scholarly journals Manitoba Breeding Range Extension and Large Clutch Size for an American Avocet

Blue Jay ◽  
1985 ◽  
Vol 43 (1) ◽  
Author(s):  
W. H. Koonz
Keyword(s):  
Clutch Size ◽  
Range Extension ◽  
Breeding Range ◽  
American Avocet ◽  
Large Clutch

scholarly journals Evidence for r - and K -selection in a wild bird population: a reciprocal link between ecology and evolution

2016 ◽  
Vol 283 (1829) ◽  
pp. 20152411 ◽  
Author(s):  
Bernt-Erik Sæther ◽  
Marcel E. Visser ◽  
Vidar Grøtan ◽  
Steinar Engen
Keyword(s):  
Density Dependence ◽  
Population Size ◽  
Clutch Size ◽  
Balancing Selection ◽  
Empirical Support ◽  
Small Population ◽  
Environmental Stochasticity ◽  
Fluctuating Environments ◽  
Population Sizes ◽  
Large Clutch

Understanding the variation in selection pressure on key life-history traits is crucial in our rapidly changing world. Density is rarely considered as a selective agent. To study its importance, we partition phenotypic selection in fluctuating environments into components representing the population growth rate at low densities and the strength of density dependence, using a new stochastic modelling framework. We analysed the number of eggs laid per season in a small song-bird, the great tit, and found balancing selection favouring large clutch sizes at small population densities and smaller clutches in years with large populations. A significant interaction between clutch size and population size in the regression for the Malthusian fitness reveals that those females producing large clutch sizes at small population sizes also are those that show the strongest reduction in fitness when population size is increased. This provides empirical support for ongoing r - and K -selection in this population, favouring phenotypes with large growth rates r at small population sizes and phenotypes with high competitive skills when populations are close to the carrying capacity K . This selection causes long-term fluctuations around a stable mean clutch size caused by variation in population size, implying that r - and K -selection is an important mechanism influencing phenotypic evolution in fluctuating environments. This provides a general link between ecological dynamics and evolutionary processes, operating through a joint influence of density dependence and environmental stochasticity on fluctuations in population size.

Parasite infestation and predation in Darwin's small ground finch: contrasting two elevational habitats between islands

2010 ◽  
Vol 26 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Jody A. O'Connor ◽  
Rachael Y. Dudaniec ◽  
Sonia Kleindorfer
Keyword(s):  
Clutch Size ◽  
Resource Availability ◽  
Nest Predation ◽  
Life History Strategies ◽  
Opposite Pattern ◽  
Bird Populations ◽  
Parasite Intensity ◽  
Large Clutch ◽  
Parasite Infestation ◽  
Small Clutch

Abstract:Contrasting ecological conditions may affect the distribution, abundance and impact of parasites and predators throughout the ranges of hosts and prey. Such patterns are evident on the archipelagos of Hawaii and the Galapagos, which vary in their distribution and abundance of avian parasites within and across islands. Previous research has documented higher intensity of parasitic fly larvae (Philornis downsi) in nests of Darwin's finches on elevated islands of the Galapagos. Here we examine P. downsi intensity and predation in 71 nests of Darwin's small ground finch (Geospiza fuliginosa) on Floreana Island. We found significant differences in parasite intensity, nest predation and clutch size between the lowland (0–100 m) and highland (300–400 m) habitats. Lowland finch nests had few P. downsi parasites (mean of 8 per nest), high nest predation (44% of nests) and large clutch size (3.4). Highland finch nests showed the opposite pattern, with many P. downsi parasites (40 per nest), low nest predation (17%) and small clutch size (2.5). This study suggests that the impacts of an introduced parasite are limited by its niche requirements and resource availability within and across islands. Our findings also imply that the vulnerability of bird populations to introduced parasites and predators is linked with variation in life history strategies across habitats.

scholarly journals American Woodcock Breeding Range Extension

Blue Jay ◽  
1986 ◽  
Vol 44 (2) ◽  
Author(s):  
Robert W. Nero
Keyword(s):  
Range Extension ◽  
American Woodcock ◽  
Breeding Range

scholarly journals Gerrhonotus parvus Knight & Scudday, 1985 (Squamata: Anguidae): New range extension and clutch size in the state of Nuevo León, Mexico

Check List ◽  
2014 ◽  
Vol 10 (4) ◽  
pp. 950-953 ◽  
Author(s):  
Javier Banda-Leal ◽  
David Lazcano ◽  
Manuel Nevárez-de los Reyes ◽  
Carlos Barriga-Vallejo
Keyword(s):  
Clutch Size ◽  
The State ◽  
Range Extension ◽  
Nuevo Leon ◽  
Nuevo León

Killdeer Breeding Range Extension

The Auk ◽  
1971 ◽  
Vol 88 (1) ◽  
pp. 171-171
Author(s):  
Joseph G. Strauch,
Keyword(s):  
Range Extension ◽  
Breeding Range

Least Tern Breeding Range Extension in Maine

The Auk ◽  
1975 ◽  
Vol 92 (1) ◽  
pp. 143-145
Author(s):  
Malcolm L. Hunter,
Keyword(s):  
Range Extension ◽  
Breeding Range ◽  
Least Tern

scholarly journals Breeding Range Extension of the Northern Saw-whet Owl in Quebec

2006 ◽  
Vol 118 (3) ◽  
pp. 411-413 ◽  
Author(s):  
Christophe Buidin ◽  
Yann Rochepault ◽  
Michel Savard ◽  
Jean-Pierre L. Savard
Keyword(s):  
Range Extension ◽  
Breeding Range

Clutch size and egg size of spruce grouse in relation to spring diet, food supply, and endogenous reserves

1989 ◽  
Vol 67 (4) ◽  
pp. 969-980 ◽  
Author(s):  
Brian J. Naylor ◽  
James F. Bendell
Keyword(s):  
Body Weight ◽  
Clutch Size ◽  
Food Supply ◽  
Crude Protein ◽  
Egg Size ◽  
Follicular Development ◽  
Egg Laying ◽  
High Rate ◽  
Large Clutch ◽  
Endogenous Reserves

We examined the hypothesis that female spruce grouse (Dendragapus canadensis) rely entirely on their spring diet or endogenous reserves for the nutrients required for clutch formation. Spring food habits of 40 radio-tagged hens were documented by direct observation (21 262 min) during the period encompassing oviducal recrudescence, follicular development, and egg laying (late April – late May 1984 – 1986) and compared with clutch size and mean egg weight. Hens consumed conifer foliage, flowers, fruits, and foliage of ground plants, grit, and arthropods. Compared with their prebreeding diet, foods preferred in spring were rich in protein and P, but not necessarily Ca. Large clutch size was associated with a high rate of intake of the two most preferred foods, flowers of trailing arbutus (Epigaea repens) and spore capsules of Polytrichum mosses, and crude protein, P, and Ca, but was not related to the size of hens (body weight) or the size of endogenous reserves (scaled body weight). Egg size was not associated with spring diet or the size of endogenous reserves, but appeared to be related to the size of hens. Rate of intake of arbutus flowers and moss capsules was correlated with their availability on territories, suggesting that clutch size might have been proximately limited by food supply. However, rough estimates of nutrient intake suggested that the spring diet provided only about 60% of the protein and 45% of the Ca needed for clutch formation. Consequently, hens appeared to rely on both their spring diet and stored reserves for the nutrients required for clutch formation.

Sign in / Sign up

Export Citation Format

Share Document