Analysis of nest occupancy and nest reproduction in two sympatric raptors: common buzzard Buteo buteo and goshawk Accipiter gentilis

Nest site selection can have important fitness consequences in birds. I analysed the habitat characteristics of 392 nests of two sympatric raptor species (common buzzard Buteo buteo and goshawk Accipiter gentilis ) in Germany and their relation to nest occupation rate and nest reproductive success. For common buzzard, multivariate models explained only small proportions of the variance in nest occupation rate and nest reproductive success (13–19%). Important variables related to nest occupation rate were human disturbances, intra- and interspecific neighbour density, the amount of forested area and nest tree crown cover. Variables related to nest site reproductive success also included human disturbance, intra- and interspecific neighbour density and nest tree crown cover as well as nest distance to the nearest forest edge. In contrast, models for the goshawk explained a much higher proportion of the variation in nest occupation rate and nest reproductive success (41–43%). Important variables related to nest occupation rate were the remoteness of the nest site and direct human disturbance. Variables related to nest site reproductive success were remoteness of the nest site and good hunting habitat. Goshawks seem to be more sensitive to human disturbance than buzzards. A multiple discriminant analysis showed that nest site characteristics substantially overlapped between the species and there is a good evidence that competition for optimal nest sites occurs. Thus, buzzards might be constrained by the dominant goshawk in their nest site selection.     

Grooming site preferences in female langurs (Presbytis entellus)

Factors influencing grooming site preferences in adult female Hanuman langurs (Presbytis entellus) were investigated. The females belonged to a free-ranging harem troop (Jodhpur, India) and were observed for 569 hr by focal-female sampling. Decisive factors for grooming site preferences were the following: autogrooming was determined mostly by site accessiblity. Allogrooming was significantly concentrated on parts that are inaccessible to the groomee. Close female kin groomed significantly longer, more frequently, and more precisely at inaccessible body parts. Lower-ranking females were groomed significantly less often and more briefly but also more precisely at inaccessible parts. However, the latter might be due to a lower-ranking subjects desire to face away from the higher-ranking groomer in order to avoid eye contact. The data suggest that the groomee determines the sites being groomed.     

Nesting behavior and nest site selection in monk parakeets (Myiopsitta monachus) in the Pantanal of Brazil

We examined nesting behavior in monk parakeets (Myiopsitta monachus) in their native habitat in the Brazilian Pantanal. Unique among parrots, monk parakeets build communal nest structures that contain many cavities, each belonging to an individual pair. We studied 41 parakeet colonies that had 104 nest structures. We hypothesized that nest structures would be located in trees providing the greatest support and protection from predators and inclement weather, and that nest sites and nest cavities would differ from random locations with respect to tree characteristics, location of houses, and presence of jabiru stork (Jabiru mycteria) nests, as suggested anecdotally by other authors. Fewer than half of the colonies were close (<350 m) to houses. There was a strong association with jabiru storks; 21 of 23 stork nests had monk parakeet nest cavities attached, accounting for 51% of parakeet colonies. Of the 21 jabiru-associated colonies, 6 had additional parakeet structures and 15 had only the jabiru-attached parakeet structure. Monk parakeet colonies associated with jabiru nests had significantly more nesting cavities than did monospecific monk parakeet colonies, due mainly to those attached directly to the jabiru nest. In jabiru-associated colonies, parakeet nest structures were located higher and in taller trees than in monospecific colonies. There was no difference in trunk diameters of parakeet nesting trees with or without jabirus. Although we tabulated 24 tree species as nest trees, nearest-neighbor trees, or matched-point trees, only 6 species were used for nesting. When compared to matched points, monk parakeet structures were preferentially located in piuva (Tabebuia spp.) and mandovi trees (Sterculia apetela). Parakeet structures were in taller trees with thicker trunk diameters than matched points. Most nest cavities (71%) faced in a northerly direction (northwest to northeast), away from cold southerly winds. Choice of a nest site and orientation appears to reflect structural, weather, and predator constraints. Thick, tall trees with stout branches provided stable sites for their large nest structures, which are known to collapse because of their own weight and strong winds. Nesting with jabirus confers structural advantages (they could attach many nests to the bottom of the jabiru nest, potentially gaining benefits from social facilitation), early warning, and predator defense.     

Nesting biology of tropical solitary and social sweat bees,Lasioglossum (Dialictus) figueresi Wcislo andL. (D.) aeneiventre (Friese) (Hymenoptera: Halictidae)

Summary The nesting biology of a mainly solitary bee,Lasioglossum (Dialictus) figueresi, is compared with that of a possible relative and mainly eusocial bee,L. (D.) aeneiventre. These bees nest in the ground in highly disturbed areas in the Meseta Central of Costa Rica. Information is provided on social organization, male production, diel and seasonal activity patterns, pollen utilization, natural enemies and nest architecture. L. (D.) figueresi nests within aggregations in vertical earthen banks, and 80–90 % of females are solitary during the nest-provisioning phase. Social nests contain two (or rarely three) females which may be either equal or unequal in reproductive status (i.e. mated with developed ovaries or not). Solitary nests and two-female nests do not experience different rates of parasitism. Mid-way through the dry season, females cease provisioning at a time when otherL. (Dialictus) remain active. Females typically remain within their nests, although they occasionally forage for nectar. This behavior is similar of that of spring gynes of temperate eusocial species. The egg-to-adult developmental rate ofL. (D.) figueresi is unusually slow for halictine bees, however, so that all the adult females die before their brood eclose in April and May, precluding overlap of generations. The eclosed offspring remain in open cells within their natal nests until mid-June, when both males and females emerge to mate. These newly mated females either establish new nests or re-use old ones. L. (D.) aeneiventre nests within aggregations in horizontal ground or in vertical banks. A foundress female digs a nest at the beginning of the dry season, although some re-activate old nests. Foundress nests develop into colonies with various kinds of social organization. In contrast toL. (D.) figueresi, L. (D.) aeneiventre is active nearly all year round, except during periods of heavy rain, and produces up to three broods per year.Sweat bees (Hymenoptera: Halictinae) are a socially heterogeneous group of mainly ground-nesting bees which are abundant world-wide. Intra-specific variation in social behavior is prevalent both within and among populations, presumably indicating social and environmental control of behavioral modifications (see e.g. Sakagami and Munakata, 1972; Eickwort, 1986; Packer, 1990; Yanega, 1988; reviewed in Michener, 1990). The initial stages of hymenopteran social evolution are represented by solitary individuals and those in undifferentiated societies, yet their biology is not well known, as is true for the numerous tropical halictine species or populations (see Michener, 1990).The subgenusDialictus ofLasioglossum is a primarily New World group of several hundred species (Moure and Kurd, 1987). These bees are monotonously similar in structure and appearance, yet diverse in social behavior. FemaleLasioglossum (Dialictus) figueresi are usually solitary, and structurally are very similar to their social relativeL. (D.) aeneiventre (Wcislo, 1990 a). The systematic placement of these species with respect to otherL. (Dialictus) is uncertain, but they have no obvious affinities to other recognized species groups (G. C. Eickwort, pers. comm.). Unusual morphological features, such as large size, yellowish wings and pubescence, and features of the genital organs, may indicate thatL. (D.) figueresi is the more derived of the pair, and may therefore be secondarily solitary, as is known for other sweat bees (Packer, 1991).     

Host and site selection by larval stages and adults of the parasitic copepod Lernaeenicus sprattae (Sowerby) (Copepoda,Pennellidae) in the Oslofjord

Sprat caught by beach seining during the period 1977–1980 were examined for adult Lernaeenicus, and both sprat and herring caught in 1981–1983 were examined for all parasitic stages. Lernaeenicus was never found on herring. Adult L. sprattae were always found in the sprat's eye, usually (89%) in the upper rear quadrant of the eye. Double and triple infection of one or both eyes were found. Infection experiments support results from field work. The sprat is the only intermediate and final host of L. sprattae. In laboratory experiments, copepodites showed no preference for particular size groups of sprat. The infective stages, copepodid and adolescent female, are both initially randomly distributed on the host before the copepodites move towards the fins and the gravid females to the eye.     

Nesting,eggs and larvae of triggerfishes (Balistidae)

Synopsis Triggerfishes construct nests by excavating depressions in sand. Eggs are laid in an adhesive mass and anchored with rubble. A photograph of a newly-hatched embryo is included.     

A study of correlates of hand preferences in squirrel monkeys (Saimiri sciureus)

The purpose of this study was to test the influence of sex, age, social rank, matriline membership, posture, and visual and tactual motor control on manual preferences inSaimiri sciureus. A well-established social group of 12 squirrel monkeys, aged 2 to 14 yrs and consisting of two matrilines with social rank known for each animal, was presented with four different food-reaching tasks and assessed for hand preferences with a minimum of 100 reaches per animal. Frequency of occurrence of hand preferences at the group level and degree of hand preferences at the individual level depended on posture and on whether the reaching act took place under visual or tactual guidance. Sex, age, social rank, and matriline membership were not found to determine frequency of occurrence, direction or degree of hand preferences with the exception of one task in which a significant negative correlation between the degree of hand preference and age was found. Nine out of 12 monkeys showed task-dependent changes in the hand they used preferentially while only three animals preferred the same hand in all four tasks. Significant preferences for the use of right or left hand on a given task were distributed almost equally between individuals. Thus, the results of this study suggest task-specific demands like posture and/or whether reaching was visually or tactually guided to be the major correlates of hand preferences in food-reaching tasks in squirrel monkeys.     

Breeding Habitat Selection of Salamandra salamandra (Linnaeus, 1758) in the Most Arid Zone of its European Distribution Range: Application to Conservation Management

The influence of environmental variables on the selection of a water body as breeding habitat by Salamandra salamandra was studied in an arid zone located in the southwestern part of its distribution range. From November 2002 to October 2003, 50 water bodies were monitored in the south east of the Iberian Peninsula. Environmental data were submitted to a stepwise logistic regression analysis at macrohabitat, water body typology and microhabitat scales in order to establish the main factors influencing the use of a given water body as breeding habitat by this species. A significant degree of dependence between the reproduction of Salamandra salamandra and environmental variables was observed at all of these levels. These results should be taken into account when populations of this species are subjected to management and/or recovery programmes in arid areas.     

Traditional and diversified crops in South Moravia (Czech Republic): Habitat preferences of common vole and mice species

Substantial changes in the composition of crops in Central Europe during the last two decades (increasing areas of maize, rape and sunflower fields) have significantly influenced the structure and dynamics of animal communities, though there is a lack of data available for small rodents. In this study, we assessed the importance of these three crops for rodents and compared it with traditional crops (alfalfa, barley, wheat). We observed that herbivorous species (especially the common vole) do not live in crops which do not have green leaves near the ground (e.g. sunflower, maize), while mobile granivorous species can inhabit all types of crop. We confirmed the presumed differences in habitat preferences; however we rejected the hypothesis of a general increase of rodent abundance during the vegetative season in managed fields. We found that (1) maize and sunflower had no importance for common voles, but they were favored habitats for wood mice; (2) numbers of wood mice in rape decreased during the season, while abundances of common voles increased; (3) common vole populations tended to increase during the season in all suitable crops (alfalfa, barley, wheat, tendency in maize and rape); (4) wood mice populations seemed stable in all crops; i.e. without a seasonal increase. It can be concluded that even if the new crop fields are an important part of the agricultural landscape, they are only a temporal habitat for small mammals, especially granivorous species.     

Microfacies and diagenesis of an upper oxfordian carbonate buildup in Mydlniki (Cracow Area,Southern Poland)

Summary A carbonate buildup near the top of the Upper Jurassic limestone sequence in the Cracow area with a rigid framework built ofTubiphytes and thrombolites, and some fragments of encrusted siliceous sponges and serpules is described. The limestones form a dome-like elevation at the eastern wall of a 15 m high quarry flanked on both sides by stratified limestones with cherts. Six microfacies have been distinguished within the buildup: (1)Tubiphytes/thrombolite boundstone and (2) bioclasticTubiphytes/thrombolite wackestone dominate in the central and bottom part of the buildup. They gradually replace the cyanobacterial crusts and siliceous sponges (3. sponge-algal boundstone), which are sporadically the rock-forming elements in the basal part of the buildup as well as the top. Serpules randomly distributed within the buildup also form small cm-sized structures with a rigid framework (4. serpula-peloid boundstone). (5) tuberoid-peloid wackestone/floatstone and (6) ooid intraclastic grainstone exhibit no significant distributional pattern. Bioclastic-peloidal packstone comprising material derived from the destruction of the buildup occurs in the highest part of the outcrop, overlying the buildup. The sediments of the buildup were subject to rapid lithification, evidence by borings and neptunian microdykes filled with internal sediments, as well as by fracturedTubiphytes. Numerous petrographic features indicate probable episodic emergence of the buildup during its growth; these include asymmetric dissolution textures, asymmetric cements, vadose crystal silt and calcite pseudomorphs after gypsum. Upper Oxfordian carbonate buildups in the Cracow area display various stages of evolution. The carbonate buildup in Mydlniki most closely resembles classical Upper Jurassic reefs.     

Development of the embryo nest ofVespa affinis (Hymenoptera: Vespidae) in Southern Japan

Summary The aerial nests ofVespa affinis on Ishigaki Island, Japan, were found mainly within 1 m of the ground, attached to a twig roughly 4 mm in diameter. These are probably adaptations to survive adverse weather conditions. The favoured nesting habitat was in open farmland areas rather than in the natural forest. The entire envelope and more than half of the comb of the embryo nest is constructed during the first 10–12 days. The first workers emerge around 34 days after nest initiation. The duration of larval development was found to be linked to the number of larvae present in the nest, with the earlier progeny developing faster. The changes in the ovarian index of the mother queen during the early stages of nesting are described.     

Natural regeneration of forest related to the spatial structure of trees: A study of two forest communities in Western Carpathians,southern Poland

The existence of a relationship between the spatial pattern of trees and the distribution of young individuals beneath the canopy has been tested in the beech (Fagus sylvatica) and spruce (Picea abies) — fir (Abies alba) forests in the mountainous region, using two different methods. The first method was the analysis of spatial pattern of individuals, the second one was based on calculating sums of influences of all trees occurring within analysed plot on a given point on the forest floor. Results of spatial pattern analyses were surprisingly consistent: almost all mature trees and seedlings didplayed a random pattern of spatial arrangement. However, there is a clear, although statistically insignificant tendency towards uniformity of spatial pattern with increasing sizes of analysed trees. Results of comparing sums of influences on regularly distributed points with sums of influences on seedlings or saplings revealed no tendency in forest regeneration to concentrate in places, where the sums were smaller than the average for a plot. This, coupled with the dominance of random spatial pattern of trees, suggests, that viewed on a small spatial scale, influence of competition among forest trees on their spatial arrangement is obscured by other factors, which are not closely related to the distribution of individuals.     

Cryptic speciation, habitat differentiation, and geography in Hamatocaulis vernicosus (Calliergonaceae, Bryophyta)

A molecular study of the wetland pleurocarpous moss Hamatocaulis vernicosus (Mitt.) Hedenäs, based on the ITS region, the trnL-trnF region, and rpl16 revealed two cryptic species. One of these is widespread in Europe, and was also sampled from several localities in Minnesota (United States). The other cryptic species occurs only south of the boreal zone in Europe, and was in addition sampled from single localities in Peru and northernmost Asiatic Russian Federation. Although it seems likely that the southern species colonized parts of Europe from southern refugia after the last glaciation, its wide distribution outside Europe indicates that the speciation event is unrelated to the European glacial history. No correlations could be found between variation in habitat preferences (pH and electric conductivity) and molecular variation.     

Reproduction and sperm structure in Galeommatidae (Bivalvia, Galeommatoidea)

Reproduction and/or sperm structure was studied in 18 species belonging to five genera of Galeommatidae from Phuket Island, Andaman Sea, Thailand, and Hong Kong. Incubation of the ova occurs in the inner and outer demibranchs of both gills, and sperm is most probably transferred to the ctenidial brood chamber as masses of agglutinated and non-encapsulated spermatozoa. The smallest specimens are males, but change into the female sex and there is a strong indication that some of the species are alternate hermaphrodites. Dwarf males occur in one species (Galeomma layardi). The sperm of all 18 species studied are of the ent-aquasperm type with a more or less hemispherical acrosome that is tilted with respect to the long axis of the moderately elongated nucleus. It is suggested that this type of sperm affords the best autapomorphy for the family Galeommatidae.