Selected aspects of the breeding biology of two Lake Erie herring gull colonies

Aspects of the breeding biology of two Lake Erie Herri ng Gull colonies were studied in 1975 and 1976. In 1976 the incubation attention given 2-egg and 3-egg clutches initiated early and late in the season was measured. Brood size at one colony was artificially increased or decreased by addition of chicks shortly after hatching. Hatching success was not consistently re~ated to clutch size but early nesters were more successful than late nes'ters. Differences in hatching success between 2-egg and 3-egg clutches were a function of the time of clutch initiation with the clutch size having the greater proportion of its nests initiated early in the season being more successful. The incubation attentiveness of parents of 2-egg and 3-ev,g , and early and late clutches was similar. Most nests were incubated greater than 95% of the time although t heir hatching success was similar ' to those incubated less than 75% of the time. Fledging success, chick growth and weight at fledging were similar among broods of one, two and three chicks and artificially increased broods of four and five chicks. Fledging success was highest for o.e chick broods reduced from two and three chick broods.

Modeling contaminant behavior in Lake Superior : a comparison of PCBs, PBDEs, and mercury

A mass‐balance model for Lake Superior was applied to polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and mercury to determine the major routes of entry and the major mechanisms of loss from this ecosystem as well as the time required for each contaminant class to approach steady state. A two‐box model (water column, surface sediments) incorporating seasonally adjusted environmental parameters was used. Both numerical (forward Euler) and analytical solutions were employed and compared. For validation, the model was compared with current and historical concentrations and fluxes in the lake and sediments. Results for PCBs were similar to prior work showing that air‐water exchange is the most rapid input and loss process. The model indicates that mercury behaves similarly to a moderately‐chlorinated PCB, with air‐water exchange being a relatively rapid input and loss process. Modeled accumulation fluxes of PBDEs in sediments agreed with measured values reported in the literature. Wet deposition rates were about three times greater than dry particulate deposition rates for PBDEs. Gas deposition was an important process for tri‐ and tetra‐BDEs (BDEs 28 and 47), but not for higher‐brominated BDEs. Sediment burial was the dominant loss mechanism for most of the PBDE congeners while volatilization was still significant for tri‐ and tetra‐BDEs. Because volatilization is a relatively rapid loss process for both mercury and the most abundant PCBs (tri‐ through penta‐), the model predicts that similar times (from 2 ‐ 10 yr) are required for the compounds to approach steady state in the lake. The model predicts that if inputs of Hg(II) to the lake decrease in the future then concentrations of mercury in the lake will decrease at a rate similar to the historical decline in PCB concentrations following the ban on production and most uses in the U.S. In contrast, PBDEs are likely to respond more slowly if atmospheric concentrations are reduced in the future because loss by volatilization is a much slower process for PBDEs, leading to lesser overall loss rates for PBDEs in comparison to PCBs and mercury. Uncertainties in the chemical degradation rates and partitioning constants of PBDEs are the largest source of uncertainty in the modeled times to steady‐state for this class of chemicals. The modeled organic PBT loading rates are sensitive to uncertainties in scavenging efficiencies by rain and snow, dry deposition velocity, watershed runoff concentrations, and uncertainties in air‐water exchange such as the effect of atmospheric stability.

The birds of Erie and Presque Island, Erie county, Pennsylavania.

Mode of access: Internet.

The birds of Buckeye Lake, Ohio /

Descriptive letterpress on versos facing the plates.

Sedimentology and stratigraphy of the Lower Silurian Grimsby formation, in subsurface, Lake Erie and Southwestern Ontario

Since the first offshore Lake Erie well was drilled in 1941, the Grimsby and Thorold formations of the Cataract Group have been economically important to the oil and gas industry of Ontario. The Cataract Group provides a significant amount of Ontario's gas production primarily from wells located on Lake Erie. The Grimsby - Thorold formations are the result of nearshore estuarine processes influenced by tides on a prograding shelf and are composed of subtidal channel complexes, discrete tidal channels, mud flats and non-marine deposits. Deposition was related to a regressive - transgressive cycle associated with eustatic sea level changes caused by the melting and resurgence of continental glaciation centred in Africa in the Late Ordovician/Early Silurian. Grimsby deposition began during a regression with the deposition of subtidal channel complexes incised into the marine deposits of the Cabot Head Formation. The presence of mud drapes and mud couplets suggest that these deposits were influenced by tides. These deposits dominate the lower half of the Grimsby. Deposition continued with a change from these subtidal channel complexes to laterally migrating, discrete, shallow tidal channels and mud flats. These were in turn overlain by the non-marine deposits of the Thorold Formation. Grimsby - Thorold deposition ended with a major transgression replacing siliciclastic deposition with primarily carbonate deposition. Sediment was sourced from the east and southeast and associated with a continuation of the Taconic Orogeny into the Early Silurian. The fluvial head of the estuary prograded from a shoreline that was located in western New York and western Pennsylvania running NNE-SSW and then turning NW-SE and paralleling the present day Lake Erie shoreline. iii The facies attributed to the Grimsby - Thorold formations can be ascribed to the three zones within the tripartite zonation suggested by Dalrymple et ale (1992) for estuaries, that is, a marine-dominated facies, a mixed energy facies, and a facies that is dominated by fluvial processes. Also, sediments within the Grimsby - Thorold are commonly fining upwards sequences which are common in estuarine settings whereas deltaic deposits are normally composed of coarsening upwards sequences in a vertical wedge shape with coarser material near the head. The only coarsening observed was in the Thorold Formation and attributed to non-marine deposition by palynological evidence. The presence of a lag deposit at the base of the sediments of the Grimsby Thorold formations suggests that they were incised into the Cabot Head Formation. Further, the thickness of Early Silurian sediments located between the top of the Queenston Formation, where Early Silurian sedimentation began, to the top of the Reynales - Irondequoit formation are constant whether the Grimsby - Thorold formations are present or not. Also, cross-sections using a sand body located in the Cabot Head Formation for correlation further imply that the Grimsby Formation has been incised into the previous deposits of the Cabot Head.

The sedimentology of the lower Silurian whirlpool sandstone in subsurface Lake Erie, Ontario

The lower Silurian Whirlpool Sandstone is composed of two main units: a fluvial unit and an estuarine to transitional marine unit. The lowermost unit is made up of sandy braided fluvial deposits, in shallow valleys, that flowed towards the northwest. The fluvial channels are largely filled by cross-bedded, well sorted, quartzose sands, with little ripple crosslaminated or overbank shales. Erosionally overlying this lower unit are brackish water to marine deposits. In the east, this unit consists of estuarine channels and tidal flat deposits. The channels consist of fluvial sands at the base, changing upwards into brackish and tidally influenced channelized sandstones and shales. The estuarine channels flowed to the southwest. Westwards, the unit contains backbarrier facies with extensive washover deposits. Separating the backbarrier facies from shoreface sandstone facies to the west, are barrier island sands represented by barrier-foreshore facies. The barrier islands are dissected by tidal inlets characterized by fining upward abandonment sequences. Inlet deposits are also present west of the barrier island, abandoned by transgression on the shoreface. The sandy marine deposits are replaced to the west by carbonates of the Manitoulin Limestone. During the latest Ordovician, a hiatus in crustal loading during the Taconic Orogeny led to erosional offloading and crustal rebound, the eroded material distributed towards the west, northwest and north as the terrestrial deposits of the fluvial Whirlpool. The "anti-peripheral bulge" of the rebound interfered with the peripheral bulge of the Michigan Basin, nulling the Algonquin Arch, and allowing the detritus of the fluvial Whirlpool to spread onto the Algonquin Arch. The Taconic Orogeny resumed in the earliest Silurian with crustal loading to the south and southeast, and causing tilting of the surface slope in subsurface Lake Erie towards the ii southwest. Lowstand terrestrial deposits were scoured into the new slope. The new crustal loading also reactivated the peripheral bulge of the Appalachian Basin, allowing it to interact with the bulge of the Michigan Basin, raising the Algonquin Arch. The crustal loading depressed the Appalachian basin and allowed transgression to occur. The renewed Algonquin Arch allowed the early Silurian transgression to proceed up two slopes, one to the east and one to the west. The transgression to the east entered the lowstand valleys and created the estuarine Whirlpool. The rising arch caused progradation of the Manitoulin carbonates upon shoreface facies of the Whirlpool Sandstone and upon offshore facies of the Cabot Head Formation. Further crustal loading caused basin subsidence and rapid transgression, abandoning the Whirlpool estuary in an offshore setting.

Foraging ecology and parental care of common terns (Sterna hirundo) nesting in Windermere Basin, Lake Ontario

The relationships among chick feeding, size and type of prey item, and foraging time away from the brood have not been well studied in seabirds. This study investigated spatial and temporal patterns of foraging and chick-provisioning among 23 radio-tagged male common terns nesting at Hamilton Harbour, Lake Ontario during 1991 and 1992. Telemetry data were collected concurrently with behavioural observations from an elevated blind. Terns fitted with transmitters did not differ from controls with respect to either brood attendance, patterns of chick mortality, species and size distributions of prey delivered to offspring, or chick-provisioning rates. There was a clear separation of parental roles: males were primarily responsible for feeding chicks while females allocated more time to brood attendance. The prey species most commonly delivered to chicks by adults were rainbow smelt (Osmerus mordax) and alewife (A/osa pseudoharengus), followed in importance by larval fish, emerald shiner (Notropis antherinoides), salmonids, and fathead minnows (Pimepha/es prome/as). The relative proportions of various fish speCies delivered to chicks by males differed over the course of each breeding season, and there was also much variability in species composition of prey between years. Sizes of prey delivered to chicks also differed between sampling periods. The modal size of fish brought to chicks during Peak 1991 was 1.5 bill lengths, while the majority of prey in Late 1991 were small larval fish. The reverse trend occurred in 1992 when small fish were delivered to chicks predominantly during the Peak nesting period. During periods when predominantly small fish were delivered to chicks, the foraging activity of radio-tagged males was concentrated within a two kilometer radius of the colony. The observed variation in prey composition and foraging locations during the study likely reflects temporal variation in the availability of prey in the vicinity of the colony. Males delivered fish to chicks at a constant rate, while females 4 increased their feeding frequency over the first six to ten brood days. The mean length of fish delivered to chicks by adults increased significantly with increasing chick age. As a group, within each nesting period, transmittered males either foraged predominantly in the same directional bearing (north during Peak 1991, south during Late 1992), or concentrated foraging activity in the immediate vicinity of the colony (Late 1991, Peak 1992). However, individual radio-tagged males exhibited unique and predictable foraging patterns, often favouring specific locations within these areas and differing in their secondary foraging patterns. Overall, the Lake Ontario shoreline between NCB Bay" (3.5 km south of colony) and the lift bridge canal (4 km north of colony) was the foraging area used most frequently by radiotagged males during the chick-rearing period. Foraging patterns of transmittered males at Windermere Basin are similar to patterns of peak-nesting common terns, but differ from those of late-nesters, at a nearby colony (Port Colborne, Lake Erie). Differences between the foraging patterns of late-nesting terns at these colonies likely reflect differences in annual patterns of fish availability between the two locations. No relationship was found between foraging proficiency of adults and survival of offspring. Stochastic factors, such as predation by black-crowned nightherons (Nycticorax nycticorax) and adverse weather conditions during the early stages of chick rearing, may be more important determinants of common tern breeding success than parental quality or fish availability.

Recreational Development and the Lake Erie Shore Photographs,1967

John N. Jackson was born and raised in London England. He served in the Royal Navy, acquired a B.A. and a Ph.D, conducted research for a city planning office and lectured at the University of Manchester. He joined Brock University’s faculty in 1965 as a Professor of Applied Geography. Since his retirement in 1991 he has been Professor Emeritus to Brock. Throughout his time in academia Jackson has focused his research on the history of the modern city, both throughout Europe and Canada. Jackson has also completed specific research on the Niagara Peninsula; including industrial geography, recreation along the Lake Erie shore, St. Catharines early history, the Welland Canals, railway development, comparisons across the Niagara River. While living in the Niagara region Jackson has become involved in many community events. He has been the Director for the Bruce Trail Association, President of the Welland Canals Foundation, and been involved in local historical groups throughout the Niagara region.

Feeding rates, parental investment, and brood reduction in Caspian terns (Sterna caspia)

Fresh egg-weights and feeding rates to chicks were related to chick survival as one means of quantifying apportionment of parental investment wi thin broods of Caspian Terns (SterDI casRla) at a colony in Georgian Bay. Lake Huron, during 1978 and 1979. Ftrst-laid eggs from 2-egg clutches were Significantly heavier and usually hatched one to three days earlier than second-laid eggs in both years of the study. In both years, first-hatched chicks were larger and generally better fed than second-hatched siblings. The disparity between feedIng rates of first- and second-hatched ehicks was greater in 1979. Brood feeding I rates correlated positively with the percentage of food fed to the least-fed sibUng through the period of B-chick ages zero to 10 days in 1978. I suggest that after this age period, parental control over whlcb cbick was fed diminished. In 1978, 10 of 16 secondhatched chicks were fed more than their older siblings during their first 5 days. 'lb.is is interpreted as a parental response to reduce the competitive advantage of the larger first-hatched chicks. Most chick losses were apparently caused by starvation or preda. tion. In 1979, seeorvl-hatched chick disappearance (due to predation) was -related to low feeding rates, whereas first-hatched chick disappearance was related to low fresh egg-weights.. First-hatched chicks survived better than second-hatched chicks both years, and more pairs fledged two chicks in 1978. Maximum estimated feeding rates at the nest and fledging ages suggested that food was more avatlable in 1978 than in 1979. In 1979, second eggs apparently functioned as "insurance" eggs. When the first-laid egg falled to hatch, or the first-hatched chick died, the second-hatched chick was often successfully fledged. When first-hatched chicks survived, the second-hatched chick usually starved or was preyed upon, reducing the brood to one chick. Parental investment patterns favored first-hatched chicks. Brood reduction, when employed, discouraged total nest failure, however, under appropriate conditions, brood reduction was avoided and full broods (or two chicks) were fledged.

Selected aspects of common tern reproductive biology

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 fCf 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.

Behavioural, mensural, and ecological correlates of polygyny in the eastern meadowlark (Sturnella magna)

During 1982 and 1983 I studied male attributes and attributes of the territory of male Eastern Meadowlarks (Sturnella magna) in order to determine whether there was a correlation between any of the attributes investigated and the number of females attracted by a male. Seventeen males, nine of which were polygynous and eight monogamous, were studied in 1982 and sixteen males.of which .. seven were polygynous and nine ~onogamous, were studied in 1983. The study was conducted in Short Hills Park, 10 km southwest of St. Catharines, Ontario and was designed to compare two hypotheses: the "sexy son" hypothesis (Weatherhead and Robertson,1977) and the polygyny threshold model (Verner and Willson,1966, Orians, 1969). Male attributes investigated were male size and song behaviour. Six measures of male size were taken: weight, flattened and natural wing chord length, culmen length, bill depth and length of the tarsometatarsus. In 1983 song repertoire size and song versatility measures were investigated. Attributes of the territory studied were: territory size, density of plant stems, percentage plant cover and measures of vegetation structure. In 1983 Arthropods were collected from each territory and sorted according to taxonomic group and size. During 1983, territory attributes were sampled twice, once early and once later in the nesting season. Analysis of data involved univariate comparisons between monogamous and polygynous males using T-tests and multivariate comparisons were made using discriminant function analysis (DFA) and principle components analysis (PCA).No correlations were found between the number of females attracted with, .ny measure of male size or with me, .sures of song versatili or size of song repertoire. Also no correlation was found between terri size and the number of females nesting on a terri . Some attributes of the male's terri id distinguish between monog,mous and po s males of thistudy. Analysis of Arthropod numbers showed that e~ .eran counts were significantly great~r on polygynous territories, a1 the total numb~rs of Arthropods collected showed no s fico .nt differences between territories of monogamous and po males. DFA chose ear teran and Hymenopteran counts as multivariate discriminators; both variables we' e more vegetation revealed that there were no univariate differences between the two groups of males fOT 1982 stem densities, but ~ spp. and Solidago spp. were chosen DFA as multivariate discriminators. The total number of plant stems and of Vicia spp. stems were s ficantly the early 1983 ing on monogamous territories for however DFA found no multivariate discriminators" Variables concerned with the overall aspects of vegetation structure showed significant differences between territories of monogamous and polygynous males. DFA of the 1982 sampling of vegetation structure showed significantly greater mat depth and vegetation height on polygynous territories, a finding which was not supported, however, by peA. For the early 1983 sampling period, plant height was greater on polygynous territories. Multivariate analysis identified greater green cover on polygynous territories, greater ground cover on monogamous territories, and greater depth of mat material on monogamous territories as discriminators between territories of monogamous and polygynous males. A DFA on the major variables of the study showed no significant difference between the territories of monogamous and polygynous male Meadowlarks. Of the correlations found, some were for non-prey Arthr~ods, for cover plants with very small samples sizes, or for variables which were greater for monogamous males during one sampling period and polygynous males during the next. While multivariate discriminators were found, peA showed no grouping of monogamous or polygynous males according to any of the variables investigated. On the basis of the univariate and multivariate analysis of major variables, I concluded that there were no correlations between the number of females attracted with male attributes and no unambiguous correlation with attributes of the territory. My study does not unequivocally support either the "sexy son" or the polygyny threshold hypothesis.

Anti-predator aggression in the Common Myna Acridotheres tristis

This note describes aggression by a small group of Common Mynas Acridotheres tristis towards omnivorous mammal, the Coati Nasua sp. Instances of aggression by Mynas towards other fauna are reviewed. The behavioural characteristics displayed in this interaction are also discussed.

Efeito do tempo de jejum pré-abate sobre o bem estar, qualidade de carne de peito e integridade intestinal em frangos de corte

Pós-graduação em Zootecnia - FMVZ

Comportamento reprodutivo e estudo bioacústico de Pionites leucogaster leucogaster (Kuhl 1829) e Pionites melanocephalus melanocephalus (Linné 1758) (Aves: Psittacidae) em cativeiro

Pós-graduação em Ciências Biológicas (Zoologia) - IBB