The status of Common Terns (Sterna hirundo) breeding in Canada is presented, with abundance trends in regions where data allow. Large (>12,000 pairs) concentrations of Common Terns nested in coastal Newfoundland, along the Gulf of St. Lawrence coast of New Brunswick, and in lakes Winnipeg, Winnipegosis and Manitoba in Manitoba. Nest numbers increased in the four provinces of Atlantic Canada (+31%; 1973-2010), the Mingan Archipelago National Park Reserve Canada (MANPRC) in the Gulf of St. Lawrence (+81%; 1986-2009) and possibly in Great Slave Lake (+10%; 1988-2010). Nest numbers declined (-41%; 1976-2009) in Canadian waters of the North American Great Lakes. Based on recent census data (1999-2010), the number of Common Terns breeding in Canada was estimated at between 82,000-89,500 pairs, with possibly thousands of additional pairs elsewhere in Canada that have never been systematically censused: Manitoba, Saskatchewan, Alberta, inland areas of eastern provinces and the boreal forest. Recommendations are that Common Terns be censused in these areas with protocols established for the Great Lakes and annual management be implemented at sites on the Great Lakes earlier identified as "high priority". Adoption of these recommendations would achieve better understanding of national abundance trends and inform future conservation initiatives. Received 29 July 2011, accepted 12 December 2011.

After near extirpation in the early 20th century, Ring-billed Gulls (Lures delawarensis) are currently (2009) the most abundant colonial waterbird nesting on the Great Lakes. Nest count data are reported from four decadal censuses (1976-2009) conducted by the Canadian Wildlife Service and the U.S. Fish and Wildlife Service. Numbers increased from 305,790 nests (1976-80) to a peak of 718,887 nests (1989-90), then decreased to 652,664 (1997-2000) and to 585,984 nests (2007-09). Changes varied spatially after the second census with greatest losses (-38.6%) at North Channel, Georgian Bay and northern Lake Huron colonies, and greatest gains (+324.2%) at Lake Michigan colonies. A total of 472 sites had nests in at least one census (Canada N = 319; U.S. N = 153). Eighteen (3.8%) colonies had >2,000 nests in all four censuses, and had 37.5-41.9% of all nests in each census. Site occupancy was fluid. A high proportion (56.8%, N = 268) of sites contained nests in only one of the four censuses, and few (N = 40,8.5%) had nests in all censuses. Thirty-nine sites had >2,000 nests gains/losses between census periods; 14 (35.9%) were on urban/industrial lands with artificial substrates. Human management and predator activities at some colonies contributed to declines in nest numbers at these locations. Movement of breeding birds among colonies and changes in local food supply may have influenced changes in nest numbers elsewhere. Reasons for the overall nest losses across the Great Lakes after the second census are unknown. Received 15 June 2010, accepted 30 August 2010.

Canadian and US federal wildlife agencies completed three surveys (1976–1980, 1989–1991, and 1997–2000) to census colonial waterbirds breeding on the Great Lakes. We here summarize and comment on nest numbers and colony site distribution of common terns (Sterna hirundo) and Caspian terns (Hydroprogne caspia). Common terns are in serious trouble on the Great Lakes. Numbers declined with substantial losses in nests (−19.1%) and colony sites (−23.2%) between the first and third censuses. An increase in numbers at US sites (+26.6%) did not compensate for losses (−33.1%) at Canadian sites. Caspian terns increased in nest numbers (+65.9%) and colony sites (+50.0%) over the same period. The increase at US sites (136.5%) was greater than at Canadian sites (11.5%). Most (70.7%, n=186) common tern sites had nests during only one census; 17 sites (6.5%) had nests during all censuses. In contrast, 9 of 33 (27.2%) Caspian tern sites had nests during all censuses and contained a majority of nests (50–82%) in each census. Pairs of both species nested on natural substrates across the Great Lakes. Common terns nested mostly on artificial (human-constructed) substrates on the lower Great Lakes. We identify site characteristics that may have contributed to long-term (three census) occupancy by common terns (small size, artificial substrates, absence of ring-billed gulls) and Caspian terns (natural substrates on large, remote islands). We suggest an urgent need for protection and conservation of common tern colonies and identify specific priority sites for implementation of management protocols.

Several factors influencing reproductive success were investigated at a Common Tern colony at Port Colborne, Ontario in 1976. In general three egg clutches hatched better than two egg clutches and early started clutches hatched eggs and fledged chicks better than late clutches; the fledging success of two and three egg clutches was similar. Early clutches took longer to hatch and hatched more synchronously than did late clutches. While hatching success differed with nesting substrate used fledging success' did not* No relationship was found between either incubation attentiveness and reproductive success or between incubation attentiveness and clutch size* At no time did food availability appear to be a factor limiting the successful upbringing of two chick broods. While C chicks (i.e. chicks hatching from the last laid eggs of three egg clutches) generally survived and grew poorly relative to their brood mates they grew best when they originated from clutches that hatched relatively asynchronously.

The Common Tern (Sterna hirundo) rarely produces more than one brood per breeding cycle. In 1996, 18 of 365 pairs (5%) of Common Terns nesting at a Lake Ontario colony laid second clutches while caring for first-brood nestlings; no second clutches were recorded during four previous breeding seasons at this location. Second clutches were smaller than first clutches of the same pairs (2 versus 3 eggs), and were initiated when first broods contained 1-3 nestlings that ranged in age from 12-22 d. Success of second clutches was low. Only two nestlings, from one second clutch, survived for > 18 d; all remaining second clutches were abandoned or predated prior to (N = 16) or just after (N = 1) hatching. Three proximate factors were examined, within and among years, related to the production of second clutches: 1) earlier initiation of first broods, 2) reduced parental effort toward first broods, and 3) foraging conditions during rearing of first broods. Second clutches were not related to earlier breeding or reduced parental effort: clutch initiation dates, clutch sizes, and egg volumes of first clutches were similar among years, and first-clutch size and initiation date did not differ between pairs producing one versus two clutches. Conversely, parental care patterns in 1996 had several Unusual characteristics compared to other years, including: (1) shorter provisioning trips, (2) higher provisioning rates, and (3) reduced rates of kleptoparasitism. These characteristics suggest that an abundant food supply close to the colony in 1996 was the likely proximate explanation for second-clutching.

Roger Malcolm Evans was born at Coronation, Alberta, on 27 May 1935. His father died when Roger was three years old, so he grew up on his grandparents' farm at Blackfalds, Alberta, where he learned perseverance, independence, and resourcefulness while tagging after his grandfather and his uncle. After completing high school at Spirit River, Alberta, Roger worked in a bank for three years. He then entered Zoology at the University of Alberta and, as a freshman, collected birds for the museum under David A. Boag, then an M.Sc. student; David's infectious enthusiasm him on. Still at the University of Alberta, Roger studied courtship and mating behavior of Sharp-tailed Grouse for his M.Sc. thesis, under the guidance of Victor Lewin, and eventually published a paper on territoriality in Sharp-tailed Grouse in The Wilson Bulletin. SGS, who years later would become Roger's colleague, was a freshman at Alberta in fall 1961; he vividly remembers Lewin entering a meeting of the Edmonton Bird Club carrying a copy of Roger's newly minted M.Sc. thesis, raving about the great job he had done. It was during this work that Roger's interest in animal behavior developed. He recognized the advantages of studying species in which large numbers of individuals could provide data in a brief reproductive season. Then he turned his attention to colonial water birds and, for his Ph.D., used playback experiments to study the ontogeny of mobility and approach responses in young Ring-billed Gulls, under John T. Emlen, Jr., at the University of Wisconsin. Creative experimentation would continue to characterize Roger's research. In 1966, Roger joined the Department of Zoology at the University of Manitoba. He was a behaviorist and wrote for a behavioral audience, but he gradually became interested in ornithology. His research continued on parent-young interactions in gulls, and by the early 1970s he had established himself as a behavioral ecologist, just as that field emerged as a recognized scientific discipline. Until his terminal illness, he maintained continuous grant support for his students and himself for a variety of studies, including work on parent-young interactions in brood-parasitic waterfowl and lekking behavior of Sharp-tailed Grouse. But his primary research focused on the American White Pelican and several species of gull. He investigated brood reduction (including a study on blackbirds) and the significance of insurance eggs; vocal communication of hunger and cold by embryos; creching and begging behavior; siblicide among young; and loafing, flocking, and foraging by adults. Most of Roger's field studies were conducted in Manitoba, but he also studied spacing and foraging behavior of Blackbilled Gulls in New Zealand and, just months before his death, behavior of endangered Dalmatian Pelicans in Greece. He was first author, with Fritz Knopf, of the account of the American White Pelican for The Birds of North America. Roger did ground-breaking work, and his many papers, authored alone and with students, were published widely in the behavioral and ornithological literature. He used a wide diversity of avian species as research organisms, and the breadth and depth of his theory-based work were impressive. Listening to Roger talk about his research was always a pleasure, and

During the past three decades, Canadian and U.S. federal wildlife agencies completed three major surveys (1976–1980; 1989–1990; 1998–2000) to census seven species of colonially nesting waterbirds breeding on the Great Lakes. We summarize and comment on distribution and abundance of herring gulls (Larus argentatus), the most widely distributed of the species. Lake Huron consistently supported the highest number of nesting pairs, followed by Lakes Superior, Michigan, Erie, and Ontario. The pattern on four lakes was an increase in numbers between the first and second censuses, then a decrease between the second and third census. Numbers on Lake Huron declined between each census. Patterns may be food based although corroborative data are lacking. At colonies censused in all periods (1,025 sites representing 80–89% of all pairs counted), the population increased from 63,618 to 69,975 pairs (first to second census), then declined to 59,590 pairs (last census). The low average annual rate of change (–0.3%) indicates that the Great Lakes herring gull population was stable over three decades at around 60,000 breeding pairs. We identify 20 sites across the Great Lakes where large changes (> 50% between two successive periods) were recorded, and suggest that inter-colony movements could explain changes in numbers among 11 of these sites on Lakes Huron and Michigan. We offer two examples of research protocols that use annual data collection from a limited number of colony sites to more directly address the causes of numerical and distributional changes in numbers of nesting pairs.

Summary Crop damage caused by pest bird species is an economic problem in agricultural areas world‐wide. Previous research in North America has focused on estimating regional loss of yield for economic purposes, and largely ignored small‐scale variation in crop damage. If a bird depredation problem is perceived, farmers need to know how to identify areas of their farms that are most susceptible to bird damage so that they may focus their deterrent efforts most efficiently. We developed sensitive sampling and analysis techniques to allow the identification of spatial and temporal patterns in bird damage to wine grapes at the level of single vineyards. We used visual estimation techniques and novel data collection and management procedures to detect small‐scale spatiotemporal patterns in bird damage to Baco Noir and Vidal (ice‐wine) grape varieties in the St Catharine’s area of Ontario, Canada, during the 1998 and 1999 ripening seasons. We detected three overall trends in study vineyards: (i) bird damage was greatest on the edges of vineyards and decreased with distance towards the centre; (ii) bird damage was vertically stratified in vineyards, with grape clusters near the top of vines sustaining more damage than those close to the ground; and (iii) bird damage increased at specific times during the ripening season. An exotic species, the European starling, was responsible for most of the crop damage. Starlings foraged by making short forays into vineyards from perches in adjacent vegetation. This kind of foraging behaviour was reflected in the spatial damage patterns measured in our study plots. We suggest that the data presented here are more useful than estimates of total loss of yield to the managers of individual farms, because they identify the areas of vineyards most susceptible to bird damage. Future field experiments should evaluate the utility of focusing deterrent measures only in the most highly susceptible areas of crop fields. More detailed knowledge of where birds concentrate their foraging efforts, when crops become susceptible, and which species are responsible will allow farmers to focus their deterrent efforts most effectively, while attenuating conflict with non‐offending species.

We assessed the nutritional importance of mate provisioning to females during egg production and its effects on clutch parameters (egg size, length of the laying period) in Common Terns Sterna hirundo: (1) we estimated the costs of egg production by modeling the daily protein, lipid, and energy requirements of laying females, and (2) compared these costs to both the amount, and the timing, of the male's contribution via mate provisioning. Net lipid, net protein, and gross energy requirements for a three‐egg clutch were estimated to be 5.4 g, 8.6 g, and 569 kJ respectively. Peak protein and lipid requirements occurred one (day −1) and two (day −2) days before laying, respectively. Peak energy requirement occurred on day −1; a cost of 127% to 157% above maintenance. Variation in male provisioning effort (in terms of energy and nutrients delivered) paralleled variation in predicted female requirements for egg production at the level of individual pairs. Males delivered protein in excess of the female's requirements on all days investigated. Male lipid delivery accounted for 45% of female net requirement on the day when demand was greatest (day −2), but exceeded requirements on all other days. However, the proportion of the female's total energy budget (egg production, maintenance, and activity costs) that was supplied by her mate rose from an average of 29% on day −2 to 76% during the interval between second and third eggs. Paradoxically, females that were fed at higher rates during the interval between first and second eggs produced clutches with lower total volumes, smaller last‐laid eggs, and clutches with a greater egg‐size hierarchy than conspecifics receiving less food from their mates. Also, females fed at higher rates during the interval between second and third eggs took longer to produce their clutch. These negative relationships between mate provisioning and clutch parameters contrast with previous studies in this and other species.

Common Tern (Sterna hirundo) nest were both clumped (high density) and solitary (low density) at Windermere Basin, Lake Ontario in 1992. Our objective was to measure egg fate and chick survival up to 14-16 d of pairs nesting in these two dispersion patterns. We first measured the distance to nearest neighbor for 100 randomly selected clutches, and defined low-density nests as those at a distance greater than 2 SD (m) away from the nearest clutch. Two sites contained nests at high density (HD1 & HD2), while low density nests (LD) were dispersed throughout the study site. We randomly selected 20, three-egg clutches in each of the three groups. Nearest neighbor distances of HD1 (1.08 +/- 0.71 m) and HD2 (2.09 +/- 1.03 m) clutches were similar and significantly different from nearest neighbor distances of LD clutches (21.9 +/- 37.3 m). There were no differences ill clutch initiation dates or C-egg volumes among the 60 clutches of the three study groups. LD and HD1 clutches experienced heavy egg and subsequent chick loss, while losses of eggs and chicks at HD2 were negligible. The evidence for type of predator was largely circumstantial, but for eggs that were destroyed and chicks that disappeared, the loss patterns suggested primary predation by Ruddy Turnstones (Arenaria interpres) and Black-crowned Night-Herons (Nycticorax nycticorax), respectively. The locations and timing of egg and chick losses indicates that opportunistic behavior of these avian predators nullifies any predatory avoidance advantages of high-density nesting once the predator(s) identify the food resource.

In 1996, we investigated the temporal relationships between courtship feeding and copulation behavior ill the Common Tern (Sterria hirundo)ata colony on Lake Erie where previous work found no relationship between feeding and subsequent mounts or copulations (Wiggins and Morris 1988). Our purpose was to determine whether a conclusion about the relationship might be influenced by an ar arbitrary decision about the required time between the two events to show a correlation. Specifically, we tested the hypothesis that there was no difference in female receptivity to copulation attempts following a single feed compared to "strings" of feeds (two or more within an observation period). Neither mounts nor copulations were predictably preceded by feeds. Of 47 mounts recorded, 36 (76.5%) were preceded by feeds; 27 occurred within 5 min of the feed (1.85+/-0.23 min),while the other nine occurred an average of 53.0 min (+/-12.67) after a feed. Of the 36 mounts preceded by a feed, only four (11.1%) were preceded by "strings" of feeds. We conclude that the data do nor provide evidence for "strings" of feeds prior to mounts or copulations, and that Common Tern females do not exchange copulations for food, at least around the time of egg laying.

ABsTAcT.-When animals that provide parental care to offspring are faced with actual or potential failure during a breeding bout, the option to continue breeding is countered by the option to cut losses and forego reproduction until the next breeding season. In 1990, we recorded laying date and laying order of eggs in 51 Ring-billed Gull (Larus delawarensis) clutches prior to their total loss by flooding. Pairs remained on territory and produced new clutches following a refractory period of 11.6 ? SD of 1.9 days. Post-loss clutches were initiated synchronously (n = 51 clutches in four days; 89% of all clutches marked in the 7 x 7 m study plot) but mostly contained significantly fewer and lighter eggs than first clutches. We contrast incubation, hatching and chick survival patterns of these storm-delayed pairs in 1990 with patterns of early-, peak- and late-nesting pairs at the same colony in 1992. The incubation and within-clutch hatching patterns of post-loss clutches 1990 were most similar to those of late nesting pairs in 1992, yet these storm-delayed pairs realized a fledging success similar to that of early-and peak-nesting pairs in 1992. We discuss larid reproductive strategies in the context of conditions that favor successful renesting. Received 22 August 1994, accepted 27 January 1995.

Hamilton Harbour, at the west end of Lake Ontario, supports breeding colonies of six piscivorous waterbirds: double-crested cormorant (Phalacrocorax auritus), black-crowned night-heron (Nycticorax nycticorax), herring gull (Larus argentatus), ring-billed gull (Larus delawarensis), common tern (Sterna hirundo), and Caspian tern (Sterna caspia). Most breeding pairs of all species nest on privately owned mainland locations that are subject to multiple industrial and development activities. The construction of three artificial islands in the eastern basin of Hamilton Harbour in the winter of 1995-1996 presents an opportunity to simultaneously reduce current land-use conflict and maintain the existing avian biodiversity. Accordingly, we used ecological information to determine suitable substrates and vegetation to satisfy nesting habitat preferences and to facilitate the occupation of the islands by nesting waterbirds. Our recommendations for habitat design and management emphasize techniques to prevent displacement of both tern species by ring-billed gulls and of night-herons by cormorants. We propose long-term management procedures based on aspects of the biology and known ecological interactions among the various species.

In the first seven years of our Brown Noddy (Anous stolidus) study (1985-1991), 1990 was atypical in several respects. Only 68% of adults alive in 1989 returned to breed in 1990, compared to about 90% in other years. In addition, adults were delayed in their diurnal occupation of the colony and in egg laying in 1990. Eggs laid in 1990 were the smallest of any year. However, head-bill length, body mass, and condition index of breeding birds that returned in 1990 were within the normal annual variation established for earlier years. None of the noddies that failed to return in 1990 has been seen through June 1993, and we suggest that they died, most likely as a result of Hurricane Hugo as it passed through the area in mid-September 1989. Despite the loss of a significant proportion of adults from the colony in 1990, the number of breeding pairs did not dramatically decline in that year, which suggests that a pool of young or inexperienced birds was available to recruit into the breeding population. The loss of regular breeders thus had the effect of reducing the average age or breeding experience in the colony, and also increasing the number of new pair bonds. These changes were the likely cause of late breeding and small egg size observed in 1990, and indicate the importance of a stochastic event such as Hugo on the population biology of a tropical seabird.