Breeding site fidelity and natal philopatry in the Redshank Tringa totanus

This paper presents the results of a study carried out on breeding Redshank in the Ribble Marshes, Lancashire, England.
Redshank tend to return to the same breeding area year after year. There was no detectable sex bias in return rates. Experienced birds were more site faithful than inexperienced birds, with previously successful birds exhibiting the highest degree of breeding site fidelity. Older, more experienced birds were more successful at hatching eggs than inexperienced birds.
Breeding dispersal was the same both within and between years. Faithful pairs and males nesting with a new mate dispersed significantly shorter distances than females nesting with a new partner. Dispersal distances in female Redshank were affected by breeding success: unsuccessful females, nesting with a new mate, dispersed significantly farther than successful females. A pair's breeding success influenced the following year's mate fidelity. However, other factors such as overwintering survival and date of return may also have influenced mate fidelity.
Redshank were highly faithful to their natal area; a high proportion of birds that survived post-fledging mortality returned to breed in their area of birth. No sex bias in natal dispersal was detected. Approximately 50% of Redshank breed in their first year of life.     

Potential consequences of angling on nest-site fidelity in largemouth bass

Breeding site fidelity has evolved in many vertebrate taxa, suggesting both that site selection has an important influence on fitness potential and that the decision to reuse a nesting site is related to the individual’s prior nesting success at that location. For a species that provides parental care, such as the Largemouth Bass Micropterus salmoides, catch-and-release angling impacts individual nesting success and fitness through physiological disturbance and by removing the nest-guarding male from its brood, thereby allowing temporary access to eggs and hatchlings by brood predators. To assess the impact of catch-and-release angling on nest site fidelity, we compared the consequences of angling on individually marked (i.e., with passive integrated transponders) nest-guarding male Largemouth Bass in Ontario. An extremely high degree of nest site fidelity in year two was observed for males that were angled only once during year one (87% within 10 m of the previous year’s nest), 96.7% of which remained on the nest and completed parental care activities. There was significantly lower fidelity in year two, however, for males that were angled multiple times during year one (27% within 10m of the previous year’s nest), only 5.6% of which remained on the nest and completed parental care activities. This observed difference suggests that angling nesting bass may cause them to avoid previously used nest sites and instead search for alternative sites during future reproductive seasons. This human-induced impact on nest site choice may impact the future reproductive success of those Largemouth Bass.     

New data on the distribution of certain psychrophilic yeasts in Moscow oblast

Several rare species and varieties of psychrophilic yeasts were isolated from the Sphagnum mosses and paludal vascular plants of Moscow oblast. Based on their 26S rDNA D1/D2 nucleotide sequences, they were assigned to the species Sterigmatosporidium polymorphum, Rhodotorula psychrophenolica, and Aureobasidium pullulans var. subglaciale. Thus, a new habitat of S. polymorphum was found and yeasts known previously only for the Alpine environments and the Arctic region have been isolated in the central regions of Russia for the first time.     

Within and between season nest-site and mate fidelity in Common Terns(Sterna hirundo)

Summary We studied nest-site and mate fidelity in renesting Common Terns (Sterna hirundo), from 1993 to 1997, in a Common Tern colony breeding on six small artificial islands in the harbour area in Wilhelmshaven (German North Sea coast). Implanted transponders made possible individual recognition of the adults throughout their lifetime. We compared intra-season rates of nest-site and mate fidelity with between-year rates. Intra-season divorce was never observed. On the other hand, inter-year divorce was estimated at about 25%, suggesting that the costs of intra-season divorce are higher or opportunities for divorce are lower than between years. For 75% of 26 pairs that renested within the same season, the distance moved was less than 4.3 m. For 75% of 57 faithful pairs between two consecutive seasons, the distance moved was less than 1.25 m. Dispersal distances between and within years did not differ significantly but were clearly shorter than a paired random distribution of nests. Most of the birds changed the nest-site either when renesting or between years, but most of the new scapes can be considered as lying within the original territory. Thus, failure of the first breeding attempt increased neither divorce nor nest-site dispersal as compared with between-year rates. We also studied the influence of parental age and the date of breeding failure on distances moved in renesting birds. Late renesting pairs did not change the nest-site. A multiple regression analysis revealed that the longer the duration of the first breeding attempt and the older the pair, the shorter the nest dispersal distance.

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Neststandort- und Partnertreue ersatzbrütender Flußseeschwalben(Sterna hirundo)

Zusammenfassung Von 1993–1997 untersuchten wir Neststandort- und Partnertreue ersatzbrütender Flußseeschwalben (Sterna hirundo) in einer Kolonie, die im Banter See, Wilhelmshaven, auf sechs künstlichen Inseln brütet. Transponder ermöglichten die lebenslange individuelle Erkennung der Altvögel. Neststandort- und Partnertreue innerhalb der Brutsaison und zwischen den Jahren wurden verglichen. Innerhalb der Brutsaison kam Scheidung nicht vor. Eine Trennungsrate von 25% zwischen den Jahren deutet darauf hin, daß die Kosten einer intrasaisonalen Scheidung höher sind als die diejenigen einer Scheidung zwischen den Jahren. 75% der ersatzbrütenden Paare wählten den neuen Neststandort weniger als 4,3 m vom Platz des Erstgeleges entfernt (n=26). 75% der partnertreuen Paare brüteten im Folgejahr nur 1,25 m entfernt vom Neststandort des Vorjahres (n=57). Die Entfernungen zum Neststandort des Folgegeleges innerhalb und zwischen den Jahren unterschieden sich nicht signifikant, waren aber deutlich geringer, als nach einer Zufallsverteilung zu erwarten war. Die meisten Flußseeschwalben wechselten den Neststandort bei einer Ersatzbrut oder im Folgejahr, aber meist wurde das folgende Gelege im ursprünglichen Territorium angelegt. Folglich führt ein Verlust der Erstbrut weder zu erhöhter Scheidungsrate noch zu stärkerer Verlagerung des Neststandorts, verglichen mit der Situation zwischen Jahren. Auch der Einfluß des Alters und Termins des Brutverlusts auf die Distanzen zwischen Erst- und Ersatzgelege wurden untersucht. Späte ersatzbrütende Paare verlegten ihren Neststandort nicht. Eine multiple Regressionsanalyse verdeutlichte, daß die Distanz zum Ersatz-Neststandort abnimmt, je länger der erste Brutversuch andauerte und je älter das Paar war.

     

Mating systems,philopatry and dispersal in birds and mammals

Many species of birds and mammals are faithful to their natal and breeding site or group. In most of them one sex is more philopatric than the other. In birds it is usually females which disperse more than males; in mammals it is usually males which disperse more than females. Reproductive enhancement through increased access to mates or resources and the avoidance of inbreeding are important in promoting sex differences in dispersal. It is argued that the direction of the sex bias is a consequence of the type of mating system. Philopatry will favour the evolution of cooperative traits between members of the sedentary sex. Disruptive acts will be a feature of dispersers.     

Detectability, philopatry, and the distribution of dispersal distances in vertebrates

Dispersal is of central importance to population biology, behavioral ecology and conservation. However, because field studies are based on finite study areas, nearly all dispersal distributions for vertebrates currently available are biased, often highly so. The inadequacy of dispersal data obtained directly by traditional methods using population studies of marked individuals is highlighted by comparing the resulting distributions with dispersal estimates obtained by radio-tracking and by using genetic estimates of gene flow.     

Feeding Territoriality in Female Northern Bats,Eptesicus nilssoni

A nursing colony of 26 Northern bats was studied in South-Central Sweden. The foraging behaviour is described with emphasis on social interactions on feeding grounds. The bats foraged in small feeding territories used night after night. The reproducing females defended feeding territories against other colony members as well as non-members by means of aggressive chases and vocalizations. A linear dominance order occurred among the females that regularly visited a feeding site. Intrusions into already occupied feeding sites resulted in territorial conflicts (47 %), passive departure by one or both opponents (43%) or mutual acceptance (11%). Conflicts occurred throughout the summer, but became less frequent in July when insect abundance increased.     

Female philopatry and male-biased dispersal in a direct-developing salamander, Plethodon cinereus

The local resource competition hypothesis and the local mate competition hypothesis were developed based on avian and mammalian systems to explain sex-biased dispersal. Most avian species show a female bias in dispersal, ostensibly due to resource defence, and most mammals show a male bias, ostensibly due to male-male competition. These findings confound phylogeny with mating strategy; little is known about sex-biased dispersal in other taxa. Resource defence and male-male competition are both intense in Plethodon cinereus, a direct-developing salamander, so we tested whether sex-biased dispersal in this amphibian is consistent with the local resource competition hypothesis (female-biased) or the local mate competition hypothesis (male-biased). Using fine-scale genetic spatial autocorrelation analyses, we found that females were philopatric, showing significant positive genetic structure in the shortest distance classes, with stronger patterns apparent when only territorial females were tested. Males showed no spatial genetic structure over the shortest distances. Mark-recapture observations of P. cinereus over 5 years were consistent with the genetic data: males dispersed farther than females during natal dispersal and 44% of females were recaptured within 1 m of their juvenile locations. We conclude that, in this population of a direct-developing amphibian, females are philopatric and dispersal is male-biased, consistent with the local mate competition hypothesis.     

Age-specific nest-site preference and success in eiders

Variation in nest concealment is puzzling given the expected strong selection for safe nest sites. Selecting a concealed nest may decrease the risk of clutch predation but hinder parents from escaping predators, providing a possible solution to this paradox. Because the relative value of current versus future reproduction may vary with breeder age or state, nest concealment may also vary as a function of these attributes. We tested four predictions of the female and clutch safety trade-off hypothesis in eiders (Somateria mollissima): (1) nest concealment is negatively related to escape possibilities, (2) our capture rate of females is higher in covered nests, (3) egg predation is higher in open nests, and (4) overall nest success is unrelated to nest habitat. We also analysed nest microhabitat preferences and nest success relative to breeder age and body condition, controlling for nest spatial centrality. As expected, nest concealment and potential escape angle were negatively related, and capture by us, indicating female predation vulnerability, increased with nest cover. Clutch size was smaller in open nests, suggesting higher partial clutch predation, while it was larger among experienced and good-condition breeders. The probability of successful hatching was unrelated to nest habitat, positively associated with breeder experience, and negatively associated with hatching date. Experienced females selected more concealed and centrally located nests without sacrificing potential escape angles. The age-specific spatial distribution of nests on islands was unrelated to nest initiation dates, indicating no apparent competition. The age-specific preference of eiders for concealed nests may reflect declining reproductive value with age or confidence in surviving despite selecting a concealed nest. The apparently positive relationship between female age and survival and fecundity in eiders refutes the former alternative. Individual improvement in choosing safe nest sites, coupled with differential survival of individuals performing well, most likely explains age-specific nest-site preference and success.     

Territoriality in Aquatic Animals and Their Sizes

The concept of territoriality proposed by E. Odum was used in this study. The territories were determined that were occupied by individuals of specific animal species and the notion territory of individual was proposed. The territories of individuals for different representatives of aquatic animals, including fish, were calculated and their relationships with mass and energy potential of animals were established. The territories of individuals and home ranges were compared in invertebrates and vertebrates. It was shown that for the entire animal world the relationship of these areas and mass can be described by a power equation with the exponent indistinguishable from 1. It was established on the example of zooplankton and zoobenthos communities that animal species with a larger size obtain advantage in the oligotrophic water bodies, since when the territories of individuals increase, they are capable of obtaining the necessary amount of food objects at their low density in such conditions. On the contrary, in the eutrophic water bodies, smaller animals have advantage, since they are capable of obtaining the necessary amount of food at a small home range and high density of food objects. A hypothesis was put forward that large and largest aquatic animals can occur in sea and oceanic waters not only because these are huge water basins, but also because these waters are, on the most part of territories, less productive, as compared to continental water bodies. In these conditions, the animals have to hunt over big territories for the necessary amount of food to be obtained and only large animals are able to do this.     

Territoriality,breeding biology and vocalisations of the Crimson-breasted Shrike

This study reports on aspects of the territoriality, breeding success and vocal behaviour of Crimson-breasted Shrikes Laniarus atrococcineus at a study site in the Nylsvley district, South Africa. Their mean territory size was c. 12ha. Breeding success was very low, with only one nestling fledging from 13 clutches. Vocalisations consisted of eight different notes: these notes were either heard as solitary calls or combined into different types of duets. Both solitary calls and duets were heard more frequently outside the breeding season. During nest-building and incubation, the shrikes were silent, but resumed calling and duetting after the chicks had hatched. Call repertoires and the time spent calling or duetting differed among pairs of shrikes.     

Mycoplasmosis in captive crows and robins from Minnesota

Mycoplasma sturni is a recently described organism previously associated with conjunctivitis in European starlings (Sturnus vulgaris), northern mockingbirds (Mimus polyglottos) and blue jays (Cyanocitta cristata). Herein we describe the isolation of M. sturni from an American crow (Corvus brachyrhynchos) presenting with conjunctivitis. A nested-PCR was designed for identification of M. sturni in clinical specimens and the sensitivity of the reaction was found to be 10 colony-changing units. The organism was found in asymptomatic American crows caged with a nestmate of the crow with conjunctivitis. Mycoplasma sturni also was found in asymptomatic American robins (Turdus migratorius) and in a European starling (Sturnus vulgaris) housed at the same facility as the crows. Heterogenity of M. sturni isolates from different host species was found by random amplified polymorphic DNA (RAPD) analyses. Heterogeneity also was found among M. sturni isolates recovered from American crows. We suggest that M. sturni can successfully infect American crows and American robins with or without the presence of clinical disease. Furthermore, we demonstrate that nested-PCR is an effective method for the detection of M. sturni and that substantial genetic heterogeneity exists among natural isolates of this bacterial pathogen.     

Sex-biased dispersal and natal philopatry in the diamondback terrapin, Malaclemys terrapin

Nesting ecology and population studies indicate that diamondback terrapins (Malaclemys terrapin) exhibit nest site fidelity and high habitat fidelity. However, genetic studies indicate high levels of gene flow. Because dispersal affects the genetics and population dynamics of a species, we used six highly polymorphic microsatellite markers to investigate sex-biased dispersal and natal philopatry of M. terrapin in Barnegat Bay, NJ. We compared results of spatial autocorrelation analysis, assignment methods and Wright's F(ST) estimators to a mark-recapture analysis. Mark-recapture analysis over a 4-year period indicated that most individuals have relatively small home ranges (<2 km), with mature females displaying greater home ranges than males. Goodness of fit analysis of our mark-recapture study indicated that some juvenile males were likely transient individuals moving through our study location. Mean assignment indices and first-generation migrant tests indicated that mature males were more prone to disperse than mature females, but first-generation migrant tests indicated that per capita there are more female than male dispersers. Thus, the relative importance of males and females on gene flow in terrapin populations may change in relation to population sex ratios. Spatial autocorrelation analysis indicated that mature females exhibited natal philopatry to nesting beaches, but first-generation migrant tests indicated that a small number of females failed to nest on natal beaches. Finally, we discuss the important conservation implications of male-biased dispersal and natal philopatry in the diamondback terrapin.     

Art and Territoriality in the Lower Pecos Archaic

Abstract

The approximate prehistoric territorial limits of an Archaic belief system in the lower Pecos area of Texas is hypothesized on the basis of the geographic distribution of a distinctive pictograph style. It is proposed that these rock art localities functioned as ritual sites for a group of Archaic bands who shared a common ideology.     

Territoriality and fighting in a colonial thrips, Hoplothrips pedicularius, and sexual dimorphism in Thysanoptera

ABSTRACT.

• 1 Hoplothrips pedicularius (Haliday) (Thysanoptera: Phlaeothripidae), a tubuliferan thrips in which males possess greatly enlarged forelegs, lives in colonies on Stereum fungus.
• 2 Females oviposit onto communal egg masses, and males fight by grasping and stabbing with their forelegs in territorial defence of oviposition areas. Prolonged escalated fights occur between males who are of similar size.
• 3 Larger males usually win fights and become dominant at the oviposition area. Dominant males secure 80% of matings, and mate most frequently during oviposition periods, with an ovipositing female.
• 4 Smaller, subordinate males avoid fights and attempt to 'sneak’copulations. However, they occasionally challenge the dominant male. Challenges tend to follow copulations by the subordinate male and occur more frequently between males who are of similar size.
• 5 Subordinate males who eventually leave the oviposition area are larger than those who remain, have frequently challenged the dominant male, and have more frequently been stabbed.
• 6 Sexual dimorphism in thrips is associated with gregariousness, claustral habitats, female-biased sex ratios, and male winglessness. In thrips genera in which males exhibit foreleg armature, males are larger relative to females. The ecological circumstances promoting sexual dimorphism and male fighting in spatially-structured populations are discussed.