47,361 research outputs found
Nest Stuctures in Bornean Orangutan
Struktur Sarang Orangutan Kalimantan. Nest-building techniques processes related partiesin choosing the trees, the basic building structure, making layers, and adding nest lockingsystem with accessories. There are Lacks of data about the pattern of the orangutan nest andonly van Schaik (1995) described four Variations of nest structure. By Following 22 orangutanswith instantaneous focal animal method, 19 vertical nest structures are found, and horizontallyvariations orangutan nest forming butterfly pattern. Tree species are Elaocarpus mastersiithat mostly used by Orangutan to build nest with type of branch direction and height of firstbranch as the Reasons. Nest was built in 5-9 meters height and they were seldom to rebuilt orreuse old nest. They seldom to develop their nest in the last fruit trees to avoid nightpredators
Nest site selection in middle and great spotted woodpeckers Dendrocopos medius & D. major: implications for forest management and conservation
Success of species conservation depends to a large extent on comprehensive management that considers all critical aspects of a species' niche. Many studies have examined habitat factors in relation to occurrence, abundance or foraging behaviour of European woodpecker species, while relatively little is known about nest site selection. I compared habitat structures used for nesting by middle and great spotted woodpeckers Dendrocopos medius and D. major with available structures in an oak forest in the Swiss lowlands. I first tested if nest trees were randomly selected among available trees by focusing on species, condition and diameter of nest trees, and on the presence of the fruiting body (hereafter sporophore) of polypores (wood-decomposing fungi). Second, I examined if the nesting niches of the two species were differentiated. Both species showed strong preferences for oaks, large trees, dead trees and for trees with sporophores. Nest sites of the two species differed most strongly with respect to the presence of sporophores, cavity age and tree condition, pointing towards interspecific competition for nest sites. Old living or dead trees with sporophores are central components of the nesting niche of middle and great spotted woodpeckers. Conservation plans for the threatened middle spotted woodpecker have so far mostly focused on the needs in terms of distribution and foraging; future conservation strategies and forest management must take into account the preference for dead and decaying trees with sporophores as another vital resource. This will also provide benefits for other woodpecker species as well as for the community of secondary cavity nester
Habitat Characteristics Associated with Nest Site Selection and Reproductive Success of House Wrens (Troglodytes aedon)
Habitat characteristics influence the survival and reproduction of animal species. House Wrens (Troglodytes aedon) are an abundant species of songbird, are tolerant of humans, and nest readily in artificial nest boxes. We hypothesized that House Wrens would attempt more nests, raise more young, and feed their young more frequently in areas that contained more natural vegetation. Nesting boxes were placed in three habitats (100-123 boxes per year): a woodland area, a golf course, and a residential area. We quantified habitat characteristics within 15m of a nest box: % canopy cover, % shrub cover, % natural grass cover, % mowed grass cover, number of trees >10cm in diameter, and the presence or absence of blacktop, pine trees and other human structures. Between April and August 2010-2012, nesting success was monitored via checking the nest boxes at least twice a week for signs of reproductive behavior such as the formation of nests or the appearance of eggs. On the tenth day after hatching, the nestlings were banded with aluminum and colored leg bands to aid in estimates of survival. We observed that more nests were attempted in boxes without blacktop or pine trees, but with more tree trunks and human structures, such as fences. Given that a nest was successful, the number of nestlings banded increased with more vegetation, but decreased with the number of trees and with the presence of human structures. Feeding rates did not vary by habitat for four day observations. However, when the nestlings were 10 days old, the number of visits increased when more blacktop was present. Our first hypothesis was supported; house wrens attempted more nests and produced more nestlings in natural areas without blacktop and pine trees. Our second hypothesis was not supported; feeding rates for House Wrens did not vary with habitat characteristics. This research supports the idea that human alteration of habitats may be detrimental to reproduction of songbirds. Particular care should be taken to maintain natural habitats if threatened or endangered birds are present.No embargoAcademic Major: Biolog
Status, Dispersal, and Breeding Biology of the Exotic Eurasian Collared-Dove (Streptopelia decaocto) in Arkansas
The exotic Eurasian Collared-Dove (Streptopelia decaocto) was first sighted in Arkansas at Harrison (Boone Co.) on 25 June 1989. Since this initial sighting the species has grown in numbers and is now present in 42 of 75 counties across the state. In the spring and summer of 2009 and 2010, 20 nests were observed in the urban areas of Fort Smith (Sebastian County). Fifteen of the 20 nests (75%) were located on human-made structures of which 13 (65%) were on an electrical substation and two (10%) were on utility poles. The remaining 5 nests (25%) were in trees. Mean nest height was 7.62 m (n = 20 nests), and the mean width of the nest site support was 40 cm (n = 6 nests). Thirteen of the 20 nests (65%) yielded fledgling(s). Three focal nests were chosen for intense observation. Nest building lasted 1 to 3 days (mean = 2 days); incubation period was 15 days; and fledging occurred 17-18 days after hatching (n = 3 nests). A total of 6 young fledged from these 3 nests
Quantifying the degree of self-nestedness of trees. Application to the structural analysis of plants
17 pagesInternational audienceIn this paper we are interested in the problem of approximating trees by trees with a particular self-nested structure. Self-nested trees are such that all their subtrees of a given height are isomorphic. We show that these trees present remarkable compression properties, with high compression rates. In order to measure how far a tree is from being a self-nested tree, we then study how to quantify the degree of self-nestedness of any tree. For this, we deïŹne a measure of the self-nestedness of a tree by constructing a self-nested tree that minimizes the distance of the original tree to the set of self-nested trees that embed the initial tree. We show that this measure can be computed in polynomial time and depict the corresponding algorithm. The distance to this nearest embedding self-nested tree (NEST) is then used to deïŹne compression coefïŹcients that reïŹect the compressibility of a tree. To illustrate this approach, we then apply these notions to the analysis of plant branching structures. Based on a database of simulated theoretical plants in which different levels of noise have been introduced, we evaluate the method and show that the NESTs of such branching structures restore partly or completely the original, noiseless, branching structures. The whole approach is then applied to the analysis of a real plant (a rice panicle) whose topological structure was completely measured. We show that the NEST of this plant may be interpreted in biological terms and may be used to reveal important aspects of the plant growth
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The evolution of shelter: ecology and ethology of chimpanzee nest building
Human beings of all cultures build some form of shelter, and the global distribution of Homo sapiens depends on this basic trait. All great apes (chimpanzee, bonobo, gorilla, and orangutan) build analogous structures (called nests or beds) at least once a day throughout their adult lives, which suggests that this elementary technology was present before the hominid lines separated. This thesis investigates the variability and function of specifically wild chimpanzee shelters.
I compared characteristics of chimpanzee nests, nesting trees, nest shape, and architecture in two savanna-dwelling populations on opposite sides of Africa: Fongoli, Senegal, and Issa, Tanzania. Savanna habitats are the most extreme habitats in which chimpanzees survive today, and may represent a similar environment to that in which early hominins evolved in the Plio-Pleistocene (Chapter 2). Investigating variation in nest-building within and between these two extreme habitats made it possible to tackle hypotheses of the shelter function of nests (Chapter 3).
The influence of environment, specifically the role of protection from disease vectors and fluctuating temperatures, was assessed through a novel experiment in which I slept overnight in arboreal chimpanzee nests and on the bare earth (Chapter 4). To assess whether or not nests serve as an anti-predation function, I compared nesting in Issa, where predators are abundant, to Fongoli, where they are absent (Chapter 5). I provided further support for the thermoregulatory function of nests by showing that chimpanzees build more insulating nests in adverse weather conditions (Chapter 6).
Nest-building is a learned behaviour, but its ontogeny is little known. I investigated social sources of variation in nest building in Fongoli to examine whether sex and age differences exist in nest building duration, nest position, shape and architecture (Chapter 7).
Finally, ecosystem engineering is a consequence of animal construction, from ants to humans. I investigated use-wear traces around nests to assess niche construction of nest- building. I showed that chimpanzees repeatedly re-used these specific nest-spots within trees, which are pre-fabricated for future building through repeated pruning and shaping of these structures (Chapter 8).
Nest building in great apes may be the foundation of constructivity in hominids. This thesis describes proximate functions and influences on nest-building variation in wild chimpanzees that help to model the evolution of shelter in hominids.This work was supported by the Carnegie Trust for Universities of Scotland (Carnegie Scholarship, Carnegie Research Grant), Corpus Christi College for a Taylor Bursary, Harold Hyam Wingate Foundation, International Primatological Society, L.S.B. Leakey Foundation, and the Wenner Gren Foundation
Evaluation of disruptive camouflage of avian cup-nests
Parent birds employ various strategies to protect their offspring against nest predators. Two wellâresearched antiânestâpredation strategies involve visual concealment of the nest by way of parental camouflage and egg camouflage. By contrast, camouflage of nest structures is relatively underâresearched, particularly in the case of cupânests in trees and bushes. We explored how birds camouflage cupânests in nature. Specifically, we tested Hansellâs hypothesis that birds use externally applied pale and white objects such as spider cocoons and lichens to achieve cupânest camouflage. To test Hansellâs hypothesis, three complementary experiments were performed: (1) an in situ nest predation experiment; (2) a photoâbased visual search experiment; and (3) contrast analyses using PATâGEOM software in IMAGEJ. White paper and chalk spots were used to mimic white objects used by birds in nature. Whereas predation rates in Experiment 1 were not affected by white spots, location rates in Experiment 2 were lower for natural nests with white spots than without white spots. Experiment 3 demonstrated that white spots significantly increased the contrast between different visual elements of nests. It was concluded that white objects can potentially camouflage nests against some nest predators, and that any improved camouflage was probably achieved via disruptive camouflage.Publisher PDFPeer reviewe
Connectivity Explains Local Ant Community Structure in A Neotropical Forest Canopy: A LargeâScale Experimental Approach
Understanding how habitat structure and resource availability affect local species distributions is a key goal of community ecology. Where habitats occur as a mosaic, variation in connectivity among patches influences both local species richness and composition, and connectivity is a key conservation concern in fragmented landscapes. Similarly, availability of limiting resources frequently determines species coexistence or exclusion. For primarily cursorial arthropods like ants, gaps between neighboring trees are a significant barrier to movement through the forest canopy. Competition for limited resources such as nest sites also promotes antagonistic interactions. Lianas (woody vines) connect normally isolated neighboring tree crowns and often have hollow stems inhabited by ants. We used two largeâscale lianaâremoval experiments to determine how connectivity and nest site availability provided by lianas affect arboreal ant species richness, species composition, and ÎČâdiversity in a lowland tropical forest in Panama. Removing lianas from a tree crown reduced ant species richness up to 35%, and disproportionately affected species that require large foraging areas. Adding artificial connectivity to trees mitigated the effects of liana removal. Ant colonization of artificial nests was higher (73% occupied) in trees without lianas vs. trees with lianas (28% occupied). However, artificial nests typically were colonized by existing polydomous, resident ant species. As a result, nest addition did not affect ant community structure. Collectively, these results indicate that lianas are important to the maintenance of arboreal ant diversity specifically by providing connectivity among neighboring tree crowns. Anticipated increases in liana abundance in this forest could increase the local (treeâlevel) species richness of arboreal ants, with a compositional bias toward elevating the density of broadâranging specialist predators
Source Code Verification for Embedded Systems using Prolog
System relevant embedded software needs to be reliable and, therefore, well
tested, especially for aerospace systems. A common technique to verify programs
is the analysis of their abstract syntax tree (AST). Tree structures can be
elegantly analyzed with the logic programming language Prolog. Moreover, Prolog
offers further advantages for a thorough analysis: On the one hand, it natively
provides versatile options to efficiently process tree or graph data
structures. On the other hand, Prolog's non-determinism and backtracking eases
tests of different variations of the program flow without big effort. A
rule-based approach with Prolog allows to characterize the verification goals
in a concise and declarative way.
In this paper, we describe our approach to verify the source code of a flash
file system with the help of Prolog. The flash file system is written in C++
and has been developed particularly for the use in satellites. We transform a
given abstract syntax tree of C++ source code into Prolog facts and derive the
call graph and the execution sequence (tree), which then are further tested
against verification goals. The different program flow branching due to control
structures is derived by backtracking as subtrees of the full execution
sequence. Finally, these subtrees are verified in Prolog.
We illustrate our approach with a case study, where we search for incorrect
applications of semaphores in embedded software using the real-time operating
system RODOS. We rely on computation tree logic (CTL) and have designed an
embedded domain specific language (DSL) in Prolog to express the verification
goals.Comment: In Proceedings WLP'15/'16/WFLP'16, arXiv:1701.0014
The Social Wasps (Hymenoptera: Vespidae) of Indiana
An updated taxonomic treatment of the social wasps (Hymenoptera: Vespidae) of Indiana is made. Illustrated identification keys are provided for species of Polistes, Vespa, Vespula, and Dolichovespula. New distributional records and biological notes are provided for each species
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