A Beetle's Mechanical Defense against an Avian Predator

1984 ◽  
Vol 29 (4) ◽  
pp. 503
Author(s):  
John S. Coons
Keyword(s):  
Avian Predator ◽  
Mechanical Defense

Post-logging effects on nest predation and avian predator assemblages in a subtropical forest

2021 ◽  
pp. 119858
Author(s):  
Ever Tallei ◽  
Luis Rivera ◽  
Alejandro Schaaf ◽  
Maila Scheffer ◽  
Natalia Politi
Keyword(s):  
Nest Predation ◽  
Subtropical Forest ◽  
Avian Predator ◽  
Logging Effects

scholarly journals Interference competition pressure predicts the number of avian predators that shifted their timing of activity

2018 ◽  
Vol 285 (1880) ◽  
pp. 20180744 ◽  
Author(s):  
Yifan Pei ◽  
Mihai Valcu ◽  
Bart Kempenaers
Keyword(s):  
Species Richness ◽  
Body Size ◽  
Interference Competition ◽  
Relative Importance ◽  
Exploitation Competition ◽  
Predator Species ◽  
Avian Predator ◽  
Avian Predators ◽  
Time Partitioning ◽  
Competition Pressure

Being active at different times facilitates the coexistence of functionally similar species. Hence, time partitioning might be induced by competition. However, the relative importance of direct interference and indirect exploitation competition on time partitioning remains unclear. The aim of this study was to investigate the relative importance of these two forms of competition on the occurrence of time-shifting among avian predator species. As a measure of interference competition pressure, we used the species richness of day-active avian predator species or of night-active avian predator species (i.e. species of Accipitriformes, Falconiformes and Strigiformes) in a particular geographical area (assemblage). As an estimate of exploitation competition pressure, we used the total species richness of avian predators in each assemblage. Estimates of the intensity of interference competition robustly predicted the number of Accipitriformes species that became crepuscular and the number of Strigiformes species that became day-active or strictly crepuscular. Interference competition pressure may depend on body size and on the total duration of the typical active period (day or night length). Our results support—to some extent—that smaller species are more likely to become time-shifters. Day length did not have an effect on the number of time-shifter species in the Accipitriformes. Among the large Strigiformes, more time-shifter species occur in areas where nights are shorter (i.e. where less of the typical time resource is available). However, in the small Strigiformes, we found the opposite, counterintuitive effect: more time-shifters where nights are longer. Exploitation competition may have had an additional positive effect on the number of time-shifters, but only in Accipitriformes, and the effect was not as robust. Our results thus support the interference competition hypothesis, suggesting that animals may have shifted their time of activity, despite phylogenetic constraints on the ability to do so, to reduce the costs of direct interactions. Our findings also highlight the influence of body size as a surrogate of competitive ability during encounters on time partitioning, at least among avian predators.

Theory and practice of instrument sterilization

1936 ◽  
Vol 32 (10) ◽  
pp. 1274-1275
Author(s):  
G. Sobernheim
Keyword(s):  
Theory And Practice ◽  
Garden Soil ◽  
Standard Object ◽  
Mechanical Defense ◽  
Number Of Authors

The author considers the use of garden soil as a standard object, which is the most unsuitable material for this purpose, as the reason for the unequal and even contradictory results obtained by a number of authors when checking the sterilizing effect of a boiling 1-2% solution of soda; the "native" spores contained in it are more persistent than spores obtained from the respective crops, since lumps of earth are a good mechanical defense for them.

An incubating northern giant petrel actively feeds on a Salvin's prion

2019 ◽  
Vol 31 (6) ◽  
pp. 317-318
Author(s):  
Christopher W. Jones ◽  
Michelle M. Risi ◽  
John Cooper
Keyword(s):  
Southern Ocean ◽  
Giant Petrel ◽  
Avian Predator ◽  
First Case

Pelagic seabirds often nest on islands that are far from productive foraging areas. The Procellariiformes (petrels, shearwaters and albatrosses) are among the longest-ranging seabirds; they have several adaptations that permit them to efficiently utilize distant foraging areas and fast for long periods during incubation (Phillips & Hamer 1999). Giant petrels (Macronectes spp.) are large surface-nesting procellariiforms. They feed both by direct predation and by scavenging carrion, and they are the largest avian predator-scavengers in the Southern Ocean. Among procellariiform seabirds, one partner forages while their mate remains on the nest to incubate their single egg (Warham 1990). Northern giant petrels (Macronectes halli) have incubation shifts lasting up to 17 days (Cooper et al. 2001). In general, incubating procellariiform seabirds do not feed during their shift (Warham 1990). We report the first case to our knowledge of a procellariiform seabird, a northern giant petrel, actively feeding at its nest whilst incubating.

Contribution of allochthonous resources to breeding in a high-arctic avian predator

Polar Biology ◽  
2013 ◽  
Vol 37 (2) ◽  
pp. 193-203 ◽  
Author(s):  
Jean-Rémi Julien ◽  
Pierre Legagneux ◽  
Gilles Gauthier ◽  
R. I. Guy Morrison ◽  
Jean-François Therrien ◽  
...  
Keyword(s):  
High Arctic ◽  
Avian Predator ◽  
Allochthonous Resources

scholarly journals Climate warming decreases the survival of the little auk ( A lle alle ), a high A rctic avian predator

2014 ◽  
Vol 4 (15) ◽  
pp. 3127-3138 ◽  
Author(s):  
Johanna E. H. Hovinen ◽  
Jorg Welcker ◽  
Sébastien Descamps ◽  
Hallvard Strøm ◽  
Kurt Jerstad ◽  
...  
Keyword(s):  
Climate Warming ◽  
Little Auk ◽  
Avian Predator
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