Native seed dispersal by rodents is negatively influenced by an invasive shrub

Refuge–mediated apparent competition is the mechanism by which invasive plants increase pressure on native plants by providing refuge for generalist consumers. In the UK, the invasive Rhododendron ponticum does not provide food for generalist seed consumers like rodents, but evergreen canopy provides refuge from rodent predators, and predation and pilferage risk are key factors affecting rodent foraging and caching behaviour. Here we used a seed removal/ seed fate experiment to understand how invasion by an evergreen shrub can alter seed dispersal, seed fate and early recruitment of native trees. We used seeds of four species, small and wind–dispersed (sycamore maple Acer pseudoplatanus and European ash Fraxinus excelsior) and large and animal–dispersed (pedunculate oak Quercus robur and common hazel Corylus avellana), and monitored seed predation and caching in open woodland, edge habitats, and under Rhododendron. In the open woodland, wind–dispersed seeds had a higher probability of being eaten in situ than cached seeds, while the opposite occurred with animal–dispersed seeds. The latter were removed from the open woodland and edge habitats and cached under Rhododendron. This pattern was expected if predation risk was the main factor influencing the decision to eat or to cach a seed. Enhanced dispersal towards Rhododendron cover did not increase the prospects for seed survival, as density of hazel and oak saplings under its cover was close to zero as compared to open woodland, possibly due to increased cache pilferage or low seedling survival under dense shade, or both. Enhanced seed predation of ash and sycamore seeds close to Rhododendron cover also decreased recruitment of these trees. Rhododendron patches biased rodent foraging behaviour towards the negative (net predation) side of the conditional rodent / tree interaction. This effect will potentially impact native woodland regeneration and further facilitate Rhododendron spread due to refuge–mediated apparent competition.

New records of leeches of the genus Limnatis (Hirudinea, Praobdellidae) from the South Caucasus and Central Asia: phylogenetic relationships of Eurasian and African populations

Leeches of the genus Limnatis Moquin–Tandon, 1827 infest mucous membranes of various mammals, including humans and domestic ungulates. The type species of the genus L. nilotica (Savigny, 1822) was initially thought to occur throughout the Western Palaearctic, from North Africa to the Middle East and Central Asia. It was later found that L. paluda (Tennent, 1859) is a widespread Western Asian species. However, the South Caucasus and vast areas of Central Asia have not been explored sufficiently in terms of leeches of the genus Limnatis. We recorded L. paluda from Azerbaijan and Uzbekistan for the first time. We also carried out the first molecular characterisation of L. nilotica herein. We found a deep genetic differentiation (8 %) between the Western Asian L. paluda and North African (Moroccan) L. nilotica based on their COI sequences. This finding corroborates a previous morphology–based hypothesis on their separate species assignments. The low genetic diversity of L. paluda is explained by the recent colonisation of arid landscapes of Western Asia.

Dietary plasticity in an invasive species and implications for management: the case of the monk parakeet in a Mediterranean city

Behavioural flexibility may play a relevant role during invasion of a new habitat. A typical example of behavioural flexibility favouring invasion success refers to changes in foraging behaviour. Here we provide data on changes in the foraging strategies of monk parakeets Myiopsitta monachus over a period of 17 years (2001–2017) in Barcelona city. During this time, consumption of food on the ground increased by more than 25 % and the consumption of anthropogenic food increased by 8 %. Detailed information about the food consumed is provided. Feeding on the ground and consumption of low plants allow parakeets to reach not only anthropogenic food but also crops, thereby increasing the risk of crop damage as the invasion evolves. Early detection of damage to crops is crucial in order to prevent further harm, and makes the precautionary principle highly relevant.

New data on the status and ecology of a galliform at risk of extinction: the Pyrenean grey partridge (Perdix perdix hispaniensis) in the Iberian System (Soria, Spain)

A study was conducted in 2008–2010 to gain knowledge on the status and ecology of the endangered subspecies of grey partridge (Perdix perdix hispaniensis), at its southernmost range edge. From an historic breeding range of 28,300 ha, 15 different coveys (adults with juveniles) were observed in an area comprising 5,550 ha, with an estimated minimum autumn population size of 103–113 birds and a maximum of 163–181 birds. Spring pair density was estimated at 2.3 pairs/1,000 ha, and when considering only coveys, 6.8 partridges/1,000 ha. The majority of birds were located at an altitude above 1,690 m a.s.l., mainly in mountain shrubland (especially Calluna vulgaris and Erica spp.). Habitat loss was the most important threat for the species’ conservation. In conclusion, efforts should prioritize urgent habitat recovery and monitoring in order to change the fate of the species.

Nesting preferences of the green sea turtle (Chelonia mydas L.) and the hawksbill sea turtle (Eretmochelys imbricata L.) in the SW of Mahe Island in the Seychelles

Data concerning 212 turtles emerging on the southwest beaches of Mahe Island in the Seychelles were collected in 2017 and 2018. These data were used to model the probability of eggs being laid in relation to several variables. The probability of successful laying after emergence was highest on certain beaches and in areas of short vegetation, between open sand and trees. We found successful laying was related to the physical properties of the soil, indicating that survivability of embryos and hatchlings is higher in certain areas. The turtles appeared to choose zones where soil had low salinity, good drainage but ability to retain water, and absence of spring tides and extreme temperatures.

New data on the status and ecology of a galliform at risk of extinction: the Pyrenean grey partridge (Perdix perdix hispaniensis) in the Iberian System (Soria, Spain)

A study was conducted in 2008–2010 to gain knowledge on the status and ecology of the endangered subspecies of grey partridge (Perdix perdix hispaniensis), at its southernmost range edge. From an historic breeding range of 28,300 ha, 15 different coveys (adults with juveniles) were observed in an area comprising 5,550 ha, with an estimated minimum autumn population size of 103–113 birds and a maximum of 163–181 birds. Spring pair density was estimated at 2.3 pairs/1,000 ha, and when considering only coveys, 6.8 partridges/1,000 ha. The majority of birds were located at an altitude above 1,690 m a.s.l., mainly in mountain shrubland (especially Calluna vulgaris and Erica spp.). Habitat loss was the most important threat for the species’ conservation. In conclusion, efforts should prioritize urgent habitat recovery and monitoring in order to change the fate of the species.

Small mammal sampling incidents related to wild boar (Sus scrofa) in natural peri–urban areas

The wild boar (Sus scrofa) has recently shown continuous population increases in many countries, leading to a rise in conflicts with human activities, including habituation to people and urban areas. Wild boar can disrupt the sampling of small mammals by reducing the number of potential captures. In this study we analysed whether sampling incidents recorded within a small mammal monitoring programme (SEMICE, www.semice.org) might be related to the density of wild boar in a network of protected parks. Our results suggested a peri–urban effect that was independent of wild boar densities in the protected parks; the number of damaged traps increased (rendering them inoperable for captures) and potentially resulted in underestimates of small mammals due to fewer functioning traps in the study area. We hypothesised that this high rate of damage to traps in a small and localised area in a peri–urban park could be related to wild boar associating human presence with greater opportunities to obtain food items of anthropogenic origin.

Human disturbance modifies the identity and interaction strength of mammals that consume Attalea butyracea fruit in a neotropical forest

Habitat loss and hunting are important drivers of mammal defaunation, affecting not only species presence but also their ecological roles. Frugivory is a key biotic interaction in the tropics due to its wide representation among mammals and its effects on forest dynamics. We assessed how human disturbance affects interactions between mammalian frugivores and Attalea butyracea fruit deposited on the forest floor by comparing visits to palms at two sites with contrasting levels of human disturbance (non–disturbed vs. disturbed sites) in the Lacandon rainforest in southern Mexico. Using camera traps, we recorded mammal species interacting with fruit and estimated their interaction strength. The frugivore ensemble was richer in the non–disturbed forest (nine species) than in the disturbed forest (four species), which lacked the largest body–sized mammals. Large–bodied mammals showed a stronger interaction with fruit in terms of the frequency and length of their visits. Our study highlights the need to undertake conservation actions not only to ensure that the species are maintained in disturbed forests but also to ensure that their biotic interactions remain unchanged.

A comparison of the diet of urban and forest great tits in a Mediterranean habitat

The low breeding performance and body condition of nestling passerine birds in urban environments has been attributed to the poor quality and low abundance of food in these settings. However, detailed data on prey provided by parents to their chicks in the urban habitat is scarce. Here we used video cameras set in nest boxes to compare the diet of urban and forest great tits Parus major when provisioning their chicks in a Mediterranean area. We additionally analysed brood size and fledgling success. Breeding success of urban great tits was lower than that of forest birds. Urban parents displayed a lower average hourly feeding rate per nestling than forest parents. Among the three prey item categories, the percentage of spiders did not vary according to habitat. However, the percentage of caterpillars delivered to the nest by great tit parents was higher in the forest than in the urban habitat while the percentage of ‘other’ prey showed a reverse pattern. ‘Other’ prey were mainly adult butterflies and wasps in the urban habitat. Our paper adds to the view that the low feeding rates and scarcity of caterpillars in urban environments may be the underlying cause constraining the growth of great tit nestlings in these areas.

Description of a new valvatoid genus and species (Gastropoda, Hydrobiidae) from Morocco

Recent field surveys conducted in the northern part of Morocco have led to the discovery of a new species belonging to a new genus Gregoia n. gen. described here. Photos of the holotype and paratype are presented in addition to the penis morphology and the female sex tract, the map of the sampling area with the type localities, and the habitat description.