The multicoloured Asian lady beetle Harmonia axyridis (Coleoptera: Coccinellidae) may potentially exploit a range of "alternative" food sources. The nutritional value of three common non-prey food groups, i.e. fruit, fungi and pollen, is examined in this study. Development, reproduction and survival of the species were assessed in the laboratory on diets of apple, pear and raspberries and the fungi Oidium lycopersicum, Botrytis cinerea, Sclerotinia sclerotiorum and Rhizoctonia solani. When fed exclusively on these foods this ladybird failed to complete its development or reproduce. However, larval and adult survival was prolonged by 4 to 8 days and 55 to 67 days, respectively, when fruit was offered compared with only water. During a field study H. axyridis adults were collected monthly from March to October at two locations near Ghent, Belgium. Gut analysis demonstrated that, despite the continued presence of aphids, over 90% of all the adults collected contained pollen throughout the year. The pollen belonged to 53 different pollen types. Monthly average numbers of pollen grains in the gut varied from 5 to 233 grains. In contrast, there were about 35,000 grains in the guts of H. axyridis females that successfully developed and reproduced in the laboratory on diet that consisted of only pollen. This suggests that in the field in the majority of cases pollinivory mainly only provided complementary nutrients for this coccinellid. The use of alternative non-prey foods like pollen and fruit may play a role in sustaining populations of this coccinellid at times when the optimal prey is absent.
There is very little information on the importance of fleshy fruit in the diet of the nestlings and fledglings of partially frugivorous Holarctic passerines. In an area of 0.6 km2 in northwestern Spain, it was verified during 2001–2003 that at least one blackcap Sylvia atricapilla pair and five blackbird Turdus merula pairs fed their offspring on a certain proportion of ivy Hedera helix fruit. Observations made on a blackcap nest in May showed that the parents fed older nestlings on animal prey on 60.7% of occasions and 39.3% on fruit (n = 140 total number of identified feeds). The female fed nestlings on fruit more often than the male. According to observations carried out on five ivy plants in May, blackcaps brought fruit in their bills to feed nestlings or fledglings on 40.3% of 67 feeding visits and blackbirds on at least 22.1% of 86 feeding visits. The blackcaps consistently carried one fruit and the blackbirds between three and five. Both species fed their young on fruit under very different meteorological conditions. Seeds found in the faecal sacs of their nestlings showed high potential germination viability (95.6% undamaged seeds and 4.4% cracked seeds; n = 46 total seeds except for those gnawed by rodents), so the adults probably acted as indirect vectors in dispersing ivy whilst carrying faecal sacs away from the nest.
Endozoochory is a mutualistic interaction between plants and animals. Such a relationship has rarely been examined in the Eurasian otter Lutra lutra. This study aimed to assess the use and electivity of fruit by this carnivore, along with the viability of ingested seeds. Otter spraints and fruit were collected from the River Bullaque (Guadiana River basin, central Spain) in June and September 2018-2019. A high occurrence of fruit (> 40%) was found in spraints during September. Otters ingested fruit in June from only one plant species: Iberian bushweed Flueggea tinctoria (Phyllanthaceae); whereas seeds ingested in September belonged to four plant species: apple mint Mentha suaveolens (Lamiaceae), common hawthorn Crataegus monogyna, dog rose Rosa canina and elmleaf blackberry Rubus ulmifolius (three Rosaceae species). According to the environmental availability, otters displayed avoidance for mint and rose, neutral selection for hawthorn and preference for blackberry. Germination was unsuccessful for mint seeds, whereas germination was the highest for blackberry (37%; 49% for blackbird Turdus merula, a well-known frugivorous species). Otters appear to display an ecological role as seed dispersers for riparian vegetation in Iberian fresh waters. These findings provide insights into this endozoochorous co-evolution between plants and Carnivora.