Do Gravid Black Flies (Diptera: Simuliidae) Oviposit at Their Natal Site?

We present information on an aniline dye marking method for black flies. In the laboratory, adults were sprayed with 2% aqueous solutions of four colors of aniline dyes; brilliant blue and methyl orange gave the best results in longevity trials. In field trials we were able to recapture 1.3% of newly emerged marked and released flies at oviposition sites. Mark–release–recapture experiments were designed to distinguish among three competing models concerning oviposition site selection by gravid female black flies: (1) larval site fidelity (“Do flies return to the site that they experienced as larvae?”), (2) adult site fidelity (“Do flies return to the site that they experienced as adults?”), and (3) no site fidelity (“Do flies oviposit at random, i.e., without regard to adult or larval experience?”). Models 1 and 2 were rejected. There is, however, no reason to reject Model 3, the no site fidelity model. Thus, we conclude that for members of the S. venustum/verecundum complex (i.e., S. rostratum, S. venustum, and S. truncatum) females find an “apparently suitable” waterway in which to oviposit; this may or may not be their natal site.     

No evidence for sex bias in winter inter‐site movements in an Arctic‐nesting goose population

Understanding movement of individuals between sites is necessary to quantify emigration and immigration, yet previous analyses exploring sex biases in site fidelity among birds have not evaluated remigration (the return of marked birds that moved to alternative areas from the site at which they were marked). Using novel Bayesian multistate models, we tested whether between‐winter emigration, remigration and survival rates were sex‐biased among 851 Greenland White‐fronted Geese Anser albifrons flavirostris marked at Wexford, Ireland. We found no evidence for sex biases in emigration, remigration or survival. Thus, sex biases in winter site fidelity do not occur in any form in this population; these techniques for modelling sex‐biased movement will be useful for a better understanding of site fidelity and connectivity in other marked animal populations.     

<Emphasis Type="Italic">Neohelice granulata</Emphasis> burrow fidelity behaviour related to landscape heterogeneity

Neohelice granulata provides an interesting animal model for studying behavioural process because it is widely distributed, ensuring variability related to different environmental conditions. The aim of this study was to analyse variation in site fidelity with relation to landscape heterogeneity. Field observations were carried out in three geographically distant marshes in Argentina (Mar Chiquita, San Antonio Oeste, and Riacho San José), which differ in their environmental characteristics and where crabs display different reproductive strategies. We analysed potential variation in burrow fidelity with relation to body size, sex and presence of vegetation (mudflat and saltmarsh) at all study sites. In addition, we analysed the influence of tidal flooding on fidelity in the Mar Chiquita saltmarsh. To achieve these goals, we used a mark–recapture method in which we tagged approximately 100 crabs during mid-summer for each zone at each site (a total of 668 crabs) for geographical comparison and approximately 370 crabs to evaluate the influence of tidal flooding. We found more faithful individuals in Mar Chiquita than in San Antonio Oeste and Riacho San José. For the San Antonio Oeste and Riacho San José populations and for Mar Chiquita previous to flooding samples we also found differences in site fidelity related to crab body size. At San Antonio Oeste and Riacho San José the relationship between size and proportion of faithful crabs was negative (smaller crabs were more faithful than larger crabs). In Mar Chiquita, a higher proportion of fidelity previous to flooding and a size-dependent response to flooding were detected, suggesting that fidelity may be modulated by tides having different effects on crabs with different body sizes. Equal proportions of males and females displaying site fidelity were observed at all study zones and sites. Our study suggests that N. granulata burrow fidelity behaviour changes with latitude and landscape (mudflat or saltmarsh) and can be sensitive to variables such as body size and frequency of flooding.     

Balance between site fidelity and habitat preferences in colony site selection by herons and egrets

Habitat selection in avian species is a hierarchical process driven by different factors acting at multiple scales. Habitat preferences and site fidelity are two main factors affecting how colonial birds choose their breeding locations. Although these two factors affect how colonial species choose their habitats, previous studies have only focused on one factor at a time to explain the distribution of species at regional scales. Here we used 28 yr of colony location data of herons and egrets around Ibaraki prefecture in Japan in order to analyze the relative importance of habitat preferences and colony site fidelity for selecting breeding locations. We used Landsat satellite images together with a ground survey‐based map to create land‐use maps for past years and determine the habitats surrounding the herons and egrets colonies. Combining the estimated colony site fidelity with the habitat data, we used a random forest algorithm to create habitat selection models, which allowed us to analyze the changes in the importance of those factors over the years. We found high levels of colony site fidelity for each year of study, with its relative importance as a predictor for explaining colony distribution increasing drastically in the most recent five years. The increase in collective site fidelity could have been caused by recent changes in the population size of grey herons Ardea cinerea, a key species for colony establishment. We observed a balance between habitat preferences and colony site fidelity: habitat preferences were a more powerful predictor of colony distribution until 2008, when colony site fidelity levels were lower. Considering changes in the relative importance of these factors can lead to a better understanding of the habitat selection process and help to analyze bird species’ responses to environmental changes.     

Defining null expectations for animal site fidelity

Site fidelity—the tendency to return to previously visited locations—is widespread across taxa. Returns may be driven by several mechanisms, including memory, habitat selection, or chance; however, pattern-based definitions group different generating mechanisms under the same label of ‘site fidelity’, often assuming memory as the main driver. We propose an operational definition of site fidelity as patterns of return that deviate from a null expectation derived from a memory-free movement model. First, using agent-based simulations, we show that without memory, intrinsic movement characteristics and extrinsic landscape characteristics are key determinants of return patterns and that even random movements may generate substantial probabilities of return. Second, we illustrate how to implement our framework empirically to establish ecologically meaningful, system-specific null expectations for site fidelity. Our approach provides a conceptual and operational framework to test hypotheses on site fidelity across systems and scales.     

Remote site control of an active site fidelity checkpoint in a viral RNA-dependent RNA polymerase

The kinetic, thermodynamic, and structural basis for fidelity of nucleic acid polymerases remains controversial. An understanding of viral RNA-dependent RNA polymerase (RdRp) fidelity has become a topic of considerable interest as a result of recent experiments that show that a 2-fold increase in fidelity attenuates viral pathogenesis and a 2-fold decrease in fidelity reduces viral fitness. Here we show that a conformational change step preceding phosphoryl transfer is a key fidelity checkpoint for the poliovirus RdRp (3Dpol). We provide evidence that this conformational change step is orientation of the triphosphate into a conformation suitable for catalysis, suggesting a kinetic and structural model for RdRp fidelity that can be extrapolated to other classes of nucleic acid polymerases. Finally, we show that a site remote from the catalytic center can control this checkpoint, which occurs at the active site. Importantly, similar connections between a remote site and the active site exist in a wide variety of viral RdRps. The capacity for sites remote from the catalytic center to alter fidelity suggests new possibilities for targeting the viral RdRp for antiviral drug development.     

Highly tolerated amino acid substitutions increase the fidelity of Escherichia coli DNA polymerase I

Fidelity of DNA synthesis, catalyzed by DNA polymerases, is critical for the maintenance of the integrity of the genome. Mutant polymerases with elevated accuracy (antimutators) have been observed, but these mainly involve increased exonuclease proofreading or large decreases in polymerase activity. We have determined the tolerance of DNA polymerase for amino acid substitutions in the active site and in different segments of E. coli DNA polymerase I and have determined the effects of these substitutions on the fidelity of DNA synthesis. We established a DNA polymerase I mutant library, with random substitutions throughout the polymerase domain. This random library was first selected for activity. The essentiality of DNA polymerases and their sequence and structural conservation suggests that few amino acid substitutions would be tolerated. However, we report that two-thirds of single base substitutions were tolerated without loss of activity, and plasticity often occurs at evolutionarily conserved regions. We screened 408 members of the active library for alterations in fidelity of DNA synthesis in Escherichia coli expressing the mutant polymerases and carrying a second plasmid containing a beta-lactamase reporter. Mutation frequencies varied from 1/1000- to 1000-fold greater compared with wild type. Mutations that produced an antimutator phenotype were distributed throughout the polymerase domain, with 12% clustered in the M-helix. We confirmed that a single mutation in this segment results in increased base discrimination. Thus, this work identifies the M-helix as a determinant of fidelity and suggests that polymerases can tolerate many substitutions that alter fidelity without incurring major changes in activity.     

Feeding site selection by workers of the Formosan subterranean termite Coptotermes formosanus (Isoptera: Rhinotermitidae) - a re-analysis of field data from a mark-recapture study

During the early stages of the development of termite baits, dyed paper was placed in specified feeding stations to ascertain whether a slow-acting toxicant could be placed in a few bait stations to be delivered to the entire colony members of the Formosan subterranean termite, Coptotermes formosanus Shiraki. Feeding frequency data, as measured by the dye concentration in individual termites, suggested the absence of feeding site fidelity. However, these results were often misinterpreted as random movement of termites that were marked and released for population estimate studies, or the random search of food in soil by subterranean termites. A computer simulation program was constructed to re-examine this feeding frequency data, and confirmed the earlier conclusion that the lack of feeding site fidelity was the most likely explanation for the data.     

Beyond habitat requirements: individual fine-scale site fidelity in a colony of the Galapagos sea lion (<Emphasis Type="Italic">Zalophus wollebaeki</Emphasis>) creates conditions for social structuring

Site fidelity has been widely discussed, but rarely been related explicitly to a species’ social context. This is surprising, as fine-scale site fidelity constitutes an important structural component in animal societies by setting limits to an individual’s social interaction space. The study of fine-scale site fidelity is complicated by the fact that it is inextricably linked to patterns of habitat use. We here document fine-scale site fidelity in the Galapagos sea lion (Zalophus wollebaeki) striving to disentangle these two aspects of spatial behaviour. Regardless of sex and age, all individuals used small, cohesive home ranges, which were stable in size across the reproductive and non-reproductive season. Home ranges showed a large individual component and did not primarily reflect age- or sex-specific habitat requirements. Site specificity could be illustrated up to a resolution of several metres. Long-term site fidelity was indicated by home range persistence over 3 years and the degree of site fidelity was unaffected by habitat, but showed seasonal differences: it was lower between reproductive and non-reproductive periods than between reproductive seasons. We further examined static and social interaction within mother–offspring pairs, which constitute a central social unit in most mammalian societies. Regardless of the occupied habitat type, adult females with offspring had smaller home range sizes than non-breeding females, demonstrating the importance of spatial predictability for mother–offspring pairs that recurrently have to reunite after females’ foraging sojourns. While social interaction with the mother dropped to naught in both sexes after weaning, analysis of static interaction suggested female-biased home range inheritance. Dispersal decisions were apparently not based on habitat quality, but determined by the offspring’s sex. We discuss the implication of observed fine-scale site fidelity patterns on habitat use, dispersal decisions and social structure in colonial breeding pinnipeds.     

Mate fidelity in monogamous birds: a re-examination of the Procellariiformes

Mate retention is classically considered advantageous for reproduction in monogamous birds: because of their low fecundity, long-lived species should show the highest year-to-year mate fidelity. However, this hypothesis remains controversial: several studies have found no correlation between mate fidelity and longevity, possibly because they did not control for potential confounding factors on each of these parameters, and one study found a negative correlation in the Procellariiformes (albatrosses and petrels). We re-examined the relations between mate fidelity and longevity, and between mate fidelity and site fidelity, in this group, using our data on 13 species and data from the literature, and after eliminating confounding factors. Procellariiformes are the most long lived of birds despite important interspecific variation in body size, and they show strong mate fidelity and bear high costs of divorce. All species lay only one egg, and the most long lived breed biennially. Because large organisms live longer than small ones and their reproductive effort is lower, we had to control for breeding frequency and body size. Mate fidelity and adult life expectancy were positively correlated, regardless of whether we controlled for these two parameters. We also evaluated whether mate fidelity was related to site fidelity. Biennial albatrosses show high mate fidelity, but low nest fidelity, although they are extremely faithful to a small area around their previous nest. After controlling for body size, adult life expectancy and breeding frequency, we found no correlation between mate fidelity and site fidelity. Because divorce is costly and mate retention advantageous in Procellariiformes, we suggest that mate fidelity does not passively result from site fidelity in these species. Rather, site fidelity would be a means for pairs to reunite, with sites serving as meeting points. Copyright 2003 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.      

A single highly mutable catalytic site amino acid is critical for DNA polymerase fidelity

DNA polymerases contain active sites that are structurally superimposable and conserved in amino acid sequence. To probe the biochemical and structure-function relationship of DNA polymerases, a large library (200,000 members) of mutant Thermus aquaticus DNA polymerase I (Taq pol I) was created containing random substitutions within a portion of the dNTP binding site (Motif A; amino acids 605-617), and a fraction of all selected active Taq pol I (291 out of 8000) was tested for base pairing fidelity; seven unique mutants that efficiently misincorporate bases and/or extend mismatched bases were identified and sequenced. These mutants all contain substitutions of one specific amino acid, Ile-614, which forms part of the hydrophobic pocket that binds the base and ribose portions of the incoming nucleotide. Mutant Taq pol Is containing hydrophilic substitution I614K exhibit 10-fold lower base misincorporation fidelity, as well as a high propensity to extend mispairs. In addition, these low fidelity mutants containing hydrophilic substitution for Ile-614 can bypass damaged templates that include an abasic site and vinyl chloride adduct ethenoA. During polymerase chain reaction, Taq pol I mutant I614K exhibits an error rate that is >20-fold higher relative to the wild-type enzyme and efficiently catalyzes both transition and transversion errors. These studies have generated polymerase chain reaction-proficient mutant polymerases containing substitutions within the active site that confers low base pairing fidelity and a high error rate. Considering the structural and sequence conservation of Motif A, it is likely that a similar substitution will yield active low fidelity DNA polymerases that are mutagenic.     

Is mate fidelity related to site fidelity? A comparative analysis in Ciconiiforms

We tested for an association between divorce rate and site fidelity in 42 avian species belonging to the order Ciconiiforms, using comparative methods that account for the influences of phylogenetic relationships on the data. Our methods enabled us to detect evidence of correlated evolution and provided information on the temporal ordering of evolutionary changes in these two variables. We found a significant correlation between divorce rate and site fidelity, indicating that species with little or no site fidelity are more likely to divorce. Our data suggest that the coupled evolution of divorce and site fidelity can be summarized by three major events. The first event corresponds to a transition from species showing high divorce rate and low or no site fidelity to species that tended to reuse the same nests over consecutive breeding seasons. This was followed by a transition towards higher mate fidelity, with the preservation of pair bonds over consecutive breeding attempts. In a third stage, divorce rate and the rate of site fidelity varied, independently of each other. We discuss our results within the context of the ancestor species and the past environments in which the traits originated, and address the importance of the potential for individual recognition in shaping the observed patterns of covariation between mate fidelity and site fidelity in Ciconiiforms. Copyright 2000 The Association for the Study of Animal Behaviour.     

Individual differences in foraging site fidelity are not related to time-activity budgets in Herring Gulls

Many populations consist of individuals that differ consistently in their foraging behaviour through resource or foraging site selection. Foraging site fidelity has been reported in several seabird species as a common phenomenon. It is considered especially beneficial in spatially and/or temporally predictable environments in which fidelity is thought to increase energy intake, thereby affecting time-energy budgets. However, the consequences for activity and energy budget have not been adequately tested. In this paper, we studied the consequences of fine-scale foraging site fidelity in adult Herring Gulls Larus argentatus in a highly predictable foraging environment with distinct foraging patches. We measured their time-activity budgets using GPS tracking and tri-axial acceleration measurements, which also made it possible to estimate energy expenditure. Individual variation in foraging site fidelity was high, some individuals spending most of their time on a single foraging patch and others spending the same amount of time in up to 21 patches. While time and activity budgets differed between individuals, we found no clear relationship with foraging site fidelity. We did find a relationship between the size of the birds and the level of site fidelity; faithful birds tend to have a larger body size. Although differences in foraging time and habitat use between individuals could play a role in the results of the current study, short-term consequences of variation in foraging site fidelity within a population remain elusive, even when focusing on individuals with a similar foraging specialization (Blue Mussels Mytilus edulis). Studying individuals over multiple years and under varying environmental conditions may provide better insight into the consequences and plasticity of foraging site fidelity.     

Selection of rendezvous sites and reuse of pup raising areas among wolvesCanis lupus of north-eastern Apennines, Italy

A coarse scale analysis was carried out of factors affecting rendezvous site selection and fidelity to pup raising areas in wolfCanis lupus Linnaeus, 1758 packs inhabiting the north eastern Apennines, Italy. From 1993 to 2004, 44 rendezvous sites were identified, and compared with random sites for variables related to topography, habitat, and human presence. Rendezvous sites were significantly more frequent inside protected areas and at a significantly greater distance from paved roads and villages than random sites. Moreover, they were located on a significantly steeper slope and at a higher absolute elevation than random sites, whereas we did not observe selection of a particular aspect. Deciduous forests were selected, whereas open areas were not used. Canopy cover above 70% was positively selected. Distance from protected areas border and paved roads, and presence of deciduous forest proved the main factors affecting rendezvous site distribution. In four cases we observed the reuse of the same rendezvous sites for two consecutive years. Some packs tended to locate their rendezvous sites in small portions of their territory, thus implying that some areas are more suitable for pup raising.     

The link between restriction endonuclease fidelity and oligomeric state: A study with Bse634I

Type II restriction endonucleases (REases) exist in multiple oligomeric forms. The tetrameric REases have two DNA binding interfaces and must synapse two recognition sites to achieve cleavage. It was hypothesised that binding of two recognition sites by tetrameric enzymes contributes to their fidelity. Here, we experimentally determined the fidelity for Bse634I REase in different oligomeric states. Surprisingly, we find that tetramerisation does not increase REase fidelity in comparison to the dimeric variant. Instead, an inherent ability to act concertedly at two sites provides tetrameric REase with a safety-catch to prevent host DNA cleavage if a single unmodified site becomes available.     

Site fidelity of intertidal fish to rockpools

Gobius paganellus, Lipophrys pholis and Coryphoblennius galerita are wide‐spread intertidal fish that spend their earlier life stages in rock pools, and yet very little is known about their site fidelity behaviour. For these species, fidelity to rockpools may result in increased fitness costs in a predicted scenario of warmer sea water, due to the low thermal inertia of these water bodies. In this context, it is relevant to investigate these species' site fidelity. We made a mark‐recapture study to assess the mentioned species' movements within and between rockpools. We tagged a total of 530 individuals of the aforementioned species with the Visible Implant Elastomer and tracked their movement for a 7‐month period. We found that site fidelity and specific rockpools conditions are important factors in distribution of intertidal blennies and gobies. We also examined the relations between rockpool volume, depth and site fidelity. We found that G. paganellus tends to remain in its original marking pool, with an average recapture rate of 20.5%, but showed no evidence of inter‐pool movement. Rockpool depth, however, proved to be important in the blennies' movements. Our findings are among the first to prove that a mark‐recapture method can be successfully used to track intertidal fish movements. In particular, we showed that G. paganellus presents site fidelity in intertidal rockpools during its early ontogeny for a period of two to three months.     

Relationship between hill plots with variable exponents and determination of average free energy of interaction per site

The Hill plot has been used by many investigators in protein ligand equilibria. As a general rule, it is used with a single exponent. In this paper, we propose the use of the Hill equation with an exponent that varies with the ligand concentration. Since Wyman [1,-2] has shown this exponent is related to free energy of interaction of the site, computing the exponent as a function of ligand concentration provides a history of the conformational changes that occur with increasing ligand concentration.     

Survival and fidelity of an enclosed white-tailed deer population using capture–recapture-reporting data

The number of animal populations enclosed by impermeable fences has increased, which poses issues related to the behavior of individuals and populations. Despite the increased number of fenced enclosures, there is a paucity of survival and fidelity data on white-tailed deer (Odocoileus virginianus) from fenced enclosures. Therefore, we examined marked deer recaptures and resightings over 13 years for an enclosed population of white-tailed deer in Oklahoma, USA, to estimate survival and fidelity parameters. We found that a step model was the best model of survival for both sexes. Survival of females and males was greater after hunting was suspended. Average female survival was 77% before hunting was suspended but increased to 98% after. Male survival was also greater after (99%) hunting was suspended compared to before (58%). Females exhibited greater site fidelity (84–94%) than males for all age groups except old individuals, which showed similar site fidelities for males and females. Fidelity was highest for old males (85%), followed by adult (74%), fawn (61%), and yearling males (56%). Our high-tensile electric fence allowed management goals to be achieved through increased survival while potentially maintaining genetic diversity through the exchange of limited numbers of individuals from surrounding areas. However, if the goal is to confine deer to limit disease spread or protect sensitive areas (e.g., airports) from deer encroachment, then other fence designs may be necessary, because our fence was not completely effective at controlling deer movements for these purposes.     

Home‐site fidelity and homing behavior of the big‐headed turtle Platysternon megacephalum

Site fidelity refers to the restriction of dispersal distance of an animal and its tendency to return to a stationary site. To our knowledge, the homing ability of freshwater turtles and their fidelity is reportedly very low in Asia. We examined mark–recapture data spanning a 4‐year period in Diaoluoshan National Nature Reserve, Hainan Province, China, to investigate the site fidelity and homing behavior of big‐headed turtles Platysternon megacephalum. A total of 11 big‐headed turtles were captured, and all individuals were used in this mark–recapture study. The site fidelity results showed that the adult big‐headed turtles (n = 4) had a 71.43% recapture rate in the original site after their release at the same site, whereas the juveniles (n = 1) showed lower recapture rates (0%). Moreover, the homing behavior results showed that the adults (n = 5) had an 83.33% homing rate after displacement. Adult big‐headed turtles were able to return to their initial capture sites (home) from 150 to 2,400 m away and precisely to their home sites from either upstream or downstream of their capture sites or even from other streams. However, none of the juveniles (n = 4) returned home, despite only being displaced 25–150 m away. These results indicated that the adult big‐headed turtles showed high fidelity to their home site and strong homing ability. In contrast, the juvenile turtles may show an opposite trend but further research is needed.