Sharing for science: high-resolution trophic interactions revealed rapidly by social media

Discrete, ephemeral natural phenomena with low spatial or temporal predictability are incredibly challenging to study systematically. In ecology, species interactions, which constitute the functional backbone of ecological communities, can be notoriously difficult to characterise especially when taxa are inconspicuous and the interactions of interest (e.g., trophic events) occur infrequently, rapidly, or variably in space and time. Overcoming such issues has historically required significant time and resource investment to collect sufficient data, precluding the answering of many ecological and evolutionary questions. Here, we show the utility of social media for rapidly collecting observations of ephemeral ecological phenomena with low spatial and temporal predictability by using a Facebook group dedicated to collecting predation events involving reptiles and amphibians in sub-Saharan Africa. We collected over 1900 independent feeding observations using Facebook from 2015 to 2019 involving 83 families of predators and 129 families of prey. Feeding events by snakes were particularly well-represented with close to 1,100 feeding observations recorded. Relative to an extensive literature review spanning 226 sources and 138 years, we found that social media has provided snake dietary records faster than ever before in history with prey being identified to a finer taxonomic resolution and showing only modest concordance with the literature due to the number of novel interactions that were detected. Finally, we demonstrate that social media can outperform other citizen science image-based approaches (iNaturalist and Google Images) highlighting the versatility of social media and its ability to function as a citizen science platform.

New species, occurrence records and observations of predation by deep-sea Asteroidea (Echinodermata) from the North Atlantic by NOAA ship Okeanos Explorer

Exploratory cruises by the NOAA Ship Okeanos Explorer have resulted in a substantial contribution in our understanding of deep-sea echinoderm biodiversity, biology, and ecology in the North Atlantic. This includes the description and in situ feeding observations of two, new corallivorous goniasterid species, Evoplosoma nizinskiae n. sp. and Sibogaster bathyheuretor n. sp. Significant in situ observations include a synchronous feeding event including multiple goniasterid asteroids and a cidaroid urchin on a large demosponge, providing new data for understanding echinoderm feeding behavior, including agonistic behavior, in deep-sea settings and new, in situ feeding observations for 28 deep-sea species including the myxasterid Pythonaster atlantidis, the korethrasterid Remaster palmatus and the poorly understood hippasterine goniasterids, Gilbertaster caribaea and Sthenaster emmae.

Breeding prerequisites for Ortolan Bunting Emberiza hortulana in Swedish farmland with special focus on foraging

Ortolan Buntings Emberiza hortulana are rapidly decreasing in Sweden. Changes in agricultural practices are the main reason. Landscape simplification due to the removal of semi-natural elements leads to a lack of breeding habitats. Furthermore, due to intensive artificial fertiliser applications and advanced agricultural equipment and technology, crops grow both taller and denser than 50 years ago. In Kvismaren, south central Sweden, Ortolan Buntings have been studied since 2009. Here, we focus on one question: what defines a good foraging microhabitat? In 2017, nesting areas for five females and four males were identified and we did 271 feeding observations. Average foraging distance at different nests varied between 47 and 114 meters. About 70% of the foraging activities took place within crop fields. Ortolans utilized mainly unsown rows, later to be used by tractors for spraying etc. and patchy parts of standing crops. Invertebrates extracted from those areas looked dark, suggestive of ground-dwelling species. Our key management recommendation to create better microhabitats for feeding can be easily achieved by most farmers: to leave two unsown sowing rows (amounting to 0.38 m in width) for each tractor wheel to follow.

The bitter end: primate avoidance of caterpillar-infested trees in a central Amazon flooded forest

Animal–plant interactions are often mediated by chemical compounds. It has been widely reported that herbivore damage to plants induces chemical defenses which may then affect subsequent interactions with both invertebrate and vertebrate herbivores. Our study investigated the effects of the interaction between larvae of an unidentified nymphalid butterfly and the tanimbuca tree (Buchenavia ochroprumna Eichl.; Combretaceae) on subsequent folivory by a primate, the golden-backed uacari (Cacajao ouakary (Spix, 1823); Pitheciidae). Primate-feeding observations, records of the extent of nymphalid – B. ochroprumna interactions, and tree distribution occurred in Jaú National Park, Amazonas State, Brazil. The values of Ivlev’s electivity index showed that C. ouakary strongly rejected trees infested by caterpillars (−0.68), whereas non-infested trees were highly selected by them (+0.84). Given this behavior, we suggest that C. ouakary may be deterred by (i) caterpillars, (ii) change in leaf chemical composition induced by caterpillars, or (iii) a combination of both.

Deep pelagic food web structure as revealed by in situ feeding observations

Food web linkages, or the feeding relationships between species inhabiting a shared ecosystem, are an ecological lens through which ecosystem structure and function can be assessed, and thus are fundamental to informing sustainable resource management. Empirical feeding datasets have traditionally been painstakingly generated from stomach content analysis, direct observations and from biochemical trophic markers (stable isotopes, fatty acids, molecular tools). Each approach carries inherent biases and limitations, as well as advantages. Here, using 27 years (1991–2016) of in situ feeding observations collected by remotely operated vehicles (ROVs), we quantitatively characterize the deep pelagic food web of central California within the California Current, complementing existing studies of diet and trophic interactions with a unique perspective. Seven hundred and forty-three independent feeding events were observed with ROVs from near-surface waters down to depths approaching 4000 m, involving an assemblage of 84 different predators and 82 different prey types, for a total of 242 unique feeding relationships. The greatest diversity of prey was consumed by narcomedusae, followed by physonect siphonophores, ctenophores and cephalopods. We highlight key interactions within the poorly understood ‘jelly web’, showing the importance of medusae, ctenophores and siphonophores as key predators, whose ecological significance is comparable to large fish and squid species within the central California deep pelagic food web. Gelatinous predators are often thought to comprise relatively inefficient trophic pathways within marine communities, but we build upon previous findings to document their substantial and integral roles in deep pelagic food webs.

Observations on the behavior of Caenolestes fuliginosus (Tomes, 1863) (Marsupialia, Paucituberculata, Caenolestidae) in captivity

We describe the behavior in captivity of the dusky shrew-opossum Caenolestes fuliginosus from 17 specimens captured at Finca La Martinica (Colombia), which were kept alive in plastic terraria for different periods of time (between 1 and 12 consecutive days). We found that C. fuliginosus can climb and jump well and uses its nonprehensile tail as a support when climbing. Feeding observations showed a preference towards an animalivorous diet, which included moths/butterflies (Insecta, Lepidoptera), stick-insects (Insecta, Phasmatoidea), flatworms (Platyhelminthes, Turbellaria), earthworms (Annelida, Oligochaeta), frogs (Amphibia, e.g., Pristimantis sp.), and dead rodents (Rodentia, Sigmodontinae, e.g., Microryzomys sp., Thomasomys sp.). Individuals were active throughout the day and night, with no indication of daily torpor. Our observations showed C. fuliginosus is not aggressive towards congeners and often aggregates during rest, especially when several individuals are placed together. Unlike other New World marsupials, C. fuliginosus showed nonagonistic group feeding behavior when consuming carcasses. Stereotyped behavior patterns (e.g., grooming) were not frequently observed. Our work provides comparative information for further studies on caenolestids and other New World marsupials. En este trabajo describimos el comportamiento en cautiverio del ratón Runcho, Caenolestes fuliginosus, a partir de la observación directa de 17 individuos capturados en Finca La Martinica (Colombia), que fueron mantenidos en terrarios plásticos por diferentes períodos de tiempo (entre 1 y 12 días consecutivos). Observamos que C. fuliginosus puede trepar y saltar bien, usando su cola no prensil como soporte al trepar. Los individuos mostraron preferencias alimenticias hacia una dieta animalívora que incluyó: polillas/mariposas (Insecta, Lepidoptera), insectos palo (Insecta, Phasmatoidea), gusanos planos de vida libre (Platyhelminthes, Turbellaria), lombrices (Annelida, Oligochaeta), ranas/sapos (Amphibia, e.g., Pristimantis sp.) y roedores muertos (Rodentia, Sigmodontinae, e.g., Microryzomys sp., Thomasomys sp.). Observamos actividad durante todo el día y la noche, sin preferencias, y no observamos torpor en ningún individuo. Los individuos no mostraron comportamiento agresivo hacia sus congéneres y, con frecuencia, se juntaron para descansar unos sobre otros. A diferencia de otros marsupiales del nuevo mundo, C. fuliginosus no mostró comportamiento agonístico cuando se alimenta de cadáveres. Patrones estereotipados de comportamiento (e.g., limpieza) no fueron frecuentemente observados. Nuestro trabajo aporta información comparativa para futuros estudios sobre el comportamiento de otros cenoléstidos y marsupiales del nuevo mundo.

The diet of brown hyaenas (Hyaena brunnea) in Shamwari Game Reserve, Eastern Cape, South Africa

Brown hyaenas (Hyaena brunnea) were introduced to Shamwari Game Reserve in the Eastern Cape Province during 2002, but their feeding ecology is poorly understood. Feeding observations of brown hyaena by field guides and the collection of 31 scats from the study area took place over an 11 month period. Standard techniques were used to analyse the scats and identify prey items present. Ten dietary categories were identified from the scats, with a mean of 3.2 dietary categories per scat. Large mammal remains were found in 30 of the 31 scats, with kudu being the most abundant (61.0% of scats). Overall the two methods indicated at least 14 mammal species being fed on by the brown hyaena. The presence of mainly large mammal remains and invertebrates (in 38.7% of all scats), together with the feeding observations of mainly large mammals by field guides, suggests that brown hyaena in Shamwari are mainly scavengers and that sufficient carrion is available, thereby reducing the need for them to hunt. A 52.0% occurrence of plant matter was found in the scats, suggesting that plant material is an important component of their diet. Further studies are underway to investigate the feeding ecology of brown hyaena in Shamwari and surrounding areas.Conservation implications: Comprehensive scat analysis over a number of years, monitoring of individual movement patterns and population numbers of brown hyaena in and around conservation areas will be beneficial in quantifying resource use of this species.