The diet of Olrog's Gull (Larus atlanticus) reveals an association with fisheries during the non-breeding season

2013 ◽  
Vol 113 (1) ◽  
pp. 69-76 ◽  
Author(s):  
María Paula Berón ◽  
Juan Pablo Seco Pon ◽  
Germán O. García ◽  
Carla A. Paterlini ◽  
Rocío Mariano-Jelicich ◽  
...  
Keyword(s):  
Breeding Season ◽  
Olrog’S Gull

scholarly journals Diet specialization of Olrog's Gull Larus atlanticus during the breeding season at Golfo San Jorge, Argentina

2005 ◽  
Vol 15 (1) ◽  
pp. 89-97 ◽  
Author(s):  
GONZALO HERRERA ◽  
GABRIEL PUNTA ◽  
PABLO YORIO
Keyword(s):  
Breeding Season ◽  
Carapace Width ◽  
Breeding Cycle ◽  
Percentage Contribution ◽  
Diet Specialization ◽  
Olrog’S Gull ◽  
Main Component ◽  
Prey Items

We studied the diet of breeding Olrog's Gulls Larus atlanticus during 1994 at two colonies in Golfo San Jorge, Argentina, through the analysis of 207 regurgitated pellets. The diet at Isla Felipe and Isla Vernaci Sudoeste comprised only a few items (9 vs 7 respectively), of which crabs were the main component. At Isla Felipe, the crabs Cyrtograpsus altimanus and C. angulatus were present in 91.2% and 89.2% of pellets, respectively, while the percentage contribution of each species was 76.1% and 21.7%, respectively. At Isla Vernaci Sudoeste, the figures were similar (96.2% and 80% of pellets, and percentage contributions 79.4% and 19.5%). All other taxa were present in less than 11% of pellets. No significant differences were found between colonies in the number of prey items, prey individuals per pellet, and consumption of crabs. Percentage contribution of crabs differed significantly between stages of the breeding cycle at Isla Felipe but not at Isla Vernaci Sudoeste. At both colonies, the proportion of male C. altimanus in pellets was larger than that of females. The proportion of female C. angulatus in pellets at Isla Vernaci Sudoeste was larger than that of males, but no significant differences were found in the consumption of each sex at Isla Felipe. Mean maximum carapace width of male crabs in pellets was not significantly different from that of females at either Isla Felipe or Isla Vernaci. Our study at Golfo San Jorge confirms that Olrog's Gull is fairly specialized, feeding mainly on crabs during the breeding season.

Use of winter habitat at an early age: spatial ecology and association with human activities of juvenile Olrog’s Gull Larus atlanticus

2019 ◽  
Vol 29 (4) ◽  
pp. 575-585 ◽  
Author(s):  
MARÍA TERESA RAVASI ◽  
JUAN PABLO SECO PON ◽  
JESICA ANDREA PAZ ◽  
MARCO FAVERO ◽  
SOFÍA COPELLO
Keyword(s):  
Breeding Season ◽  
Spatial Ecology ◽  
Buenos Aires ◽  
Conservation Status ◽  
Atlantic Coast ◽  
Fishing Effort ◽  
Marine Conservation ◽  
Limited Area ◽  
Winter Habitat ◽  
Olrog’S Gull

SummaryOlrog’s Gull Larus atlanticus is an endemic species of the Atlantic coast of southern South America and is currently listed as ‘Near Threatened’ on the IUCN Red List. The species breeds in coastal wetlands of Buenos Aires and Chubut provinces of Argentina and during winter migrates northwards as far as southern Brazil. During the breeding season the species is considered to have a specialised diet, foraging mostly on crabs. However, during the non-breeding season the gull presents a wider dietary spectrum (including fish) as a result of a potential association with commercial and sport fishing activities. The main goal of this study was to analyse the habitat use and overlap with natural and anthropogenic food resources of juvenile Olrog’s Gull during the winter in Mar Chiquita Lagoon, Buenos Aires. Twenty-two GPS devices were deployed during the winters of 2013 and 2014. A total of 1,088 fixes was gathered by GSM (both seasons combined). Analysis showed that the individuals were (kernel 95%) distributed in a limited area along the mouth of the lagoon. The core area (kernel 50%) covered only 0.3 km2 and was located in the south of the mouth. The overlap between juveniles and crab densities was lower than expected, while the overlap between juveniles and fishing effort was higher than expected during weekdays and lower during weekends. These results are of value for the further development of marine conservation measures for wintering areas which have so far been somewhat neglected while addressing the conservation status of the species.

Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.
Keyword(s):  
Sexual Dimorphism ◽  
Breeding Season ◽  
Sound Production ◽  
Reproductive Function ◽  
Breeding Biology ◽  
Tree Frog ◽  
University Campus ◽  
Morphometric Measurements ◽  
Advertisement Calls ◽  
Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

An Ethogram of the Toad-headed Lizard Phrynocephalus vlangalii during the Breeding Season

2011 ◽  
Vol 2 (2) ◽  
pp. 110-116 ◽  
Author(s):  
QI Yin ◽  
LI Shasha ◽  
SUO Langduoerji ◽  
LI Hua ◽  
WANG Yuezhao
Keyword(s):  
Breeding Season
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