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Abstract

The effects of host-parasite interactions can be measured in ecologically relevant ways through behavioural indicators based on foraging theory. These include, assessing how parasites alter foraging aptitudes, harvest rates, and risk management of foragers. Consequences of infection can be measured from individuals to ecosystems. At the individual level, sick animals need to trade-off finding food with remaining safe from predators, while potentially facing debilitating effects from infection. This potentially results in reduced foraging efficiencies, compromised risk awareness, and increased apprehension. To investigate this, we assessed how a Mycoplasma bacterial infection impacted individual Allenby’s gerbils’ foraging aptitudes, resource harvest rates, and anti-predator responses. We monitored individuals through three stages, from uninfected, to acutely (newly) and finally chronically (long term) infected. We identified three distinct responses. While acutely infected, some individuals increased their foraging effort in patches and spent less time vigilant. This may reflect increased future value of food for these individuals. Some individuals immediately reduced their foraging effort and displayed increased apprehension while acutely infected. This likely reflects a lethargy, where sick individuals are compromised in their ability to harvest seeds efficiently while also remaining vigilant. As all individuals became progressively sicker with a chronic infection, their foraging declined and apprehension levels increased. Two individuals employed a ‘grab and go’ foraging strategy to minimize time spent in patches. Foraging costs of long-term infection increase dramatically over time. These findings point to some behavioural plasticity in response to initial infection, yet the consequences of long-term infection are similar for all individuals.

Open Access
In: Israel Journal of Ecology and Evolution
In: Worldviews: Global Religions, Culture, and Ecology

Abstract

Pathogens can impose substantial ecological costs on infected individuals, including reduced cognition, foraging ability, and predator avoidance. In a prior experiment, gerbils infected with Mycoplasma haemomuris-like bacteria had higher giving up densities, despite spending more time foraging, and were more likely to be killed by predators. One hypothesis to explain this is that infected gerbils suffer from cognitive impairment that reduces their ability to forage efficiently, causing them to spend more time foraging and placing themselves at higher risk of predation. We tested this hypothesis by comparing the ability of gerbils uninfected, acutely infected, or chronically infected with Mycoplasma to equalize giving up densities (GUDs) in seed patches with different initial abundances and detect micropatches within seed patches in a semi-natural vivarium enclosure. We predicted that uninfected gerbils would equalize GUDs and detect micropatches better than infected gerbils. Contrary to our predictions, infected gerbils performed equally well as uninfected gerbils on both tasks. These experiments did not support the hypothesis that cognitive impairment explains past results regarding Mycoplasma and gerbil foraging.

Open Access
In: Israel Journal of Ecology and Evolution

Abstract

Ciliate interactions including mode of nutrition contribute significantly to freshwater and marine ecosystems. Ciliates associations with their bacterial communities, and symbionts have crucial contributions to biomass productivity, transfer of nutrients to higher trophic levels and thus to sustain the ecosystems. The mixotrophic and heterotrophic ciliates are crucial in nutrient cycling by increasing nitrogen, phosphorus, and sulphur. Bacterial predator ciliates regulate the bacterial population and function as bioindicators. Endosymbionts in ciliates illustrate the incorporation of photosynthesis, nitrogen fixation and recycling, and methanogenesis, into ciliate hosts by endosymbionts. Endosymbiosis represents an evolutionary strategy of protists to acquire novel biochemical functions. Herein, I briefly give an account for the impact of ciliate nutrition on aquatic systems.

In: Israel Journal of Ecology and Evolution

Abstract

The Bonelli’s Eagle exhibits a wide geographic distribution yet remains relatively understudied on the island of Cyprus. Between 1999 and 2002, we examined 32 pairs of Bonelli’s Eagles, totaling 64 breeding attempts. During this period, a total of 116 eggs were laid, with an average clutch size of 2.0 ± 0.1 eggs per pair. Incubation, predominantly performed by the female, lasted an average of 38.7 ± 0.2 days. Of the eggs laid, 71 hatched, resulting in an average hatching rate of 82.6%. Hatchability varied, with the highest rate (91.3%) observed in 1999 and the lowest (76.2%) in 2001. Nestlings spent an average of 61 ± 0.5 days in the nest before fledging. Remarkably, 92.6% of pairs successfully fledged young (n = 60), with a mean breeding success of 1.6 ± 0.1 fledglings per pair. Significant differences were observed in the average number of eggs laid, hatched, and young fledged between the two types of habitats. Nest sites varied in altitude, ranging from 170 to 1,242 meters, with a nearest-neighbor distance between adjacent nests averaging 7.86 ± 0.43 kilometers.

Open Access
In: Israel Journal of Ecology and Evolution
Author:

Abstract

This work aimed to explore a pheromone effect during food handling using food choice field experiments with Messor arenarius ants. The results showed that the proportion of times ants touched the two food items placed in the artificial food patch (collection point) with their antennae was significantly higher in their first collection attempt than in subsequent attempts. However, when the soil was replaced after each collection attempt, there were no significant differences in the proportions of cases in which ants touched the two food items with their antennae between the first and subsequent food collection attempts. This difference may indicate that ants deposited a pheromone in their first food collection attempt that faded away when the soil in the patch was replaced after each collection attempt.

Open Access
In: Israel Journal of Ecology and Evolution

Abstract

Rapana venosa, a well-known and economic species mainly distributed in the Asian region, has three distinct color patterns in the peristome: pure orange, pure dark stripes, and part stripes. The present study combined microsatellite, DNA methylation, and transcriptome to assess the genetic basis of three color patterns of R. venosa in the peristome. The different color patterns of R. venosa showed no significant genetic differentiation, and each color group was relatively independent with respect to gene flow. Each color pattern showed a high methylation rate of more than 60%. The full-methylation rates for the three color patterns were 34.47%, 35.67%, and 32.54%, respectively. The Gene Ontology (GO) classification and functional enrichment revealed three ontologies: molecular function, cellular components, and biological processes. The function of translation, ribosomal structure, and biogenesis accounted for the top classification, followed by general function prediction. This study also revealed some functional genes related to color and shell formation, including Scavenger receptor cysteine-rich protein (SRCR), beta-carotene ketolase, tyrosinase proteins, and Lustrin A. These findings suggest that the color polymorphism of R. venosa is possibly attributed to environmental effects. The research is also essential for selecting better germplasm for the breeding of Rapana venosa.

In: Israel Journal of Ecology and Evolution

Abstract

The river lapwings are inhabitant of river banks with sand or gravel bars and river islands. In this study, we investigated vital threats (natural and anthropogenic) and the conservation status of river lapwing in the riverine ecosystem of Northern India. In this regard, we frequently visited selected study sites along the banks of the river Ganges in the district of Raebareli (Uttar Pradesh), India, from January 2016 to December 2019. To estimate perceived threats for river lapwing, we developed a questionnaire and collected threat scores. The line transect method was used to estimate the density of river lapwing. Predation and farming activities were the most potent threats influencing the survival and abundance of river lapwing. River lapwings were primarily observed at open unvegetated river banks and open unvegetated islands. They were seen in significant density near the water in the breeding season. We concluded that the population of river lapwing is relatively stable in the Gangetic plains of Northern India. However, it is declining in other parts of the world, for example, in Southern Laos. Though it is a relatively common species, robust scientific information about its population and habitat relation is mainly absent. Therefore, accurate counts from other parts of the world are needed to place the estimate for river lapwing into a comprehensible, inclusive perspective. Furthermore, detailed information on habitat relationships is also necessary to develop conservation strategies.

In: Israel Journal of Ecology and Evolution

Abstract

Foraging profitability is one of the significant factors affecting habitat selection in fishes. The food habits of the fish species vary seasonally due to the dynamic nature of their environment. For that, the dietary analysis of a fish is essential in the case of fish diversity research. Most of the variations in prey size consumed by piscivores were correlated to the differences in piscivore body size, which morphological constraints can explain. The present study aimed to investigate the ecomorphological assemblage of small indigenous freshwater fish species from smaller lentic freshwater bodies based on a range of morphological traits and evaluate fish assemblages with respect to the feeding guilds. Freshwater ponds around Birbhum district, West Bengal (India) were selected for the collection of fish species, namely Amblypharyngodon mola, Puntius sophore, Esomus danrica, Lepidocephalichthys guntea, Chanda nama, Parambassis lala, Trichogaster fasciata, Anabas testudineus and Glossogobius giuris. Morphometric and gut content analysis were done, and the trophic guild matrix, taxonomic distance matrix, and morphological matrix were calculated. The result showed a strong association between ecomorphological traits and trophic structure, indicating an independent assemblage pattern beyond the taxonomic influence.

In: Israel Journal of Ecology and Evolution

Abstract

Reflecting upon the distressing situation of human-wildlife conflict (HWC), this study has identified numerous factors that exacerbate the HWC issue in Bangladesh, including a lack of awareness, a prevalent disregard for the law, inadequate punitive measures, institutional weaknesses, socio-economic challenges, a burgeoning population, a refugee crisis, rampant deforestation, encroachment upon natural habitats, migratory challenges faced by wildlife, and the influence of national and global politics. It is evident that these multifaceted elements significantly contribute to the escalation of HWC. The regions of Chittagong-Hill Tracts (CHT), the Sundarbans, and central-northern Bangladesh are facing a pressing HWC issue that demands our immediate attention. Tragically, over the past two decades, more than 118 elephants have lost their lives, while these creatures claimed 13 human lives in 2017–2018. Furthermore, tigers, an emblem of strength and beauty, have been responsible for the demise of approximately 50 individuals between 2009 and 2010. Astonishingly, the year 2022 has already witnessed a count of 375 HWCs. Therefore, this study delves deeper into the root causes of HWC in Bangladesh and proposes effective preventive measures to safeguard the endangered species, specifically the Asian elephants (Elephas maximus) and Bengal tigers (Panthera tigris tigris), who bear the brunt of these conflicts.

In: Israel Journal of Ecology and Evolution