The occurrence of Corvomeyenia carolinensis (Harrison, 1971) (Porifera: Spongillidae) in Connecticut

Examination of spicules from a living sponge confirmed thepresenceof Corvomeyenia carolinensis in Mohawk Pond, LitchfieldCounty, Connecticut. Until recently this species had only beenreported from one locality in South Carolina. Based uponspiculeobservations in dated sediment samples this species appears tohaveexisted within Mohawk Pond throughout the past 100+years.     

Subspecific selectivity by a mammalian herbivore: Geographic differentiation of interactions between two taxa of Sciurus aberti and Pinus ponderosa

We compared host selection by two subspecies of Abert's squirrel, a highly specialized and selective herbivore. Both subspecies are restricted to stands of ponderosa pine, upon which they are ecologically dependent, but the two subspecies are geographically disjunct and each is closely associated with stands of trees that represent strongly differentiated chemical races. The criteria by which trees were selected as sources of phloem by each subspecies of squirrel included heritable features of xylem oleoresin and phloem. Trees that were potentially available to the subspecies of squirrel in Colorado differed substantially in biochemical features from trees that were available to the subspecies in Arizona; as a result, chemically mediated feeding patterns were distinct between the two squirrel subspecies. Based on multivariate analysis of chemical characteristics, trees utilized by the squirrels for feeding (target trees) differed significantly from control trees (non-target tre es) for each subspecies. However, the discriminant functions that separated target trees from non-target trees within a site generated different patterns of predicted classification when applied to trees at the other site. Vertebrate herbivores that are feeding specialists can exert selection pressures in populations of their host plants, and results suggest that geographically differentiated herbivore–host interactions can produce different sets of selection pressures, which may result in different evolutionary outcomes. Such geographic differentiation is a potentially important evolutionary aspect of chemically mediated mammal–plant interactions.     

Predators of Spotted Flycatcher Muscicapa striata nests in southern England as determined by digital nest-cameras

Capsule Avian predators are principally responsible.

Aims To document the fate of Spotted Flycatcher nests and to identify the species responsible for nest predation.

Methods During 2005–06, purpose-built, remote, digital nest-cameras were deployed at 65 out of 141 Spotted Flycatcher nests monitored in two study areas, one in south Devon and the second on the border of Bedfordshire and Cambridgeshire.

Results Of the 141 nests monitored, 90 were successful (non-camera nests, 49 out of 76 successful, camera nests, 41 out of 65). Fate was determined for 63 of the 65 nests monitored by camera, with 20 predation events documented, all of which occurred during daylight hours. Avian predators carried out 17 of the 20 predations, with the principal nest predator identified as Eurasian Jay Garrulus glandarius. The only mammal recorded predating nests was the Domestic Cat Felis catus, the study therefore providing no evidence that Grey Squirrels Sciurus carolinensis are an important predator of Spotted Flycatcher nests. There was no evidence of differences in nest survival rates at nests with and without cameras. Nest remains following predation events gave little clue as to the identity of the predator species responsible.

Conclusions Nest-cameras can be useful tools in the identification of nest predators, and may be deployed with no subsequent effect on nest survival. The majority of predation of Spotted Flycatcher nests in this study was by avian predators, principally the Jay. There was little evidence of predation by mammalian predators. Identification of specific nest predators enhances studies of breeding productivity and predation risk.     

Along Came a Spider: Using Live Arthropods in a Predator–Prey Activity

We developed a predator–prey activity with eighth-grade students in which they used wolf spiders (Lycosa carolinensis), house crickets (Acheta domestica), and abiotic factors to address how (1) adaptations in predators and prey shape their interaction and (2) abiotic factors modify the interaction between predators and prey. We tested student understanding with pre- and postquizzes, written observations, and interpretations of graphical results.     

Importance of scale in nest-site selection by Arizona gray squirrels

Nests provide a place for individuals to rest, raise young, avoid predators, and escape inclement weather; consequently, knowledge of habitat characteristics important to nest placement is critical for managing species of conservation concern. Arizona gray squirrels (Sciurus arizonensis) are endemic to mountains of southwestern United States and northwestern Mexico. We investigated factors influencing nest-site selection at 4 spatial scales (forest-type, nest-site, nest-tree, and within-canopy placement) to provide ecological information and management recommendations for this sensitive species. Nest densities were 2.6 times higher in riparian than pine-oak woodlands. Nest sites had more large trees, snags, logs, and canopy cover and had lower slope. Arizona gray squirrels selected tall trees with more interlocking trees and tended to place nests adjacent to the main trunk. Regardless of scale, Arizona gray squirrels seemed to select nesting areas for their ability to provide protection from predators and the elements as well as access to food. Consequently, maintaining large trees with closed canopies and downed logs should be considered when determining land management plans. © 2011 The Wildlife Society.     

Coevolution between crossbills and black pine: the importance of competitors,forest area and resource stability

Studies of predator‐prey interactions have found that geographically structured coevolution has played an important role in the adaptive diversification of crossbills (Loxia spp.). We extend those studies by considering common crossbills (L. curvirostra) in the Mediterranean where they rely on seeds in the cones of black pine (Pinus nigra). On the continent, where tree squirrels (Sciurus vulgaris) are present, enhanced defenses against crossbills were most evident in larger areas of pine forest. On islands in the absence of tree squirrels, crossbills and black pine have coevolved in a predator‐prey arms race on Cyprus but not Corsica. In contrast to other conifers that island endemic crossbills rely upon, black pine does not hold seeds in its cones year round. Consequently, key to the strong crossbill–pine interaction on Cyprus is likely the presence of an alternative conifer that provides seeds during early summer when black pine seeds are scarce.     

Species’ surrogacy for conservation planning: caveats from comparing the response of three arboreal rodents to habitat loss and fragmentation

The use of surrogate species in conservation planning has been applied with disappointing results on relatively large sets of species. It could still prove useful for optimizing conservation efforts when considering a small set of species with similar ecological requirements, however few field tests of this nature have been carried out. The aim of this research is to compare the response of three arboreal rodent species—the fat dormouse (Glis glis), the hazel dormouse (Muscardinus avellanarius) and the red squirrel (Sciurus vulgaris)—to habitat loss and fragmentation, with the aim of identifying priorities for conservation and evaluating possible optimization of conservation efforts under different scenarios: habitat restoration and selection of focal patches. We studied the distribution of the three species in a sample of patches in a highly fragmented landscape in central Italy, using a patch-landscape scale approach. The distribution was studied by using hair tubes, nestboxes and nocturnal surveys. The three species showed analogous responses to increasing isolation and decreasing size of habitat patches; what differed however, was the magnitude of responses. Our results show possible application of surrogacy within this restricted group of species, however several caveats arise depending on the conservation strategy and available funding. If habitat restoration is the objective, then the fat dormouse should be the target species for guiding size and isolation of patches. On the other hand, the magnitude of the differences and patch requirements for this species, question the feasibility of these conservation actions. If selection of focal patches for conservation is the objective then selecting the fat dormouse as a focal/umbrella species would overlook areas suitable for the other two species. Feasible optimisation of conservation efforts may be possible only between the red squirrel and the hazel dormouse.