scholarly journals Catching the thief: Nectar robbing behaviour by bumblebees on naturalised Fuchsia magellanica in Ireland

2021 ◽  
Vol 29 ◽  
pp. 240-248
Author(s):  
Dara Anne Stanley ◽  
Emmeline Cosnett

Fuchsia magellanica (Ongaraceae) is a plant with a traditionally ornithopholous pollination system, pollinated primarily by hummingbirds in its native range. As a naturalised alien plant in Ireland, F. magellanica is visited largely by bumblebees, with evidence for nectar robbing behaviour of the long-tubed flowers. We aimed to investigate nectar robbing behaviour of bumblebees on F. magellanica, and in particular whether floral and pollinator traits (size) determined likelihood of nectar robbing. While F. magellanica was visited by a number of bumblebee species, only two with shorter tongue lengths were observed to rob nectar from flowers. Although there was no observed relationship between intra-specific bee body size and nectar robbing behaviour, nectar robbing was observed most frequently in the site with the highest number of bees. Proportions of robbed flowers were low overall and varied between populations, but there was a significant relationship between flower size and whether it was nectar robbed with larger flowers robbed more often. Our work suggests that floral size determines whether a flower-visitor will choose to nectar rob or not in this system. Nectar robbing may also be related to bee density which could suggest this behaviour is driven by competition for resources, or that it is learnt by observing other bees.

2007 ◽  
Vol 105 (1) ◽  
pp. 215-220 ◽  
Author(s):  
Julio Conzález

Generally, there is a significant relationship between some acoustic measures (F0 and formant parameters) and the body size of speakers; however, data become less clear when age and sex variables are controlled. To date, no other vocal parameter apart from F0 has been studied in relation to body size. In the present study, correlations between a set of 27 parameters of the Multi-dimensional Voice Program (Kay Elemetrics Corp.) and 4 body measures were obtained from 134 speakers of both sexes belonging to one age group (20–29 years). Correlations within sex groups were null or very weak, and all significant coefficients were below .35.


2018 ◽  
Vol 48 (2) ◽  
pp. 146-150 ◽  
Author(s):  
Mannfred M.A. BOEHM

ABSTRACT I report on nectar robbing behavior of the wedge-billed hummingbird, Schistes geoffroyi (Trochilidae) on the Andean bellflower, Centropogon granulosus (Campanulaceae). Many species of Centropogon are characterized by an abruptly curved corolla tube which is likely specialized for pollination by sicklebill hummingbirds (Eutoxeres), as evident from the matching curvature of flower and bill. Nectar robbing has been documented for some Centropogon spp., but not for sicklebill pollinated C. granulosus. Given recent developments and interest in the Centropogon-sicklebill mutualism, it is pertinent to document any natural history observations that may underlie the ecology and evolution of this pollination system. The establishment of wedge-billed hummingbird as a nectar robber of C. granulosus calls for a new assessment of the ecology and evolution of the highly specialized Centropogon-sicklebill mutualism.


1985 ◽  
Vol 117 (2) ◽  
pp. 233-239 ◽  
Author(s):  
D.B. Donald

AbstractFunctional wing length (wing length/head-capsule width) of female Sweltsa revelstoka (Jewett) from streams was measured for 19 sites that have been free of Wisconsin glacial ice for about 15 000 years and possibly longer, and from 23 sites that have been ice free for about 10 000 years. At the former sites brachypterous populations were common and there was a significant negative relationship between functional wing length and elevation, and a positive relationship between functional wing length and stream size. In the area that deglaciated more recently, populations were not or only slightly brachypterous and there was no significant relationship between wing length and elevation or between wing length and stream size. Functional wing length was not related to body size. These analyses indicate that the brachypterous condition is probably genotypic in origin. I suggest that streams were colonized by macropterous forms shortly after deglaciation, and that brachyptery takes several millennia to develop at small, high-elevation streams.


2017 ◽  
Vol 23 (1) ◽  
pp. 59-63
Author(s):  
Sean M. Hartzell

Abstract In crayfish, intraspecific coloration can vary due to a variety of factors such as diet, genetic variation, environment, and ontogeny. Ortmann (1906) hypothesized that the crayfish Cambarus bartonii bartonii and Faxonius obscurus exhibit an ontogenetic shift in color change, with greener coloration in younger individuals of both species diminishing with age in larger specimens. However, this hypothesis has never been quantitatively tested. This work incorporated digital image analysis to quantify coloration of samples of C. b. bartonii and F. obscurus collected from two locations, respectively, in an eastern Pennsylvania stream. Examination for relationships between coloration (percent “green dominance”, i.e., the proportion of green in comparison to blue and red in photographs) and body size did not reveal any significant relationship between these variables in either crayfish species. Therefore, this study does not support the presence of ontogenetic color change in C. b. bartonii and F. obscurus, and suggests intraspecific variation of color in both species may be primarily influenced by other factors.


2018 ◽  
Vol 65 (5) ◽  
pp. 493-497 ◽  
Author(s):  
C M Gienger ◽  
Ned A Dochtermann ◽  
C Richard Tracy

Abstract Attributing biological explanations to observed ecogeographical and ecological patterns require eliminating potential statistical and sampling artifacts as alternative explanations of the observed patterns. Here, we assess the role of sample size, statistical power, and geographic inclusivity on the general validity and statistical significance of relationships between body size and latitude for 3 well-studied species of turtles. We extend those analyses to emphasize the importance of using statistically robust data in determining macroecological patterns. We examined intraspecific trends in body size with latitude in Chelydra serpentina, Chrysemys picta, and Trachemys scripta using Pearson’s correlations, diagnostic tests for influential points, and resampling. Existing data were insufficient to ascertain a latitudinal trend in body size for C. serpentina or T. scripta. There was a significant relationship for C. picta, however, resampling analyses show that, on average, 16 of the 23 available independent populations were needed to demonstrate a significant relationship and that at least 20 of 23 populations were required to obtain a statistically powerful correlation between body size and latitude. Furthermore, restricting the latitudes of populations resampled shows that body size trends of C. picta were largely due to leveraging effects of populations at the edge of the species range. Our results suggest that broad inferences regarding ecological trends in body size should be made with caution until underlying (intraspecific) patterns in body size can be statistically and conclusively demonstrated.


1998 ◽  
Vol 76 (5) ◽  
pp. 925-930 ◽  
Author(s):  
Robert Poulin

To evaluate the influence of host mass and environmental temperature on the evolution of body size in ticks, a comparative analysis was performed using data from 193 species. Using the 20 possible phylogenetically independent contrasts among tick species, no relationship was found between body size of female ticks and either host mass or temperature. The statistical power of these analyses was low. Within the two most speciose genera of soft ticks, however, separate cross-species analyses revealed a positive and highly significant relationship between female tick size and host mass. Also, within the two most speciose genera of hard ticks, cross-species analyses showed a positive and highly significant relationship between scutum size of female ticks and host mass. The latter correlation is based on measurements of tick body size that are independent of the level of blood engorgement. No effect of temperature was observed in the within-genera analyses. These within-genera trends may be artefacts of unknown phylogenetic relationships. Another explanation, however, is that host body mass may have influenced the evolution of tick body size.


2009 ◽  
Vol 185 (4) ◽  
pp. 1087-1099 ◽  
Author(s):  
Daniel R. Schlaepfer ◽  
Melanie Glättli ◽  
Markus Fischer ◽  
Mark Van Kleunen

2005 ◽  
Vol 17 (2) ◽  
pp. 190-200 ◽  
Author(s):  
Linda M. Gagen ◽  
Kathleen M. Haywood ◽  
Steven D. Spaner

This study tested the hypothesis that scaling environmental objects can afford differently sized individuals the opportunity to make similarly effective movements with that object. Four similar tennis rackets were scaled to provide consistent differences in length, weight, and grip size. Children between 4 and 10 years of age were asked to strike with each racket for speed and accuracy. A significant relationship existed between body size and strength and the ability to both generate racket head speed and control the racket for an accurate strike; racket size and weight, however, were not significant factors in the ability to swing effectively.


2006 ◽  
Vol 33 (4) ◽  
pp. 313 ◽  
Author(s):  
Bonnie Lauck

Fluctuating asymmetry has been proposed as an indicator of environmental stress and population health. However, a notable feature of research examining the relationship between fluctuating asymmetry and population fitness is that of inconsistency. Logging dramatically alters habitat and has the potential to increase or decrease environmental stress. To evaluate the response of fluctuating asymmetry to logging, I conducted research to determine whether fluctuating asymmetry differs in the frog Crinia signifera captured at logged and unlogged sites and if any differences were correlated with body size or body condition. There was a decrease in fluctuating asymmetry but also a decrease in body size and body condition as a result of logging. I also investigated whether any relationship existed between the subtle asymmetry of individuals and the following indicators of fitness: clutch size, clutch mass, average egg mass, testes size, body size and body condition. There was no significant relationship between subtle asymmetry and the fitness indicators.


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