Diel Activity Patterns of Juvenile Late Fall-run Chinook Salmon with Implications for Operation of a Gated Water Diversion in the Sacramento-San Joaquin River Delta

2015 ◽  
Vol 32 (4) ◽  
pp. 711-720 ◽  
Author(s):  
J. M. Plumb ◽  
N. S. Adams ◽  
R. W. Perry ◽  
C. M. Holbrook ◽  
J. G. Romine ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Activity Patterns ◽  
River Delta ◽  
Water Diversion ◽  
Diel Activity ◽  
Late Fall ◽  
San Joaquin River ◽  
Diel Activity Patterns

Habitat-, season-, and size-specific variation in diel activity patterns of juvenile chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss)

2001 ◽  
Vol 58 (2) ◽  
pp. 365-374 ◽  
Author(s):  
Michael J Bradford ◽  
Paul S Higgins
Keyword(s):  
Oncorhynchus Mykiss ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Activity Patterns ◽  
Diel Activity ◽  
Steelhead Trout ◽  
Juvenile Chinook Salmon ◽  
Diel Activity Patterns ◽  
Specific Variation ◽  
Juvenile Chinook

Juvenile salmonids that live in streams are sometimes nocturnal and may spend the day concealed in the stream substrate. We observed the diel activity patterns of juvenile chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) in two areas of the Bridge River, British Columbia, in all four seasons. In a reach with higher flows, most fish were nocturnal year-round, and they emerged from the substrate only at dusk to forage. In the reach with lower flows, some fish were active in the water column in the day in summer, but others remained concealed in the substrate until dusk. Parr and older fish were more nocturnal in summer than fry. All fish were nocturnal in winter. Because our study design controlled for temperature and photoperiod, we concluded that the differences in behaviour that we observed between reaches were due to habitat conditions that likely affected the trade-off between more risky daytime foraging and less efficient, but safer, nighttime foraging. Habitat-driven variation in activity patterns will likely affect the processes that regulate these populations and could make the prediction of the effects of ecosystem manipulations such as changes in flow very difficult.

Activity patterns of wild Bactrian camels (Camelus bactrianus) in the northern piedmont of the Altun Mountains, China

2015 ◽  
Vol 65 (3-4) ◽  
pp. 209-217 ◽  
Author(s):  
Yadong Xue ◽  
Diqiang Li ◽  
Wenfa Xiao ◽  
Fang Liu ◽  
Yuguang Zhang ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Endangered Species ◽  
Activity Patterns ◽  
Relative Activity ◽  
Diel Activity ◽  
Arid Areas ◽  
Critically Endangered Species ◽  
Camelus Bactrianus ◽  
Diel Activity Patterns ◽  
Bactrian Camels

There are significant gaps in our knowledge of wild camel ecology; especially the activity patterns that allow them to adapt to desert environments. The wild Bactrian camel (Camelus bactrianus) is a critically endangered species that survives in the extreme desert conditions of Central Asia. We conducted camera trapping surveys at seven watering sites in the northern piedmont of the Altun Mountains from 2010 to 2012. We analyzed the frequency of photo-captures to elucidate the wild camels’ diel activity patterns, and the seasonal variation in their activity at watering sites. We found that these wild camels were predominantly diurnal at watering sites, with an increase in relative activity from sunrise, reaching a peak toward midday, and then gradually decreasing in activity until sunset. The camels visited watering sites more often in winter than in summer. These results provide a guide for water development in the conservation of ungulates in arid areas.

scholarly journals Effects of human settlement and roads on diel activity patterns of elephants (Loxodonta africana )

2018 ◽  
Vol 56 (4) ◽  
pp. 872-881 ◽  
Author(s):  
Kaitlyn M. Gaynor ◽  
Paola S. Branco ◽  
Ryan A. Long ◽  
Dominique D. Gonçalves ◽  
Petter K. Granli ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Loxodonta Africana ◽  
Diel Activity ◽  
Human Settlement ◽  
Diel Activity Patterns

scholarly journals Activity patterns of the small and medium felid (Mammalia: Carnivora: Felidae) guild in northeastern India

2019 ◽  
Vol 11 (4) ◽  
pp. 13432-13447 ◽  
Author(s):  
Shomita Mukherjee ◽  
Priya Singh ◽  
André Pinto Silva ◽  
Chandan Ri ◽  
Kashmira Kakati ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Regional Scale ◽  
Diel Activity ◽  
Point Scale ◽  
Clouded Leopard ◽  
Northeastern India ◽  
Additional Information ◽  
Extant Species ◽  
Diel Activity Patterns ◽  
Leopard Cat

Fifteen extant species of cats inhabit India, and the northeastern region of the country is among the richest with nine species.  Among these are the “standard four”, an assemblage of Clouded Leopard Neofelis nebulosa, Asiatic Golden Cat Catopuma temminckii, Marbled Cat Pardofelis marmorata, and Leopard Cat Prionailurus bengalensis, which also occur across southeastern Asia.  Within India, despite several surveys in this region, very little information exists on the ecology of this assemblage to explain their co-occurrence.  In this paper, we put together data from several independent camera trapping studies over 10 sites across northeastern India to examine and interpret diel activity patterns of this group.  While we present results for all the four species, we focus on two species, the Marbled Cat and Leopard Cat, which are of very similar body size and are potential competitors.  We used kernel density estimates to measure diel activity patterns of all four species and overlap in activity between Marbled Cat and Leopard Cat at the regional scale as well as the point scale.  We obtained 783 captures of the standard four from >27,500 trap nights.  The Asiatic Golden Cat and Marbled Cat were strongly diurnal, Clouded Leopard largely crepuscular and nocturnal, and Leopard Cat largely nocturnal.  The degree of overlap between Marbled Cat and Leopard Cat activity was low and in consensus with other studies across southeastern Asia.  We interpret this as the differing niche spaces of the two cats due to their specific pre-existing adaptations, not restricted to the effects of competition.  The point scale analysis when both cats are captured at the same location and separately show no shift in activity pattern, supporting our hypothesis of pre-existing differences in resources, such as food, playing a major role in facilitating co-existence.  Our study, however, is preliminary and additional information with robust analysis is required to test this finding.

scholarly journals Non-uniform evolutionary response of gecko eye size to changes in diel activity patterns

2018 ◽  
Vol 14 (5) ◽  
pp. 20180064 ◽  
Author(s):  
Lars Schmitz ◽  
Timothy E. Higham
Keyword(s):  
Phenotypic Diversity ◽  
Activity Patterns ◽  
Model Fitting ◽  
Regime Shifts ◽  
Least Square ◽  
Diel Activity ◽  
Relevant Variable ◽  
Eye Size ◽  
Evolutionary Response ◽  
Diel Activity Patterns

Geckos feature a large range of eye sizes, but what drives this phenotypic diversity is currently unknown. Earlier studies point towards diel activity patterns (DAPs) and locomotory mode, but phylogenetic comparative studies in support of the proposed adaptive mode of eye evolution are lacking. Here, we test the hypothesis of DAPs as the driver of eye size evolution with a dataset on 99 species of gecko. Results from phylogenetic generalized least-square analysis (PGLS) and multivariate model-fitting reveal smaller eyes in diurnal geckos consistent with different phenotypic optima. However, Bayesian analyses of selective regime shifts demonstrate that only two of nine transitions from nocturnal to diurnal activity are coupled with decreases in eye size, and two other regime shifts are not associated with DAP transitions. This non-uniform evolutionary response suggests that eye size is not the only functionally relevant variable. Evolutionary adaptations may therefore include different combinations of several traits (e.g. photoreceptors), all with the same functional outcome. Our results further demonstrate that DAP only partially explains eye size diversity in geckos. As open habitats favour the evolution of large eyes while obstructed habitats favour small eyes, the degree of habitat clutter emerges as another potential axis of eye diversification.

Seasonal Diel Activity Patterns of Three Sympatric Ungulates in Forested Area in Central Japan

Mammal Study ◽  
2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Takashi Ikeda ◽  
Satuski Nakamori ◽  
Masaki Ando ◽  
Takumi Shirakawa ◽  
Takuya Okamoto ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Diel Activity ◽  
Central Japan ◽  
Forested Area ◽  
Diel Activity Patterns
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