Shoshanah R. Jacobs

Determining Seabird Body Condition Using Nonlethal Measures

Energy stores are critical for successful breeding, and longitudinal studies require nonlethal methods to measure energy stores (“body condition”). Nonlethal techniques for measuring energy reserves are seldom verified independently. We compare body mass, size-corrected mass (SCM), plasma lipids, and isotopic dilution with extracted total body lipid content in three seabird species (thick-billed murres Uria lomvia, all four measures; northern fulmars Fulmarus glacialis, three measures; and black-legged kittiwakes Rissa tridactyla, two measures). SCM and body mass were better predictors of total body lipids for the species with high percent lipids (fulmars; ) than for the species with low percent lipids (murres and kittiwakes; ). The relationship between SCM and percent body lipids, which we argue is often a better measure of condition, was also poor () for species with low lipids. In a literature comparison of 17 bird species, percent lipids was the only predictor of the strength of the relationship between mass and total body lipids; we suggest that SCM be used as an index of energy stores only when lipids exceed 15% of body mass. Across all three species we measured, SCM based on the ordinary least squares regression of mass on the first principal component outperformed other measures. Isotopic dilution was a better predictor of both total body lipids and percent body lipids than were mass, SCM, or plasma lipids in murres. Total body lipids decreased through the breeding season at both sites, while total and neutral plasma lipid concentrations increased at one site but not another, suggesting mobilization of lipid stores for breeding. A literature review showed substantial variation in the reliability of plasma markers, and we recommend isotopic dilution (oxygen-18, plateau) for determination of energy reserves in birds where lipid content is below 15%.

HARBOR SEAL (PHOCA VITULINA) NUMBERS ALONG THE NEW BRUNSWICK COAST OF THE BAY OF FUNDY IN AUTUMN IN RELATION TO AQUACULTURE

Abstract Seal interference with Atlantic Salmon (Salmo salar) aquaculture cages is a financial burden to the industry. Harbor seals (Phoca vitulina) on haul-out sites along portions of the New Brunswick coastline of the Bay of Fundy, Canada, were counted during the autumn and early winter of 1998. Semi-monthly aerial and shipboard surveys were conducted when low tide occurred in the afternoon. The maximum number of seals counted (1032) and the rate of population decline (6.7 per day) were similar to those reported in 1984 and 1987. The average number of seals per group (35.8 ± 39.9) did not change over the season but fewer groups occurred in early winter. The seals vacated some areas which coincidentally contained Atlantic salmon aquaculture cage sites. Similar movements were observed 11 and 14 years previously, before the cage sites were established. Harbor seals are not attracted to areas containing aquaculture cage sites.

Parents are a Drag: Long-Lived Birds Share the Cost of Increased Foraging Effort with Their Offspring, but Males Pass on More of the Costs than Females

Life history theory predicts that parents will balance benefits from investment in current offspring against benefits from future reproductive investments. Long-lived organisms are therefore less likely to increase parental effort when environmental conditions deteriorate. To investigate the effect of decreased foraging capacity on parental behaviour of long-lived monogamous seabirds, we experimentally increased energy costs for chick-rearing thick-billed murres (Uria lomvia). Handicapped birds had lighter chicks and lower provisioning rates, supporting the prediction that long-lived animals would pass some of the costs of impaired foraging ability on to their offspring. Nonetheless, handicapped birds spent less time underwater, had longer inter-dive surface intervals, had lower body mass, showed lower resighting probabilities in subsequent years and consumed fewer risky prey items. Corticosterone levels were similar between control and handicapped birds. Apparently, adults shared some of the costs of impaired foraging, but those costs were not measurable in all metrics. Handicapped males had higher plasma neutral lipid concentrations (higher energy mobilisation) and their chicks exhibited lower growth rates than handicapped females, suggesting different sex-specific investment strategies. Unlike other studies of auks, partners did not compensate for handicapping, despite good foraging conditions for unhandicapped birds. In conclusion, parental murres and their offspring shared the costs of experimentally increased foraging constraints, with females investing more than males.

The dandelion evolution outreach program: learning through inquiry-based community engagement

BackgroundScience outreach programs have positive effects on students in both elementary and high school, but are often developed as internships, thus limiting access and requiring significant financial investment. Several larger scale evolution-themed outreach programs have been developed in the United States where academic institutions are addressing a specific need to actively promote science-thinking in direct opposition to other ways. This context is unfamiliar in other countries.ResultsHere we present a pilot implementation of the Dandelion Evolution Outreach Program designed to provide an inquiry-based learning opportunity in evolution for grade 11 high school students in Ontario, Canada. This program is flexible with respect to time commitment, low cost, is applicable throughout North America and many other regions of the world, and is learner-centered through active learning with both simulation and inquiry-based activities. We found that students were engaged with our lesson plan including both the simulation and inquiry-based activities. Results of our post-assessment suggested that students were able to formulate appropriate predictions relevant to the concepts of natural selection. The scalability of this program will be demonstrated further as more schools become involved in future offerings.ConclusionsThe Dandelion Evolution Outreach Program is an effective means of engaging secondary school students in active, inquiry-based learning that does not restrict access.

Variation in organochlorine and mercury levels in first and replacement eggs of a single-egg clutch breeder, the thick-billed murre, at a breeding colony in the Canadian Arctic

Contaminant concentrations may vary among sequentially-laid eggs in multi-egg clutches, and this variation has implications for the interpretation of contaminant concentrations in monitoring programs. The thick-billed murre (Uria lomvia) is a key species for monitoring contaminants in the Canadian Arctic and lays only a single egg per year. Therefore, the potential issue of intra-clutch variation in contaminant concentrations is avoided. However, if the egg is removed or lost early in the incubation stage, the adult female murre will relay. In this study, we examined contaminant concentrations and patterns in first-laid and replacement eggs of thick-billed murres breeding in northern Hudson Bay in order to determine whether or not these eggs could be sampled interchangeably. Concentrations of the major legacy organochlorines (e.g. PCBs, DDT, chlordanes) were generally higher, and total mercury concentrations lower, in the replacement eggs compared with the first-laid eggs. The organochlorine profile was comprised primarily of ΣDDT and Σ70PCB, and Σ70PCB was comprised primarily of hexa-hepta PCBs in both first-laid and replacement eggs. As both concentrations and organochlorine patterns showed differences between first-laid and replacement eggs, we recommend that randomly selected first-laid eggs of thick-billed murres be consistently sampled for contaminant monitoring in the Canadian Arctic.

Host Specificity in Subarctic Aphids

Abstract Plants and herbivorous (or parasitic) insects form the majority of macroscopic life. The specificity of interaction between host plant and parasitic insect depends on the adaptations of both the host and the parasite. Over time, these interactions evolve and change as a result of an ‘arms race’ between host and parasite, and the resulting species-specific adaptations may be maintained, perpetuating these interactions across speciation events. This can lead to specialisation between species or clades. With speciation and species sorting over time, complex interactions evolve. Here, we elucidate a three-tier method to test these interactions using the aphids (Hemiptera: Aphididae) and plants of Churchill (Manitoba, Canada) as a model system. We analyzed these interactions by testing for three patterns in host specificity: monophagy, phylogenetic clustering, and cophylogeny. We defined monophagy strictly as one species feeding exclusively upon a single host plant species (an association likely driven by arms races in morphology, chemical resistance/tolerance, and visual appearance) and observed this in 7 of 22 aphid species. In all the remaining ‘polyphagous’ cases, there was a strong trend toward monophagy (80% of individuals were found on a single host plant species). Second, we observed two separate examples of phylogenetic clustering where groups of closely related aphid species fed upon individual plant species. Finally, we found no support for cophylogenetic relationships where both aphids and plants cospeciate to form congruent phylogenetic trees (evidence of coadaptation through an ongoing arms race). One explanation for uncovering species-specific interactions in a recently deglaciated, subarctic locality is that the species involved in the associations moved north together. Testing different levels of specificity in the most predominant species–species interactions on the planet will allow us to elucidate these patterns accurately and gives us insight into where to direct future research.

An Analysis of the Perceptions and Resources of Large University Classes

This paper presents a mixed-methods analysis of large, medium, and small classes by combining the results of a qualitative survey with a multivariate statistical analysis. The qualitative analysis reveals patterns in student and instructor perception, while the quantitative results reveal how large classes are being modified to accommodate more students.

Biomimetics: A Simple Foundation Will Lead To New Insight About Process

From Bionics and Biomimetics to Biomimicry, these terms have been used to describe the transfer of knowledge from biology to other disciplines. They have been poorly defi ned and inappropriate uses are becoming more frequent. In addition, the organization of the framework for describing biological innovations is being developed in such a way as to reduce access to biological innovation. A need for clarifi cation and the development of a rigorous method still exist. An analysis of the frequency of use of the terms associated with mimicking biological models reveals that biomimetics is more widely used than biomimicry, but it is unclear whether these terms are being used uniformly or accurately. The following defi nition of biomimetics is proposed: ‘the study of biological functions, its forms, processes, and interactions for the purpose of solving analogous human problems’, and it is suggested that biomimicry be reserved to describe sustainable biomimetics. Two case studies are presented on products widely claimed to be examples of biomimicry that do not meet the criteria for the defi nition of biomimetic presented here. They are discussed in the context of biological function. Biomimetic research activities are often organized into ‘levels’ ‐ Shape, Process, and Ecosystem ‐ suggesting a hierarchy. Here, it is proposed that these levels be referred to as ‘types’ nested within Function and be called: Form, Process, and Interaction. A classifi cation system based upon the number of types of biomimetics that are incorporated into the innovation is also described. This simple framework will permit the study of biomimetic activity ‘in the wild’ as it currently exists so that it will better inform the development of a more rigorous process.