Species-specific foraging strategies and segregation mechanisms of sympatric Antarctic fulmarine petrels throughout the annual cycle

Ibis ◽  
2016 ◽  
Vol 158 (3) ◽  
pp. 569-586 ◽  
Author(s):  
Karine Delord ◽  
Patrick Pinet ◽  
David Pinaud ◽  
Christophe Barbraud ◽  
Sophie De Grissac ◽  
...  
Keyword(s):  
Annual Cycle ◽  
Foraging Strategies ◽  
Fulmarine Petrels ◽  
Species Specific

scholarly journals Year-Round Dive Characteristics of Male Beluga Whales From the Eastern Beaufort Sea Population Indicate Seasonal Shifts in Foraging Strategies

2022 ◽  
Vol 8 ◽  
Author(s):  
Luke Storrie ◽  
Nigel E. Hussey ◽  
Shannon A. MacPhee ◽  
Greg O’Corry-Crowe ◽  
John Iacozza ◽  
...  
Keyword(s):  
Annual Cycle ◽  
Environmental Variables ◽  
Marine Mammals ◽  
Beaufort Sea ◽  
Optimal Foraging Theory ◽  
Sampling Interval ◽  
Foraging Strategies ◽  
Vertical Movements ◽  
Beluga Whales ◽  
Seasonal Shifts

Dive behavior represents multiple ecological functions for marine mammals, but our understanding of dive characteristics is typically limited by the resolution or longevity of tagging studies. Knowledge on the time-depth structures of dives can provide insight into the behaviors represented by vertical movements; furthering our understanding of the ecological importance of habitats occupied, seasonal shifts in activity, and the energetic consequences of targeting prey at a given depth. Given our incomplete understanding of Eastern Beaufort Sea (EBS) beluga whale behavior over an annual cycle, we aimed to characterize dives made by belugas, with a focus on analyzing shifts in foraging strategies. Objectives were to (i) characterize and classify the range of beluga-specific dive types over an annual cycle, (ii) propose dive functions based on optimal foraging theory, physiology, and association with environmental variables, and (iii) identify whether belugas undergo seasonal shifts in the frequency of dives associated with variable foraging strategies. Satellite-linked time-depth-recorders (TDRs) were attached to 13 male belugas from the EBS population in 2018 and 2019, and depth data were collected in time series at a 75 s sampling interval. Tags collected data for between 13 and 357 days, including three tags which collected data across all months. A total of 90,211 dives were identified and characterized by twelve time and depth metrics and classified into eight dive types using a Gaussian mixed modeling and hierarchical clustering analysis approach. Dive structures identify various seasonal behaviors and indicate year-round foraging. Shallower and more frequent diving during winter in the Bering Sea indicate foraging may be energetically cheaper, but less rewarding than deeper diving during summer in the Beaufort Sea and Arctic Archipelago, which frequently exceeded the aerobic dive limit previously calculated for this population. Structure, frequency and association with environmental variables supports the use of other dives in recovery, transiting, and navigating through sea ice. The current study provides the first comprehensive description of the year-round dive structures of any beluga population, providing baseline information to allow improved characterization and to monitor how this population may respond to environmental change and increasing anthropogenic stressors.

scholarly journals The influence of organic matter content and media compaction on the dispersal of entomopathogenic nematodes with different foraging strategies

Parasitology ◽  
2017 ◽  
Vol 144 (14) ◽  
pp. 1956-1963 ◽  
Author(s):  
APOSTOLOS KAPRANAS ◽  
ABIGAIL M. D. MAHER ◽  
CHRISTINE T. GRIFFIN
Keyword(s):  
Organic Matter ◽  
Entomopathogenic Nematode ◽  
Organic Matter Content ◽  
Matter Content ◽  
Steinernema Feltiae ◽  
Foraging Strategies ◽  
Infective Juvenile ◽  
Soil Parameters ◽  
Biological Pest Control ◽  
Species Specific

SUMMARYIn laboratory experiments, we investigated how media with varying ratio of peat:sand and two levels of compaction influence dispersal success of entomopathogenic nematode (EPN) species with different foraging strategies: Steinernema carpocapsae (ambusher), Heterorhabditis downesi (cruiser) and Steinernema feltiae (intermediate). Success was measured by the numbers of nematodes moving through a 4 cm column and invading a wax moth larva. We found that both compaction and increasing peat content generally decreased EPN infective juvenile (IJ) success for all three species. Of the three species, H. downesi was the least affected by peat content, and S. carpocapsae was the most adversely influenced by compaction. In addition, sex ratios of the invading IJs of the two Steinernema species were differentially influenced by peat content, and in the case of S. feltiae, sex ratio was also affected by compaction. This indicates that dispersal of male and female IJs is differentially affected by soil parameters and that this differentiation is species-specific. In conclusion, our study shows that organic matter: sand ratio and soil compaction have a marked influence on EPN foraging behaviour with implications for harnessing them as biological pest control agents.

scholarly journals Species-specific foraging strategies of the syntopical and synchronous bees Panurgus calcaratus (Scopoli, 1763) and Dasypoda hirtipes (Fabricius, 1793) (Hymenoptera: Apidae).

2000 ◽  
Vol 50 (1) ◽  
pp. 179-191
Author(s):  
Eva-Maria Levermann ◽  
Inge Bischoff ◽  
Thomas Wagner
Keyword(s):  
Optimal Foraging ◽  
Resource Partitioning ◽  
Foraging Strategies ◽  
Separation Mechanisms ◽  
Species Specific

Die Sammelstrategie der beiden endogäischen, oligolektischen syntop und synchron auftretenden Wildbienenarten Panurgus calcaratus (Scopoli, 1763) und Dasypoda hirtipes (Fabricius, 1793) wurden im Naturschutzgebiet Wahner Heide (Rheinland, BRD) untersucht. Saisonale und diurnale Rhythmik sowie die Sammelstrategien beider Arten wurden erfaßt, um eventuell bestehende Trennungsmechanismen oder Nischendiffenzierung aufzudecken. Neben dem Verproviantierungsverhalten der Bienen wurde die Oligolektie durch Pollenentnahme von Weibchen und durch Beobachtung an den Pollenquellen überprüft. Beide Arten nutzen ausschließlich gelbe, photonastische, zungenblütige Asteraceae als Pollenquellen, präferieren sandige Flächen mit geringer Vegetation als Nistplatz und sind von Anfang Juli bis Ende August aktiv. Eine Spezialisierung innerhalb der Oligolektie auf einzelne Arten zungenblütiger Asteraceae konnte nicht erkannt werden. Dasypoda hirtipes wies eine allgemein längere diurnale Aktivität auf und war zudem auch bei geringeren Temperaturen noch aktiv. Die Pollensammelaktivitäten werden bei beiden Arten maßgeblich von den photonastischen Pollenquellen limitiert. Desweiteren ist die Bienenaktivität von klimatischen Faktoren wie Lichtintensität, Bewölkung und Lufttemperatur abhängig. Artspezifische diurnale und saisonale Verhaltensweisen und Aktivitätsrhythmen werden im Hinblick auf Körpergröße und -farbe, Hitzeabsorptions- und Reflektions-Fähigkeit, Überhitzungsgefahr sowie Effekte der Ekto- und Heterothermie auf den Wärmehaushalt diskutiert. Jede Art verfolgt eine eigene Sammelstrategie, welche hauptsächlich durch ultimative Faktoren wie die Physiologie der jeweiligen Bienenart beeinflußt und zugleich limitiert wird. Weder Nistplatzangebot noch die Ressourcen Pollen oder Nektar sind im Untersuchungsgebiet begrenzt, so daß keine Evidenz für Konkurrenz zwischen den beiden Arten besteht.StichwörterInterspecific competition, oligolecty, optimal foraging strategies, photonasty, resource partitioning, separation mechanisms.

Electron Microscopy in the Study of Natural Phytoplankton Assemblages

1985 ◽  
Vol 43 ◽  
pp. 620-623
Author(s):  
Linda Sicko-Goad
Keyword(s):  
Electron Microscopy ◽  
Aquatic Environment ◽  
Size Range ◽  
Physical Parameters ◽  
Specific Information ◽  
Phytoplankton Assemblages ◽  
Phytoplankton Productivity ◽  
Ecosystem Effects ◽  
Time Of Year ◽  
Species Specific

Although the use of electron microscopy and its varied methodologies is not usually associated with ecological studies, the types of species specific information that can be generated by these techniques are often quite useful in predicting long-term ecosystem effects. The utility of these techniques is especially apparent when one considers both the size range of particles found in the aquatic environment and the complexity of the phytoplankton assemblages.The size range and character of organisms found in the aquatic environment are dependent upon a variety of physical parameters that include sampling depth, location, and time of year. In the winter months, all the Laurentian Great Lakes are uniformly mixed and homothermous in the range of 1.1 to 1.7°C. During this time phytoplankton productivity is quite low.

64: Rapid, Species-Specific Detection of Uropathogens from Clinical Urine Specimens Using an Electrochemical Microsensor Array

2005 ◽  
Vol 173 (4S) ◽  
pp. 18-18
Author(s):  
Joseph C. Liao ◽  
Mitra Mastali ◽  
David A. Haake ◽  
Bernard M. Churchill
Keyword(s):  
Specific Detection ◽  
Species Specific ◽  
Urine Specimens
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