scholarly journals Effects of Body Size and Sex on Foraging Territoriality of the Little Egret (Egretta Garzetta) in Japan

The Auk ◽  
2003 ◽  
Vol 120 (3) ◽  
pp. 791-798 ◽  
Author(s):  
Yukiko Nota
Keyword(s):  
Body Size ◽  
Foraging Behavior ◽  
Foraging Efficiency ◽  
Type I ◽  
Long Period ◽  
Foraging Area ◽  
Feeding Efficiency ◽  
Strong Attachment ◽  
Little Egret ◽  
Egretta Garzetta

Abstract I studied the characteristics of foraging territoriality in the Little Egret (Egretta garzetta) and effects of body size and sex on territoriality. Sixty-eight birds were captured and sexed, and foraging behavior (usage of area, defense rate, and foraging efficiency) of 26 birds identified by color bands was observed in detail for 3 years. I categorized territoriality within the foraging area into three types according to the birds' exclusiveness and attachment to the area: high exclusiveness and strong attachment to the same area for a long period, moderate exclusiveness and attachment, and minimal exclusiveness and attachment. Body size was largest and feeding efficiency was highest in the first type. I propose a model that predicts a relationship between body size and defense rate to explain the behavior of egrets.

Little Egret (Egretta garzetta)

2020 ◽  
Author(s):  
Josep del Hoyo ◽  
Albert Martínez-Vilalta ◽  
Anna Motis ◽  
Nigel Collar ◽  
Guy M. Kirwan ◽  
...  
Keyword(s):  
Little Egret ◽  
Egretta Garzetta

scholarly journals Foraging Behavior of Bottlenose Dolphins in the Shannon Estuary, Ireland as Determined through Static Acoustic Monitoring

2021 ◽  
Vol 9 (3) ◽  
pp. 275
Author(s):  
Mathijs Carmen ◽  
Simon D. Berrow ◽  
Joanne M. O’Brien
Keyword(s):  
Foraging Behavior ◽  
Bottlenose Dolphins ◽  
Industrial Area ◽  
Acoustic Monitoring ◽  
Habitats Directive ◽  
Foraging Area ◽  
Special Area ◽  
High Conservation ◽  
Eu Habitats Directive ◽  
The Eu

The Shannon Estuary in Ireland is home to a resident population of bottlenose dolphins (Tursiops truncatus) and is designated as a Special Area of Conservation under the EU Habitats Directive. It is an important industrial area, with numerous deep-water berths for shipping. Despite its high conservation value, there are few published studies on habitat use or foraging behavior of the Shannon dolphins throughout the year. The present study assessed the year-round presence and foraging activity of bottlenose dolphins at different locations in the middle and inner estuary using static acoustic monitoring. Dolphin presence was found to decrease with increased distance from the estuary mouth, i.e., where the estuary meets the Atlantic Ocean, while at the same time, foraging was found to be considerably higher in the upriver areas, suggesting the inner estuary was an important foraging area. Model predictions for seasonal, tidal and diel foraging were highly variable across locations, indicating that changes in dolphin behavior occurred over relatively small geographical scales. These results indicate that conservation efforts should consider the Shannon Estuary as a dynamic aggregation of habitats and future development initiatives should attempt to mitigate disturbance to the dolphins during important foraging periods on seasonal and diel scales.

Prey Body Size and Ranking in Zooarchaeology: Theory, Empirical Evidence, and Applications from the Northern Great Basin

2011 ◽  
Vol 76 (3) ◽  
pp. 403-428 ◽  
Author(s):  
Jack M. Broughton ◽  
Michael D. Cannon ◽  
Frank E. Bayham ◽  
David A. Byers
Keyword(s):  
Body Size ◽  
Great Basin ◽  
Diet Breadth ◽  
Foraging Theory ◽  
Return Rate ◽  
The Body ◽  
Foraging Efficiency ◽  
Large Prey ◽  
Abundance Indices ◽  
Game Hunting

The use of body size as an index of prey rank in zooarchaeology has fostered a widely applied approach to understanding variability in foraging efficiency. This approach has, however, been critiqued—most recently by the suggestion that large prey have high probabilities of failed pursuits. Here, we clarify the logic and history of using body size as a measure of prey rank and summarize empirical data on the body size-return rate relationship. With few exceptions, these data document strong positive relationships between prey size and return rate. We then illustrate, with studies from the Great Basin, the utility of body size-based abundance indices (e.g., the Artiodactyl Index) when used as one component of multidimensional analyses of prehistoric diet breadth. We use foraging theory to derive predictions about Holocene variability in diet breadth and test those predictions using the Artiodactyl Index and over a dozen other archaeological indices. The results indicate close fits between the predictions and the data and thus support the use of body size-based abundance indices as measures of foraging efficiency. These conclusions have implications for reconstructions of Holocene trends in large game hunting in western North America and for zooarchaeological applications of foraging theory in general.

scholarly journals Trabeculae In The Egretal (Egretta garzetta) Cervical Vertebrae

2020 ◽  
Vol 3 ◽  
pp. 553-554
Author(s):  
Faris Choirudin ◽  
Kholifah Nyawiji ◽  
Wahyu Priyambodo
Keyword(s):  
Body Size ◽  
Cervical Vertebrae ◽  
Anatomical Structure ◽  
Trabecular Structure ◽  
Lateral Part ◽  
Bone Segment ◽  
Result Show ◽  
Egretta Garzetta

The egretta bird (Egretta zegretta) has a body size of 55-65 centimeters, it is wings stretches 88-106 centimeters, has a long neck and typical neck like the letter “S”. The purpose of this research is to find out the anatomical structure of trabeculae in the egretta bird. To find out the trebeculae in the egretta bird, meat on the neck cleaned. Then, each bone segment is cut and sanded on the ventral and lateral part until spongiosa tissue (trabeculae) is seen, and transversely cut. The observation result show that on the C6 bone segment has a trabecular structure more dense comepared to the structure of the trabelucae in other bone segments. That is because in the C6 bone segment gets pressure from top and bottom, so C6 bone segment stronger.

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