As the terrestrial human footprint continues to expand, the amount of native forest that is free from significant damaging human activities is in precipitous decline. There is emerging evidence that the remaining intact forest supports an exceptional confluence of globally significant environmental values relative to degraded forests, including imperilled biodiversity, carbon sequestration and storage, water provision, indigenous culture and the maintenance of human health. Here we argue that maintaining and, where possible, restoring the integrity of dwindling intact forests is an urgent priority for current global efforts to halt the ongoing biodiversity crisis, slow rapid climate change and achieve sustainability goals. Retaining the integrity of intact forest ecosystems should be a central component of proactive global and national environmental strategies, alongside current efforts aimed at halting deforestation and promoting reforestation.

Abstract. Since its development, occupancy modeling has become a popular and useful tool for ecologists wishing to learn about the dynamics of species occurrence over time and space. Such models require presence-absence data to be collected at spatially indexed survey units. However, only recently have researchers recognized the need to correct for spatially induced overdisperison by explicitly accounting for spatial autocorrelation in occupancy probability. Previous efforts to incorporate such autocorrelation have largely focused on logitnormal formulations for occupancy, with spatial autocorrelation induced by a random effect within a hierarchical modeling framework. Although useful, computational time generally limits such an approach to relatively small data sets, and there are often problems with algorithm instability, yielding unsatisfactory results. Further, recent research has revealed a hidden form of multicollinearity in such applications, which may lead to parameter bias if not explicitly addressed. Combining several techniques, we present a unifying hierarchical spatial occupancy model specification that is particularly effective over large spatial extents. This approach employs a probit mixture framework for occupancy and can easily accommodate a reduced-dimensional spatial process to resolve issues with multicollinearity and spatial confounding while improving algorithm convergence. Using open-source software, we demonstrate this new model specification using a case study involving occupancy of caribou (Rangifer tarandus) over a set of 1080 survey units spanning a large contiguous region (108 000 km 2 ) in northern Ontario, Canada. Overall, the combination of a more efficient specification and open-source software allows for a facile and stable implementation of spatial occupancy models for large data sets.

Carnivores are difficult to survey due, in large part, to their relative rarity across the landscape and wariness toward humans. Several noninvasive methods may aid in overcoming these difficulties, but there has been little discussion of the relative merits and biases of these techniques. We assess the value of 5 noninvasive techniques based on results from 2 multiyear studies of carnivores (including members of Carnivora and Didelphidae) in New York forests. Two metrics were particularly valuable in assessing the species‐specific value of any particular survey technique: latency to initial detection (LTD) and probability of detection (POD). We found differences in the value of techniques in detecting different species. For midsized species (raccoon [Procyon lotor], fisher [Martes pennanti], opossum [Didelphis virginiana], and domestic cat [Felis catus]), camera traps and track‐plates were approximately equivalent in detection efficiency, but the potential for wariness toward the survey apparatus resulted in higher LTD for track‐plates than for cameras. On the other hand, track‐plates detected small carnivores (marten [M. americana] and weasels [Mustela spp.]) more often than cameras and had higher PODs for small and midsized species than did cameras. Cameras were efficient mechanisms for surveying bears (Ursus americanus; low LTD, high POD) but functioned poorly for discerning presence of coyotes (Canis latrans; high LTD, low POD). Scat surveys and snowtracking were the best methods for coyotes, which avoided camera traps and artificial tracking surfaces. Our analysis of fecal DNA revealed that trail‐based fecal surveys were inefficient at detecting species other than coyotes, with the possible exception of red foxes (Vulpes vulpes). Genetic analyses of feces and snowtracking revealed the presence of foxes at sites where other techniques failed to discern these species, suggesting that cameras and track‐plates are inefficient for surveying small canids in this region. The LTD of coyotes by camera traps was not correlated with their abundance as indexed by scat counts, but for other species this metric may offer an opportunity to assess relative abundance across sites. Snowtracking surveys were particularly robust (high POD) for detecting species active in winter and may be more effective than both cameras and track‐plates where conditions are suitable. We recommend that survey efforts targeting multiple members of the carnivore community use multiple independent techniques and incorporate mechanisms to truth their relative value.

Many global environmental agendas, including halting biodiversity loss, reversing land degradation, and limiting climate change, depend upon retaining forests with high ecological integrity, yet the scale and degree of forest modification remain poorly quantified and mapped. By integrating data on observed and inferred human pressures and an index of lost connectivity, we generate a globally consistent, continuous index of forest condition as determined by the degree of anthropogenic modification. Globally, only 17.4 million km2 of forest (40.5%) has high landscape-level integrity (mostly found in Canada, Russia, the Amazon, Central Africa, and New Guinea) and only 27% of this area is found in nationally designated protected areas. Of the forest inside protected areas, only 56% has high landscape-level integrity. Ambitious policies that prioritize the retention of forest integrity, especially in the most intact areas, are now urgently needed alongside current efforts aimed at halting deforestation and restoring the integrity of forests globally.

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Despite increasing pressure to harvest timber from African tropical forests, the short-and longterm ecological effects of qualitative and quantitative variation in extraction practices rarely have been examined. At a site in the southwestern Central African Republic, we surveyed rodent and tree communities and vegetation structure in unlogged forest and along skid trails and secondary and primary access roads at 12 and 19 years after logging. The most important source of variation among transects was the type of logging road: primary and secondary access roads showed the greatest change and skid trails the least. An intercorrelated suite of changes occurred along the margins of the roads, including changes in rodent community composition, increases in rodent abundance and diversity, changes in the height distribution of rodent abundance, increases in understory foliage density, and decreases in sapling density and tree species richness. Ecological changes along the secondary roads were nearly as strong as those along primary roads, despite the fact that secondary roads had been abandoned immediately after logging, whereas primary roads had been traveled up to the time of the research. Continuing edge-induced effects along graded road margins at between 12 and 19 years after logging were indicated by differences in tree species composition, sapling and tree densities, and understory density. Our results support conclusions of increased disturbance to rainforest communities with increasingly destructive road construction techniques and suggest that canopy damage rather than stem damage is the most appropriate measure of logging damage. Although minimizing the length of access roads is important in reducing ecological effects, it should not be achieved at the expense of increased canopy damage. Rodent communities appear to be an easily measured indicator of these ecological changes and may be responsive to landscape-level changes in forest cover and degradation.Influencia de las Rutas de Extracción de Madera sobre las Comunidades de Mamíferos Pequeños, la Estructura del Bosque y la Diversidad de Arboles en Africa Central Resumen: A pesar de la creciente presión para cosechar la madera de los bosques tropicales africanos, los efectos ecológicos a corto y largo plazo de la variación cualitativa y cuantitativa de las prácticas de extracción rara vez han sido estudiados. En un sitio del sudoeste de la República Centroafricana, evaluamos las comunidades de roedores y de árboles y la estructura de la vegetación en bosques sin talar y a lo largo de senderos de arrastre y caminos de acceso secundarios y primarios en bosques 12 y 19 años posteriores a la tala. Los muestreos se llevaron a cabo en transectos de 280 m de largo. La fuente de variación más importante entre los transectos fue el tipo de camino de acceso: los caminos de acceso primarios y secundarios mostraron los cambios mayores y los senderos de arrastre los menores. Una serie de cambios intercorrelacionados ocurrieron a lo largo de los márgenes de los caminos, i...

The factors that promote ecological separation among closely related sympatric carnivores in tropical forests are poorly understood due to a paucity of field studies. Here, we report on community-wide food resource utilization patterns among eight co-existing carnivores in the Dzanga-Sangha Reserve, Central African Republic, based on a collection of 666 scats that were identified using a combination of methods, including thin-layer chromatography. Members of the assemblage took advantage of the diverse array of food resources characteristic of tropical forest habitats by adopting a variety of feeding strategies, such as carnivory, insectivory, frugivory, and piscivory. Broad-scale dietary separation was evident among most pairs, with only 6 of 21 exhibiting food niche overlaps that exceeded 50%. The marsh mongoose (Atilax paludinosus) and African civet (Civettictis civetta) were the most specialized with respect to food habits. Highest trophic overlaps were evident between the most carnivorous [leopard (Panthera pardus) and golden cat (Profelis aurata)] or insectivorous [mongooses (Herpestes naso and Bdeogale nigripes)] species. Unlike other animal groups, species richness of the food resource base was not a key factor structuring this rainforest community. Stronger roles were instead played by the size diversity and abundance of mammalian prey, and the perhaps superabundant or at least highly renewable nature of insects. Ecological separation was further facilitated by some segregation along the spatial (habitat) and temporal (activity) niche dimensions. The average weight of prey taken by leopards was considerably lower than that in other African and Asian sites. Mammals weighing over 20 kg were taken rarely, while use of small (<5 kg) prey was unusually high, signaling either the relatively depauperate base of the former, or high level of abundance and/or profitability of the latter.

We have studied the relationship between dominance rank and physiology among male olive baboons (Papio anubis) living freely in a national park in Africa. In stable hierarchies, dominant males consistently have lower basal concentrations than do subordinates of the adrenal glucocorticoid cortisol. Because of the known catabolic actions of glucocorticoids, dominant males may be less at risk for some of the pathogenic consequences of glucocorticoid overexposure. We find that low basal cortisol concentration is not, in fact, a marker of social dominance; instead, it is only found among dominant males with a certain style of dominance. Lower basal cortisol concentrations occurred among males with any of the following behaviors: the most marked ability to distinguish between threatening and merely neutral interactions with rivals and, if the former, the greatest likelihood of initiating a fight; the most skill at distinguishing between winning and losing a fight and, if the latter, the greatest likelihood of displacing aggression onto a third party. Collectively, these behaviors suggest high degrees of social skillfulness, control, and predictability over social contingencies, all recognized as psychological features that minimize the pathophysiological impact of stress. Dominant males lacking these behavioral features, in contrast, had as high cortisol concentrations as did subordinate males. Finally, low basal cortisol concentrations were also a feature of males with the longest tenures in the dominant cohort, suggesting that this endocrine dichotomy is meaningful in terms of life histories.