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971.
Citizen science may be especially effective in urban landscapes due to the large pool of potential volunteers. However, there have been few evaluations of the contributions of citizen scientists to knowledge of biological communities in and around cities. To assess the effectiveness of citizen scientists' monitoring of species in urban areas, we compared butterfly data collected over 10 years in Chicago, Illinois (U.S.A.), and New York City, New York (U.S.A.). The dates, locations, and methods of data collection in Chicago were standardized, whereas data from New York were collected at any location at any time. For each city, we evaluated whether the number of observers, observation days (days on which observations were reported), and sampling locations were associated with the reported proportion of the estimated regional pool of butterfly species. We also compared the number of volunteers, duration of volunteer involvement, and consistency of sampling efforts at individual locations within each city over time. From 2001 to 2010, there were 73 volunteers in Chicago and 89 in New York. During this period, volunteers observed 86% and 89% of the estimated number of butterfly species present in Chicago and New York, respectively. Volunteers in New York reported a greater proportion of the estimated pool of butterfly species per year. In addition, more species were observed per volunteer and observation day in New York, largely due to the unrestricted sampling season in New York. Chicago volunteers were active for more years and monitored individual locations more consistently over time than volunteers in New York. Differences in monitoring protocol--especially length of sampling season and selection protocol for monitoring locations--influenced the relationship between species accrual and sampling effort, which suggests these factors are important in volunteer-based species-monitoring programs. 相似文献
972.
Some conservation initiatives provoke intense conflict among stakeholders. The need for action, the nature of the conservation measures, and the effects of these measures on human interests may be disputed. Tools are needed to depolarize such situations, foster understanding of the perspectives of people involved, and find common ground. We used Q methodology to explore stakeholders' perspectives on conservation and management of grizzly bears (Ursus arctos horribilis) in Banff National Park and the Bow River watershed of Alberta, Canada. Twenty-nine stakeholders participated in the study, including local residents, scientists, agency employees, and representatives of nongovernmental conservation organizations and other interest groups. Participants rank ordered a set of statements to express their opinions on the problems of grizzly bear management (I-IV) and a second set of statements on possible solutions to the problems (A-C). Factor analysis revealed that participants held 4 distinct views of the problems: individuals associated with factor I emphasized deficiencies in goals and plans; those associated with factor II believed that problems had been exaggerated; those associated with factor III blamed institutional flaws such as disjointed management and inadequate resources; and individuals associated with factor IV blamed politicized decision making. There were 3 distinct views about the best solutions to the problems: individuals associated with factor A called for increased conservation efforts; those associated with factor B wanted reforms in decision-making processes; and individuals associated with factor C supported active landscape management. We connected people's definitions of the problem with their preferred solutions to form 5 overall problem narratives espoused by groups in the study: the problem is deficient goals and plans, the solution is to prioritize conservation efforts (planning-oriented conservation advocates); the problem is flawed institutions, the solution is to prioritize conservation efforts (institutionally-oriented conservation advocates); the problems have been exaggerated, but there is a need to improve decision-making processes (optimistic decision-process reformers); the problems have been exaggerated, but managers should more actively manage the landscape (optimistic landscape managers); and the problem is politicized decision making, solutions vary (democratizers). Although these 5 groups differed on many issues, they agreed that the population of grizzly bears is vulnerable to extirpation, human use of the area should be designed around ecological constraints, and more inclusive decision-making processes are needed. We used our results to inform a series of workshops in which stakeholders developed and agreed on new management strategies that were implemented by Parks Canada. Our research demonstrates the usefulness of Q method to illuminate people's perspectives and identify common ground in settings where conservation is contested. 相似文献
973.
Kátya?G.?AbrantesEmail author Jayson?M.?Semmens Jeremy?M.?Lyle Peter?D.?Nichols 《Marine Biology》2012,159(1):57-64
Stable isotope analysis is increasingly used in ecological studies. Because lipid content influences δ13C, lipids should be removed from lipid-rich samples before δ13C analysis. To account for differences in δ13C arising from differences in lipid content, relationships between lipid content, C:N ratio and Δδ13C with lipid removal can be used to normalise lipid content to uniform levels. We investigate these relationships for salmonid
muscle and evaluate the suitability of previously published normalisation equations for these fish. Salmonids with a wide
range of condition (muscle lipid content = 3–35% of dry weight) were considered. There were no consistent relationships between
lipid content or C:N ratio and Δδ15N. There were linear relationships between C:N ratio and lipid content (L = −16.53 + 6.27 × C:N); C:N ratio and Δδ13C (Δδ13C = −1.87 + 0.65 × C:N); and lipid content and Δδ13C (Δδ13C = 0.01 + 0.10 × L), which should be used on salmonid stable isotope studies. 相似文献
974.
I.?Calderón Lucía?Pita S.?Brusciotti C.?Palacín X.?TuronEmail author 《Marine Biology》2012,159(1):187-197
Spatio-temporal variability in settlement and recruitment, high mortality during the first life-history stages, and selection
may determine the genetic structure of cohorts of long-lived marine invertebrates at small scales. We conducted a spatial
and temporal analysis of the common Mediterranean Sea urchin Paracentrotus
lividus to determine the genetic structure of cohorts at different scales. In Tossa de Mar (NW Mediterranean), recruitment was followed
over 5 consecutive springs (2006–2010). In spring 2008, recruits and two-year-old individuals were collected at 6 locations
along East and South Iberian coasts separated from 200 to over 1,100 km. All cohorts presented a high genetic diversity based
on a fragment of mtCOI. Our results showed a marked genetic homogeneity in the temporal monitoring and a low degree of spatial
structure in 2006. In 2008, coupled with an abnormality in the usual circulation patterns in the area, the genetic structure
of the southern populations studied changed markedly, with arrival of many private haplotypes. This fact highlights the importance
of point events in renewing the genetic makeup of populations, which can only be detected through analysis of the cohort structure
coupling temporal and spatial perspectives. 相似文献
975.
Understanding physiological and environmental variables that initiate sexual maturity would provide fundamental information
on life history dynamics. The aim of this study was to test the usefulness of the common circumnuclear ring (CNR), an oocytic
structure similar to the Balbiani body, which appears just prior to oocyte development as a predictor of first maturation
in Atlantic herring (Clupea harengus). The relative roles of physiology (e.g. fat) and photoperiod as triggers of maturation were also investigated. Samples were
collected in May 2008 (72°26′–73°84′N/11°26′–18°40′E) and February 2009 (56°12′–59°45′N/00°25′–03°06′W). These data suggested
that thresholds in body size may influence the decision to mature. We also found that short days (winter solstice) may be
the photoperiod trigger for a first-decision window for both Norwegian spring-spawning (NSS) and North Sea autumn-spawning
(NSAS) herring. The second-decision window for NSAS herring maturation appears to be triggered by longer days (spring equinox),
while a decreasing rate of day lengthening may trigger NSS herring maturation. So, photoperiodic cycle is a key determinate
of the timing of maturation in Atlantic herring. 相似文献
976.
Michael?D.?ArendtEmail author Albert?L.?Segars Julia?I.?Byrd Jessica?Boynton J.?David?Whitaker Lindsey?Parker David?W.?Owens Ga?lle?Blanvillain Joseph?M.?Quattro Mark?A.?Roberts 《Marine Biology》2012,159(1):127-139
Thirty-four juvenile loggerhead sea turtles captured by trawling from the Charleston, South Carolina (USA), shipping channel
(32°42′N; −79°47′W) between May 2004 and August 2007 were tagged with satellite transmitters to assess the extent to which
they remained near the capture location given their collection along a seasonal migratory corridor. Seventy-five percent of
juveniles were classified as seasonal residents. Migrants predominantly swam north in the spring and nomads wandered south
in the summer, but predictive indicators for non-resident status were not identified. All but one juvenile generally remained
south of 34°N, within 40 km of shore, and in waters <30 m deep throughout the year. Nine of 14 loggerhead sea turtles monitored
during the winter remained exclusively over the continental shelf, three briefly occurred in oceanic habitats, and two foraged
extensively in oceanic habitats. Residents distributed >15 km from shore between spring and autumn were three times as likely
to occur in oceanic habitats in winter. Modest seasonal movements contrasted with adults tagged at similar latitudes and with
juveniles tagged further north and suggest distinct foraging groups within a regional foraging ground. 相似文献
977.
M.?C.?KrautzEmail author L.?R.?Castro M.?González J.?C.?Vera H.?E.?González 《Marine Biology》2012,159(2):303-317
In this study, we determined variations in ascorbic acid (AA) concentrations in the gonads and liver, and of the innate immune
response (lysozyme activity and antiprotease) in the plasma of Engraulis ringens (anchoveta) and Strangomera bentincki (common sardine) during their reproductive seasons of 2007 and 2008 in the central area of the Humboldt Current. During the
main spawning season in 2007, colder environmental conditions, higher phytoplankton biomasses, low dinoflagellate abundance
and the dominance of large copepods in winter-early spring and of small copepods in late spring contributed to explain higher
AA concentrations in anchoveta tissues. During the warmer year of 2008, lower phytoplankton biomasses, a notable increase
of dinoflagellate abundance and the dominance of small-size copepods in winter and of larger copepods in spring occurred along
with a drastic drop in AA concentrations in anchoveta tissues. These results contrasted with those in common sardine, a species
in which AA did not vary as much as in anchoveta. An inverse trend between AA concentration in the liver and the gonadosomatic
index suggested the AA utilization during gonadic maturation. Innate immune parameters were determined for the first time
in small pelagic fish and constitute a new baseline data to evaluate their natural response to environmental changes. Changes
in the distribution and abundance of edible taxa containing AA and edible for fish along with variations in AA in fish tissues
during their reproductive season could become good indicators of the overall fish physiological condition resulting from variations
in the trophic web structure. 相似文献
978.
Time of departure and landing of nocturnal migrants are of great importance for understanding migratory strategy used by birds.
It allows us to estimate flying time and hence the distance that migrants cover during a single night. In this paper, I studied
the temporal schedule of nocturnal departures of European robins during spring migration. The study was done on the Courish
Spit on the Baltic Sea in 1998–2003 by retrapping 51 ringed birds in high mist nets during nocturnal migratory departure.
Take-offs of individual birds occurred between the first and tenth hour after sunset (median 176 min after sunset). Departure
time was not related to fuel stores at arrival and departure, stopover duration and progress of the season. The results suggest
that one reason for temporal variation in take-off time was differential response of European robins with high and low motivation
to depart to such triggers as air pressure and its trend. If these parameters reach a certain minimum threshold shortly before
sunset, robins with a high migratory motivation take off in the beginning of the night. When air pressure or its trend reaches
a maximum, it may trigger to take off later during the night birds with lower initial motivation for departure, including
those that have low refuelling efficiency. In regulation of timing of take-offs of robins, an important role is also played
by their individual endogenous circadian rhythm of activity which is related to the environment in a complex way. 相似文献
979.
Virginia?Gonzalez-JimenaEmail author Patrick?S.?Fitze 《Behavioral ecology and sociobiology》2012,66(2):305-315
Glucocorticoids affect physiology and behaviour, reproduction and potentially sexual selection as well. Short-term and moderate
glucocorticoid elevations are suggested to be adaptive, and prolonged and high elevations may be extremely harmful. This suggests
that optimal reproductive strategies, and thus sexual selection, may be dose dependent. Here, we investigate effects of moderate
and high elevations of blood corticosterone levels on intra- and intersexual behaviour and mating success of male common lizards
Lacerta vivipara. Females showed less interest and more aggressive behaviour towards high corticosterone males and blood corticosterone levels
affected male reproductive strategy. Males of moderate and high corticosterone elevations, compared with Control males, showed
increased interest (i.e., higher number of chases, tongue extrusions, and approaches) towards females and high corticosterone
males initiated more copulation attempts. However, neither increased male interest nor increased copulation attempts resulted
in more copulations. This provides evidence for a best-of-a-bad-job strategy, where males with higher corticosterone levels
compensated for reduced female interest and increased aggressive female behaviour directed towards them, by showing higher
interest and by conducting more copulation attempts. Blood corticosterone levels affected intrasexual selection as well since
moderate corticosterone levels positively affected male dominance, but dominance did not affect mating success. These findings
underline the importance of female mate choice and are in line with adaptive compensatory behaviours of males. They further
show that glucocorticoid effects on behaviour are dose dependent and that they have important implications for sexual selection
and social interactions, and might potentially affect Darwinian fitness. 相似文献
980.
Julie?A.?TeichroebEmail author Pascale?Sicotte 《Behavioral ecology and sociobiology》2012,66(3):453-466
Vigilance often decreases with increasing group size, due to lower predation risk or greater scramble competition for food.
A group size effect on vigilance is seldom seen in primates, perhaps because scanning and feeding often occur simultaneously
or because the distinction between routine and induced vigilance has not been investigated. We analyzed feeding and resting
observations separately while distinguishing between routine and induced scans in four groups of wild ursine colobus monkeys
(Colobus vellerosus) experiencing scramble competition for food and infanticide risk. We used linear mixed-effect models to test the effect of
group size, age–sex class, number of neighbors, number of adult male neighbors, and height in the canopy on scanning rates
(vigilance) with and without evident conspecific threat. Food type was also examined in the feeding models. Perceived predation
risk affected vigilance more than scramble competition for food and infanticide risk. Routine and induced vigilance were greatest
at lower canopy heights during feeding and resting and increased when individuals had fewer neighbors while resting. A group
size effect was found on induced vigilance while resting, but scanning increased with group size, which probably indicates
visual monitoring of conspecifics. Scanning rates decreased while feeding on foods that required extensive manipulation. This
supports the idea that vigilance is relatively cost free for upright feeders when eating food that requires little manipulation,
a common feature of folivore diets. In the presence of threatening conspecific males, close proximity to resident males decreased
individual vigilance, demonstrating the defensive role of these males in the group. 相似文献