Diet, Diel Activity Pattern, Habitat Use, and Reproductive Effort ofHylodes nasus(Anura: Hylodidae) in One of the World's Largest Urban Parks (Tijuca National Park), Southeastern Brazil

2016 ◽  
Vol 11 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Aricia de Oliveira Machado ◽  
Gisele Winck ◽  
Thiago Arnt Dorigo ◽  
Carlos Frederico Duarte Rocha
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.


1980 ◽  
Vol 37 (9) ◽  
pp. 1454-1458 ◽  
Author(s):  
James S. Diana

Movements of six northern pike (Esox lucius) were monitored for 5 to 51 days by ultrasonic transmitters implanted surgically. The pike were inactive during 80% of the eight hundred and eighty-nine 5-min intervals monitored during summer and winter. No regular diel changes in activity were noted, except that pike were inactive at night. Swimming velocities calculated from gross displacements were maximum, 42 cm/s (0.91 body lengths (BL)/s); average, 23.1 cm/s (0.45 BL/s).Key words: movements, diel activity, seasonal activity, northern pike, Esox lucius; swimming speeds


2019 ◽  
Vol 11 (8) ◽  
pp. 13960-13966
Author(s):  
Kangaraj Muthamizh Selvan ◽  
Bawa Mothilal Krishnakumar ◽  
Pasiyappazham Ramasamy ◽  
Thangadurai Thinesh

Sympatric and similar body-sized species exhibit interspecific competition for resources.  The present study investigated diel activity of five meso-carnivore species (Canis aureus, Felis chaus, Paradoxurus hermaphroditus, Viverricula indica, and Herpestes edwardsii) in a human-dominated region of Auroville and around Pondicherry University using camera-trap survey data.  Diel activity pattern and overlap were estimated using the kernel density method.  The Jungle Cat Felis chaus and the Golden Jackal Canis aureus exhibited cathemeral diel activity with a high overlap between them (Δ̂1 = 0.78).  The Indian Grey Mongoose Herpestes edwardsii displayed a diurnal activity pattern and had low overlap with the Small Indian Civet Viverricula indica (Δ̂1 = 0.34).  Moderate overlap was found between the Small Indian Civet and the Palm Civet Paradoxurus hermaphroditus (Δ̂1 = 0.32).  Therefore, diel activity patterns of mesocarnivores indicate inter- and intra-specific trade-off competition avoidance resulting in successful foraging.  The present camera-trap survey has provided insights into diel activity patterns and more attention is required to be paid to the study of feeding and breeding ecology of these species in human-dominated landscapes. 


2020 ◽  
Vol 8 ◽  
Author(s):  
Nilanjan Chatterjee ◽  
Parag Nigam ◽  
Bilal Habib

Studies on carnivores are skewed toward larger species in India, limiting ecological information of the smaller ones. Basic ecological understanding like population density, distribution, habitat-use patterns of small carnivores is lacking. This inadequate knowledge has led to disagreement between conservation approaches in different landscapes. Honey badgers (Mellivora capensis) are cryptic carnivores distributed across large areas of Africa and Asia; however, fundamental ecological knowledge is scarce. The species is thought to exist at low population densities throughout its range. We used a large camera trap dataset from a tiger reserve in Maharashtra State, India to understand the population density, habitat preference, and diel activity pattern of the species. We applied an extension of the spatial count model for the estimation of population. Habitat preference analyses were carried out using generalized linear models and activity patterns were analyzed using kernel-density functions. The population density was estimated as 14.09 (95% CI 10–22.25) individuals per 100 km2. Habitat use revealed a positive association with forest cover and negative association with elevation. This may expose the species to other large carnivores in the habitat but honey badger activity pattern peaked at midnight retaining minimum temporal overlap with other large carnivores (e.g., tiger Panthera tigris, leopard Panthera pardus, and dhole Cuon alpinus) and moderate overlap with small carnivores (e.g., jungle cat Felis chaus, rusty-spotted cat Prionailurus rubiginosus). These behaviors, in turn, may facilitate the coexistence of species at such high density even with high carnivore density. We hope the findings of this study will fill the existing knowledge gap of this species and aid in guiding the conservation of the species in other landscapes and reserves.


1976 ◽  
Vol 54 (9) ◽  
pp. 1481-1487 ◽  
Author(s):  
P. A. Anderson ◽  
J. W. Nowosielski ◽  
N. A. Croll

The emergence pattern of cercariae of Trichobilharzia ocellata from Lymnaea stagnalis was examined at 2-h intervals from infected snails acclimatized to 12 h light – 12 h dark periods. A marked diel pattern of emergence was found during the periods of illumination; this was reversed when the light–dark regime was reversed.A method for the continuous recording of the locomotory activity of L. stagnalis is described. Snails acclimatized to either normal or reversed dark–light regimes showed a consistent diel pattern of activity during illumination. Peak activity occurred in the first few hours of illumination.It is proposed that the diel activity pattern results from an internal rhythm in which the snail becomes entrained to the lighting regime. The close association between the diel activity pattern of the snail and the emergence of T. ocellata indicates that host movement stimulates cercarial emergence. Light is thought to influence the cercariae directly and indirectly through the snail.


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