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Ring-billed Gulls (Larus delawarensis) were rare at the beginning of the 20th century, possibly because of intensive exploitation. Once they became protected in 1916, their numbers increased throughout eastern North America, reaching a maximum of 875,000 breeding pairs around 1990. Since then, an overall decline of 19% has been recorded in the Great Lakes and the St. Lawrence River while their numbers tripled in Atlantic Canada. The largest concentrations are still found on the Great Lakes with 38% and 42% of the birds breeding in Canada and the USA, respectively. The remaining individuals breed along the St. Lawrence River (15%), on Lake Champlain (2%), and in the Gulf of St. Lawrence including the Atlantic Provinces and Saint-Pierre-et-Miquelon (3%). In 2009, a study was undertaken in the largest colony located on Ile Deslauriers near Montreal, Quebec, to determine the factors that regulate the number of breeding birds. This colony supported 52,000 pairs in 2000 and 44,000 in 2012. Ring-billed...

Landfill managers often need to implement scaring programmes to deter gulls from feeding at their sites because the birds can be a significant nuisance for both site employees and residents of the surrounding area. Our objective was to assess the efficiency of firing rubber shots, a method assumed to be non-lethal but never tested in a bird deterrence context. This method was compared to selective culling, a well-known lethal technique that some people find ethically unacceptable. Both methods were employed in combination with the use of pyrotechnics. Our study was conducted at the Ste-Sophie landfill site near Montreal (Canada) located 37 km from a Ring-billed gull (Larus delawarensis) colony supporting 48,000 pairs. Daily counts and behavioural observations were conducted throughout the breeding and post-breeding periods. Firing rubber shots was ineffective in deterring gulls as we observed the same number of birds at the landfill during periods with and without deterrence (P = 0.949). However, we counted 38% less birds during the culling periods than during the rubber shot treatment (P = 0.014). We detected no sign of habituation during the 7-day culling trials. Culling was also more effective in getting the gulls to leave the site than was rubber shots (47 vs. 11%; P

Simple Summary We evaluated the long-term effect of an intensive integrated program based on falconry to deter gulls, mostly ring-billed gulls (Larus delawarensis), from a landfill. Gulls were counted at different periods each day, and the annual sum of the maximum count at any observation period each day declined from over 1.1 million to only 20,300 during the 20 years of the study. This could not be explained by a decline in the local breeding population that remained relatively large throughout this period as determined in a concomitant study. The effectiveness of the falconry program was also confirmed by tracking individual birds fitted with GPS data loggers. The tagged gulls stopped less often and spent less time at the landfill with falconry than at another one where a selective culling program was conducted. We conclude that the use of an integrated program using falconry, which we consider more socially acceptable than culling, can be effective in deterring gulls from landfills. Abstract Gulls are commonly attracted to landfills, and managers are often required to implement cost-effective and socially accepted deterrence programs. Our objective was to evaluate the effectiveness of an intensive program that integrated the use of trained birds of prey, pyrotechnics, and playback of gull distress calls at a landfill located close to a large ring-billed gull (Larus delawarensis) colony near Montreal, Quebec, Canada. We used long-term survey data on bird use of the landfill, conducted behavioral observations of gulls during one season and tracked birds fitted with GPS data loggers. We also carried out observations at another landfill located farther from the colony, where less refuse was brought and where a limited culling program was conducted. The integrated program based on falconry resulted in a 98% decrease in the annual total number of gulls counted each day between 1995 and 2014. A separate study indicated that the local breeding population of ring-billed gulls increased and then declined during this period but remained relatively large. In 2010, there was an average (±SE) of 59 ± 15 gulls/day using the site with falconry and only 0.4% ± 0.2% of these birds were feeding. At the other site, there was an average of 347 ± 55 gulls/day and 13% ± 3% were feeding. Twenty-two gulls tracked from the colony made 41 trips towards the landfills: twenty-five percent of the trips that passed by the site with falconry resulted in a stopover that lasted 22 ± 7 min compared to 85% at the other landfill lasting 63 ± 15 min. We concluded that the integrated program using falconry, which we consider more socially acceptable than selective culling, was effective in reducing the number of gulls at the landfill.

In this study we analyzed geographic variation in the Northern Waterthrush (Seiurus noveboracensis) and reassessed the status of the four subspecies described between 1880 and 1948, three of which were recognized by the AOU Check-list (1957) and Godfrey (1986). We examined 490 specimens that came from throughout the breeding range of the Northern Waterthrush and used four morphometric data sets and three color variables to investigate geographic variation. Males differed from females based on morphometric characters. Males, unlike females, showed a morphometric trend with latitude and longitude. Their wing chord, tail and tarsus lengths showed a gradual decrease in length from north to south, while their tail and tarsus lengths gradually decreased eastward. The body shape showed a longitudinal trend where western specimens tended to have proportionally longer tails than wings compared to specimens from the eastern part of the range. Color was more strongly related to geography than morphometric characters and showed both longitudinal and latitudinal trends. Specimens from the southeastern part of the range were more olive dorsally and yellow ventrally and had fewer underpart markings than most specimens from the northwestern part of the range. Only the wing length permitted us to discriminate between the most distant populations. These trends are clinal and cannot support the recognition of subspecies.

After a review of electrophysiological studies in 1,500 cases concerning different types of lesions of the trigeminal nerve, the acousticofacial complex, and the brain stem, one can conclude that beside the intensive clinical examination which most often allows a precise topographic diagnosis, study of trigeminofacial and facial reflexes appears to be an essential diagnostic method to determine the topography of the lesions. On the other hand, this study can sometimes contribute to the prognostic evaluation as well as the choice of the approach in some lesions concerning the acousticofacial complex.