Estimating the annual distribution of monarch butterflies in Canada over 16 years using citizen science data

Monarch butterflies (Danaus plexippus, Linnaeus, 1758) are comprised of two migratory populations separated by the Rocky Mountains and are renowned for their long-distance movements among the United States, Canada, and Mexico. Both populations have declined over several decades across North America prompting all three countries to evaluate conservation efforts. Monitoring monarch distribution and abundance is a necessary aspect of ongoing management in Canada where they are a species at risk. We used presence-only data from two citizen science data sets to estimate the annual breeding distribution of monarch butterflies in Canada between 2000 and 2015. Monarch breeding distribution in Canada varied widely among years owing to natural variation, and when considering the upper 95% of the probability of occurrence, the annual mean breeding distribution in Canada was 484 943 km(2) (min: 173 449 km(2); max: 1 425 835 km(2)). The area of occurrence was approximately an order of magnitude larger in eastern Canada than in western Canada. Habitat restoration for monarch butterflies in Canada should prioritize productive habitats in southern Ontario where monarchs occur annually and, therefore, likely contribute most to the long-term viability of monarchs in eastern North America. Overall, our assessment sets the geographic context to develop successful management strategies for monarchs in Canada.Liber Ero Postdoctoral Fellowship; University Research Chair from the University of GuelphOpen access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

The spatial response of male hooded warblers to edges in isolated fragments

We tested whether Hooded Warblers (Wilsonia citrina) avoided abrupt forest edges by radiotracking males breeding in small, isolated forest patches (0.5–2.0 ha) in northwest Pennsylvania. Because territory edges were synonymous with abrupt forest edges in all cases, we compared space use patterns with males radiotracked in a nearby continuous forest (150 ha), where we defined edge from territorial boundaries. Based on the proportion of edge to core area, males in both habitats avoided the area within 20 m of the edge, implying that males responded to the presence of territory edge rather than forest edge. Surprisingly, however, males in isolated fragments used the edge area significantly more than males in continuous forest, even when measured against the relative amount of edge area within each territory. Elevated levels of edge use were not related to distance of nests to edges, nest stage, or time of day. We conclude that the presence of physical edges is not the sole determinant of territorial space use in this species and there are likely additional social factors influencing occupancy rates in small, isolated woodlots. Therefore, definitions of forest-interior species based on edge use need to be reconsidered

Experienced migratory songbirds do not display goal-ward orientation after release following a cross-continental displacement: an automated telemetry study

The ability to navigate implies that animals have the capability to compensate for geographical displacement and return to their initial goal or target. Although some species are capable of adjusting their direction after displacement, the environmental cues used to achieve this remain elusive. Two possible cues are geomagnetic parameters (magnetic map hypothesis) or atmospheric odour-forming gradients (olfactory map hypothesis). In this study, we examined both of these hypotheses by surgically deactivating either the magnetic or olfactory sensory systems in experienced white-throated sparrows (Zonotrichia albicollis) captured in southern Ontario, Canada, during spring migration. Treated, sham-treated, and intact birds were then displaced 2,200 km west to Saskatchewan, Canada. Tracking their initial post-displacement migration using an array of automated VHF receiving towers, we found no evidence in any of the groups for compensatory directional response towards their expected breeding grounds. Our results suggest that white-throated sparrows may fall back to a simple constant-vector orientation strategy instead of performing true navigation after they have been geographically displaced to an unfamiliar area during spring migration. Such a basic strategy may be more common than currently thought in experienced migratory birds and its occurrence could be determined by habitat preferences or range size

Egg Laying Behaviour and Larval Shelter-Construction Patterns of the endangered Mottled Duskywing (Erynnis martialis) in Canada

The Mottled duskywing (Erynnis martialis) butterfly is endangered, living in pine forests and oak barrens in Canada and the eastern United States of America. While host plants and larval behaviour is documented in Mottled duskywing’s eastern range, these life components are poorly known in Manitoba. We observed adult behaviour, host plant species used and larval foraging to better understand these biological aspects of E. martialis. We observed eggs laid exclusively on Ceanothus herbaceus, and larvae consuming C. herbaceus in leaf shelters near the periphery of plants. Early instar larvae tied leaves together with cells of silk creating partly open shelters while later instar larvae completely sealed shelters. Shelters constructed out of young leaves at the edge of plants are likely easier to digest. Later-instar larvae may nocturnally harvest food to consume in shelters during the day to reduce predation risk. Larvae were found in clearings adjacent to Pinus banksiana dominated forests, with these openings likely providing suitable microhabitats for egg development and larval feeding. We observed newly emerged adults during weeks 1 to 5 of the flight period; eggs, larvae and adults overlapped. We recommend direct observations of larval foraging—during the day and night, as well as transitions into and out of diapause—to more accurately describe their behaviour and physiology. We started to characterise microhabitats, however further research is needed. Our research may help to guide critical habitat designations, leading to successful Mottled duskywing recovery in Manitoba."Funding was provided by the Canadian Wildlife Service (Environment and Climate Change Canada, Government of Canada) and an Alliance Grant from the Natural Sciences and Engineering Research Council of Canada. JH thanks the support for publication fees by the University of Winnipeg Graduate Student Travel / Publication Grant."https://bioone.org/journals/the-journal-of-the-lepidopterists-society/volume-76/issue-1/lepi.76i1.a6/Egg-Laying-Behaviour-and-Larval-Shelter-Construction-Patterns-of-the/10.18473/lepi.76i1.a6.shor

Chemical Composition of the Carbon-rich, Extremely Metal-Poor Star CS 29498--043: A New Class of Extremely Metal-Poor Stars with Excesses of Magnesium and Silicon

We analyze a high-resolution, high signal-to-noise spectrum of the carbon-rich, extremely metal-poor star CS29498-043, obtained with the Subaru Telescope High Dispersion Spectrograph. We find its iron abundance is extremely low ([Fe/H] = -3.7), placing it among the few stars known with [Fe/H] < -3.5, while Mg and Si are significantly overabundant ([Mg/Fe] = +1.8, and [Si/Fe] = +1.1) compared with stars of similar metallicity without carbon excess. Overabundances of N and Al were also found. These characteristics are similar to the carbon-rich, extremely metal-poor star CS22949-037. Though the sample is small, our discovery of CS29498-043 suggests the existence of a class of extremely metal-poor stars with large excesses of C, N, Mg, and Si.Comment: 12 pages, 3 figures, ApJL, in pres

Extremely Metal-Poor Stars. VII. The Most Metal-Poor Dwarf, CS 22876-032

We report high-resolution, high-signal-to-noise, observations of the extremely metal-poor double-lined spectroscopic binary CS 22876-032. The system has a long period : P = 424.7 $\pm$ 0.6 days. It comprises two main sequence stars having effective temperatures 6300 K and 5600 K, with a ratio of secondary to primary mass of 0.89 $\pm$ 0.04. The metallicity of the system is [Fe/H] = -3.71 $\pm$ 0.11 $\pm$ 0.12 (random and systematic errors) -- somewhat higher than previous estimates. We find [Mg/Fe] = 0.50, typical of values of less extreme halo material. [Si/Fe], [Ca/Fe], and [Ti/Fe], however, all have significantly lower values, ~ 0.0-0.1, suggesting that the heavier elements might have been underproduced relative to Mg in the material from which this object formed. In the context of the hypothesis that the abundance patterns of extremely metal-poor stars are driven by individual enrichment events and the models of Woosley and Weaver (1995), the data for CS 22876-032 are consistent with its having been enriched by a zero-metallicity supernova of mass 30 M$_{\odot}$. As the most metal-poor near-main-sequence-turnoff star currently known, the primary of the system has the potential to strongly constrain the primordial lithium abundance. We find A(Li) (= log(N(Li)/N(H)) + 12.00) = 2.03 $\pm$ 0.07, which is consistent with the finding of Ryan et al. (1999) that for stars of extremely low metallicity A(Li) is a function of [Fe/H].Comment: 27 pages, 9 figures, accepted for publication in The Astrophysical Journal, Sept. 1, 2000 issu

An Evaluation of Studies on the Potential Threats Contributing to the Decline of Eastern Migratory North American Monarch Butterflies (Danaus plexippus)

The migratory monarch butterflies (Danaus plexippus) of eastern North America have undergone large-scale declines, which may be attributable to a variety of underlying causes. The uncertainty about the primary cause of declines and whether individual threats are likely to increase in the future presents challenges for developing effective conservation management and policy initiatives that aim to improve population viability. This paper identifies five potential threats and classifies these threats according to the types of studies (observational, experimental, simulation/models) and their current impact and anticipated risk. Broadly, the threats can be classified into five categories: (1) change in suitable abiotic environmental conditions; (2) deforestation in the overwintering range; (3) exposure to contaminants including the bacteria Bacillus thuringiensis, herbicides, and insecticides; (4) loss of breeding habitat; and (5) predation, parasitism, and species-specific pathogens. The vast distribution of the monarch butterfly makes it likely that population declines are attributed to a suite of interacting factors that vary spatially and temporally in their contribution. Nonetheless, the published papers we reviewed suggest the decline in suitable environmental conditions in addition to overwintering (i.e., deforestation) and breeding habitat loss are the most likely threats to continue to affect the population viability of monarch butterflies