M. simoni appear mostly on rocky and pebbly-bare ground substrates, A. erythrurus and C. polylepis are found on sandy-pebbly substrates while S. brosseti occurs in pebbly soils. By contrast, there were large overlaps in the taxonomic composition of their diets which are numerically dominated by Formicidae, Isoptera, Coleoptera and Araneidae with...
Revue d'Écologie (La Terre et La Vie)
SSRN Electronic Journal, 2022
Sustainable Marine Structures, 2021
This article summarizes the state of stocks of sardine, sardina pilchardus in Moroccan waters at ... more This article summarizes the state of stocks of sardine, sardina pilchardus in Moroccan waters at the end of 2016 and 2018. These stocks varies according to the region,They are now in a sustainable exploitation situation:Atlantic sardine, but also stocks that have reached or are still in over-exploitation levels: Mediterranean sardine. The fi shing pressure exerted on the sardine stock exceeds the optimal level by 40%. Due to the degradation of the fragile marine environment of the Mediterranean region, generated by pollution of various origins, the overexploitation of juveniles in the coastal strip, non-responsible practices and the use of non-fi shing gearselective, it is imperative to take the necessary measures to protect the marine environment and ensure rational and sustainable exploitation of the resource. (High commission plan 2006 report).