• Science recently published further evidence of the “broken window” theory, which suggests that people act badly in degraded environments. These studies are about human-dominated environments, but it seems likely that the same is true for more “natural” areas, too.
• Christopher Dunn argues in Nature that cultural diversity ought to be preserved alongside biodiversity. He even suggests that maps of hotspots of the two tend to overlap. Okay, so let’s make a deal: people can stay in and around areas of high biodiversity if they agree to live according to their “traditional” culture — any development or significant growth and you’ve got to move to the city. Fair?
• Yesterday I mentioned some worry about homogenizing landscapes in rural areas. There was a paper published in Conservation Biology by Rahmig et al. recently that suggested exactly that: homogenization of farming practices has led to declines in avian diversity.
• Also in Cons Bio, Ben Collen and colleagues at ZSL take a closer look at the “Living Planet Index,” one of the 22(!) headline indicators established by the Convention on Biological Diversity used to assess trends in biodiversity loss. Their conclusion: it’s good, but we need more data.
• Kindberg et al. have shown that hunter-reported observations of moose in Sweden were (if corrected) a pretty good method of monitoring.

As a spatial ecologist, I tend to think of biodiversity in terms of things you can easily map: if a bird requires old growth forest to breed, I can tell you where to focus preservation efforts. But there’s a rich literature about all the secondary effects of human influence on wildlife. Take roads, for example. While it’s true that roads are not very good habitat for wildlife, in addition to creating sometimes unpenetrable barriers to movement and increased mortality from car strikes, roads can also degrade living conditions for wildlife by modifying their behavior. There’s a review in press at Biological Conservation that discusses ungulate flight response to human disturbance. Depending on a population’s habituation to humans, cars can increase stress hormone levels in individuals, which is not healthy. Anyone who’s been to Yellowstone will recognize, however, that ungulate behavior is incredibly malleable and many species seem happy to habituate to human activity.

A more distressing report has been published in Conservation Letters that suggests even low levels of human activity can have large effects on sensitive carnivores. Merenlender and Reed found that protected and recreational areas of California are associated with five-fold decreases in carnivore numbers. They conducted paired transects in oak woodlands, comparing areas accessible and inaccesible to humans. That simply walking/jogging/bird-watching could have such an impact on the behavior of wildlife is a sobering — if not entirely surprising — finding.

Stankowich, T. Ungulate flight responses to human disturbance: A review and meta-analysis. Biological Conservation, In Press. (doi:10.1016/j.biocon.2008.06.026)

Reed, S. and A. Merenlender. Quiet, Nonconsumptive Recreation Reduces Protected Area Effectiveness. Conservation Letters, In Press. (doi:10.1111/j.1755-263X.2008.00019.x)

Nielsen et al. model long-term persistence of a grizzly bear population in Alberta under different management scenarios. Young grizzlies prefer second-growth forest, so timber harvesting might in fact benefit them. Unfortunately, the roads needed to recover the timber, and the number of bears killed on those roads, more than offset the gains from improving the habitat. Can’t forget about the roads.

Nielsen, S., et al. Can natural disturbance-based forestry rescue a declining population of grizzly bears? Biological Conservation, in press. doi:10.1016/j.biocon.2008.06.020.

Mattila et al. propose that many species at risk of extinction may be linked by similar ecological traits. In their discussion, for example, they cite studies that species with high diet or habitat specificity are at greater risk of extinction (surprise!), and that’s true across taxa. Their study looks at moths in Finland and compares their ecological traits with IUCN red list status (clumped into threatened and non-threatened). Of course, this is really comparing ecological traits with the probability of being listed as threatened/endangered under IUCN standards. I’m curious to know if there is something else that pushes a species over the edge from critically endangered to extinct. That is, some species can be quite successful at low densities; others might be endangered due to habitat loss, but at high densities within the remaining habitat. What are the patterns that actually cause extinction, as opposed to the threat of extinction?

Matilla, N., et al. The use of ecological traits in exctinction risk assessments: A case study on gemetrid moths. Biological Conservation, in press. doi:10.1016/j.biocon.2008.06.024.

This article by Hawes et al. suggests that remnant forest strips in Eucalpytus plantations in the Amazon can serve as potential refuge for tropical forest birds. Their study was a snapshot of bird communities within continuous forest and within forest remnants near and far from the continuous forest, so their results only confirm current conditions. Unlike the paper on novel ecosystems cited below, they found little evidence that many birds typical of the Eucalyptus plantations were using the remnants, with the exception being a pair of hummingbird species.

Hawes, J., et al. The value of forest strips for understorey birds in an Amazonian plantation landscape. Biological Conservation, in press. doi:10.1016/j.biocon.2008.06.017.