Relative palatability and efficacy of brodifacoum-25D conservation rodenticide pellets for mouse eradication on Midway Atoll

Invasive mice (Mus spp.) can negatively impact island species and ecosystems. Because fewer island rodent eradications have been attempted for mice compared to rats (Rattus spp.), less is known about efficacy and palatability of rodenticide baits for mouse eradications. We performed a series of bait acceptance and efficacy cage trials using a standard formulation of brodifacoum-based rodenticide on wild-caught mice from Sand Island, Midway Atoll, to help inform a proposed eradication there. Mice were offered ad libitum brodifacoum pellets along with various alternative food sources, and a “no choice” treatment group received only bait pellets. Mortality in the no choice trial was 100%; however, when offered alternative foods, mice preferred the alternative diets to the bait, leading to low mortality (40%). Because there was concern that the bittering agent Bitrex® in the formulation may have reduced palatability, we conducted a subsequent trial comparing brodifacoum bait with and without Bitrex. Mortality in the with-Bitrex treatment group was slightly higher, indicating that the bittering agent was not likely responsible for low efficacy. Laboratory trials cannot account for the numerous environmental and behavioral factors that influence bait acceptance nor replicate the true availability of alternative food sources in the environment, so low efficacy results from these trials should be interpreted cautiously and not necessarily as a measure of the likelihood of success or failure of a proposed eradication

Similar dispersal patterns between two closely related birds with contrasting migration strategies

Studying dispersal is crucial to understand metapopulation and sink-source dynamics and invasion processes. The capability to disperse is especially important for species living in fragmented habitats like wetlands. We investigated the distribution of natal and breeding dispersal distances and philopatry in Spanish populations of two closely related reedbed-nesting birds, the Moustached Warbler Acrocephalus melanopogon and the Eurasian Reed Warbler Acrocephalus scirpaceus. These warblers are morphologically very similar, but differ in migration strategy and, in our study area, in population size. Our aims were to find the best model for dispersal distances and to assess the occurrence of intra- or interspecific differences in dispersal patterns. We used ringing data from the Spanish marking scheme and selected recaptures to avoid including migrating individuals. In both species, most individuals were philopatric but dispersing birds were able to cross large distances (up to more than 100 km), suggesting the capability to compensate for habitat fragmentation. We found the heavy-tailed Cauchy distribution to be the best conceptual description for our data, in all cases but natal dispersal of Moustached Warblers. Among Eurasian Reed Warblers, natal philopatry was lower than breeding philopatry. We found no significant interspecific differences. This does not confirm the hypothesis of higher dispersal ability in long distance migrants (like Eurasian Reed Warblers) than in resident/short distance migrant bird species (like Moustached Warblers). The similarity in dispersal patterns among the two warblers may be explained by their close phylogenetic relatedness, similar constraints imposed on both species by a patchy habitat or similar evolutionary pressures.We are grateful to the many ringers who collected the data during years of fieldwork in Spain. Francesco Ceresa is supported by an "Atraent talent'' grant from the University of Valencia.Ceresa, F.; Belda, E.; Monrós González, JS. (2016). Similar dispersal patterns between two closely related birds with contrasting migration strategies. Population Ecology. 58(3):421-427. doi:10.1007/s10144-016-0547-0S421427583Banco de datos de anillamiento del remite ICONA – Ministerio de Medio Ambiente (2015) Datos de anillamiento y recuperaciones en España. Ministerio de Agricultura, Alimentación y Medio Ambiente, SEO/BirdLife, ICO, EBD-CSIC y GOB. Madrid (in Spanish)Begon M, Townsend CR, Harper JL (2006) Ecology: from individual to ecosystems, 4th edn. Blackwell Publishing, OxfordBlomqvist D, Fessl B, Hoi H, Kleindorfer S (2005) High frequency of extra-pair fertilisation in the moustached warbler, a songbird with a variable breeding system. Behaviour 142:1133–1148Bohonak AJ (1999) Dispersal, gene flow, and population structure. Q Rev Biol 74:21–45Burnham KP, Anderson DR (2002) Model selection and multi-model inference: a practical information-theoretic approach. Springer Verlag, New YorkCantos FJ, Tellería JL (1994) Stopover site fidelity of four migrant warblers in the Iberian Peninsula. J Avian Biol 25:131–134Carrascal LM, Palomino D (2008) Las aves comunes reproductoras en España. Población en 2004–2006. SEO/BirdLife, Madrid (in Spanish with English abstract)Carrascal LM, Weykam S, Palomino D, Lobo JM, Díaz L (2005) Atlas Virtual de las Aves Terrestres de España. http://www.vertebradosibericos.org/atlasaves.html . Accessed 16 Feb 2016Castany J (2003) El carricerín real (Acrocephalus melanopogon) en el P. N. del Prat de Cabanes-Torreblanca. Doctoral thesis. University of Valencia, Valencia (in Spanish)Castany J, López G (2006) El carricerín real en España. I Censo Nacional (2005). SEO/BirdLife, Madrid (in Spanish with English abstract)Ceresa F, Belda EJ, Kvist L, Rguibi-Idrissi H, Monrós JS (2015) Does fragmentation of wetlands affect gene flow in sympatric Acrocephalus warblers with different migration strategies? J Avian Biol 46:577–588Cooper NW, Murphy MT, Redmond LJ, Dolan AC (2009) Density-dependent age at first reproduction in the eastern kingbird. Oikos 118:413–419Delignette-Muller ML, Dutang C (2015) fitdistrplus: An R Package for fitting distributions. J Stat Softw 64:1–34. http://www.jstatsoft.org/v64/i04/ . Accessed 2 Sep 2015Frankham R, Ballou JD, Briscoe DA (2010) Introduction to conservation genetics, 2nd edn. Cambridge University Press, CambridgeHengeveld R (1994) Small step invasion research. 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Viability of piping plover \u3ci\u3eCharadrius melodus\u3c/i\u3e metapopulations

The meta-population viability analysis package, vortex, was used to examine viability and recovery objectives for piping plovers Charadrius melodus, an endangered shorebird that breeds in three distinct regions of North America. Baseline models indicate that while Atlantic Coast populations, under current management practices, are at little risk of near-term extinction, Great Plains and Great Lakes populations require 36% higher mean fecundity for a significant probability of persisting for the next 100 years. Meta-population structure (i.e. the delineation of populations within the meta-population) and inter-population dispersal rates had varying effects on model results; however, spatially-structured meta-populations exhibited lower viability than that reported for single-population models. The models were most sensitive to variation in survivorship; hence, additional mortality data will improve their accuracy. With this information, such models become useful tools in identifying successful management objectives; and sensitivity analyses, even in the absence of some data, may indicate which options are likely to be most effective. Meta-population viability models are best suited for developing conservation strategies for achieving recovery objectives based on maintaining an externally derived, target population size and structure

A Study of Earthquake Seasonality in Japan Through Network Analysis

Earthquakes are some of the most mysterious events that occur on planet Earth. Their complex nature makes them difficult to analyze and fully understand. In an attempt to look at earthquakes and the many factors that contribute to them, it is essential to break down the multitude of questions surrounding the natural occurrence into much smaller and focused analyses. In order to better predict earthquakes, seismologists and data scientists look for patterns in the data sets. This thesis looks at earthquake seasonality through node importance, a measure of how important nodes are relative to one another. By framing earthquake data as a network, with regions as nodes and successive earthquakes as edges/links, PageRank analysis, closeness centrality and betweenness centrality are used to find any major differences in node importance measures across all four seasons in Japan. Looking at the results as a directed graph and geographically as well, no major differences are found in node importance across the algorithms and across seasons in Japan

Bird Response to Habitat Restoration at Fernhill Wetlands

In 2014-15 Clean Water Services implemented a massive habitat restoration project at Fernhill Wetlands in Forest Grove, Oregon that transformed 90 acres of unused sewage ponds into native wetland habitats designed to naturally treat wastewater. Since spring 2015 the Audubon Society of Portland (ASOP) has assessed bird response to this habitat restoration effort through a community science effort involving local birders, formal bird surveys conducted by ASOP, and analysis of historical eBird surveys conducted at the site for decades. Our general predictions were that 1) Overall avian species richness and abundance would increase, 2) Open-water dependent species would diminish in abundance, and 3) Species dependent on native wetland habitats would increase. Our key preliminary findings include: 1) Species richness was significantly higher post-restoration and is particularly accentuated during the summer season; 2) Overall species abundance does not appear to have changed significantly between pre- and post-restoration periods, however, at the individual species level we document significant shifts in abundance. Most of these shifts fit our a priori predictions. In general, most waterbird species (including Virginia Rail and Sora), wetland-dependent songbirds (including Red-winged Blackbird and Common Yellowthroat), and dabbling ducks (Mallard and Gadwall) have higher abundances post-restoration while wintering grebes and fall migratory shorebirds have lower abundances post-restoration, and 3) We provide evidence that community science eBird surveys and the formal transect surveys were directly comparable. Our findings demonstrate benefits to native bird communities that can be achieved through integration of green infrastructure strategies to manage wastewater

Association of Male and Female American Robins (Turdus migratorius) during the Breeding Season: Paternity Assurance by Sexual Access or Mate-Guarding

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Aggressive behaviour affects selection on morphology by influencing settlement patterns in a passerine bird

The importance of behaviours as instigators or inhibitors of evolutionary change remains largely unresolved and this is in part because there are very few empirical examples of how behaviours affect evolutionary processes. By determining the environment of breeding, aggressive interactions over territories have the potential to strongly impact selection pressures experienced by individuals. Western bluebirds (Sialia mexicana) provide a unique opportunity to investigate the evolutionary importance of aggression, since their highly variable breeding habitat favours distinct foraging techniques and they also compete aggressively for nest boxes, a resource that is easy to manipulate. Here, I show experimentally that more aggressive males compete more effectively for territories with a high density of nest boxes and, as a consequence, aggressive and non-aggressive males are sorted into distinct breeding habitats that differ in the strength of selection on morphological traits. Specifically, males with longer tails and tarsi were favoured in open habitats where high agility is required to forage efficiently, whereas in forested habitats, where agility is less important, selection was weak. These results show that aggression can affect selection on a local scale by determining individual settlement patterns. More generally, because territorial interactions are important across a wide variety of taxa, these results suggest that aggressive behaviour has the potential to impact the evolutionary trajectory of many animal populations