I am interested in ecology and conservation in real landscapes, human decisions affact other species, I have undertaken most of my research on reptiles and plants, which have some important practical and theoretical similarities. Both plants and reptiles are relatively sedentary compared to mammals, birds, and even many insects, and both groups contain some members, which are very long-lived. Both reptiles and plants have been systematically under represented in public perception of conservation priorities.I am also interested in the development of organizations with conservation objectives, their engagement with science, and the role of natural history and archival collections.
... Snapping turtles display the "bet-hedging" set of life-history characteristics (ie,... more ... Snapping turtles display the "bet-hedging" set of life-history characteristics (ie, pronouncediteroparity, a relatively low reproductive effort/year, and little chance of successful hatching [Obbard 1983, Congdon et al. 1987, Galbraith and Brooks 1987c]). ...
Multiple paternity is the occurrence within a single clutch of offspring fathered by more than on... more Multiple paternity is the occurrence within a single clutch of offspring fathered by more than one male. This pattern may be an an adaptive feature of the mating system of turtles. Mating systems are the adaptive features of reproduction which contribute lo variation in the probability of a particular egg being fertilized by a particular sperm. Turtle populations have rarely been studied specifically in terms of multiple paternity or mating systems. Five features related to multiple paternity are discussed: spacing behaviour prior to courtship, mate-seeking and mate choice, agonistic encounters between individuals, sperm storage, and sperm competition. Several studies have examined movements and spacing behaviours in turtles, and have drawn inferences about mate seeking. At present, multiple paternity has been detected in clutches of loggerhead turtles (Caretta carella), wood turtles (Clemmys insculpta), and snapping turtles (Chelydra serpentina). In wood turtles, a relationship be...
As leaders calling for the conservation of the world忆s plants, botanical gardens protect plants w... more As leaders calling for the conservation of the world忆s plants, botanical gardens protect plants within living collections. Many also study, manage and restore plants in natural habitats. Royal Botanical Gardens (Ontario, Canada) has integrated both horticultural and natural heritage in its mission for decades. Envisioned by municipal leaders in the 1920s as a combination of nature sanctuaries and civic gardens, RBG now includes forests, wetlands and other habitats, gardens and built spaces. Today RBG is Canada忆s largest botanical garden on the basis of area. In the 1950s RBG began to inventory plant diversity. The checklist of spontaneous vascular plants now exceeds 1170 species, of which 752 are native. This is 37% of Ontario忆s native vascular plants and 19% of the native vascular flora of Canada. The RBG nature sanctuaries are among the richest locations in Canada for species鄄level diversity. We examine the history of floristic exploration within RBG and compare plant species鄄area...
The Princess Point promontory at Cootes Paradise, Hamilton, Ontario has a long, rich history of h... more The Princess Point promontory at Cootes Paradise, Hamilton, Ontario has a long, rich history of human activity. This paper provides a synopsis of the archaeological work conducted on Princess Point, and summarizes the history of human activity on the promontory. The Princess Point site was discovered on the promontory in the 1960s by archaeologists from McMaster University. Excavations were conducted by McMaster in the late 1960s, and by the University of Toronto, Mississauga since 2000. These excavations demonstrate that Princess Point was used by native peoples from Early Archaic times (8000–6000 B.C.) through to the end of the Woodland period at A.D. 1650. The most intense occupation occurred during the Early Late Woodland period (A.D. 500–1000) by people of the Princess Point Complex. Euro-Canadians began using Princess Point during the late eighteenth century. In the twentieth century, the promontory was incorporated into the Royal Botanical Gardens.
Public gardens are contributing to ex-situ conservation, but do much more. We seek to better conn... more Public gardens are contributing to ex-situ conservation, but do much more. We seek to better connect people and plants, and make sure that people benefit from the sustainable use of plants. How can individual gardens link their work to the global scene and make the case that they are part of the biggest picture possible? Using the Global Strategy for Plant Conservation is a great way to do it: a flexible, non-binding list of targets ranging from conservation of species-at-risk to managing invasive species to education and capacity-building. This presentation is intended to spread awareness of the GSPC and share ideas on how the public garden community can support and benefit from the Strategy.
Page 1. J. Parasitol., 76(2), 1990, p. 190-195 ? American Society of Parasitologists 1990 OCCURRE... more Page 1. J. Parasitol., 76(2), 1990, p. 190-195 ? American Society of Parasitologists 1990 OCCURRENCE OF PLACOBDELLA PARASITICA (HIRUDINEA) ON SNAPPING TURTLES, CHELYDRA SERPENTINA, IN SOUTHEASTERN ONTARIO ...
Page 1. NOTES Journal of Herpetology, Vol. 21, No. 4, pp. 359-363, 1987 Copyright 1987 Society fo... more Page 1. NOTES Journal of Herpetology, Vol. 21, No. 4, pp. 359-363, 1987 Copyright 1987 Society for the Study of Amphibians and Reptiles Addition of Annual Growth Lines in Adult Snapping Turtles Chelydra serpentina DAVID ...
... the significance of the Darwin finches' David A. Galbraith, Alexander M. Mills, and ... more ... the significance of the Darwin finches' David A. Galbraith, Alexander M. Mills, and Ronald J. Brooks ... Island Baltra Barrington Culpepper Duncan Floreana Fernandina Hood Isabela James Jervis Marchena Pinta San Cristobal Santa Cruz Tower Wenman ...
We replicated DNA fingerprints of snapping turtles (Chelydra serpentina) and hypervariable restri... more We replicated DNA fingerprints of snapping turtles (Chelydra serpentina) and hypervariable restriction fragments of red‐winged black birds (Agelaius phoeniceus) to estimate the between‐blot and between‐lane components of variance in molecular weights of restriction fragments. Molecular weight standards were included in every lane, and bands were sized using a sonic digitizer. In both studies, a strong positive correlation was found between band size and coefficient of variation (CV; mean = 0.7 %). In the DNA fingerprint study, 26 % of the variance in estimates of band size was due to differences between blots, 10 % due to differences between lanes on the same blot, and 64 % due to error in the digitizing process. In the restriction fragment length polymorphism (RFLP) study, 16 % of the variance was due to difference between lanes, and 84 % to digitizing. Statistical models were developed to measure the effect of sizing error on identifying identical fragments in different lanes or o...
-- , AND J. VILLA R. 1986. Introduction to the herpetology of Costa Rica. Contr. to Herp., Soc. S... more -- , AND J. VILLA R. 1986. Introduction to the herpetology of Costa Rica. Contr. to Herp., Soc. Stud. Amph. Rept. 3:1-207. SCOTT, N. J. 1969. A zoogeographic analysis of the snakes of Costa Rica. Unpubl. Ph.D. dissert., Uni- versity of Southern California.
Female common snapping turtles (Chelydra serpentina) are capable of storing viable sperm for at l... more Female common snapping turtles (Chelydra serpentina) are capable of storing viable sperm for at least several months and are likely to be inseminated by more than one male. Consequently, we tested the hypothesis that multiple paternity occurred within individual clutches of three common snapping turtles from Algonquin Provincial Park, Ontario, Canada, by examining DNA fingerprints. Positive evidence of multiple paternity was detected among samples of offspring from two of the three clutches. In these clutches, the distributions of both paternal DNA fingerprint bands and band-sharing coefficients deviated from those expected under the assumption of a single father, suggesting that paternity was distributed between two or more males in each clutch. Multiple paternity and the ability of females to store sperm make turtles good animals in which to study sperm competition. The mating systems and life-history features of turtles should be studied with the consequences of sperm storage and...
Survivorship of adult female snapping turtles (Chelydra serpentina) in a marked population in Alg... more Survivorship of adult female snapping turtles (Chelydra serpentina) in a marked population in Algonquin Provincial Park, Ontario, was estimated using recapture records and catch-curve analysis of age structure. Known mortality was less than 1% per year, and a 13-year average of survivorship was 96.6% per year. Even the conservatively biased catch-curve estimate (92.9% per year) was among the highest yet reported for any turtle population. We compared two hypotheses to account for these high values. Although not at variance with our results, we rejected Rubner's proximal "rate of living" hypothesis because of lack of any other evidence that this process operates in reptiles. The second hypothesis was that high survivorship was the consequence of specific demographic features in a bet-hedging life-history strategy. Females would be more successful, given the high and stochastic clutch mortality and lack of predation on adults in this northern population, if they produced...
Density, biomass, and sex ratio were measured in two populations of snapping turtles (Chelydra se... more Density, biomass, and sex ratio were measured in two populations of snapping turtles (Chelydra serpentina) in Ontario in 1984 and 1985. The more southern population inhabited a nutrient-enriched pond at an unusually high density and biomass density (66/ha, 340 kg/ha), and exhibited a significantly male-biased sex ratio (1.96:1) but no significant sexual dimorphism in adult size. The northern population inhabited dystrophic or oligotrophic ponds at a low density (2.4/ha, 16 kg/ha), did not show a significant bias in adult sex ratio, but did have a strong sexual dimorphism in adult size, males having approximately twice the mass of females. A comparison among several populations indicated that density was negatively correlated with latitude and with surface area of suitable habitat. Density and biomass density were significantly higher in habitats of relatively high primary productivity, which tended to be at relatively low latitudes. Therefore, important proximal factors affecting de...
... Snapping turtles display the "bet-hedging" set of life-history characteristics (ie,... more ... Snapping turtles display the "bet-hedging" set of life-history characteristics (ie, pronouncediteroparity, a relatively low reproductive effort/year, and little chance of successful hatching [Obbard 1983, Congdon et al. 1987, Galbraith and Brooks 1987c]). ...
Multiple paternity is the occurrence within a single clutch of offspring fathered by more than on... more Multiple paternity is the occurrence within a single clutch of offspring fathered by more than one male. This pattern may be an an adaptive feature of the mating system of turtles. Mating systems are the adaptive features of reproduction which contribute lo variation in the probability of a particular egg being fertilized by a particular sperm. Turtle populations have rarely been studied specifically in terms of multiple paternity or mating systems. Five features related to multiple paternity are discussed: spacing behaviour prior to courtship, mate-seeking and mate choice, agonistic encounters between individuals, sperm storage, and sperm competition. Several studies have examined movements and spacing behaviours in turtles, and have drawn inferences about mate seeking. At present, multiple paternity has been detected in clutches of loggerhead turtles (Caretta carella), wood turtles (Clemmys insculpta), and snapping turtles (Chelydra serpentina). In wood turtles, a relationship be...
As leaders calling for the conservation of the world忆s plants, botanical gardens protect plants w... more As leaders calling for the conservation of the world忆s plants, botanical gardens protect plants within living collections. Many also study, manage and restore plants in natural habitats. Royal Botanical Gardens (Ontario, Canada) has integrated both horticultural and natural heritage in its mission for decades. Envisioned by municipal leaders in the 1920s as a combination of nature sanctuaries and civic gardens, RBG now includes forests, wetlands and other habitats, gardens and built spaces. Today RBG is Canada忆s largest botanical garden on the basis of area. In the 1950s RBG began to inventory plant diversity. The checklist of spontaneous vascular plants now exceeds 1170 species, of which 752 are native. This is 37% of Ontario忆s native vascular plants and 19% of the native vascular flora of Canada. The RBG nature sanctuaries are among the richest locations in Canada for species鄄level diversity. We examine the history of floristic exploration within RBG and compare plant species鄄area...
The Princess Point promontory at Cootes Paradise, Hamilton, Ontario has a long, rich history of h... more The Princess Point promontory at Cootes Paradise, Hamilton, Ontario has a long, rich history of human activity. This paper provides a synopsis of the archaeological work conducted on Princess Point, and summarizes the history of human activity on the promontory. The Princess Point site was discovered on the promontory in the 1960s by archaeologists from McMaster University. Excavations were conducted by McMaster in the late 1960s, and by the University of Toronto, Mississauga since 2000. These excavations demonstrate that Princess Point was used by native peoples from Early Archaic times (8000–6000 B.C.) through to the end of the Woodland period at A.D. 1650. The most intense occupation occurred during the Early Late Woodland period (A.D. 500–1000) by people of the Princess Point Complex. Euro-Canadians began using Princess Point during the late eighteenth century. In the twentieth century, the promontory was incorporated into the Royal Botanical Gardens.
Public gardens are contributing to ex-situ conservation, but do much more. We seek to better conn... more Public gardens are contributing to ex-situ conservation, but do much more. We seek to better connect people and plants, and make sure that people benefit from the sustainable use of plants. How can individual gardens link their work to the global scene and make the case that they are part of the biggest picture possible? Using the Global Strategy for Plant Conservation is a great way to do it: a flexible, non-binding list of targets ranging from conservation of species-at-risk to managing invasive species to education and capacity-building. This presentation is intended to spread awareness of the GSPC and share ideas on how the public garden community can support and benefit from the Strategy.
Page 1. J. Parasitol., 76(2), 1990, p. 190-195 ? American Society of Parasitologists 1990 OCCURRE... more Page 1. J. Parasitol., 76(2), 1990, p. 190-195 ? American Society of Parasitologists 1990 OCCURRENCE OF PLACOBDELLA PARASITICA (HIRUDINEA) ON SNAPPING TURTLES, CHELYDRA SERPENTINA, IN SOUTHEASTERN ONTARIO ...
Page 1. NOTES Journal of Herpetology, Vol. 21, No. 4, pp. 359-363, 1987 Copyright 1987 Society fo... more Page 1. NOTES Journal of Herpetology, Vol. 21, No. 4, pp. 359-363, 1987 Copyright 1987 Society for the Study of Amphibians and Reptiles Addition of Annual Growth Lines in Adult Snapping Turtles Chelydra serpentina DAVID ...
... the significance of the Darwin finches' David A. Galbraith, Alexander M. Mills, and ... more ... the significance of the Darwin finches' David A. Galbraith, Alexander M. Mills, and Ronald J. Brooks ... Island Baltra Barrington Culpepper Duncan Floreana Fernandina Hood Isabela James Jervis Marchena Pinta San Cristobal Santa Cruz Tower Wenman ...
We replicated DNA fingerprints of snapping turtles (Chelydra serpentina) and hypervariable restri... more We replicated DNA fingerprints of snapping turtles (Chelydra serpentina) and hypervariable restriction fragments of red‐winged black birds (Agelaius phoeniceus) to estimate the between‐blot and between‐lane components of variance in molecular weights of restriction fragments. Molecular weight standards were included in every lane, and bands were sized using a sonic digitizer. In both studies, a strong positive correlation was found between band size and coefficient of variation (CV; mean = 0.7 %). In the DNA fingerprint study, 26 % of the variance in estimates of band size was due to differences between blots, 10 % due to differences between lanes on the same blot, and 64 % due to error in the digitizing process. In the restriction fragment length polymorphism (RFLP) study, 16 % of the variance was due to difference between lanes, and 84 % to digitizing. Statistical models were developed to measure the effect of sizing error on identifying identical fragments in different lanes or o...
-- , AND J. VILLA R. 1986. Introduction to the herpetology of Costa Rica. Contr. to Herp., Soc. S... more -- , AND J. VILLA R. 1986. Introduction to the herpetology of Costa Rica. Contr. to Herp., Soc. Stud. Amph. Rept. 3:1-207. SCOTT, N. J. 1969. A zoogeographic analysis of the snakes of Costa Rica. Unpubl. Ph.D. dissert., Uni- versity of Southern California.
Female common snapping turtles (Chelydra serpentina) are capable of storing viable sperm for at l... more Female common snapping turtles (Chelydra serpentina) are capable of storing viable sperm for at least several months and are likely to be inseminated by more than one male. Consequently, we tested the hypothesis that multiple paternity occurred within individual clutches of three common snapping turtles from Algonquin Provincial Park, Ontario, Canada, by examining DNA fingerprints. Positive evidence of multiple paternity was detected among samples of offspring from two of the three clutches. In these clutches, the distributions of both paternal DNA fingerprint bands and band-sharing coefficients deviated from those expected under the assumption of a single father, suggesting that paternity was distributed between two or more males in each clutch. Multiple paternity and the ability of females to store sperm make turtles good animals in which to study sperm competition. The mating systems and life-history features of turtles should be studied with the consequences of sperm storage and...
Survivorship of adult female snapping turtles (Chelydra serpentina) in a marked population in Alg... more Survivorship of adult female snapping turtles (Chelydra serpentina) in a marked population in Algonquin Provincial Park, Ontario, was estimated using recapture records and catch-curve analysis of age structure. Known mortality was less than 1% per year, and a 13-year average of survivorship was 96.6% per year. Even the conservatively biased catch-curve estimate (92.9% per year) was among the highest yet reported for any turtle population. We compared two hypotheses to account for these high values. Although not at variance with our results, we rejected Rubner's proximal "rate of living" hypothesis because of lack of any other evidence that this process operates in reptiles. The second hypothesis was that high survivorship was the consequence of specific demographic features in a bet-hedging life-history strategy. Females would be more successful, given the high and stochastic clutch mortality and lack of predation on adults in this northern population, if they produced...
Density, biomass, and sex ratio were measured in two populations of snapping turtles (Chelydra se... more Density, biomass, and sex ratio were measured in two populations of snapping turtles (Chelydra serpentina) in Ontario in 1984 and 1985. The more southern population inhabited a nutrient-enriched pond at an unusually high density and biomass density (66/ha, 340 kg/ha), and exhibited a significantly male-biased sex ratio (1.96:1) but no significant sexual dimorphism in adult size. The northern population inhabited dystrophic or oligotrophic ponds at a low density (2.4/ha, 16 kg/ha), did not show a significant bias in adult sex ratio, but did have a strong sexual dimorphism in adult size, males having approximately twice the mass of females. A comparison among several populations indicated that density was negatively correlated with latitude and with surface area of suitable habitat. Density and biomass density were significantly higher in habitats of relatively high primary productivity, which tended to be at relatively low latitudes. Therefore, important proximal factors affecting de...
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Papers by David A Galbraith