Acoustic activity across a seabird colony reflects patterns of within‐colony flight rather than nest density

Ibis ◽  
2019 ◽  
Vol 162 (2) ◽  
pp. 416-428 ◽  
Author(s):  
Gavin E. Arneill ◽  
Emma Jane Critchley ◽  
Saskia Wischnewski ◽  
Mark J. Jessopp ◽  
John L. Quinn
Ecography ◽  
2000 ◽  
Vol 23 (5) ◽  
pp. 575-578 ◽  
Author(s):  
L. Scott Forbes ◽  
Martin Jajam ◽  
Gary W. Kaiser
Keyword(s):  

The Auk ◽  
1983 ◽  
Vol 100 (2) ◽  
pp. 335-343 ◽  
Author(s):  
M. Robert McLandress

Abstract I studied the nesting colony of Ross' Geese (Chen rossii) and Lesser Snow Geese (C. caerulescens caerulescens) at Karrak Lake in the central Arctic of Canada in the summer of 1976. Related studies indicated that this colony had grown from 18,000 birds in 1966-1968 to 54,500 birds in 1976. In 1976, geese nested on islands that were used in the late 1960's and on an island and mainland sites that were previously unoccupied. Average nest density in 1976 was three-fold greater than in the late 1960's. Consequently, the average distance to nearest neighbors of Ross' Geese in 1976 was half the average distance determined 10 yr earlier. The mean clutch size of Ross' Geese was greater in island habitats where nest densities were high than in less populated island or mainland habitats. The average size of Snow Goose clutches did not differ significantly among island habitats but was larger at island than at mainland sites. Large clutches were most likely attributable to older and/or earlier nesting females. Habitat preferences apparently differed between species. Small clutches presumably indicated that young geese nested in areas where nest densities were low. The establishment of mainland nesting at Karrak Lake probably began with young Snow Geese using peripheral areas of the colony. Young Ross' Geese nested in sparsely populated habitats on islands to a greater extent than did Snow Geese. Ross' Geese also nested on the mainland but in lower densities than Ross' Geese nesting in similar island habitats. Successful nests with the larger clutches had closer conspecific neighbors than did successful nests with smaller clutches. The species composition of nearest neighbors changed significantly with distance from Snow Goose nests but not Ross' Goose nests. Nesting success was not affected by the species of nearest neighbor, however. Because they have complementary antipredator adaptations, Ross' and Snow geese may benefit by nesting together.


Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 20
Author(s):  
Justyna Zapała-Sławeta ◽  
Grzegorz Świt

The study analyzed the possibility of using the acoustic emission method to analyse the reaction of alkali with aggregate in the presence of lithium nitrate. Lithium nitrate is a chemical admixture used to reduce adverse effects of corrosion. The tests were carried out using mortars with reactive opal aggregate, stored under the conditions defined by ASTM C227. The acoustic activity of mortars with a corrosion inhibitor was referred to linear changes and microstructure of specimens in the initial reaction stages. The study found a low acoustic activity of mortars with lithium nitrate. Analysis of characteristic parameters of acoustic emission signals, combined with the observation of changes in the microstructure, made it possible to describe the corrosion processes. As the reaction progressed, signals with different characteristics were recorded, indicating aggregate cracking at the initial stage of the reaction, followed by cracking of the cement paste. The results, which were referred to the acoustic activity of reference mortars, confirmed that the reaction of opal aggregate with alkali was mitigated in mortars with lithium nitrate, and the applied acoustic emission method enabled the detection and monitoring of ASR progress.


Ibis ◽  
2008 ◽  
Vol 118 (2) ◽  
pp. 208-217 ◽  
Author(s):  
Malte Andersson
Keyword(s):  

2007 ◽  
Vol 85 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Peter J. Harmata ◽  
Marco Restani ◽  
Alan R. Harmata

In 1998 and 1999, we determined the spatial distribution, foraging behavior, and reproductive success of ospreys ( Pandion haliaetus (L., 1758)) nesting along the upper Missouri River, Montana. We combined our data with that collected in the same area in 1981–1982 and 1990–1991 to investigate factors influencing settlement patterns. The study area was composed of four distinct habitats, three reservoirs and one free-flowing river section. Although number of occupied nests on each habitat increased from 1981–1982 to 1998–1999, the greatest percentage increases in nest density occurred on habitats previously hypothesized to contain the least prey. Osprey reproductive success was positively related to foraging rates, which differed across habitats, being highest on reservoirs and lowest on the free-flowing river. However, reproductive success was adequate for replacement on each habitat. Most fish consumed by ospreys on each habitat were suckers (Catostomidae), followed by salmonids and cyprinids. Fish density, determined from gill netting, was highest on the largest and shallowest reservoir. Over two decades, ospreys shifted their relative spatial use of the upper Missouri River such that reservoirs were occupied first and the free-flowing river section was occupied last. The degree to which presence of conspecifics, distribution of nest trees and prey, and dispersal affected settlement patterns probably varied by spatial scale.


2015 ◽  
Vol 58 (1) ◽  
pp. 105-119 ◽  
Author(s):  
Ginger A. Rebstock ◽  
P. Dee Boersma ◽  
Pablo García-Borboroglu

1995 ◽  
Vol 62 (1) ◽  
pp. 9-11 ◽  
Author(s):  
Guglielmo Marin ◽  
Elisa Bettella ◽  
Andrea Pilastro ◽  
Stefano Amato ◽  
Giovanni Tiloca

Sign in / Sign up

Export Citation Format

Share Document