Availability of nest sites does not limit population size of southern flying squirrels

2000 ◽  
Vol 78 (7) ◽  
pp. 1144-1149 ◽  
Author(s):  
Matthew J Brady ◽  
Thomas S Risch ◽  
F Stephen Dobson
Keyword(s):  
South Carolina ◽  
Population Size ◽  
Nest Site ◽  
Nest Density ◽  
Glaucomys Volans ◽  
Flying Squirrels ◽  
Nest Sites ◽  
Nest Boxes ◽  
Before And After ◽  
Population Sizes

Among factors that may limit population size, nest site is generally considered important for cavity-nesting species. We tested the hypothesis that nest-site availability limits population size in the southern flying squirrel (Glaucomys volans) by examining the effect of experimentally increasing the number of nest sites. We compared population sizes before and after adding 100 nest boxes (high-quality nests, increasing overall nest density by at least about 65%) on each of three experimental sites on the Savannah River Site in South Carolina. We also compared the experimental populations with three reference (unmanipulated) sites in a paired-block experimental design. All six populations were similarly monitored with livetrapping grids, and flying squirrels readily nested in the supplemental boxes. We predicted that population size would increase where nest sites were added. No increases in population size were observed after nest boxes were added to the three experimental sites, however, nor were populations higher on the experimental sites than on the reference sites. The lack of increase in population size after nest boxes were added demonstrates that the availability of nest sites was not limiting the size of these populations.

Southern Flying Squirrels (Glaucomys volans) as Major Predators of Avian Nest Boxes in Conecuh National Forest, Alabama

2019 ◽  
Vol 18 (3) ◽  
pp. 476
Author(s):  
Brett A. DeGregorio ◽  
Jinelle H. Sperry ◽  
Daniel G. Kovar ◽  
David A. Steen
Keyword(s):  
National Forest ◽  
Glaucomys Volans ◽  
Flying Squirrels ◽  
Nest Boxes ◽  
Avian Nest

scholarly journals Relationships Between Black-Legged Kittiwake Nest-Site Characteristics and Susceptibility to Predation by Large Gulls

The Condor ◽  
2001 ◽  
Vol 103 (4) ◽  
pp. 793-801 ◽  
Author(s):  
Melanie Massaro ◽  
John W. Chardine ◽  
Ian L. Jones
Keyword(s):  
Nest Site ◽  
Nest Density ◽  
Nest Location ◽  
Rissa Tridactyla ◽  
Nest Sites ◽  
Site Characteristics ◽  
Risk Of Predation ◽  
Breeding Failure ◽  
Larus Marinus ◽  
The Relationship

Abstract We quantified the relationship between Black-legged Kittiwake (Rissa tridactyla) nest-site characteristics and risk of predation by Great Black-backed (Larus marinus) and Herring (L. argentatus) Gulls at Gull Island, Newfoundland, Canada, during 1998 and 1999. We monitored kittiwake nesting cliffs to identify nest sites attacked by large gulls and compared characteristics of attacked and successful nests among four study plots. We also examined which nest sites were attacked by Herring or Great Black-backed Gulls during calm (≤10 km hr−1) or windy conditions (>10 km hr−1). We found that kittiwake nests on plots with fewer nests were more likely to be attacked by gulls and less likely to fledge young. Nest density and nest location relative to the cliffs' upper edges significantly affected the risk of gull predation. Breeding success was correlated with nest density and ledge width and differed significantly among plots. Regardless of wind conditions both gull species were more likely to attack nests located on upper sections of cliffs than nests on lower sections. However, during calm conditions, nest sites located on narrow ledges were less likely to be attacked by Great Black-backed Gulls. Our results demonstrate that for kittiwake colonies where predation is an important source of breeding failure, the size of subcolonies and nest density affect the survival of kittiwake offspring. Relación entre las Características de los Sitios de Nidificación de Rissa tridactyla y la Susceptibilidad a la Depredación por parte de Gaviotas Resumen. Cuantificamos la relación entre las características de los sitios de nidificación de Rissa tridactyla y el riesgo de depredación por parte de Larus marinus y L. argentatus en la Isla Gull, Newfoundland, Canadá, durante 1998 y 1999. Con el objetivo de identificar los nidos atacados por gaviotas de gran tamaño, monitoreamos acantilados de nidificación de R. tridactyla en cuatro localidades de estudio y comparamos las características de los nidos atacados y exitosos. También examinamos qué nidos fueron atacados por L. marinus o por L. argentatus durante condiciones de viento calmo (≤10 km hr−1) o ventosas (>10 km hr−1). Encontramos que los nidos de R. tridactyla ubicados en localidades con menor número de nidos tuvieron mayor probabilidad de ser atacados y menor probabilidad de criar volantones. Tanto la densidad como la ubicación de los nidos en relación al vértice superior del acantilado afectaron significativamente el riesgo de depredación por gaviotas. El éxito de cría se diferenció significativamente entre localidades y se correlacionó con la densidad de nidos y con el ancho de la plataforma. Independientemente de la velocidad del viento, las dos especies de gaviotas atacaron con mayor probabilidad a los nidos ubicados en las secciones superiores del acantilado que en las secciones inferiores. Sin embargo, durante condiciones de viento calmo, los nidos localizados en plataformas angostas presentaron una menor probabilidad de ser atacados por L. marinus. Nuestros resultados demuestran que para colonias de R. tridactyla en las cuales la depredación de nidos es un factor importante en el fracaso reproductivo, el tamaño de las subcolonias y la densidad de nidos afecta la supervivencia de la progenie de R. tridactyla.

scholarly journals Win – and stay, but not too long: cavity selection by Boreal Owls to minimize nest predation by Pine Marten

2021 ◽  
Author(s):  
Geir A. Sonerud
Keyword(s):  
Nest Predation ◽  
Site Fidelity ◽  
Nest Site ◽  
Nest Site Selection ◽  
Pine Marten ◽  
Aegolius Funereus ◽  
Young Males ◽  
Nest Sites ◽  
Nest Boxes ◽  
Boreal Owl

AbstractSite fidelity after successful nesting and site shift after nest predation (win–stay, lose–shift) is a well-documented adaptation to spatially heterogeneous and temporally auto-correlated predation risk. However, site shift even after a successful nesting (win–shift) may become a better tactic than site fidelity (win–stay), if a successful nest site becomes more risky until the next nesting opportunity, and if new low-risk nest sites regularly appear. Correspondingly, selecting a new non-used nest site may become a better tactic than selecting one previously used successfully by a conspecific. I studied this dynamic by focusing on nest cavities that may be available for many years, and using nest boxes to allow an experimental design. At localities where Boreal Owls (Aegolius funereus) had nested successfully, a dyad of nest boxes was made available each year, one box in the original nest tree and one in a new tree for the season, each containing either old nest material from the successful nesting or new wood shavings. Boreal owls were more likely to select the box in the new tree when more years had elapsed since the successful nesting and since a box was installed in the original nest tree, independent of box content. The pattern of selection differed between young and old individuals for males, but not females. Young males based their selection of nest tree mainly on box content, while old males based it on time elapsed since the successful nesting in the original nest tree and how long a box had been present there. The probability of depredation of Boreal Owl nests by Pine Marten (Martes martes) has previously been found to increase with cavity age and number of nesting seasons elapsed since the previous successful nesting. This pattern of nest predation thus predicted the pattern of nest site selection found.

scholarly journals Does nest site availability limit the density of hole nesting birds in small woodland patches?

Web Ecology ◽  
2006 ◽  
Vol 6 (1) ◽  
pp. 37-43 ◽  
Author(s):  
J. Loman
Keyword(s):  
Agricultural Landscape ◽  
Nest Site ◽  
Parus Major ◽  
Great Tit ◽  
Pied Flycatcher ◽  
Blue Tit ◽  
Forest Patches ◽  
Short Supply ◽  
Nest Sites ◽  
Nest Boxes

Abstract. By providing nest boxes, previous studies have shown that nest sites are in short supply and limit the populations of several small passerines, including the Great Tit Parus major, the Blue Tit P. caeruleus, and the Pied Flycatcher Ficedula hypoleuca. Can this influence their distribution over a range of small woodland patch sizes in a heterogeneous landscape? To investigate this, a study was conducted in a heterogeneous agricultural landscape, with a mixture of wooded patches and cropped fields, in southern Sweden. The descriptive part of the study involved mapping territories of the three species in 135 patches. These species avoided small (<1 ha, Pied Flycatcher) or very small (<0.2 ha, the two tit species) forest patches in this landscape. In an experimental part, a subset of 34 patches, 0.01 to 24 ha in size was used. Territories were mapped in a first year as a control. In a second year, patches were matched by size and vegetation and nest-boxes were provided in one patch of each pair. Territories were again mapped. Providing nestboxes increased the density of breeding Great Tits in patches of all sizes and expanded their use of very small patches. The nest-boxes increased the density of Pied Flycatchers in large patches but not in small patches. So, is the lack of territories in small patches due to shortage of nest sites? The outcome of the experiment suggests nest site limitation as a cause of the observed Great Tit discrimination against very small habitat patches. The lack of Pied Flycatchers in small patches must however have another basis than lack of nest sites. The effect of providing nest-boxes on Blue Tit distribution was inconclusive.

scholarly journals Use of landmarks for nest site choice and small-scale navigation to the nest in birds

Behaviour ◽  
2021 ◽  
Vol 158 (8-9) ◽  
pp. 705-726
Author(s):  
Tore Slagsvold ◽  
Karen L. Wiebe
Keyword(s):  
Nest Site ◽  
Parus Major ◽  
Ficedula Hypoleuca ◽  
Small Scale ◽  
Cyanistes Caeruleus ◽  
Nest Sites ◽  
Nest Boxes ◽  
Cavity Opening ◽  
Nest Site Choice ◽  
Blue Tits

Abstract Nest sites of animals are often concealed to keep vulnerable offspring from being detected by predators. Parents may use landmarks near the nest to relocate it quickly. We allowed blue tits (Cyanistes caeruleus) to choose between two nest boxes fixed on the same tree with either none, the same, or different white painted markings. Surprisingly, the female brought material to both boxes and sometimes laid eggs in both. In a second experiment, we let pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) become familiar with a marking on the initial nest box and then let them choose between two new nest boxes erected on different, nearby trees. Neither species preferred the box with the matching mark. In nature, the birds may locate the correct entrance of a cavity using other landmarks near the nest opening, like branches and the height of the cavity opening above the ground.

scholarly journals Equilibrium dynamics of European pre-industrial populations: the evidence of carrying capacity in human agricultural societies

2018 ◽  
Vol 285 (1871) ◽  
pp. 20172500 ◽  
Author(s):  
Václav Fanta ◽  
Miroslav Šálek ◽  
Jan Zouhar ◽  
Petr Sklenicka ◽  
David Storch
Keyword(s):  
Population Size ◽  
Carrying Capacity ◽  
Indirect Evidence ◽  
Population Data ◽  
Coarse Grained ◽  
Human Populations ◽  
Agricultural Technologies ◽  
Before And After ◽  
Agricultural Societies ◽  
Population Sizes

Human populations tend to grow steadily, because of the ability of people to make innovations, and thus overcome and extend the limits imposed by natural resources. It is therefore questionable whether traditional concepts of population ecology, including environmental carrying capacity, can be applied to human societies. The existence of carrying capacity cannot be simply inferred from population time-series, but it can be indicated by the tendency of populations to return to a previous state after a disturbance. So far only indirect evidence at a coarse-grained scale has indicated the historical existence of human carrying capacity. We analysed unique historical population data on 88 settlements before and after the Thirty Years War (1618–1648), one the longest and most destructive conflicts in European history, which reduced the population of Central Europe by 30–50%. The recovery rate of individual settlements after the war was positively correlated with the extent of the disturbance, so that the population size of the settlements after a period of regeneration was similar to the pre-war situation, indicating an equilibrium population size (i.e. carrying capacity). The carrying capacity of individual settlements was positively determined mostly by the fertility of the soil and the area of the cadastre, and negatively by the number of other settlements in the surroundings. Pre-industrial human population sizes were thus probably controlled by negative density dependence mediated by soil fertility, which could not increase due to limited agricultural technologies.

scholarly journals Nest density drives productivity in chestnut-collared longspurs: Implications for grassland bird conservation

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256346
Author(s):  
John P. Pulliam ◽  
Scott Somershoe ◽  
Marisa Sather ◽  
Lance B. McNew
Keyword(s):  
Nest Site ◽  
Nest Survival ◽  
Grassland Birds ◽  
Population Level ◽  
Survival Models ◽  
Nest Density ◽  
Bird Conservation ◽  
Grassland Bird ◽  
Nest Sites ◽  
Conservation Concern

Grassland birds are declining faster than any other avian guild in North America and are increasingly a focus of conservation concern. Adaptive, outcome-based management of rangelands could do much to mitigate declines. However, this approach relies on quantitative, generalizable habitat targets that have been difficult to extrapolate from the literature. Past work relies heavily on individual versus population response, and direct response to management (e.g. grazing) versus response to outcomes. We compared individual and population-level responses to vegetation conditions across scales to identify quantitative targets of habitat quality for an imperiled grassland songbird, the chestnut-collared longspur (Calcarius ornatus) in northern Montana, USA during 2017–2018. We estimated nest density and nest survival within 9-ha survey plots using open N-mixture and nest survival models, respectively, and evaluated relationships with plot- and nest-site vegetation conditions. Plot-scale conditions influenced nest density, whereas nest survival was unaffected by any measured condition. Nest-site and plot-scale vegetation measurements were only weakly correlated, suggesting that management targets based on nest sites only would be incomplete. While nest survival is often assumed to be the key driver of bird productivity, our results suggest that nest density and plot-scale conditions are more important for productivity of longspurs at the core of the breeding distribution. Habitat outcomes for grassland birds should incorporate nest density and average conditions at scale(s) relevant to management (e.g. paddock or pasture).

scholarly journals Effect of Pheromone Blend Components, Sex Ratio, and Population Size on the Mating of Cadra cautella (Lepidoptera: Pyralidae)

2020 ◽  
Vol 20 (6) ◽  
Author(s):  
Abeysinghe Mudiyanselage Prabodha Sammani ◽  
Dissanayaka Mudiyanselage Saman Kumara Dissanayaka ◽  
Leanage Kanaka Wolly Wijayaratne ◽  
William Robert Morrison
Keyword(s):  
Sex Ratio ◽  
Population Size ◽  
Management Practices ◽  
Mating Disruption ◽  
Current Knowledge ◽  
Mating Status ◽  
Cadra Cautella ◽  
Synthetic Chemicals ◽  
Population Sizes ◽  
Lepidoptera Pyralidae

Abstract The almond moth Cadra cautella (Walker), a key pest of storage facilities, is difficult to manage using synthetic chemicals. Pheromone-based management methods remain a high priority due to advantages over conventional management practices, which typically use insecticides. Cadra cautella females release a blend of pheromone including (Z, E)-9,12-tetradecadienyl acetate (ZETA) and (Z)-9-tetradecadien-1-yl acetate (ZTA). The effect of these components on mating of C. cautella and how response varies with the population density and sex ratio remain unknown. In this study, the mating status of C. cautella was studied inside mating cages under different ratios of ZETA and ZTA diluted in hexane and at different population sizes either with equal or unequal sex ratio. The lowest percentage of mated females (highest mating disruption [MD] effects), corresponding to roughly 12.5%, was produced by a 5:1 and 3.3:1 ratio of ZETA:ZTA. Populations with equal sex ratio showed the lowest percentage of mated females, at 20% and 12.5% under lower and higher density, respectively. The next lowest percentage of mated females was produced when the sex ratio was set to 1: 2 and 2:1 male:female, with just 25% and 22.5% of moths mated, respectively. This study shows that mating status of C. cautella is influenced by ZETA:ZTA ratio, sex ratio, and population size. This current knowledge would have useful implications for mating disruption programs.

scholarly journals EFFECTS OF POPULATION SIZE AND SELECTION INTENSITY ON SHORT-TERM RESPONSE TO SELECTION FOR POSTWEANING GAIN IN MICE

Genetics ◽  
1973 ◽  
Vol 73 (3) ◽  
pp. 513-530
Author(s):  
J P Hanrahan ◽  
E J Eisen ◽  
J E Legates
Keyword(s):  
Population Size ◽  
Selection Response ◽  
Selection Intensity ◽  
Realized Heritability ◽  
Family Selection ◽  
Effective Population ◽  
Population Sizes ◽  
Selection For ◽  
Selection Intensities ◽  
Term Response

ABSTRACT The effects of population size and selection intensity on the mean response was examined after 14 generations of within full-sib family selection for postweaning gain in mice. Population sizes of 1, 2, 4, 8 and 16 pair matings were each evaluated at selection intensities of 100% (control), 50% and 25% in a replicated experiment. Selection response per generation increased as selection intensity increased. Selection response and realized heritability tended to increase with increasing population size. Replicate variability in realized heritability was large at population sizes of 1, 2 and 4 pairs. Genetic drift was implicated as the primary factor causing the reduced response and lowered repeatability at the smaller population sizes. Lines with intended effective population sizes of 62 yielded larger selection responses per unit selection differential than lines with effective population sizes of 30 or less.

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