Environmental and Human Influences on Trumpeter Swan Habitat Occupancy in Alaska

The Condor ◽  
2009 ◽  
Vol 111 (2) ◽  
pp. 266-275 ◽  
Author(s):  
Joshua H. Schmidt ◽  
Mark S. Lindberg ◽  
Devin S. Johnson ◽  
Joel A. Schmutz
2018 ◽  
Vol 11 (1) ◽  
pp. 14-24
Author(s):  
Chabi A.M.S. Djagoun ◽  
Etotépé A. Sogbohossou ◽  
Barthélémy Kassa ◽  
Christian B. Ahouandjinou ◽  
Hugues A. Akpona ◽  
...  

Background: The habitat degradation together with fragmentation and illegal hunting represent a major threat for biodiversity conservation in Lama protected areas. Method: We used a combination of questionnaire survey with local communities for ranking the hunted mammal species as bushmeat and track surveys in gridded-cell system of 500x500 m2 (n=268) to assess at what extend the management design, the anthropogenic factors and habitat type affect the occupancy model of those mammal species. Results: Twenty mammal species have been predominantly reported by the local inhabitants to consume bushmeat species and 5 of them have been identified as the most preferable as hunted game mammals. The selection of the preferred habitat among the swampy forest, the dense forest, the tree plantations and cropland for the prioritized game species varies between species but looks similar when grouping in different orders. Some bushmeat species were found to select the more secure habitat (natural forest); suggesting the zoning system in the Lama forest can passively protect those species. However, some species such as T. swinderianus although highly hunted showed preference to anthropogenic habitat, avoiding the well secured core zone in Lama Forest. Conclusion: Our findings highlighted the importance of the zoning system with different management objectives in the habitat occupancy model of the highly hunted wildlife species.


2008 ◽  
Vol 45 (2) ◽  
pp. 549-557 ◽  
Author(s):  
Jonathan R. Rhodes ◽  
John G. Callaghan ◽  
Clive A. McAlpine ◽  
Carol de Jong ◽  
Michiala E. Bowen ◽  
...  

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Cinzia Podda ◽  
Andrea Sabatini ◽  
Francesco Palmas ◽  
Antonio Pusceddu

Catadromous fish species are very important organisms for their ecological, economical, and cultural value. For its complex life species catadromous fish result in worldwide decline since the beginning of the 20th century. Among the most iconic catadromous species, the European eel Anguilla anguilla L. 1758 has aroused considerable interest since very ancient times. Because, to date, many aspects of their life cycle remain relatively unknown, to implement our knowledge about the main natural and anthropogenic threats to its survivorship and identify possible solutions to preserve it, in this narrative review, we present the state of the knowledge about the life cycle, habitat occupancy, recruitment, and migration patterns of the European eel and about the major threats most likely have contributed to the decline of eels’ populations.


Blue Jay ◽  
1953 ◽  
Vol 11 (4) ◽  
Author(s):  
Fred .G. Bard
Keyword(s):  

Author(s):  
Kimberly Szcondronski ◽  
Diane Debinski

The pristine, protected ecosystem of Grand Teton National Park (GRTE) is the ideal location to study the relationships between butterfly populations and the habitats on which these insects depend. Two montane meadow butterfly species, Parnassius clodius and Parnassius smintheus, were investigated in this study to identify patterns of habitat occupancy relating to variables across GRTE and into the surrounding territory of Bridger–Teton National Forest (BTNF). Population dynamics of P. clodius have been intensively studied by our research group over several consecutive years in one isolated population in Grand Teton National Park. However, little has been investigated regarding the Parnassian butterflies’ population range across the GRTE ecosystem. For this study, presence-absence butterfly surveys were conducted across 45 meadow sites in preferred habitat during the Parnassius flight season (June – July 2013). We found that P. clodius occupied 80% of the meadows surveyed, which was far greater than was originally predicted. P. smintheus, the more rare Parnassian butterfly in the GRTE ecosystem, was only found at 9% of the meadows surveyed. Understanding population ranges and habitat limits of these butterfly populations will be useful for managers and scientists within GRTE, and will assist conservation efforts for other related Parnassian species that are threatened or endangered worldwide due to habitat loss and climate change.


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