Comparison of foraging tool use in two species of myrmicine ants (Hymenoptera: Formicidae)

Many ant species are known to exhibit foraging tool use, during which ants place various debris items (e.g., pieces of soil, leaves, pine needles, etc.) into liquid food, and then they carry the food-soaked tools back to the nest. In the present study, we compared the tool-using behavior in captive colonies of two closely related myrmicine ants with different feeding preferences: Aphaenogaster subterranea, an omnivorous species, and Messor structor, a mainly granivorous seed-harvester species. We supplied foraging ants with honey-water baits and six types of objects they could use as tools: sand grains, small soil grains, large soil grains, pine needles, leaves, and sponges. We found that the workers of A. subterranea both dropped more tools into honey-water baits and retrieved more of these tools than the workers of M. structor. While A. subterranea preferred smaller tools over larger ones, tool preferences for M. structor did not differ significantly from random. In addition, tool dropping was significantly faster in A. subterranea, and both the dropping and retrieving of tools began significantly earlier than in M. structor. For Aphaenogaster species that regularly utilize and compete for liquid food sources, the ability to efficiently transport liquid food via tools may be more important than it is for seed-harvester ants. Dropping tools into liquids, however, may still be useful for seed-harvester species as a means to supplement diet with liquid food during periods of seed shortage and also to serve as a means of getting rid of unwanted liquids close to the nest.

First Record of Oleacina cyanozoaria (Gundlach in Pfeiffer, 1857) Feeding on a Eleutherodactylus Frog in Pico San Juan, Cumanayagua, Cienfuegos Province, Cuba

Around twenty species of the landsnail subfamily Oleacininae inhabit Cuba. However, only five species were found in south-central region of the island. Despite the frequency of Oleacina in Cuba, these species have been poorly studied and little is known about their ecology, ethology and carnivorous feeding preferences. This field study is the first record showing Oleacina cyanozoaria to be an active predator on a small Eleutherodactylus frog. Small vertebrates have not been previously noted to be part of these voracious species’ diet.

PSII-15 Investigations of feeding preferences for common palatants in equine weanlings

Work in other species has demonstrated an impact of gestational exposure on flavor preferences. Although equine palatability preferences in mature horses have been identified, feeding behaviors in growing horses are not well documented. The objective of this study was to evaluate the impact of exposure to common palatants in utero on feeding preferences of weanlings. Stock-type weanlings (n = 4) weighing 225(±18.15) kg at 29(±2.55) weeks of age were used in a side-by-side comparison test with a divided feeding platform. Common palatants (apple and anise) were utilized throughout the broodmare gestational period. A novel palatant, peppermint, was withheld during gestation to identify impacts associated with neophobic tendencies. Treatments were offered once daily for three consecutive days across three periods (4 weeks apart) using a pelleted concentrate feed with an application rate of 0.375 mL/0.23 kg. Weanlings were allowed free access to the feeding platform with identical pans spaced 6” apart for 20 minutes. Treatment location within the feeding platform was changed daily to limit effects associated with side-eating. Data were measured as a Chi Square test of SAS using PROC FREQ statement with α ≤. 0.05. Despite gestational exposure to apple and anise, no preference was measured in palatability assessments including First Sniff (P = 0.29), First Consumed (P = 0.70), First Finished (P = 0.29). These data suggest that exposure in utero failed to elicit a preference for common palatants in weanling horses. Additionally, these data fail to demonstrate a neophobic effect for a novel palatant, peppermint.

Jaguar Panthera onca (Linnaeus, 1758) (Mammalia: Carnivora: Felidae) presumably feeding on Flathead Catfish Pylodictis olivaris (Rafinesque, 1818) (Actinopterygii: Siluriformes: Ictaluridae) at Aros and Yaqui rivers, Sonora, Mexico

Despite the abundant literature on the feeding preferences of the Jaguar Panthera onca throughout its range in America, few studies report fish consumed as prey by Jaguars. This paper reports two accounts of Jaguars presumably feeding on the introduced Flathead Catfish Pylodictis olivaris at the Aros and Yaqui rivers in Sonora, northwestern Mexico.

Feeding behavior of the great spotted woodpecker Dendrocopos major in the south of the european part of Russia (Stavropol region)

Кормовое поведение самцов и самок большого пёстрого дятла (БПД) Dendrocopus major исследовано в Ставропольском крае в период 2013-2021 гг. В целом, зарегистрировано 58 посещений дятлами 12 видов кормовых деревьев. Выявлено предпочтение БПД следующих видов деревьев: дуб (22%), граб (20%), ясень (17%). Проведено сравнение кормовых предпочтений самцов и самок БПД в различные сезоны года. В холодный период БПД предпочитали разыскивать корм на стволах и толстых ветвях деревьев, где было больше шансов обнаружить зимующих беспозвоночных. Выявлены различия в кормовых методах, используемых самцами и самками БПД. We studied the feeding behavior of males and females of the Great Spotted Woodpecker (GSW) Dendrocopos major in the Stavropol Region over 2013-2021. In general, 58 woodpeckers’ visits to 12 forage tree species were recorded. The preference of GSW of the tree species was as following: oak (22% of visits), hornbeam (20%), ash (17%). A comparison of the feeding preferences of males and females of GSW in different seasons revealed that in the cold period the GSW preferred to search for food on the trunks and thick branches of trees, where it was more likely to find wintering invertebrates.

Alteration of the feeding behavior of an omnivorous fish, Scardinius acarnanicus (Actinopterygii: Cypriniformes: Cyprinidae), in the presence of fishing lights

Fishing with light is an old and common practice yielding a substantial catch volume globally. Despite the popularity of the method and the efforts to improve it, there is a lack of field studies on the effects of light on the feeding preferences of the attracted fishes. A previous report suggested that purse seine fishing lights can differentiate the feeding preferences of the approaching fishes, such as Atherina boyeri Risso, 1810 in Lake Trichonis (Greece). The presently reported study aims to verify these findings by investigating the diet of the endemic Scardinius acarnanicus Economidis, 1991. The feeding behavior of S. acarnanicus was studied from 2016 to 2019 through gut content analysis, in specimens from Lake Trichonis that came from purse seining with light and specimens caught without light. The same investigation was carried out comparatively in specimens taken by gillnets from two nearby lakes (lakes Ozeros and Amvrakia), where S. acarnanicus is present, but no fishing with light is exercised. The stomach content analysis conducted on 699 S. acarnanicus specimens revealed the intense effect of light on its diet resulting in the alteration of its feeding habits towards fish predation and especially Atherina boyeri. On the contrary, the specimens taken with the use of gillnets, from the three lakes, showed a typical omnivorous feeding behavior. The findings of the presently reported study support the assumption that the elevated concentration of fish close to fishing lights alters the feeding behavior of certain species making them predators. Considering that fishing with light is practiced worldwide, this could be of great ecological significance to the ichthyofauna not only of inland waters but also of marine areas, affecting perhaps several commercial species.