scholarly journals Habitat use and Breeding Distribution of Magellanic Penguins in Northern San Jorge Gulf, Patagonia, Argentina

The Auk ◽  
2002 ◽  
Vol 119 (1) ◽  
pp. 233-239 ◽  
Author(s):  
Pablo García Borboroglu ◽  
Pablo Yorio ◽  
P. Dee Boersma ◽  
Héctor Del Valle ◽  
Marcelo Bertellotti

Abstract We evaluated distribution and size of Magellanic Penguin (Spheniscus magellanicus) colonies in northern San Jorge Gulf, Argentina, characterizing nesting habitat at 14 islands with colonies (IC) and 28 islands without nesting penguins (INC). Digital analysis of a Landsat TM satellite image and field measurements were used to assess vegetation and substrate. The 14 breeding colonies ranged in size from 13 to 96,300 nests, and number of breeding pairs was estimated at 218,460. Colonies were only located on islands. Digital analysis of the satellite image showed that the proportion of area with shrub–steppe vegetation was significantly higher at IC than at INC (38.6 vs. 4.9%), whereas percentage of rocky substrate was lower at IC (33.6 vs. 64.8%). Percentage of vegetation cover was positively correlated with island area and with number of breeding pairs. Most nests (98.6%) were located under bushes, whereas the rest were burrows dug into the substrate. Mean size of bushes used for nesting was higher at IC (4.47 vs. 0.99 m2) as was the percentage of silt–clay substrate (47.31 vs. 1.98%). Coast minimum slopes at INC were steeper than the slopes of entrance routes at IC (27.6 vs. 5.7°). Probability of occupation of islands increased with amount of shrub-type vegetation cover and silt–clay substrate, and decreased with increasing slopes and amount of sandy substrate. Magellanic Penguins selected islands with shrub-type vegetation and soil that allow building nests with adequate cover. These results are consistent with other studies showing vegetation cover is an important nesting requirement for Magellanic Penguins.


2020 ◽  
Vol 12 (4) ◽  
pp. 710 ◽  
Author(s):  
Trinidad del Río-Mena ◽  
Louise Willemen ◽  
Anton Vrieling ◽  
Andy Nelson

Landscape processes fluctuate over time, influencing the intra-annual dynamics of ecosystem services. However, current ecosystem service assessments generally do not account for such changes. This study argues that information on the dynamics of ecosystem services is essential for understanding and monitoring the impact of land management. We studied two regulating ecosystem services (i. erosion prevention, ii. regulation of water flows) and two provisioning services (iii. provision of forage, iv. biomass for essential oil production) in thicket vegetation and agricultural fields in the Baviaanskloof, South Africa. Using models based on Sentinel-2 data, calibrated with field measurements, we estimated the monthly supply of ecosystem services and assessed their intra-annual variability within vegetation cover types. We illustrated how the dynamic supply of ecosystem services related to temporal variations in their demand. We also found large spatial variability of the ecosystem service supply within a single vegetation cover type. In contrast to thicket vegetation, agricultural land showed larger temporal and spatial variability in the ecosystem service supply due to the effect of more intensive management. Knowledge of intra-annual dynamics is essential to jointly assess the temporal variation of supply and demand throughout the year to evaluate if the provision of ecosystem services occurs when most needed.



2015 ◽  
Vol 67 (1) ◽  
pp. 125-130 ◽  
Author(s):  
A.M. Martins ◽  
R.P. Silva Filho ◽  
M.O. Xavier ◽  
M.C.A. Meireles ◽  
R.B. Robaldo

During the austral winter the appearance of the Magellanic penguin (Spheniscus magellanicus) is common on the southern coast of Brazil. The oil pollution constitutes a major cause of death of these birds. The monitoring of the weight and blood variables is important to make decisions during the rehabilitation and release of these animals. Thus, the aim of this study was to evaluate the relationship between the penguins' survival during rehabilitation and the values of hematocrit (Hct), total plasma protein (TPP) and body weight (BW) of the birds received at Centro de Recuperação de Animais Marinhos (Recovery Centre for Sea Animals) between 2006 and 2009. The analysis took place weekly, and penguins were classified according to the outcome of the rehabilitation process, when 101 specimens were rehabilitated and released, and 67 died. Released animals showed a decrease in the Hct in the second and third weeks (41±6% and 40±5% respectively) followed by recovery of the values in the fourth and fifth week (41±4% and 43±4% respectively). TPP levels increased steadily over the collections, stabilizing at 7.3±0.8g/dL in the fourth week. On the other hand, animals that died, although following the same response for TPP, showed no significant difference in Hct between collections, and showed a tendency for loss of BW in the last weeks of rehabilitation. The curves of BW and Hct during rehabilitation were considered a potential prognostic indicator of penguins in rehabilitation. Animals that arrived at the recovery centre with BW, Hct and TPP above 2.700g, 45% and 5.6 g / dL, respectively, have a greater chance of recovery, making these parameters crucial points in decision making regarding the treatment to be conducted during rehabilitation.



1992 ◽  
Vol 2 (3) ◽  
pp. 161-173 ◽  
Author(s):  
Pablo Yorio ◽  
P. Dee Boersma

SummaryMagellanic Penguins Spheniscus magellanicus along the Patagonian coast, Argentina, are increasingly exposed to human activities, especially to a growing tourist industry. We quantified the effects of human visitation and disturbance on the behaviour and breeding of Magellanic Penguins. Nesting penguins differed in their response to human approach, allowing a significantly closer approach before responding with threat and defensive displays in the tourist area than in areas rarely visited by people. When approached during incubation, no penguins abandoned their nest. Breeding success and fledgling weights were similar in the tourist area and non-tourist areas. Magellanic Penguins appear to be tolerant of human visitation, and penguins breeding in the tourist area become accustomed to people walking among their nests. We suggest visitation may be compatible with penguin reproduction if visits are controlled.El Pingüino de Magallanes Spheniscus magellanicus de las costas patagónicas de la Argentina, esta expuesto a las crecientes actividades humanas, especialmente el aumento de la demanda turistica. Se han cuantificado los efectos de las visitas y molestias del hombre en el comportamiento y reproducción de la especie. Los pingüinos mostraron diferencias en su respuesta frent a la proximidad humana, permitiendo un acercamiento signifi-cativamente mayor antes de responder con actitudes defensivas en áreas frecuentadas por los turistas en comparicion con aquellas rara vez visitadas. La proximidad humana durante la época de incubación no supuso en ninguna ocasión el abandono de nidos. El éxito reproductive y los pesos de los jóvenes al abandonar el nido resultaron similares en a l zona turística y en la menos frecuentada. El Pingüino de Magallanes parece tolerar la presencia del hombre, y aquellos que nidifican en el área turistica se habitúan a los visitantes que caminan entre sus nidos. Sugerimos que las visitas pueden ser compatibles con la reproducción de la especie siempre y cuando las mismas estén controladas.



2021 ◽  
Vol 166 ◽  
pp. 112232
Author(s):  
Hugo Gallo Neto ◽  
Carla Gomes Bantel ◽  
John Browning ◽  
Natalia Della Fina ◽  
Tami Albuquerque Ballabio ◽  
...  


2020 ◽  
Vol 13 (1) ◽  
pp. 19
Author(s):  
Lauren E. H. Mathews ◽  
Alicia M. Kinoshita

A combination of satellite image indices and in-field observations was used to investigate the impact of fuel conditions, fire behavior, and vegetation regrowth patterns, altered by invasive riparian vegetation. Satellite image metrics, differenced normalized burn severity (dNBR) and differenced normalized difference vegetation index (dNDVI), were approximated for non-native, riparian, or upland vegetation for traditional timeframes (0-, 1-, and 3-years) after eleven urban fires across a spectrum of invasive vegetation cover. Larger burn severity and loss of green canopy (NDVI) was detected for riparian areas compared to the uplands. The presence of invasive vegetation affected the distribution of burn severity and canopy loss detected within each fire. Fires with native vegetation cover had a higher severity and resulted in larger immediate loss of canopy than fires with substantial amounts of non-native vegetation. The lower burn severity observed 1–3 years after the fires with non-native vegetation suggests a rapid regrowth of non-native grasses, resulting in a smaller measured canopy loss relative to native vegetation immediately after fire. This observed fire pattern favors the life cycle and perpetuation of many opportunistic grasses within urban riparian areas. This research builds upon our current knowledge of wildfire recovery processes and highlights the unique challenges of remotely assessing vegetation biophysical status within urban Mediterranean riverine systems.



2021 ◽  
Vol 13 (16) ◽  
pp. 3062
Author(s):  
Guo Zhang ◽  
Boyang Jiang ◽  
Taoyang Wang ◽  
Yuanxin Ye ◽  
Xin Li

To ensure the accuracy of large-scale optical stereo image bundle block adjustment, it is necessary to provide well-distributed ground control points (GCPs) with high accuracy. However, it is difficult to acquire control points through field measurements outside the country. Considering the high planimetric accuracy of spaceborne synthetic aperture radar (SAR) images and the high elevation accuracy of satellite-based laser altimetry data, this paper proposes an adjustment method that combines both as control sources, which can be independent from GCPs. Firstly, the SAR digital orthophoto map (DOM)-based planar control points (PCPs) acquisition is realized by multimodal matching, then the laser altimetry data are filtered to obtain laser altimetry points (LAPs), and finally the optical stereo images’ combined adjustment is conducted. The experimental results of Ziyuan-3 (ZY-3) images prove that this method can achieve an accuracy of 7 m in plane and 3 m in elevation after adjustment without relying on GCPs, which lays the technical foundation for a global-scale satellite image process.



2021 ◽  
Vol 168 (6) ◽  
Author(s):  
Monserrat Del Caño ◽  
Flavio Quintana ◽  
Ken Yoda ◽  
Giacomo Dell’Omo ◽  
Gabriela S. Blanco ◽  
...  


2002 ◽  
Vol 14 (1) ◽  
pp. 19-28 ◽  
Author(s):  
J. Moreno ◽  
P. Yorio ◽  
P. Garcia-Borboroglu ◽  
J. Potti ◽  
S. Villar


1967 ◽  
Vol PAS-86 (8) ◽  
pp. 1001-1006
Author(s):  
Frank Smith ◽  
Lewis McKenzie ◽  
Dorothy Coleman ◽  
R. Shipley


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