Eighty-six cases of kleptoparasitism in grey herons, most of which were intraspecific, were observed in northern Spain and southwest France during four winters (1992-1995). Herons more often attacked individually than in groups, but the success was similar in both cases. Robbing success was significantly higher when herons attacked a young bird (44.4%) compared to adults (17.6%). Adult herons were significantly more successful (37.5%) than young herons (10.0%). Handling time had a great effect on the size of the prey item robbed by the herons. Adult herons were more frequently attacked by both young and adult birds. Age- related differences in winter foraging parameters (total time foraging, feeding success and biomass intake) may favour discrimination between victim age classes by kleptoparasites. Adult heron ingested 0.82 g min-1 during the winter season and young heron 0.45 g min-1. For kleptoparasites adult herons seems to be a more profitable species than young. Kleptoparasitism increased the biomass intake of the pirate (62.8 g more than the normal intake of a young heron), probably to compensate for the inefficiency of young birds.
The trout barb Capoeta trutta is native to the Middle East only and little is known of its life-history in Iranian waters. Life history characteristics were examined in 366 specimens collected from the River Meymeh (western Iran) monthly during the reproductive seasons (March-May) of 2008 and 2009. Observed maximum age was 6+ years in both sexes, sex ratio (male : female) was 1 : 1.35, and length-weight relationships were TL = 0.0266TW2.7134 (males), TL = 0.0258TW2.7251 (females), and TL = 0.026TW2.7217 (entire population). Mean egg diameter (ED) was 1.61 (± 0.03 SE), ranging from 1.6 to 1.9 mm. Mean absolute (AF) and relative fecundity (RF) were 7594 (± 283.04 SE) eggs/female, and 70 (± 241.86 SE) eggs·g–1 body weight, respectively. AF and ED were found to increase significantly with increasing fish size, whereas RF decreased significantly with both fish TL and weight. Simplified von Bertalanffy growth estimates were also calculated.
The influence of female mating status on ovarian development of the ladybird, Propylea dissecta (Mulsant) (Coleoptera: Coccinellidae), was investigated under laboratory conditions. We assessed the extent to which ovariole development was affected by mating and for that we initially created a base line by observing age specific ovariole development. Results show that the number of follicles in each ovariole increased with the age of both virgin and mated females up to the age of 3 days, thereafter, no increase in number of follicles was recorded. Ovariole width also increased with age in both virgin and mated females up to 4 days, thereafter, no increase in ovariole width was recorded. The ovariole width of mated females was significantly greater than that of virgin females. Egg maturation and the egg load started to increase at the age of 8 days in virgin females. Thereafter, it increased with increase in female age. While in mated females, immature eggs were recorded in their ovarioles from the age of 1 to 2 days. In mated females, however, the increase in the number of mature eggs per ovariole and egg load started when they were 3 days old. Egg load continuously increased with increasing female age., Mhd Shahid, Arshi Siddiqui, Omkar, Geetanjali Mishra., and Obsahuje bibliografii
In this study, aspects of the reproductive performance and behaviour of male Myzus persicae (Sulzer) (Hemiptera: Aphididae) were investigated. We report that males of clones possessing an autosomal 1,3 translocation conferring insecticide resistance show a weak trend for a reduction in reproductive potential. Clones with the translocation that can produce males but no mating females (androcyclic clones) did not have an additional disadvantage. The age of virgin males and females affected mating success. Young males and females, 0-5 days old, were the most successful with respect to the number of females mated and number of eggs produced. There was a decline in reproductive potential after 9-10 days into adult life for males and after 4-5 days for females. Mating behaviour was observed in the laboratory and described. Some pre-copulatory stroking behaviour by the fore and hind legs of the male was observed. Females occasionally walked in copula sometimes resulting in the disengagement of the male before the termination of mating. Average mating duration in the experimental conditions was 10.5 ± 4.0 minutes and both males and females readily mated more than once.
Little is known of the life history of Cobitiscf. satunini, a loach species native to the Caucasus and southern Caspian Basin. Life history characteristics of this species were examined in 568 specimens collected from the Siahroud stream (northern Iran) between February and June 2010. The specimens ranged in size from 27 to 103 mm total length and weighed from 0.13 to 8.93 g total weight. The overall sex ratio was unbalanced as females dominated, with 342 females and 226 males being caught (sex ratio 1.5 : 1). Length-weight relationships implied that growth was positively allometric for both sexes. The von Bertalanffy growth function was estimated to be Lt = 94.95 (1 – e– 0.49 (t + 0.34)) for males and Lt = 121.65 (1 – e–0.39(t + 0.43)) for females. Egg diameter ranged from 0.44 to 1.02 mm, with a mean value of 0.77 mm. Absolute fecundity varied from 212 to 4666 eggs. Fecundity relative to total weight fluctuated from 383 to 268 eggs g–1. These growth and reproduction traits may be interpreted as species life history capacity and/or adaptation to environmental conditions caused by the southern Caspian climate.
Wild boar population structure was studied in two well-preserved forests of western Iberian Peninsula, one located in a typically Mediterranean zone (vegetation mainly holm oak Quercus ilex and various tall-shrubs species), and the other in a more Atlantic area (mainly oak Q. pyrenica but with abundant cork oak Q. suber in some places). Data were colleted during hunts in monterías’ area between the 1994/95 and 2000/2001 hunting seasons (October to February). 972 hunted wild boars were sexed and aged in the field, using growth patterns and tooth attrition. The mean age of hunted wild boars differed in the two zones. 2.11 years old in holm oak forest, and 1.78 years old in oak forest. This difference may result from shurb cover density and its effect on hunting dog, efficiency in rooting out wild boar. However, mean age was similar other zones of Europe. Proportionately more females were taken than males demonstrate the usefulness of Mediterranean hunting in contributing to management and conservation.
V práci autor předkládá hypotézy, podle nichž mají pocity životního štěstí a spokojenosti zpětné vlivy na percepci a hodnocení objektivních podmínek života. Pro výklad těchto účinků na percepci objektivních podmínek předkládá hypotézu kognitivní konzistence (halo efektu), pro výklad účinků kvality života na interpretaci a hodnocení vstupních informací předkládá autor hypotézu kauzálních atribucí. Podle první hypotézy je při percepci podmínek života ve hře jev podobný halo efektu. Ten vede k tomu, že šťastní lidé nahlíží řadu podmínek svého života v lepším světle než lidé nešťastní. Podle druhé hypotézy používáme odlišná kauzální schémata pro výklad nespokojenosti a spokojenosti se životem.
Tyto hypotézy – především hypotézu týkající se účinku kauzálních atribucí – autor specifikoval zvlášť pro úroveň jedinců a států a testoval na datech ze tří šetření ESS (z let 2002, 2004 a 2006). Zaměřil se na účinky vzdělání, zdraví a politicko-ekonomické situace státu. Tyto tři faktory mají na pocity životního štěstí a spokojenosti významné nezávislé vlivy. Jejich účinky jsou však současně moderovány kvalitou života. U jedinců, kteří jsou v rámci státu nadprůměrně šťastní a spokojení se svými životy, neexistují téměř žádné souvislosti mezi jejich pocity životního štěstí a jejich vzděláním, subjektivním zdravím a spokojeností s politicko-ekonomickou situací. Avšak u jedinců, kteří jsou v rámci státu relativně nešťastní a jsou se svými životy nespokojení, existují mezi těmito proměnnými velmi silné souvislosti. Na úrovni států se analogicky ukázalo, že čím jsou v určitém státě jedinci v průměru šťastnější a spokojenější, tím nižší jsou v tomto státě souvislosti (korelace) mezi těmito třemi proměnnými a kvalitou života.
The observations of Sunda pangolin reproductive parameters in this paper were based on the wild-caught animals and those that had spent time in captive environments, however, when analyzing the results, we did not consider differences in terms of breeding habits between the two. Still, this research has led to an increase in knowledge of the breeding habits of the Sunda pangolin. Our results suggest that there is no breeding season or season of parturition for the Sunda pangolin, which breeds all year round. We estimated the gestation period in this species to be around six months. Sexual maturity occurred at one year old or as early as six-seven months
old in some individuals, and requires further investigation. Each Sunda pangolin in this study gave birth to one offspring at a time. The sex ratio at birth was 0.875:1 (♀:♂) (n = 15); and the weaning age was estimated at four months with a weight of 1.19 ± 0.50 kg (n = 3), which concurs with recent research. Findings in this study will contribute to future analyses of population dynamics, species conservation, and both in situ and ex situ management of the Sunda pangolin. Despite this contribution, further studies are needed on the reproductive parameters of Sunda pangolin.
A bag-seine net (18-22 mm bar length mesh size) was used to collect two native, the Albanian barbel, Barbus albanicus Steindachener, 1870 and the chub, Leuciscus cf. svallize (Heckel et Knerr, 1858) and one introduced, the pumpkinseed, Lepomis gibbosus (Linnaeus, 1758), fish species of the Tavropos reservoir (western Greece). The soamtic lengths were linearly correlated to each other for all three species. B. albanicus and L. cf. svallize exhibited negative allometric growth, while the L. gibbosus grew isometrically. The mouth dimension were linearly or exponentially correlated to body size for all species. However, the mouth morphology differed among the species indicating differences in foraging ability and resource utilization. The lifespan of B. albanicus, L. cf. svallize and L. gibbosus in Tavropos reservoir was 21, 9 and 3 years respectively. The corresponding growth parameters were: L∞ = 47.0 cm, K = 0.064 yr-1, t0 = -2.76 yr for B. albanicus, L∞ = 24.3 cm, K = 0.257 yr-1, t0 = -1.46 yr for L. cf. svallize and L∞ = 11.9 cm, K ´0.506 yr-1, t0 = 1.67 yr for L. gibbosus.
The striped hyaena Hyaena hyaena (Linnaeus, 1758) is globally categorised as “Near Threatened” and is nearly extinct in the Caucasus. In Armenia, the last published record dates back to 1925 and the last trustworthy sighting was in the late 1940s. Here, a dead hyaena is described which was found in 2010 near the Nrnadzor village in the extreme south of Armenia. Its skull was investigated, age was estimated by several methods (cementum layers, tooth eruption, fusion of cranial sutures, pulp cavity closure and tooth wear) and sex was determined from the sagittal, occipital and nuchal crests and by genotyping of skin DNA. The specimen was found out to be a female aged ca. 17-18 months. As this is the age of disperal and females play a pivotal role in the social life of this carnivore, the possibilities for recolonization and establishment of hyaena population in the Meghri district of southern Armenia are discussed. This area holds sufficient prey base and suitable arid landscapes for survival of this species. The recent record of another individual’s fresh tracks on sand near Nrnadzor supports this hypothesis. Usability of different techniques of sex determination and age estimation in the striped hyaena is considered.