Stable Territories Research Articles

Genetically identical mice express alternative reproductive tactics depending on social conditions in the field.

In many species, establishing and maintaining a territory is critical to survival and reproduction, and an animal's ability to do so is strongly influenced by the presence and density of competitors. Here we manipulate social conditions to study the alternative reproductive tactics displayed by genetically identical, age-matched laboratory mice competing for territories under ecologically realistic social environmental conditions. We introduced adult males and females of the laboratory mouse strain C57BL/6J into a large, outdoor field enclosure containing defendable resource zones under one of two social conditions. We first created a low-density social environment, such that the number of available territories exceeded the number of males. After males established stable territories, we introduced a pulse of intruder males and observed the resulting defensive and invasive tactics employed. In response to this change in social environment, males with large territories invested more in patrolling but were less effective at excluding intruder males as compared with males with small territories. Intruding males failed to establish territories and displayed an alternative tactic featuring greater exploration as compared with genetically identical territorial males. Alternative tactics did not lead to equal reproductive success-males that acquired territories experienced greater survival and had greater access to females.

Comparative characteristics of the land use structure for different types of territorial communities

Purpose. The assess and compare the structure of land use of urban, township and rural territorial communities, to develop an optimization model to land use in case of decentralization Methods. Assessment, comparative-geographical, geoinformation, statistical, mathematical, geoecological analysis and optimization modeling. During the study, special methods were used to determine the anthropogenic pressure, coefficients of ecological stability and anthropogenic transformation of different types territorial communities. Results. According to the results of comparative assessment of the land use structure of urban, township and rural territorial communities, it was found that all three types of communities are characterized by a high degree of plowing (˃60%) and low forest share (5-10%). The share of natural lands within the studied territorial communities is 23-30%. The calculated coefficients of anthropogenic transformation, ecological stability, anthropogenic load, showed that Vyshnivets township and Borsukivska rural territorial communities belong to the category of ecologically unstable territories, Lanovets urban territorial community - to medium ecologically stable territories. In all three types of territorial communities, landscapes are moderately transformed. Urban, township and rural territorial communities experience a sufficiently high (above average) anthropogenic pressure. The obtained results of calculations create objective preconditions for optimizing the structure of land use of the studied territorial communities. Conclusions. To correct and improve the situation, to bring the territories of the studied territorial communities of different types to ecological stability, it is necessary to implement a number of optimization measures. The developed optimization model of land use of Lanovets city, Vyshnivets township and Borsukivka rural territorial communities envisages reduction of arable lands by 20-26%, increase of forest cover by 13-18% and bringing the share of natural lands to the optimal 50%. The implementation of such an approach requires a change in the purpose of individual land plots and the organization of their landscape-adapted use.

Evidence for acoustic discrimination in lemurs: A playback study on wild indris Indri indri.

Indris Indri indri are group-living lemurs that occupy stable territories over several years and perform remarkable long-distance vocal displays. Vocal exchanges between long-term territory neighbors may contribute to assessing reciprocal resource-holding potentials, thus adaptively reducing the costs of territorial defense by limiting aggressive escalation. Previous work showed that indris' songs show distinctive acoustic features at individual and group level. However, the possibility that indris use such cues for individual or group-level recognition has never been investigated experimentally. We conducted a playback experiment to test whether indris discriminate between familiar and nonfamiliar songs. Our rationale lies in the hypothesis of the dear enemy phenomenon, which predicts that territorial animals will show reduced aggression levels toward familiar neighbors compared with novel rivals. We played back stimulus recordings to wild indris from their territory boundaries and examined their responses in terms of vocal and behavioral indicators of willingness to engage in a fight. In line with our predictions, focal animals responded more rapidly and approached more often the speaker in response to playback stimuli of nonfamiliar individuals than to stimuli of neighboring groups. These results indicate that indris can discriminate between different classes of intruders based on distinctive acoustic features of their song choruses. We suggest that increased aggression directed toward unfamiliar intruders may be explained by higher threat levels associated with dispersal and group formation dynamics. We further discuss the relevance of these findings in a strepsirrhine primate model for comparative studies of vocal communication and sociality.

Konzentrierte Nahrungssuche bei Magellanspechten: Die Bedeutung von Baumalter, Waldzusammensetzung und Offenhabitaten

Animals with stable territories, specialized diets and narrow habitat choices, such as some woodpecker species, should concentrate foraging activity in areas of higher quality, a behavior consistent with the area-restricted search (ARS) behavior. The assessment of ARS behavior in specialized woodpeckers contributes to identify feeding areas important for not only their conservation but also habitats negatively affecting their foraging behavior. We addressed the effects of tree senescence, forest succession, stand composition and open habitats on the adoption of ARS behavior in Magellanic Woodpecker (Campephilus magellanicus) in a heterogeneous landscape in southern South America. Using GPS relocations from 24 woodpeckers, we estimated the First-Passage Time (FPT), a measure of the time individuals remain in a given area, with longer FPT values indicating the adoption of an ARS behavior. We determined the effects of habitat variables on FPT using a methodological framework based on Linear Mixed Effect models and a randomization procedure intended to reduce spatial autocorrelation. Averaged model coefficients showed that woodpeckers spent less time in sites dominated by the Antarctic beech (Nothofagus antarctica) and partially covered by open habitats. Conversely, FPT increased in stands and home ranges where tree senescence was higher. Thus, the ARS behavior in Magellanic Woodpecker is explained by forest composition, avoidance of open habitats and tree senescence. Our results suggest the conservation of Magellanic Woodpeckers in heterogeneous landscapes involves retention of senescent trees and maintenance of canopy continuity.

Mast Cells Occupy Stable Clonal Territories in Adult Steady-State Skin

Mast cells (MCs) are tissue-resident hematopoietic cells intensely studied for their role as effectors in allergic immune responses. Yolk sac-derived embryonic MCs first populate tissues and are later replaced by definitive MCs. We show that definitive MC progenitors expand locally in skin and form clonal colonies that cover stable territories. In MC-deficient skin, colonies grow by proliferation of MCs at the border of the clonal territory. Clonal growth ceases at common borders of neighboring colonies. In steady state, colony self-renewal is independent of bone marrow contribution, and the clonal architecture remains fixed if not disturbed by skin inflammation. Inflammatory cues increase MC density setpoint, stimulating the influx of new progenitors from the bone marrow as well as proliferation of skin-resident cells. The expanding new arrivals disrespect territories of preexisting MC clones. We conclude that during a limited window early in development, definitive MC precursors efficiently enter the skin, expand, and self-maintain, occupying stable territories. In adulthood, circulating progenitors, excluded from steady-state skin, are recruited only into inflamed skin where they clonally expand alongside proliferating skin-resident MCs, disorganizing the original architecture of clonal territories.

ОЦЕНКА ТРАНСФОРМАЦИИ ПРИРОДНО-ТЕРРИТОРИАЛЬНЫХ КОМПЛЕКСОВ ПРИ ГОРНОПРОМЫШЛЕННОМ ТЕХНОГЕНЕЗЕ

Актуальность. Структуризация и формирование природно-территориальных комплексов происходит на протяжении длительного времени. За весь период преобразования и установления стабильно устойчивых территорий ландшафты претерпевают значительные изменения. Одним из факторов аналогичной трансформации является техногенная деятельность горнопромышленной отрасли, в связи с чем проводится оценка преобразованности, изучение процессов и схем преобразованности ландшафтов под действием техногенеза как одного из главных критериев, учитывающих месторасположение и расширение данных отраслей промышленности, что и обуславливает актуальность данной работы. Цель: произвести оценку экологической напряженности и видоизмененности ландшафтов, подверженных интенсивной техногенной нагрузке, в районе деятельности медеплавильного комбината. Объекты: компоненты ландшафтного комплекса и почвенный покров в районе интенсивной техногенной нагрузки, расположенные в окрестностях города Красноуральск, Свердловской области. Методы: оценка экологической напряженности территории; расчет коэффициента экологической защищенности ландшафтов по методике Б.И. Кочурова; расчет коэффициента радиальной дифференциации мышьяка в почвенном покрове в зоне интенсивной техногенной нагрузки. Результаты. Произведен анализ отдельных компонентов ландшафтных комплексов. Выявлены характеристики процессов видоизменения территорий, подверженных техногенной нагрузке. После расчетов коэффициента экологической стабильности по методике Б.И. Кочурова выявлено, что исследуемые ландшафты имеют острую экологическую ситуацию и обладают малой стабильностью. В качестве подтверждения техногенной нагрузки измерялась концентрация мышьяка в почвах исследуемых территорий, в результате чего зафиксированы превышения предельно допустимой концентрации в видоизмененных ландшафтах. В ходе подсчета коэффициента радиальной миграции мышьяка в почве объясняются процессы техногенной нагрузки.

Reducing nest predation of ground-nesting birds through conditioned food aversion

Populations of many ground-nesting bird species have declined substantially due to several factors, and predation can be a leading contributor to these declines. As a method for reducing the nest predation on ground-nesting birds, we tested whether conditioned food aversion (CFA) can reduce red-legged partridge (Alectoris rufa) nest predation by red foxes (Vulpes vulpes). With a before-after control-impact design we deployed 1329 artificial nests in two different habitats in Central Spain using thiram as an aversive. Artificial nests were monitored by camera traps to identify the red fox individuals during the predation events. 26 foxes were GPS-tagged to monitor their spatial movements and feeding behavior. Partridge density and productivity were monitored to assess the thiram treatment effect on partridge population. Thiram treatment decreased artificial nest predation by foxes in both study sites by 26.8–50.1%, but this was compensated by an increased predation by other predators, possibly enhanced by the availability of our artificial nests. 78% of identified foxes that ingested thiram-treated eggs, stopped nest predation after treatment. Foxes maintained stable territories during the whole study period. Partridge productivity was 132–677% higher in thiram-treatment areas than in control areas, and partridge density after treatment increased more in thiram-treated areas (193–292%) than in control areas (1.8–99%). Our study shows that CFA reduced ground nest predation by foxes, and had a positive effect on the partridge population despite the compensatory predation. This method could be used as a non-lethal tool for conservation of endangered ground-nesting bird species.

Long-term movements and home-range changes: Rapid territory shifts in meerkats.

Territoriality and stable home ranges are a common space-use pattern among animals. These ranges provide its inhabitants with important resources and thus favourable territories are associated with an increased fitness. While the role of territory quality and changes of territory ownership have often been investigated, the changes of territorial boundaries have been less studied. Here, we investigated space-use changes in a social mammal species, applying a novel analytical approach, calculating long-term dissimilarity in space use using distancematrices based on periodic utilization distributions. This approach makes it possible to identify different space-use patterns, which cannot be distinguished by only considering changes between consecutive time periods. We analysed meerkat (Suricata suricatta) movements of a total of 24 different groups over a 16-year period, resulting in 134 group years. We then correlated the identified home-range changes to life-history events and possible environmental drivers. Groups had stable territories for several years before they abandoned their home range mostly to move quickly to new areas where they again remained for several years. Of 26 identified sudden shifts, 22 occurred in the summer months and often involved distances larger than the original home-range size. Home-range movements that were close together in time were often also spatially clustered and moved in a similar direction. These shifts were often preceded by more frequent interactions between groups, but did not seem to be a product of direct displacements by other groups. The normalized difference vegetation index as a measure of food production and social factors such as dominance changes did not correlate to changes. Against our expectation space-use changes were not accumulations of small changes, but more often involved long-distance moves into unknown ranges. This means that the groups enter areas where they cannot profit from local knowledge. The methods used identify episodes of long stability alternated by sudden changes in meerkats and in general provides insight into long-term space use. Our methods can be used to analyse long-term space use, either within or across species.

Fecal Glucocorticoid Response to Periodic Social Stress in Male Green Anoles, Anolis carolinensis

Agonistic encounters necessary for territory establishment and maintenance can be stressful for those involved. Stress responsiveness associated with territorial behavior can occur on both acute and chronic temporal scales contingent upon social status. Social interactions that recur for territory maintenance pose periodic stressors that incur variable physiological costs across social ranks. Adult males of the Green Anole, Anolis carolinensis, experience stressful social encounters during territorial disputes as individuals contest status within a dominance hierarchy. Dominant males in stable territories are known to exhibit greener body coloration and lower levels of stress hormone, corticosterone, relative to their subordinate counterparts. Periodic interactions with novel competitors, however, may induce comparable levels of cumulative glucocorticoid secretion regardless of social status. Glucocorticoid metabolites excreted in feces can be quantified to assess the chronic hypothalamic–pituitary–adrenal (HPA) axis response to periodic social stressors. Fecal glucocorticoid metabolite (FGM) levels in male A. carolinensis were hypothesized to increase in response to novel social encounters that simulated territory establishment and maintenance. Adrenocortical response to recurring episodes of territoriality was predicted to generate similar longitudinal FGM levels across social ranks. FGM analysis was combined with behavioral assessment of body coloration to further contextualize measured stress levels of dominant and subordinate anoles. Prolonged social interaction led to similarly increased levels of fecal glucocorticoid metabolites in both dominant and subordinate anoles relative to those that were solitary. This study provides an alternative perspective on the activity of the HPA axis in dominant–subordinate relationships of A. carolinensis over prolonged periods of territoriality.

Females and males maintain similar-sized, stable territories between breeding and nonbreeding seasons in a tropical oriole (Icterus icterus)

ABSTRACT Territories provide important breeding and nonbreeding resources for many bird species. Most songbird territory research has been conducted in temperate regions during the breeding season,...

ЖИТТЄВІ ПЕРСПЕКТИВИ ОСОБИСТОСТІ, ЩО ЗНАХОДИТЬСЯ В УМОВАХ АТО (АНТИ-ТЕРОРИСТИЧНОЇ ОПЕРАЦІЇ)

The article deals with the peculiarities of the formation of the life perspective of people who are in the conditions of ATO. The main parameters, functions and forms of awareness of personal life perspectives are revealed. The following characteristics and components of the life perspective of the individual are singled out: differentiation / non-differentiation - the content component, optimism / pessimism - the emotional and experiencing component, realism / unrealism - the pragmatic-practical component, normativity / personality - the semantic component. According to these components, the author made the analysis of the structure of the life perspective of the respondents in the ATO zone, in particular ATO fighters, internally displaced people, residents of the gray zones and residents of stable territories of Ukraine. The divergences in the presented perspectives of their own lives in the consciousness of these groups of respondents were revealed and analyzed. It was stated that the least differentiated perspective is among the representatives of the military men participating in the ATO. Optimism about their own future was demonstrated by all categories of respondents. The sense of the own perspective is at a fairly high level for all groups of respondents related to ATO, but events are most often selected on a normative basis, as opposed to representatives of the group of stable territories. The reflexivity concerning the actions which are to be taken in order to reach this or that planned or anticipated event was shown by the representatives of IDP group, they surpassed the representatives of the group of stable regions for this indicator. According to the results of the conducted research, we can note that for the construction of a differentiated, optimistic, realistic and personal perspective of the individual, it is necessary to take into account the content of the perspective, its emotional assessment, semantic and pragmatic-practical component. The results of the above research can be used to create a program of psychological assistance to ATO fighters, IDP and residents of the border areas with the zone of ATO (gray zones) to facilitate the construction of their own future perspectives.

Geoinformation modeling of antropogenic transformation of the basin geosystems (case study of Dnister right tributaries)

The purpose of the article is to analyze anthropogenic transformation of river-basin geosystems of the outer Subcarpathian region by geoinformational modeling tools using various methods of quantitative estimation of anthropogenic pressure; comparison of modeling results on the basis of administrative-territorial and natural units, selection of optimal structural units for the study of anthropogenic changes in basin geosystems. Research methods. The features of estimation methods of anthropogenic transformation level of territorial complexes, based on various conceptual approaches to the study of anthropogenic changes in the components of the environment were investigated. In particular, the article compares methods of F.M. Milkov, P.G. Shyshchenko, E. Klementova and V. Geinige, P.P. Borschevsky, M.V. Boyarin, I.P. Kovalchuk, N.M. Ridey and D.L. Shofolov, A.M. Tretyak and others and by the means of geoinformation modeling of river-basin geosystems (namely, the case study of the outer Subcarpathian Dniester tributaries) shows the degree of representativeness of the results produced by each of them. It is noted that the technique by P.G. Shyshchenko allows to more accurately reflect the state of anthropogenic transformation of the river-basin system’s natural conditions Results. A range of digital cartographic models was developed to evaluate and compare anthropogenic transformation level of the two Carpathian basin systems and to identify similar and distinctive features of the state and the transformation level of the basin systems’ natural environment andstability of agricultural and forest landscapes in the studied basin geosystems. In particular, the study has revealed that the anthropogenic transformation of the outer Carpathian river basins is rising downstream. In the upper parts of the basins, it manifests itself in deforestation, while in the lower parts agricultural influence dominates. In addition, the index of anthropogenic transformation is rising with an increase in the order of sub-basins. The worst conditions of agro-landscapes are observed in the reclaimed valleys of the main rivers and their tributaries (due to the considerable level of plowing in the plain parts of the basins due to low fertility of soils, high levels of their acidity, degradation processes and chemical pollution). Stable territories are inherent exclusively in sub-basins which remain in their natural state or bear only traces of human activity. Settlements, which influence adjacent areas, are characterized by unsustainable land use. As for anthropogenic transformation, in the basin geosystem of the Berezhnytsia river its indicators increase upwards due to an increase in the share of arable land. On the contrary, in the basin of Bystrica much more land is occupied by industrial facilities, which affect the components of the geosystem the hardest. In this regard, the largest values of nature anthropogenic transformation indicators are found in the northern part of the basin and upstream of the city of Nadvirna and the town of Bykiv. Scientific significance. Case study of the administrative regions and the river basin located within them reveals the advantages of studying the geoenvironmental state of the territories according to their natural geographic taxonomic units, which allows to determine the most strained areas in geosystems. Particular attention is paid to the choice of optimum sized geospatial objects during the study of diverse basin systems. River sub-basins of the third order (according to the classification scheme of A. Strahler) were chosen to this purpose. Their size corresponds to that of the combined territorial communities’ area. The importance of formation a database that reflects on the state of the geospatial entities under study is emphasized. For this purpose, it is appropriate to convey the structure of land use, represented by indices of different land cover and land use types (protected areas, forest covered areas, swamps and wetlands, meadows, gardens and vineyards), arable land, land under rural and urban development, natural objects modified by human activities (reservoirs , ponds, channels), land utilized by industry and transport in each investigated object. The article shows that the best solution to this problem is provided by the processing of high-resolution spatial (in panchromatic and multispectral) remote sensing data. The most appropriate in this case are QuickBird satellite imagery, designed to create and update topographic maps and plans, to make inventories of forests and agricultural lands and to assess their condition, therefore allowing mapping of land use types that are not identified in statistical inventories. Practical significance. The results of this work will be helpful in selecting the specific technique allowing the most complete representation of anthropogenic transformation of natural objects; in choosing the most optimal spatial units to carry out the analysis and, accordingly, to fill in the database. The developed models reveal the most anthropogenically loaded parts of river-basin geosystems of the outer Subcarpathian region, which is essential for the extrapolation of the obtained results to other right tributaries of the Dniester River.

Brilliant-thighed poison frogs do not use acoustic identity information to treat territorial neighbours as dear enemies

Some territorial animals recognize familiar neighbours and are less aggressive to established neighbours than they are to strangers. This form of social recognition produces a ‘dear enemy’ effect, which may allow animals to reduce the costs of territory defence. The dear enemy effect is thought to reflect either the decreased threat posed by neighbours relative to strangers (the relative threat hypothesis) or the decreased need for escalation with increasing familiarity between neighbours (the familiarity hypothesis). We tested for a vocally mediated dear enemy effect in male brilliant-thighed poison frogs, Allobates femoralis. In this species, the familiarity hypothesis predicts a dear enemy effect, because males defend long-term stable territories and should be familiar with the calls of their neighbours. In contrast, the relative threat hypothesis does not predict a dear enemy effect, because neighbours and strangers both represent competitors for mates and likely pose equivalent threats. Acoustic analyses showed that males produce individually distinctive advertisement calls. Two playback experiments were conducted to determine whether territorial males respond less aggressively to neighbours' calls than to strangers' calls based on this acoustic identity information. In the first experiment, males pursued acoustically simulated neighbours and strangers to similar distances when calls were played both from the direction of the neighbour's territory and from a direction with no neighbours. In the second experiment, males responded aggressively to neighbours' and strangers' calls at similar threshold amplitudes and pursued these calls to similar distances. Hence, two different playback experiments failed to find evidence of a vocally mediated dear enemy effect. Our results support the hypothesis that territorial animals respond to the relative threat posed by neighbours and strangers regardless of their level of familiarity with neighbours.

Invasive Asian Earthworms Negatively Impact Keystone Terrestrial Salamanders.

Asian pheretimoid earthworms (e.g. Amynthas and Metaphire spp.) are invading North American forests and consuming the vital detrital layer that forest floor biota [including the keystone species Plethodon cinereus (Eastern Red-backed Salamander)], rely on for protection, food, and habitat. Plethodon cinereus population declines have been associated with leaf litter loss following the invasion of several exotic earthworm species, but there have been few studies on the specific interactions between pheretimoid earthworms and P. cinereus. Since some species of large and active pheretimoids spatially overlap with salamanders beneath natural cover objects and in detritus, they may distinctively compound the negative consequences of earthworm-mediated resource degradation by physically disturbing important salamander activities (foraging, mating, and egg brooding). We predicted that earthworms would exclude salamanders from high quality microhabitat, reduce foraging efficiency, and negatively affect salamander fitness. In laboratory trials, salamanders used lower quality microhabitat and consumed fewer flies in the presence of earthworms. In a natural field experiment, conducted on salamander populations from “non-invaded” and “pheretimoid invaded” sites in Ohio, salamanders and earthworms shared cover objects ~60% less than expected. Earthworm abundance was negatively associated with juvenile and male salamander abundance, but had no relationship with female salamander abundance. There was no effect of pheretimoid invasion on salamander body condition. Juvenile and non-resident male salamanders do not hold stable territories centered beneath cover objects such as rocks or logs, which results in reduced access to prey, greater risk of desiccation, and dispersal pressure. Habitat degradation and physical exclusion of salamanders from cover objects may hinder juvenile and male salamander performance, ultimately reducing recruitment and salamander abundance following Asian earthworm invasion.

Age related decline in female lar gibbon great call performance suggests that call features correlate with physical condition.

BackgroundWhite-handed gibbons (Hylobates lar) are small Asian apes known for living in stable territories and producing loud, elaborate vocalizations (songs), often in well-coordinated male/female duets. The female great call, the most conspicuous phrase of the repertoire, has been hypothesized to function in intra-sexual territorial defense. We therefore predicted that characteristics of the great call would correlate with a caller’s physical condition, and thus might honestly reflect resource holding potential (RHP). Because measurement of RHP is virtually impossible for wild animals, we used age as a proxy, hypothesizing that great call climaxes are difficult to produce and maintain over time, and that older adults will therefore perform lower quality great calls than young adults. To test this we analyzed the great call climaxes of 15 wild lar gibbon females at Khao Yai National Park, Thailand and 2 captive females at Leo Conservation Center, Greenwich, CT.ResultsFindings show that call climaxes correlate with female age, as young animals (n = 8, mean age: 12.9 years) produced climaxes with a higher frequency range (delta F0), maximum F0 frequency and duty cycle than old animals (n = 9, mean age: 29.6 years). A permuted discriminant function analysis also correctly classified calls by age group. During long song bouts the maximum F0 frequency of great call climaxes’ also decreased. Additional data support the hypothesis that short high notes, associated with rapid inhalation as an individual catches its breath, reflect increased caller effort. Older females produced more high notes than younger females, but the difference only approached statistical significance, suggesting that calling effort may be similar across different ages. Finally, for the first time in this species, we measured peak intensity of calls in captive females. They were capable of producing climaxes in excess of 100 dB at close range (2.7 m).ConclusionsAge and within-bout differences in the lar gibbon great call climax suggest that call features correlate with physical condition and thus the call may have evolved as an honest signal in the context of intra-sexual territorial defense and possibly also in male mate choice via sexual selection, although further testing of these hypotheses is necessary.

Evaluation of formation and reparcelling of land parcel projects

The article presents an analysis of two subjects: the motives of formation and reparcelling of land parcel projects and evaluation of their solution effects on landscape, and rationality and compatibility of projected land use. The main intentions of the projects were estimated after the research. The first intention is to divide land parcels according to parts belonging to co-owners (to form separate parcels). The second intention is to divide land parcels in order to sell or grant to other persons. The third intention is to specify borders between owned and neighbouring parcels. An analysis of ecological balance rate indicators of project solutions shows a result that a scarcely stable territory was in 8 parcels (K es = 0.34–0.50), a totally ecological unstable territory was in 13 parcels (K es ≤ 0.33), and a moderately stable territory was only in 2 parcels. It was noticed that in many cases there were small negative changes of the ecological balance rate. It depends on the dividing process of arable land and more ecologically stable territories.

Individuality and stability in male songs of cao vit gibbons (Nomascus nasutus) with potential to monitor population dynamics.

Vocal individuality and stability has been used to conduct population surveys, monitor population dynamics, and detect dispersal patterns in avian studies. To our knowledge, it has never been used in these kinds of studies among primates. The cao vit gibbon is a critically endangered species with only one small population living in a karst forest along China-Vietnam border. Due to the difficult karst terrain, an international border, long life history, and similarity in male morphology, detailed monitoring of population dynamics and dispersal patterns are not possible using traditional observation methods. In this paper, we test individuality and stability in male songs of cao vit gibbons. We then discuss the possibility of using vocal individuality for population surveys and monitoring population dynamics and dispersal patterns. Significant individuality of vocalization was detected in all 9 males, and the correct rate of individual identification yielded by discriminant function analysis using a subset of variables was satisfactory (>90%). Vocal stability over 2–6 years was also documented in 4 males. Several characters of cao vit gibbons allowed long-term population monitoring using vocal recordings in both China and Vietnam: 1) regular loud calls, 2) strong individuality and stability in male songs, 3) stable territories, and 4) long male tenure. During the course of this research, we also observed one male replacement (confirmed by vocal analysis). This time- and labor-saving method might be the most effective way to detect dispersal patterns in this transboundary population.

Singing in Africa: no evidence for a long supposed function of winter song in a migratory songbird

Animal sexual signals have been well studied in the context of mate attraction, but less attention has focused on the function of signals produced at other times of the year. Despite decades of research on bird song, we still do not know why many migratory songbirds also sing intensely on their wintering grounds. It has long been assumed that winter song is used to defend individual feeding territories; however, this assumption has never been tested. I studied willow warblers (Phylloscopus trochilus) that regularly sing on their African wintering grounds to test this supposition using a combination of behavioral experiments and radio telemetry. Contrary to expectations for individual territory defense, I found that individuals foraged in conspecific groups with fluid group membership, moved itinerantly from site to site rather than remaining in stable territories, and were highly aggressive toward model presentations combined with song playback, but in groups rather than individually. These results suggest a puzzling alternative function for winter song—singing for group territory defense—where territories are short term and group membership is not fixed. This work highlights the scarcity of our knowledge on the nonbreeding behavior of Palearctic–African songbirds and the unexpected complexity of avian social organization during this period of the annual cycle.

Lek Structure and Male Display Repertoire of Blue-Crowned Manakins in Eastern Ecuador

Abstract. Among lek-breeding manakins (Pipridae), courtship repertoires are extremely diverse and have played a central role in establishing phylogenetic relationships within the family. Behaviorally, Lepidothrix is among the least known genera in the family, with brief accounts published for only two of the eight species. Here, I describe the lek structure, territory characteristics, vocalizations and behavioral display elements of the Blue-crowned Manakin (Lepidothrix coronata coronata) in eastern Ecuador. From 2003 to 2006, I located all leks in two 100-ha study plots (average of 13.5 leks 100 ha-1) and recorded behavior at individual territories in ten leks. Males displayed solitarily or at exploded leks with up to seven individual territories of ∼0.1 ha; within a lek, territory centers were separated by about 90 m. Males in definitive and predefinitive plumage (2 years and older) held stable territories, whereas first-year, female-plumaged males did not hold stable territories but sometimes associate...

Skillnader i reviretablering under hösten mellan adulta och årsunga hannar av svart rödstjärt Phoenicurus ochruros på Cypern och Kreta

Competition for food and protection from predators are two important reasons for the development of winter territories. In their breeding areas, older males of several species signal their quality and possession of resources with attributes and behaviours. This can also be valid in winter quarters. This study of Black Redstart shows significant differences between adult and yearling males and also between habitats. Adult males were found solitary more frequently, they were fighting less and they were also singing more often in urban areas than in shrubland compared to yearlings. Urban areas, in comparison to shrubland, were characterised by lower individual density, higher proportion of males, more “intensive fights” and also higher singing activity from tall song perches. This indicates that territories are mainly established by adult males in urban areas. In shrubland males often appeared in groups and interacted in social behaviours with a high proportion of female-like birds. They also interacted with other species. I conclude that only the most dominant males are capable of maintaining stable territories when suitable habitats are scarce.