Notes on the diet and foraging habits of the Giant Barred Frog Mixophyes iteratus

2020 ◽  
Author(s):  
G. Madani
Keyword(s):  
Stomach Content ◽  
Prey Capture ◽  
Limited Information ◽  
Foraging Patterns ◽  
Faecal Analysis ◽  
Hunting Behaviour ◽  
Direct Observations ◽  
Ambush Predators

Australian anurans generally display little prey specialisation. Most data available of frog diet is limited to stomach content and faecal analysis with few direct observations of prey capture. Limited information is available on the diet of adult Giant Barred Frogs Mixophyes iteratus. In this paper I report on several observations of M. iteratus feeding on a variety of prey from various taxa. These observations suggest that M. iteratus are opportunistic, ambush predators with a broad diet. Their morphology and hunting behaviour align with existing models of amphibian foraging patterns.

Functional implications of supercontracting muscle in the chameleon tongue retractors

2001 ◽  
Vol 204 (21) ◽  
pp. 3621-3627 ◽  
Author(s):  
Anthony Herrel ◽  
Jay J. Meyers ◽  
Peter Aerts ◽  
Kiisa C. Nishikawa
Keyword(s):  
Prey Capture ◽  
Three Dimensional ◽  
Force Production ◽  
Retractor Muscle ◽  
Muscle Physiology ◽  
Large Prey ◽  
Wide Range ◽  
Ambush Predators ◽  
Full Body

SUMMARYChameleons capture prey items using a ballistic tongue projection mechanism that is unique among lizards. During prey capture, the tongue can be projected up to two full body lengths and may extend up to 600 % of its resting length. Being ambush predators, chameleons eat infrequently and take relatively large prey. The extreme tongue elongation (sixfold) and the need to be able to retract fairly heavy prey at any given distance from the mouth are likely to place constraints on the tongue retractor muscles. The data examined here show that in vivo retractor force production is almost constant for a wide range of projection distances. An examination of muscle physiology and of the ultrastructure of the tongue retractor muscle shows that this is the result (i) of active hyoid retraction, (ii) of large muscle filament overlap at maximal tongue extension and (iii) of the supercontractile properties of the tongue retractor muscles. We suggest that the chameleon tongue retractor muscles may have evolved supercontractile properties to enable a substantial force to be produced over a wide range of tongue projection distances. This enables chameleons successfully to retract even large prey from a variety of distances in their complex three-dimensional habitat.

scholarly journals The diet of the brown hyaena hyaena brunnea in the Southern Kalahari

Koedoe ◽  
1978 ◽  
Vol 21 (1) ◽  
Author(s):  
M.G.L. Mills ◽  
M.E.J. Mills
Keyword(s):  
Arid Region ◽  
Small Animal ◽  
Information Analysis ◽  
Food Items ◽  
Faecal Analysis ◽  
Wild Fruits ◽  
Direct Observations ◽  
Harsh Conditions

Four methods for studying the diet of the brown hyaena are discussed. A combination of direct observations (of individuals Fitted with radio collars and beta lights) and faecal analysis yielded the best information. Analysis of food items found at dens was also useful, but tracking spoor had severe limitations. The brown hyaena in the southern Kalahari is predominantly a scavenger of all kinds of vertebrate remains, supplementing its diet with insects, wild fruits, birds' eggs and the occasional small animal which it kills. It is thus well adapted to the harsh conditions of this arid region where large ungulates are thinly distributed.

scholarly journals Proteotranscriptomic Insights into the Venom Composition of the Wolf Spider Lycosa tarantula

Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 501
Author(s):  
Dominique Koua ◽  
Rosanna Mary ◽  
Anicet Ebou ◽  
Celia Barrachina ◽  
Khadija El Koulali ◽  
...  
Keyword(s):  
Prey Capture ◽  
Wolf Spider ◽  
Secretory Proteins ◽  
Crude Venom ◽  
Wolf Spiders ◽  
Original Source ◽  
Venom Composition ◽  
Venom Glands ◽  
Ambush Predators ◽  
Venom Proteins

Spider venoms represent an original source of novel compounds with therapeutic and agrochemical potential. Whereas most of the research efforts have focused on large mygalomorph spiders, araneomorph spiders are equally promising but require more sensitive and sophisticated approaches given their limited size and reduced venom yield. Belonging to the latter group, the genus Lycosa (“wolf spiders”) contains many species widely distributed throughout the world. These spiders are ambush predators that do not build webs but instead rely strongly on their venom for prey capture. Lycosa tarantula is one of the largest species of wolf spider, but its venom composition is unknown. Using a combination of RNA sequencing of the venom glands and venom proteomics, we provide the first overview of the peptides and proteins produced by this iconic Mediterranean spider. Beside the typical small disulfide rich neurotoxins, several families of proteins were also identified, including cysteine-rich secretory proteins (CRISP) and Hyaluronidases. Proteomic analysis of the electrically stimulated venom validated 30 of these transcriptomic sequences, including nine putative neurotoxins and eight venom proteins. Interestingly, LC-MS venom profiles of manual versus electric stimulation, as well as female versus male, showed some marked differences in mass distribution. Finally, we also present some preliminary data on the biological activity of L. tarantula crude venom.

scholarly journals Parallel channels for motion feature extraction in the pretectum and tectum of larval zebrafish

2019 ◽  
Author(s):  
Kun Wang ◽  
Julian Hinz ◽  
Yue Zhang ◽  
Tod R. Thiele ◽  
Aristides B Arrenberg
Keyword(s):  
Feature Extraction ◽  
Visual Field ◽  
Prey Capture ◽  
Receptive Fields ◽  
Lower Visual Field ◽  
Motion Feature ◽  
Hunting Behaviour ◽  
Sensorimotor Transformations ◽  
Visual Areas ◽  
Tectal Neurons

AbstractNon-cortical visual areas in vertebrate brains extract different stimulus features, such as motion, object size and location, to support behavioural tasks. The optic tectum and pretectum, two primary visual areas, are thought to fulfil complementary biological functions in zebrafish to support prey capture and optomotor stabilisation behaviour. However, the adaptations of these brain areas to behaviourally relevant stimulus statistics are unknown. Here, we used calcium imaging to characterize the receptive fields of 1,926 motion-sensitive neurons in diencephalon and midbrain. We show that many caudal pretectal neurons have large receptive fields (RFs), whereas RFs of tectal neurons are smaller and mostly size-selective. RF centres of large-size RF neurons in the pretectum are predominantly located in the lower visual field, while tectal neurons sample the upper-nasal visual field more densely. This tectal visual field sampling matches the expected prey item locations, suggesting that the tectal magnification of the upper-nasal visual field might be an adaptation to hunting behaviour. Finally, we probed optomotor responsiveness and found that even relatively small stimuli drive optomotor swimming, if presented in the lower-temporal visual field, suggesting that the pretectum preferably samples information from this region on the ground to inform optomotor behaviour. Our characterization of the parallel processing channels for non-cortical motion feature extraction provides a basis for further investigation into the sensorimotor transformations of the zebrafish brain and its adaptations to habitat and lifestyle.

Feeding Behaviour and Food Availability of the Yellow-Bellied Glider in North Queensland.

1996 ◽  
Vol 23 (6) ◽  
pp. 637 ◽  
Author(s):  
D Quin ◽  
R Goldingay ◽  
S Churchill ◽  
D Engel
Keyword(s):  
Keystone Species ◽  
Faecal Analysis ◽  
Direct Observations ◽  
Open Forest ◽  
Four Seasons ◽  
Large Numbers ◽  
Pollen Types ◽  
Sap Feeding ◽  
A Site ◽  
Feeding Observations

The diet of the yellow-bellied glider (Petaurus australis) was examined at a site in north Queensland by extensive observation of individuals from 10 glider groups. The diet was assessed in four seasons over 12 months by collating large numbers of qualitative feeding observations and by analysis of faeces. Data were also collected on flowering and bark shedding in the forest. Sap feeding accounted for more than 80% of the feeding observations throughout the year. Nectar and pollen of eucalypts (Eucalyptus spp.) and banksias (Banksia spp.) accounted for much of the remainder of the diet although arthropods and honeydew were present in spring and summer. Faecal analysis was based on much smaller sample sizes but confirmed the qualitative result obtained from direct observations. It also revealed the presence of a wide variety of pollen types. Many of these could be attributed to incidental ingestion but at least six rain forest genera were moderately common in faeces, which is consistent with observations of brief and infrequent visits by gliders to these trees. Examination of eucalypt, banksia and other pollen types showed that 60-70% of pollen was devoid of cell contents, supporting earlier suggestions that gliders obtained protein from pollen digestion, but at this site also from harvesting arthropods. This study confirms the dependence of the yellow-bellied glider in north Queensland on the sap of the red stringybark (Eucalyptus resinifera) and that conservation of the yellow-bellied glider is intimately associated with the management of this tree species. The use of various species for nectar and pollen suggests that the yellow-bellied glider may be an important pollinator in these forests. Moreover, sap from the wounds created by gliders is used by a range of other animal species. These observations suggest that the yellow-bellied glider is likely to be a keystone species in the open-forest ecosystems of north Queensland and that it deserves special emphasis in management.

scholarly journals Colour and motion affect a dune wasp’s ability to detect its cryptic spider predators

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dulce Rodríguez-Morales ◽  
Horacio Tapia-McClung ◽  
Luis E. Robledo-Ospina ◽  
Dinesh Rao
Keyword(s):  
Prey Capture ◽  
Threat Assessment ◽  
Abiotic Conditions ◽  
Need To Evaluate ◽  
Close Range ◽  
Modelling Techniques ◽  
Detection Capabilities ◽  
Body Colouration ◽  
Crab Spiders ◽  
Ambush Predators

AbstractAmbush predators depend on cryptic body colouration, stillness and a suitable hunting location to optimise the probability of prey capture. Detection of cryptic predators, such as crab spiders, by flower seeking wasps may also be hindered by wind induced movement of the flowers themselves. In a beach dune habitat, Microbembex nigrifrons wasps approaching flowerheads of the Palafoxia lindenii plant need to evaluate the flowers to avoid spider attack. Wasps may detect spiders through colour and movement cues. We tracked the flight trajectories of dune wasps as they approached occupied and unoccupied flowers under two movement conditions; when the flowers were still or moving. We simulated the appearance of the spider and the flower using psychophysical visual modelling techniques and related it to the decisions made by the wasp to land or avoid the flower. Wasps could discriminate spiders only at a very close range, and this was reflected in the shape of their trajectories. Wasps were more prone to making errors in threat assessment when the flowers are moving. Our results suggest that dune wasp predation risk is augmented by abiotic conditions such as wind and compromises their early detection capabilities.

scholarly journals Past thermal conditions affect hunting behaviour in larval antlions

2021 ◽  
Vol 8 (6) ◽  
pp. 210163
Author(s):  
Krzysztof Miler ◽  
Marcin Czarnoleski
Keyword(s):  
Elevated Temperatures ◽  
Prey Capture ◽  
Thermal Conditions ◽  
Thermal Exposure ◽  
Hunting Behaviour ◽  
Abiotic And Biotic Factors ◽  
Trap Size ◽  
Harsh Conditions ◽  
Antlion Larvae ◽  
Past Conditions

Some sit-and-wait predators, such as antlion larvae, construct traps to capture passing prey. The location of these traps depends on many abiotic and biotic factors, including temperature and the presence of conspecifics, which probably stimulate behaviours that minimize the costs and maximize the benefits of trap building. Here, we exposed second instar antlion larvae to elevated temperatures of 25°C (mild treatment) or 31°C (harsh treatment) for one month and then transferred them to common conditions (20°C) to examine the effects of previous thermal treatment on aggregation tendency and trap size. We predicted that antlions that experienced harsh conditions would subsequently increase the neighbouring distance and trap diameter to reduce competition with conspecifics and improve prey capture success, compensating for past conditions. In contrast with these predictions, antlions exposed to harsh conditions displayed a trend in the opposite direction, towards the decreased neighbouring distance. Furthermore, some of these antlions also built smaller traps. We discuss possible reasons for our results. The effects of previous thermal exposure have rarely been considered in terms of trap construction in antlions. Described effects may possibly apply to other sit-and-wait predators and are significant considering that many of these predators are long-lived.

scholarly journals Research Recruitment: A Case Study on Women with Substance Use Disorder

2021 ◽  
Author(s):  
Kristy Cook ◽  
Kim Larson
Keyword(s):  
Substance Use ◽  
Substance Use Disorder ◽  
Research Participation ◽  
Macro Level ◽  
Drug Rehabilitation ◽  
Limited Information ◽  
Women's Voices ◽  
Research Recruitment ◽  
Direct Observations

Women with substance use disorder may evade research participation because of individual and societal factors. Limited information exists on recruitment of women with substance use disorder. The purpose of this study was to delineate recruitment challenges among women with substance use disorder and identify successful recruitment strategies. An exploratory case study was used to examine recruitment of women with substance use disorder. This case study was informed by a pilot study in 2017-2018, where data were generated from 25 direct observations and three key informants from a drug rehabilitation treatment agency. Analysis took an explanation-building approach, which incorporated chronological field notes from direct observations, memos from key informant conversations, and the extant literature to revise our initial proposition. Macro-level contextual factors influencing recruitment were: (a) establishment of a triage system, (b) reactivation of agency ethics committee, (c) scheduled accreditation site visits, (d) varied guidelines, and (e) required treatment regimen. Recruitment may benefit from multiple sites, staff training in protocol, increased researcher presence, and the opportunity for women’s voices to be heard. This study advances knowledge of macro-level challenges faced during recruitment of women with substance use disorder in southeast USA. Indirect and direct recruitment, when combined, could maximize participation.

Diet Choise and Food Availability in the Omnivorous Lizard, Trachydosaurus rugosus

1991 ◽  
Vol 18 (2) ◽  
pp. 147 ◽  
Author(s):  
G Dubas ◽  
CM Bull
Keyword(s):  
Content Analysis ◽  
Stomach Content ◽  
Food Choice ◽  
South Australia ◽  
Land Snail ◽  
Stomach Content Analysis ◽  
Home Range Size ◽  
Food Plants ◽  
Home Ranges ◽  
Direct Observations

The diet of sleepy lizards, Trachydosaurus rugosus, from a population near Tickera, South Australia, was determined by direct observations, stomach content analysis and food choice trials. They were found to be opportunistic feeders with a diverse diet of mainly flowers and berries, selected from 27 of the 85 plant species identified on two study plots. They were also found to feed on invertebrates, mainly the introduced land snail, Thebapisana. Availability of different food types changed with season, and the lizard diet adjusted to the changes. The spring home ranges of lizards contained a higher proportion than random, of sampling squares in which common spring food plants were recorded. However, the abundance of food plants makes it unlikely that food resources influence home range size.

Sign in / Sign up

Export Citation Format

Share Document