Translocation experiments showed that a woodcreeper bird species is able to move between isolated forest fragments, but this ability is limited by increasing interpatch distances. Larger distances (> 100 m) were overcome by using small stepping‐stones (isolated trees), which enhance connectivity and are useful for the species conservation in fragmented landscapes.

One of the main consequences of habitat loss and fragmentation is the increase in patch isolation and the consequent decrease in landscape connectivity. In this context, species persistence depends on their responses to this new landscape configuration, particularly on their capacity to move through the interhabitat matrix. Here, we aimed first to determine gap-crossing probabilities related to different gap widths for two forest birds (Thamnophilus caerulescens, Thamnophilidae; and Basileuterus culicivorus, Parulidae) from the Brazilian Atlantic rainforest. These values were defined with a playback technique and then used in analyses based on graph theory to determine functional connections among forest patches. Both species were capable of crossing forest gaps between patches, and these movements were related to gap width. The probability of crossing 40 m gaps was 50% for both species. This probability falls to 10% when the gaps are 60 m (for B. culicivorus) or 80 m (for T. caerulescens). Actually, birds responded to stimulation about two times more distant inside forest trials (control) than in gap-crossing trials. Models that included gap-crossing capacity improved the explanatory power of species abundance variation in comparison to strictly structural models based merely on patch area and distance measurements. These results highlighted that even very simple functional connectivity measurements related to gap-crossing capacity can improve the understanding of the effect of habitat fragmentation on bird occurrence and abundance.

No abstract

2017-08-25T16:28:22

The need for basic information on tropical crop pollinators remains a key priority. Here, we used a dataset on Brazilian bee-crop interactions to determine important bee species for crop pollination and discuss their management in Brazilian croplands. We developed an analytical approach to select key bee species and genera from datasets based on different criteria, selecting only interactions reported as effective pollination events. Data on pollination included 261 records of unique crop-pollinator interaction, 144 bee species, and 23 crops. Despite the importance of social species, solitary bees accounted for 56% of the observed interactions. Of the 14 most important species, eight are solitary and six are social. A few of the selected species are already reared in Brazil, e.g., honeybees and some stingless bees, but practical knowledge on their management for crop pollination is poorly disseminated among farmers, hindering such an application.