Understanding how biodiversity responds to urbanization is challenging, due in part to the single‐city focus of most urban ecological research. Here, we delineate continent‐scale patterns in urban species assemblages by leveraging data from a multi‐city camera trap survey and quantify how differences in greenspace availability and average housing density among 10 North American cities relate to the distribution of eight widespread North American mammals. To do so, we deployed camera traps at 569 sites across these ten cities between 18 June and 14 August. Most data came from 2017, though some cities contributed 2016 or 2018 data if it was available. We found that the magnitude and direction of most species' responses to urbanization within a city were associated with landscape‐scale differences among cities. For example, eastern gray squirrel (Sciurus carolinensis), fox squirrel (Sciurus niger), and red fox (Vulpes vulpes) responses to urbanization changed from negative to positive once the proportion of green space within a city was >~20%. Likewise, raccoon (Procyon lotor) and Virginia opossum (Didelphis virginiana) responses to urbanization changed from positive to negative once the average housing density of a city exceeded about 700 housing units/km2. We also found that local species richness within cities consistently declined with urbanization in only the more densely developed cities (>~700 housing units/km2). Given our results, it may therefore be possible to design cities to better support biodiversity and reduce the negative influence of urbanization on wildlife by, for example, increasing the amount of green space within a city. Additionally, it may be most important for densely populated cities to find innovative solutions to bolster wildlife resilience because they were the most likely to observe diversity losses of common urban species.

Research on urban wildlife can help promote coexistence and guide future interactions between humans and wildlife in developed regions, but most such investigations are limited to short‐term, single‐species studies, typically conducted within a single city. This restricted focus prevents scientists from recognizing global patterns and first principles regarding urban wildlife behavior and ecology. To overcome these limitations, we have designed a pioneering research network, the Urban Wildlife Information Network (UWIN), whereby partners collaborate across several cities to systematically collect data to populate long‐term datasets on multiple species in urban areas. Data collected via UWIN support analyses that will enable us to build basic theory related to urban wildlife ecology. An analysis of mammals in seven metropolitan regions suggests that common species are similar across cities, but relative rates of occupancy differ markedly. We ultimately view UWIN as an applied tool that can be used to connect the public to urban nature at a continental scale, and provide information critical to urban planners and landscape architects. Our network therefore has the potential to advance knowledge and to improve the ability to plan and manage cities to support biodiversity.

Time is a fundamental component of ecological processes. How animal behavior changes over time has been explored through well-known ecological theories like niche partitioning and predator-prey dynamics. Yet, changes in animal behavior within the shorter 24-hour light-dark cycle have largely gone unstudied. Understanding if an animal can adjust their temporal activity to mitigate or adapt to environmental change has become a recent topic of discussion and is important for effective wildlife management and conservation. While spatial habitat is a fundamental consideration in wildlife management and conservation, temporal habitat is often ignored. We formulated a temporal resource selection model to quantify the diel behavior of eight mammal species across ten U.S. cities. We found high variability in diel activity patterns within and among species and species-specific correlations between diel activity and human population density, impervious land cover, available greenspace, vegetation cover, and mean daily temperature. We also found that some species may modulate temporal behaviors to manage both natural and anthropogenic risks. Our results highlight the complexity with which temporal activity patterns interact with local environmental characteristics, and suggest that urban mammals may use time along the 24-hour cycle to reduce risk, adapt, and therefore persist, and in some cases thrive, in human-dominated ecosystems.

One of the biggest challenges in predicting ecohydrologic fluxes is scaling from easily measured variables to more difficult, often emergent patterns and processes. This is especially true in spatially heterogeneous systems such as black spruce (Picea mariana)‐dominated boreal forests containing excessive and low soil moisture conditions. Traditional hypotheses suggest that transpiration is controlled by hydraulic responses to vapor pressure deficit (D) and soil moisture; however, these may potentially be misinformed because of omission of soil drainage gradients. Thus, we predict that 1) spatial heterogeneity in tree transpiration along a soil drainage gradient is positively correlated with D, 2) sap flux (JS) and leaf‐level transpiration (EL) are higher and whole‐tree transpiration (EC) lower in the poorly drained than well‐drained stands, and 3) spatial heterogeneity of EC is regulated primarily by tree‐related covariates such as sapwood and leaf area and secondarily by environmental covariates including peat and moss depth. With the use of 122 black spruce sap flux measurements, the range of autocorrelation (inverse of spatial variation) decreased from 20 m at low D (<0.7 kPa) to 2 m at midday D values (>0.9 kPa). JS and EL were significantly greater and EC less in poorly drained than well‐drained stands; controlled primarily by tree‐related covariates (sapwood and leaf area) representing long‐term growth conditions and secondarily by soil moisture and spatially sampled D reflecting shorter‐term environmental variation. Quantification of spatial heterogeneity informs predictive models of the distance at which homogeneity can no longer be assumed and will improve mechanistic predictions of transpiration at multiple spatial scales. Copyright © 2012 John Wiley & Sons, Ltd.

The Canadian boreal forest consists of a mosaic of landscapes of varying soil drainage and forest age driven by wildfire. The hydrological consequences are complicated by plant responses to soil moisture and forest age, both potentially influencing evapotranspiration. Evapotranspiration was measured using the energy balance residual technique in 2006 and 2007 at forested upland and fen sites that originated following fire in 1964, 1930 and about 1850, near Thompson, Manitoba, Canada. Both net radiation and sensible heat flux density were greater at the older sites than those at the younger sites. Evapotranspiration was also greater at the older sites by between 4 and 19% for the 1930-1964 comparison, and 15% for the 1930-1850 comparison. There was no difference in net radiation between upland and fen sites of the same age, although upland sites had a higher sensible heat flux density. Albedo was greater at the fen sites. Evapotranspiration was greater at the upland sites by 11-20%, likely driven by greater leaf area at the upland sites. These intermediate to mature boreal forest sites still show the persistence of the impact of fire, and it is clear that changes in drainage and local hydrology will also have an impact on local evapotranspiration. The implication is that even these small changes in evapotranspiration can have a great regional and global effect because of the large land area of the boreal forest.