Diet composition and prey choice of New Zealand falcons nesting in anthropogenic and natural habitats

In a biodiversity conservation exercise a native raptor has been reintroduced to Marlborough, a winegrowing area in New Zealand’s South Island, on the assumption that the abundant passerines attracted to the grapes will provide a natural food resource for this predator. As part of a study to assess the value of vineyards as habitat for the threatened New Zealand falcon (Falco novaeseelandiae) we used remote videography and prey remains to compare the diet composition of falcons nesting in a vineyard-dominated landscape with that of falcons nesting in natural habitat in nearby hills. We also quantified the abundance and species composition of avian prey in the habitats surrounding each falcon nest. Generally there were more birds in the vineyards but the composition of available prey did not differ between vineyards and the nearby hills, nor did the composition of avian species in the breeding-season diet of falcons. Avian prey was the main food source for falcons during the breeding season, representing 97.9% of prey items by frequency and 83.3% of prey items by biomass. Mammals represented only 1.9% of prey items by frequency, but made up 16.7% of prey items by biomass. We also found that falcons preyed on introduced species more than would be expected, and on endemic species less than would be expected, based on their availability in the landscape. The absence of any significant differences in diet between native and vineyard habitats during the breeding season suggests that the latter may be a suitable alternative when natural habitats are unavailable, although further study must be conducted into the role of supplementary feeding on these effects. These findings pave the way for research in other production landscapes that could be used for conservation measures

Ensuring food production: native biodiversity provides pollination and biological control services

Land use intensification drives extinctions of species and alters the ways in which they interact with one another. This loss of biodiversity may result in reduced rates of ecosystem services such as pollination and biological control, with loss of functional group and response diversity having the greatest effects on function. Biodiversity also acts as insurance in changing conditions, so in addition to reduced mean rates of ecosystem services, stability of these services may also decline. Similarly, alterations to the dynamic structure of networks of interactions among species may affect their resilience to other environmental changes. Conservation of natural forests, as well as ‘softer’ agricultural/silvicultural systems can help to conserve regional biodiversity, which can enhance ecosystem functioning in adjacent managed habitats. Conservation of heterogeneous landscapes, including natural forests, will be necessary to maintain ecosystem services in the face of a suite of interacting global environmental changes

Landscape constraints on functional diversity of birds and insects in tropical agroecosystems

10.1890/07-0455.1Ecology894944-951ECOL

Conservation biological control and enemy diversity on a landscape scale

Conservation biological control in agroecosystems requires a landscape management perspective, because most arthropod species experience their habitat at spatial scales beyond the plot level, and there is spillover of natural enemies across the crop–noncrop interface. The species pool in the surrounding landscape and the distance of crop from natural habitat are important for the conservation of enemy diversity and, in particular, the conservation of poorly-dispersing and specialized enemies. Hence, structurally complex landscapes with high habitat connectivity may enhance the probability of pest regulation. In contrast, generalist and highly vagile enemies may even profit from the high primary productivity of crops at a landscape scale and their abundance may partly compensate for losses in enemy diversity. Conservation biological control also needs a multitrophic perspective. For example, entomopathogenic fungi, plant pathogens and endophytes as well as below- and above-ground microorganisms are known to influence pest-enemy interactions in ways that vary across spatiotemporal scales. Enemy distribution in agricultural landscapes is determined by beta diversity among patches. The diversity needed for conservation biological control may occur where patch heterogeneity at larger spatial scales is high. However, enemy communities in managed systems are more similar across space and time than those in natural systems, emphasizing the importance of natural habitat for a spillover of diverse enemies. According to the insurance hypothesis, species richness can buffer against spatiotemporal disturbances, thereby insuring functioning in changing environments. Seemingly redundant enemy species may become important under global change. Complex landscapes characterized by highly connected crop–noncrop mosaics may be best for long-term conservation biological control and sustainable crop production, but experimental evidence for detailed recommendations to design the composition and configuration of agricultural landscapes that maintain a diversity of generalist and specialist natural enemies is still needed

Limiting factors in the restoration of UK grassland beetle assemblages

Grasslands restoration is a key management tool contributing to the long-term maintenance of insect populations, providing functional connectivity and mitigating against extinction debt across landscapes. As knowledge of grassland insect communities is limited, the lag between the initiation of restoration and the ability of these new habitats to contribute to such processes is unclear. Using ten data sets, ranging from 3 to 14 years, we investigate the lag between restoration and the establishment of phytophagous beetleassemblages typical of species rich grasslands. We used traits and ecological characteristics to determine factorslimitingbeetle colonisation, and also considered how food-web structure changed during restoration. For sites where seed addition of host-plants occurred the success in replicating beetleassemblages increased over time following a negative exponential function. Extrapolation beyond the existing data set tentatively suggested that success would plateau after 20 years, representing a c. 60% increase in assemblage similarity to target grasslands. In the absence of seed addition, similarity to the target grasslands showed no increase over time. Where seed addition was used the connectance of plant–herbivore food webs decreased over time, approaching values typical of species rich grasslands after c. 7 years. This trend was, however, dependent on the inclusion of a single site containing data in excess of 6 years of restoration management. Beetles not capable of flight, those showing high degrees of host-plant specialisation and species feeding on nationally rare host plants take between 1 and 3 years longer to colonise. Successful grasslandrestoration is underpinned by the establishment of host-plants, although individual species traits compound the effects of poor host-plant establishment to slow colonisation. The use of pro-active grasslandrestoration to mitigate against future environmental change should account for lag periods in excess of 10 years if the value of these habitats is to be fully realised

Native and alien flower visitors differ in partner fidelity and network integration

<div><div>These data files support the following publication</div><div><br></div><div>Trøjelsgaard, K., Heleno, R., & Traveset, A. <b>Native and alien flower visitors differ in partner fidelity and network integration</b>. Ecology Letters, <i>accepted. </i>doi: 10.1111/ele.13287</div><div><i><br></i></div><div>For more details see the Read Me file or the original publication.</div></div><div><br></div><div><b><u>Abstract</u></b></div><div>Globalisation persistently fuels the establishment of non-native species outside their natural ranges. While alien plants have been intensively studied little is known about alien flower visitors, and especially, how they integrate into natural communities. Here we focus on mutualistic networks from five Galápagos islands to quantify whether alien and native flower visitors differ consistently in their pairwise interactions. We find that i) alien flower visitors have more interaction partners and larger species strengths (i.e. plants are more connected to alien insects), ii) native insects tend to have higher partner fidelity as they deviate more from random partner utilization, and iii) the difference between native and alien flower visitors in network integration intensifies with island degradation. Thus, native and alien flower visitors are not interchangeable, and alien establishment might have yet unforeseen consequences for the pairwise dynamics between plants and flower visitors on the Galápagos – especially on the heavily disturbed islands. <br></div

Conservation needs to integrate knowledge across scales

International audienc