Cathemerality in a small, folivorous primate: proximate control of diel activity in Hapalemur meridionalis

2015 ◽  
Vol 69 (6) ◽  
pp. 991-1002 ◽  
Author(s):  
Timothy M. Eppley ◽  
Jörg U. Ganzhorn ◽  
Giuseppe Donati
1991 ◽  
Vol 6 (3) ◽  
pp. 305-313 ◽  
Author(s):  
Carl W. Prophet ◽  
Thomas B. Brungardt ◽  
N. Kay Prophet

2021 ◽  
pp. 074873042199811
Author(s):  
Franziska Ruf ◽  
Oliver Mitesser ◽  
Simon Tii Mungwa ◽  
Melanie Horn ◽  
Dirk Rieger ◽  
...  

The adaptive significance of adjusting behavioral activities to the right time of the day seems obvious. Laboratory studies implicated an important role of circadian clocks in behavioral timing and rhythmicity. Yet, recent studies on clock-mutant animals questioned this importance under more naturalistic settings, as various clock mutants showed nearly normal diel activity rhythms under seminatural zeitgeber conditions. We here report evidence that proper timing of eclosion, a vital behavior of the fruit fly Drosophila melanogaster, requires a functional molecular clock under quasi-natural conditions. In contrast to wild-type flies, period01 mutants with a defective molecular clock showed impaired rhythmicity and gating in a temperate environment even in the presence of a full complement of abiotic zeitgebers. Although period01 mutants still eclosed during a certain time window during the day, this time window was much broader and loosely defined, and rhythmicity was lower or lost as classified by various statistical measures. Moreover, peak eclosion time became more susceptible to variable day-to-day changes of light. In contrast, flies with impaired peptidergic interclock signaling ( Pdf01 and han5304 PDF receptor mutants) eclosed mostly rhythmically with normal gate sizes, similar to wild-type controls. Our results suggest that the presence of natural zeitgebers is not sufficient, and a functional molecular clock is required to induce stable temporal eclosion patterns in flies under temperate conditions with considerable day-to-day variation in light intensity and temperature. Temperate zeitgebers are, however, sufficient to functionally rescue a loss of PDF-mediated clock-internal and -output signaling


2015 ◽  
Vol 65 (3-4) ◽  
pp. 209-217 ◽  
Author(s):  
Yadong Xue ◽  
Diqiang Li ◽  
Wenfa Xiao ◽  
Fang Liu ◽  
Yuguang Zhang ◽  
...  

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.


2011 ◽  
Vol 27 (2) ◽  
pp. 322-326 ◽  
Author(s):  
B. M. Wrege ◽  
M. S. Duncan ◽  
J. J. Isely

2018 ◽  
Vol 56 (4) ◽  
pp. 872-881 ◽  
Author(s):  
Kaitlyn M. Gaynor ◽  
Paola S. Branco ◽  
Ryan A. Long ◽  
Dominique D. Gonçalves ◽  
Petter K. Granli ◽  
...  

2007 ◽  
Vol 5 (2) ◽  
pp. 229-232 ◽  
Author(s):  
Carlos Bernardo Mascarenhas Alves ◽  
Luiz Gustavo Martins da Silva ◽  
Alexandre Lima Godinho

Jaú, Zungaro jahu (Ihering, 1898), a large migratory catfish endemic to the rio da Prata basin, has a fragile conservation status and its ecology is poorly known. We radio-tracked a female jaú with a total length of 1.5 m that was passed upstream of Funil Dam, rio Grande, to describe its migratory movements, habitat use, linear home range, and diel activity. To track the fish, we made five tracking trips in the period from April, 2003 to January, 2004. In addition to the main body of Funil Reservoir, the fish also used a reservoir-river transition zone located in a branch of Funil Reservoir that flooded part of rio das Mortes. Most of the times, we found the fish in the former beds of streams flooded by the reservoir, at depths that ranged from 8-9 m in the reservoir-river transition zone to 18-21 m in Funil Reservoir. Linear home range of the fish was 31.4 km. The onset of activity occurred early in the evening, but we also detected daytime activity. The conclusion from our study was that the passed adult female jaú used reservoir habitats, migrated between the main body and the reservoir-river transition zone, preferred deep habitats, showed a relatively short home range, and had diurnal and nocturnal activities.


1989 ◽  
Vol 53 (1) ◽  
pp. 264 ◽  
Author(s):  
Jay A. Alderman ◽  
Paul R. Krausman ◽  
Bruce D. Leopold

2010 ◽  
Vol 8 (4) ◽  
pp. 893-898 ◽  
Author(s):  
Leo G. Nico

Several Pterygoplichthys species, members of the Neotropical catfish family Loricariidae, have been widely introduced outside their native ranges. In this paper, I present observations on the diel activity pattern of non-native Pterygoplichthys, tentatively identified as P. disjunctivus, with respect to their attachment and grazing on endangered Florida manatees, Trichechus manatus latirostris. The study was conducted in December 2009 at Volusia Blue Spring, an artesianal spring system in the St. Johns River basin, Florida (USA). Supplemented by information gathered during previous visits to the spring site, this study revealed that adult Pterygoplichthys are active throughout the diel period (day, twilight and night). However, juvenile Pterygoplichthys were largely nocturnal and only at night did they consistently join adults in attaching to manatees. The juveniles generally remain hidden during the day, probably responding to presence of diurnal predators, mainly birds. Differences in diel behaviors among different Pterygoplichthys size classes in Florida are consistent with published observations on loricariids inhabiting clearwater streams within their native ranges.


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