Valuska, A. J., Leighty, K. A., Schutz, Paul. J., Ferrie, G. M., Sky, C. C. and Bettinger, T. L. (2013), The use of visual barriers to reduce aggression among a group of marabou storks (Leptoptilos crumeniferus). Zoo Biol.. doi: 10.1002/zoo.21094
Marabou storks are one of the most commonly held birds in zoos, but the captive population faces challenges related to high mortality. One of the most common causes of death among captive marabou storks is conspecific aggression. There is a pressing need to better understand how to manage this aggression. One method that has been used successfully to reduce aggression in other species is the addition of visual barriers to the enclosure, though there are no published studies on their effect on storks. We studied the behavioral changes in a group of 2.2 marabou storks following the addition of two shade cloth barriers to their enclosure; we documented all occurrences of aggressive behavior, as well as time spent proximate to the barriers (or the space between barrier posts, when the shade cloth was removed) and time spent using the barriers to block the view of other storks. The presence of the shade cloth did not change the amount of time storks spent proximate to the barriers, nor did they spend more than 2% of their time using the barriers to block other storks, but the presence of the barriers significantly reduced displacement activity. Barriers may afford captive marabou storks an important means of escaping conflict, as flight-restriction and housing in an enclosure can limit their opportunities to give a signal of retreat or submission.
Pavel Linhart, Pavel Jaška, Tereza Petrusková, Adam Petrusek, Roman Fuchs, Being angry, singing fast? Signalling of aggressive motivation by syllable rate in a songbird with slow song, Behavioural Processes, Available online 16 September 2013, ISSN 0376-6357, http://dx.doi.org/10.1016/j.beproc.2013.06.012.
Syllable rate has been shown to play a role in male-male aggressive interactions and has been proposed to serve as a male quality indicator in several bird species. In those with fast syllable rates, males often increase rates when singing in aggressive context, and respond differently to test stimuli of varying rates. We asked whether the syllable rate fulfils a similar signalling function in the chiffchaff (Phylloscopus collybita), a songbird species with a slow syllable rate. We confronted 36 chiffchaff males with one of three playback types differing in syllable rate: control (non-manipulated rate), fast, or slow (artificially increased and decreased syllable rate, respectively). We recorded tested males’ songs and behaviour before and during the experiment. Our results indicate that syllable rate might be an aggressive signal in chiffchaff. Males that physically attacked the loudspeaker during experiments sang faster songs spontaneously, and those that continued singing during the playback responded to fast and non-manipulated stimuli with substantial increase of syllable rate. Indirect evidence further suggests that syllable rate in chiffchaff is unlikely constrained by respiratory demands; thus, we propose that syllable rate in this species functions as a conventional signal of male aggressiveness rather than an index of quality.
Baker, K. C., Bloomsmith, M. A., Oettinger, B., Neu, K., Griffis, C. and Schoof, V. A. M. (2013), Comparing options for pair housing rhesus macaques using behavioral welfare measures. Am. J. Primatol.. doi: 10.1002/ajp.22190
In a biomedical research environment, research or management procedures may render continuous full contact pairing of rhesus macaques (Macaca mulatta) unfeasible. This study aimed to determine whether separation on a frequent basis or housing in adjacent cages with tactile contact interferes with the behavioral benefits of continuous full contact. Behavioral data (1260 hours) were collected from 32 adult females and 16 adult males housed at two National Primate Research Centers. Subjects were studied in four housing conditions: single housing, full contact pair housing, intermittent contact pair housing, and protected contact housing. After introduction, each pair was housed in each of the three social housing conditions in varying order. Among females, but not males, introducing animals into full and intermittent contact reduced levels of abnormal behavior. There was a trend toward this reduction in protected contact. In both females and males, full and intermittent contact was associated with lower levels of anxiety-related behavior, but protected contact was not. Females spent more time inactive in protected contact than either full or intermittent contact, and males showed a trend toward less inactivity following introduction into full contact. Both sexes showed less affiliation in protected contact compared to the other forms of social housing. Agonistic behavior among females was not affected by housing condition; among males, levels were equivalent in full and intermittent contact but were higher in intermittent than protected contact. Frequent separation of pairs does not appear to detract from the behavioral benefits of pair housing. Separation by a barrier permitting tactile contact is inferior to other forms of social housing but showed modest improvements over single housing nonetheless. This study can guide the provision of social contact to rhesus macaques under conditions restricting pairs from continuous full contact.
Martin Šálek, Jaroslav Červinka, Petr Pavluvčík, Simona Poláková, Emil Tkadlec, Forest-edge utilization by carnivores in relation to local and landscape habitat characteristics in central European farmland, Mammalian Biology – Zeitschrift für Säugetierkunde, Available online 17 September 2013, ISSN 1616-5047, http://dx.doi.org/10.1016/j.mambio.2013.08.009.Rapid changes in agricultural landscape structure and composition affect many different farmland biotas, including carnivores, which are a key element of ecosystem stability, yet little is known about their distribution and habitat use. In this study, we evaluated how habitat characteristics on two different spatial scales (local and landscape scale) affected the forest-edge utilization by small and medium-sized carnivores in fragmented central European farmland. Based on an indirect method for detecting carnivores (scent stations), we sampled 212 forest fragments of different sizes (1–7864 ha) during April to May from 2006 to 2009. Our results indicate that carnivore utilization of forest-edge habitats was driven by landscape rather than local characteristics even though the overall extent of explained variation was small. The most important factors that determined response of the carnivore community were the area of farmland and that of urban land on a landscape scale. The corridor connectivity between small forest fragments and other spatial elements played a crucial role in the occurrence of red fox. Our results suggest that comprehensive studies on multi-species carnivore assemblage using scent station might be useful in evaluating species-specific response to habitat characteristics, especially if large numbers of stations visited by carnivores are available.
Rates of Phenotypic and Genomic Evolution during the Cambrian Explosion
Michael S.Y. Lee, Julien Soubrier, Gregory D. Edgecombe
Current Biology – 12 September 2013
The near-simultaneous appearance of most modern animal body plans (phyla) ∼530 million years ago during the Cambrian explosion is strong evidence for a brief interval of rapid phenotypic and genetic innovation, yet the exact speed and nature of this grand adaptive radiation remain debated. Crucially, rates of morphological evolution in the past (i.e., in ancestral lineages) can be inferred from phenotypic differences among living organisms—just as molecular evolutionary rates in ancestral lineages can be inferred from genetic divergences . We here employed Bayesian  and maximum likelihood  phylogenetic clock methods on an extensive anatomical  and genomic  data set for arthropods, the most diverse phylum in the Cambrian and today. Assuming an Ediacaran origin for arthropods, phenotypic evolution was ∼4 times faster, and molecular evolution ∼5.5 times faster, during the Cambrian explosion compared to all subsequent parts of the Phanerozoic. These rapid evolutionary rates are robust to assumptions about the precise age of arthropods. Surprisingly, these fast early rates do not change substantially even if the radiation of arthropods is compressed entirely into the Cambrian (∼542 mega-annum [Ma]) or telescoped into the Cryogenian (∼650 Ma). The fastest inferred rates are still consistent with evolution by natural selection and with data from living organisms, potentially resolving “Darwin’s dilemma.” However, evolution during the Cambrian explosion was unusual (compared to the subsequent Phanerozoic) in that fast rates were present across many lineages.
K.P. Lampert, K. Blassmann, K. Hissmann, J. Schauer, P. Shunula, Z. el Kharousy, B.P. Ngatunga, H. Fricke, M. Schartl (2013): Single male paternity in coelacanths, Nature Communications, doi: 10.1038/ncomms3488
Latimeria chalumnae, a ‘living fossil,’ is of great scientific interest, as it is closely related to the aquatic ancestors of land-living tetrapods. Latimeria show internal fertilization and bear live young, but their reproductive behaviour is poorly known. Here we present for the first time a paternity analysis of the only available material from gravid females and their offspring. We genotype two L. chalumnae females and their unborn brood for 14 microsatellite loci. We find that the embryos are closely related to each other and never show more than three different alleles per locus, providing evidence for a single father siring all of the offspring. We reconstruct the father’s genotype but cannot identify it in the population. These data suggest that coelacanths have a monogamous mating system and that individual relatedness is not important for mate choice.
Zootaxa 3714 (1): 001–063 (19 Sept. 2013)
A new genus of cardinalfish (Apogonidae: Percomorpha), redescription of Archamia and resemblances and relationships with Kurtus (Kurtidae: Percomorpha)
THOMAS H. FRASER
Archamia is restricted to a single species, A. bleekeri. A recently described genus, Kurtamia, a reference to a suggested relationship with the enigmatic Kurtus, is the junior synonym of Archamia. Kurtamia bykhovskyi is a junior synonym of A. bleekeri. Archamia is redescribed using osteological, color pattern, pore and free neuromast patterns supplementing those characters used in other publications noting clear differences between A. bleekeri and all other species formerly in that genus. The new genus Taeniamia, type species Archamia leai contains the remaining species. Osteology, color patterns and lateralis characters are reviewed for Taeniamia leai and other species. Species placed in Taeniamia have two broadly different color patterns: 1) yellow, orange, red or dark bars with or without a dark basicaudal spot, and 2) yellow or dark midline stripe with
another stripe above the lateral line, lacking bars. These color patterns suggest two lineages exist within Taeniamia. New species combinations are: Taeniamia ateania, T. biguttata, T. bilineata, T. buruensis, T. dispilus, T. flavofasciata, T. fucata, T. kagoshimana, T. leai, T. lineolata, T. macroptera, T. melasma, T. mozambiquensis, T. pallida, and T. zosterophora. Archamia and Taeniamia are sister genera. A diagnosis is provided for the Apogonidae: one or two anal spines, first spine small, supernumerary in position, second spine or first anal fin-ray (only Paxton) in serial association with first distal and proximalmiddle radials; first segmented anal ray branched; males mouth brood fertilized eggs; swim bladder simple without anterior or posterior modifications, a dorsal oval and ventral gas glands; free neuromasts on head, body and caudal fin. Characters of Holapogon were used to help identify common plesiomorphic characters for the Apogonidae, elsewhere among percoids using the Centropomidae and information for basal Percomorpha. A table of basal characters and derived changes is provided for the
Apogonidae. Characters for two species Kurtus indicus and K. gulliveri are described and examined in a search for morphological synapomorphies with Archamia, Taeniamia, Holapogon and other apogonids. A diagnosis is provided for the Kurtidae: highly modified ribs, anterior dorsal spines individually fused with all radials of the pterygiophore complex, medially fused pterosphenoids, gill rakers on second branchial arch, tooth plates between each gill raker, serrated curved extension of the male’s supraoccipital crest, tiny cycloid scales on head and body, very short pored lateral-line scales and free neuromast patterns on the head and body. The second epibranchial articulating with third pharyngobranchial and radial ridges simple or bifid filaments around the micropyle of the egg related to egg ball organization are supported as possible non-exclusive synapomorphic characters for kurtids and apogonids. Parental care of eggs has not been demonstrated for Kurtus indicus, an estuarine/coastal marine species. Kurtids share foramina in the lateral lower part of each caudal vertebra with carangine species, some ephippids, some leiognathids, some priacanthids and scatophagids and share tiny cycloid scales with carangoids: possible synapomorphies or independently derived features.
Zootaxa 3711 (1): 001–064 (19 Sept. 2013)
Annotated list and key to the stream fishes of Trinidad & Tobago
DAWN A.T. PHILLIP, DONALD C. TAPHORN, ERLING HOLM, JAMES F. GILLIAM, BRADLEY A. LAMPHERE & HERNÁN LÓPEZ-FERNÁNDEZ
Based on historical and museum records and recent extensive collecting we compiled a checklist of 77 fish species reported from the streams of Trinidad and Tobago. A key with photographs is provided to aid in identifications, as well as brief notes on habitat, diet, reproduction, maximum size, local common names and distribution.
Mirjam Knörnschild, Marion Feifel, Elisabeth K.V. Kalko, Mother–offspring recognition in the bat Carollia perspicillata, Animal Behaviour, Available online 17 September 2013, ISSN 0003-3472, http://dx.doi.org/10.1016/j.anbehav.2013.08.011.
Parental care is crucial for offspring survival in many taxa but its burden and costs are often not equally distributed between the sexes. In bats, the majority of parental care is provided by females, making examples of paternal support towards pups exceedingly rare. One exception to this general pattern seemed to be the polygynous Seba’s short-tailed fruit bat Carollia perspicillata; two earlier studies suggested that paternal care occurs, i.e. that harem males prompt females to retrieve vocalizing pups. To corroborate this suggestion, we investigated the occurrence of maternal and paternal care in reaction to pup isolation calls in C. perspicillata. Acoustic measurements of 905 isolation calls from 17 pups revealed sufficient interindividual variation to encode an individual vocal signature. Correspondingly, mothers were capable of using this individual signature to discriminate between their own pups and age-matched pups from other females belonging to their colony. Maternal experience was positively correlated with the strength of response behaviour during playbacks. Thus, our results indicate that pup isolation calls were used to elicit maternal care and that mothers recognize their pups based on an individual signature in isolation calls. However, in contrast to the previous studies mentioned above, we found no evidence that harem males reacted to pup isolation calls by prompting the respective mothers to retrieve their vocalizing pups. Instead, our results demonstrate that harem males engaged in courtship activities that were unaffected by pup isolation calls.
Stachowicz, J. B., Vannoni, E., Pitcher, B. J., Briefer, E. F., Geffen, E. and McElligott, A. G. (2013), Acoustic divergence in the rut vocalizations of Persian and European fallow deer. Journal of Zoology. doi: 10.1111/jzo.12083
We conducted a study of the male rut vocalizations (groans) of two closely related species, Persian and European fallow deer. Persian fallow deer are endangered, restricted to Iran and Israel, and their rut vocalizations have never been studied. By contrast, European fallow deer are one of the most common deer species in the world, and have been the subject of numerous detailed studies. Persian bucks are approximately 16% larger than European bucks, and this can have important implications for vocalizations. Persian bucks were recorded in Israel, and European bucks were recorded in the UK and Ireland. We measured temporal, fundamental frequency-related and formant-related parameters of groans and determined which acoustic parameters differed among species and populations. The comparisons revealed important structural similarities and differences, with the differences more strongly related to temporal than spectral vocal parameters. Persian buck groans were relatively long, pulsed calls of almost 1-s duration, with low fundamental frequencies, and relatively weak formant modulation. European buck groans were much shorter (0.38 s), but with similarly low fundamental frequencies and clearer formant modulation. We found some minor differences in the formant frequencies (F4 and F5) of calls of the two European fallow populations. Given the length of time since Persian and European fallow deer diverged, and that both their mitochondrial and nuclear genomes are very different, it is notable that the structure of their groans is still so similar. Our findings suggest that the factors influencing the evolution of these vocalizations (e.g. sensory system characteristics, environment and mate choice) have probably been similar for both species.
M. Laporte, A. Bertolo, P. Berrebi, P. Magnan, Detecting anthropogenic effects on a vulnerable species, the freshwater blenny (Salaria fluviatilis): The importance of considering key ecological variables, Ecological Indicators, Volume 36, January 2014, Pages 386-391, ISSN 1470-160X, http://dx.doi.org/10.1016/j.ecolind.2013.08.006.
The inclusion of key environmental covariables in habitat quality models is crucial to improve the ability of indicators to predict the response of aquatic organisms to anthropogenic stress. The sensitivity of the freshwater blenny (Salaria fluviatilis) to anthropogenic factors was found to be inconsistent among studies, and this might have been because background environmental heterogeneity was not considered. The goal of this study was to assess whether the inclusion of key environmental variables in habitat models would improve the ability to detect the effects of anthropogenic stress on vulnerable fishes. We used a theoretical–information approach to rank different models intended to predict the relative abundance of freshwater blenny in 10 Corsican rivers based on a combination of environmental and anthropogenic indicators. The results show a clear relationship between water velocity and blenny abundance in the studied streams. When this key variable is taken into account in the model, anthropogenic variables such as Enterococcus spp. and Escherichia coli counts, which are indicators of fecal pollution, and the number of competitor species also explain a significant proportion of the variation in blenny abundance. This study reveals the importance of statistically accounting for natural environmental variability, which may conceal other effects, when modeling anthropogenic impacts on a species.
David S. Jachowski, Rob Slotow, Joshua J. Millspaugh, Corridor use and streaking behavior by African elephants in relation to physiological state, Biological Conservation, Volume 167, November 2013, Pages 276-282, ISSN 0006-3207, http://dx.doi.org/10.1016/j.biocon.2013.08.005.
Wildlife populations occur in increasingly fragmented landscapes, making corridor ecology important to conservation managers. Human disturbance has been identified as a proximate cause of limiting corridor use or increasing streaking behavior by wild elephants, but there are likely to be physiological triggers that directly initiate these risk averse behaviors. We simultaneously monitored elephant stress hormone concentrations and movement in two reserves to test whether elephants in an elevated physiological state restricted use of corridors, or, if they still used corridors, exhibited relatively rapid unidirectional movements indicative of streaking behavior. Contrary to predictions, the elephant population in an elevated physiological state did not reduce use of corridors between core areas. However, as predicted, when the population was in an elevated physiological state, elephant family groups exhibited less tortuosity, and moved 77% faster when in corridors as opposed to core areas, compared to only a 20% difference between corridor and core area speed when not in an elevated physiological state. Rapid movement along corridors by elephants in elevated physiological states is likely an adaptive behavioral response to avoid further exposure to stressors. Furthermore, because chronically stressed elephants can be more aggressive towards humans, understanding when and where elephants exhibit streaking behavior can guide human–elephant conflict mitigation. We demonstrate that corridor use can exist at relatively fine spatial scales within fenced reserves, and the persistent use of corridors regardless of physiological state suggests that they are likely an important, but neglected, component of animal spatial ecology within reserves.
Blomberg, E. J., Sedinger, J. S., Nonne, D. V. and Atamian, M. T. (2013), Annual male lek attendance influences count-based population indices of greater sage-grouse. The Journal of Wildlife Management. doi: 10.1002/jwmg.615
Populations of greater sage-grouse (Centrocercus urophasianus) are monitored using counts of males displaying on breeding leks (lek counts). When count-based indices are used to assess population growth (λ), an implicit assumption is that detection is constant through time and space. If detection depends on breeding behavior, annual variation in the proportion of individuals that attend a breeding site may lead to a violation of this assumption. We used 8 years of banding data from male sage-grouse in eastern Nevada and capture–mark–recapture analyses to evaluate how temporary absence of males from lek sites during a given year may influence estimates of population trends derived from lek counts. We estimated the proportion of variance in annual lek count trends that corresponded with an independent estimate of λ, versus variance associated with temporary absence. The probability a male sage-grouse attended 1 of our study leks at least once in a given year ranged from a low of 0.56 (±0.22 SE) to a high of 0.87 (±0.11 SE). Variance in annual lek count trends was associated with both realized λ (semipartial R2 = 0.57), and sampling error associated with temporary absence (semipartial R2 = 0.40). We found discrepancies between lek count and realized λ in 3 out of 7 intervals, whereas estimates of λ for the entire study interval were extremely similar between count-based and capture–mark–recapture methods (λ = 0.90 ± 0.05 SE and λ = 0.91 ± 0.05 SE, respectively). Temporary absence was influenced by male density during the previous year and associated with exotic grasslands surrounding leks, although some uncertainty was associated with this latter effect. Lek counts are well suited for estimating λ across multi-year intervals, whereas annual estimates of λ should be viewed cautiously if variation in annual lek attendance is not directly incorporated.
Paepke, H.-J. and Schindler, I. (2013), The type specimens of Neotropical Cichlidae (Teleostei: Perciformes) in the Museum für Naturkunde Berlin. Zool. Reihe, 89: 259–274. doi: 10.1002/zoos.201300012
The type specimens of the Neotropical Cichlidae in the collection of the Museum of Natural History of Berlin (formerly known as the Zoologisches Museum Berlin; ZMB) are listed, and their taxonomic status and nomenclature are discussed. Several primary type specimens are depicted for the first time. Morphometric data for primary type specimens of the taxa Apistogramma ornatipinnis, Apistogramma aequipinnis, Apistogramma reitzigi, Apistogramma weisei, Chaetobranchopsis bitaeniatus, Crenicara praetoriusi, Cichlasoma arnoldi and Crenicichla polysticta are given. A lectotype for Crenicichla polysticta is designated
Silje Kittilsen, Functional Aspects Of Emotions In Fish, Behavioural Processes, Available online 19 September 2013, ISSN 0376-6357, http://dx.doi.org/10.1016/j.beproc.2013.09.002.
There is an ongoing scientific discussion on whether fish have emotions, and if so how they experience them? The discussion has incorporated important areas such as brain anatomy and function, physiological and behavioural responses, and the cognitive abilities that fish possess. Little attention has however, been directed towards what functional aspects emotions ought to have in fish. If fish have emotions – why? The elucidation of this question and an assessment of the scientific evidences of emotions in fish in an evolutionary and functional framework would represent a valuable contribution in the discussion on whether fish are emotional creatures. Here parts of the vast amount of literature from both biology and psychology relating to the scientific field of emotions, animal emotion, and the functional aspects that emotions fulfil in the lives of humans and animals are reviewed. Subsequently, by viewing fish behaviour, physiology and cognitive abilities in the light of this functional framework it is possible to infer what functions emotions may serve in fish. This approach may contribute to the vital running discussion on the subject of emotions in fish. In fact, if it can be substantiated that emotions are likely to serve a function in fish similar to that of other higher vertebrate species, the notion that fish do have emotions will be strengthened.
Marialba Ventricelli, Valentina Focaroli, Francesca De Petrillo, Luigi Macchitella, Fabio Paglieri, Elsa Addessi, How capuchin monkeys (Cebus apella) behaviorally cope with increasing delay in a self-control task, Behavioural Processes, Available online 19 September 2013, ISSN 0376-6357, http://dx.doi.org/10.1016/j.beproc.2013.09.001.
Displacement activities are behavior patterns apparently irrelevant to the situation in which they are performed, that facilitate transitions between behavioral states. Scratching is one of the most commonly described displacement activities in primates and is related to frustration and anxiety. In chimpanzees scratching during cognitive tasks increases with task difficulty. We analyzed behavioral data obtained from video clips on nine capuchin monkeys tested in a delay choice task, a potentially stressful self-control task where subjects choose between a small immediate and a large delayed option. Scratching, response latency, and motor impulsivity scored during the delay decreased across sessions, as capuchins became indifferent between options, whereas the bias for choosing the option placed on one side of the apparatus increased. Capuchins might have found the delay choice task less stressful over time because they shifted from slower discriminatory responses in the earlier sessions to more ‘automatic’, faster responses in the later sessions. However, it cannot be excluded that they habituated over time to the contingencies of the task. In contrast with previous data on chimpanzees, handedness in scratching behavior or preferential scratching on one side of the body did not emerge, but further studies are needed to corroborate this finding.
DEKEUKELEIRE, Daan; JANSSEN, René; VAN SCHAIK, Jaap. Frequent melanism in Geoffroy’s bat (Myotis emarginatus, Geoffroy 1806). Hystrix, the Italian Journal of Mammalogy, [S.l.], v. 24, n. 2, p. 3, sep. 2013. ISSN 1825-5272. Available at: <http://www.italian-journal-of-mammalogy.it/article/view/8770>. Date accessed: 19 Sep. 2013. doi:10.4404/hystrix-24.2-8770.
Melanistic, or otherwise atypically coloured bats, are rarely observed. Here we report on a survey of melanistic individuals of Myotis emarginatus (Geoffroy’s bat) in the Northwestern edge of its distribution. Across the sampled region, 31 sites and over 3000 individuals of M. emarginatus were observed. Overall, melanism was found in approximately 2-4% of the populations. To our knowledge this is the highest proportion of melanistic individuals recorded in any bat species thus far. Such large levels of melanism may indicate a recent bottleneck in the population. Further research on the genetic structure and behaviour of this population may help identify the possible causes and consequences of this peculiarity.
Juan Arizaga, Asier Aldalur, Alfredo Herrero, Juan F. Cuadrado, Eneko Díez, Ariñe Crespo
Foraging distances of a resident yellow-legged gull (Larus michahellis) population in relation to refuse management on a local scale
European Journal of Wildlife Research September 2013
Seasonal fluctuations in marine prey availability around breeding colonies are one of the major factors affecting resident behaviour in seabirds. This is particularly applicable to large gulls (Larus spp.). The effect of refuse management on large gulls has been studied chiefly in relation to breeding dynamics, but it is less understood with regard to movement patterns. Our aim was to test whether the closure of one large dump and the use of falconry to deter gull access to two others, within the southeastern Bay of Biscay area, affected the foraging distance of local yellow-legged gulls (Larus michahellis). During a period of seven consecutive winters between 2005 and 2011, the proportion of gulls that moved less than 50 km from their natal site was 70 %. However, during the winter of 2010, when they were deterred from accessing refuse tips within the region, gulls were found to travel longer distances. This result was explained neither by a decreasing survey effort near colonies nor by a decrease in apparent availability of marine prey, thus supporting the hypothesis that refuse management within the region influenced the movement patterns of local gulls.