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Open-source species locality data are widely used in species distribution modeling but may be spatially biased by uneven sampling effort across a species' range. Spatial biases may vary across ecological trait groups if traits affect associations with landscape features and capture probability. Furthermore, spatial biases may change across time as research priorities, funding, and methodologies change, which may confound modeling of temporal changes in distributions. We used locality records from 93 bat species from the Global Biodiversity Information Facility to characterize the differential contribution of bias variables to spatial bias and how contribution varied across ecological trait groups. Next, we examined how historical changes in protected area proliferation, economic development, and sampling method advancement affected protected area and university biases. Roosting and foraging traits influenced spatial bias, but distance to protected areas was the greatest contributor to spatial sampling bias in a pooled model and 8 out of 10 ecological trait group models. Over time, distance to protected areas significantly decreased following protected area proliferation, but economic improvement did not influence distance to universities. Sampling method advancements increased protected area bias for two out of three foraging groups. Although sampling effort has increased over time, effort is becoming more biased towards protected areas, which may not encompass the entirety of species' ranges or allow for equal sampling across taxa. Characterizing spatial bias differences among species and across time clarifies underlying causes of spatial bias, information that can be leveraged to improve spatial bias correction.

Arid environments are characterized by resource pulses that cause spatio-temporal variability in species abundance, which can make population assessments difficult. Mobile acoustic methods may improve survey success by maximizing geographic extent, characterizing landscape distribution patterns, and improving encounter rates. Bats exemplify survey challenges in arid environments as they are highly mobile and aggregate around spatio-temporal resource hotspots. We compared bat detection success of stationary acoustic methods to that of mobile acoustic transects. In a semi-arid landscape, we recorded bat echolocation calls and compared three different sampling methods along the same 24 km route: a driven transect; a set of five, permanent ten-minute point counts; and a set of point counts at nightly randomized locations. The effect of method on the number of bat passes was analyzed using a bootstrapped generalized linear mixed effect model. The mean number of passes for the mobile method was 2.14 (CI: 1.45–2.99) and 0.98 (CI: 0.77–1.21) for the pooled stationary methods. We suggest that driven transects more effectively measure bat activity in arid and open landscapes. Testing of novel survey methods in arid environments is vital to conservation success as climate change increases the extent of these biomes and the variability of resource pulses.

Vagrancy laws conjure up a distant past when authorities punished people without a home or permanent residence. Whether the objects of pity or scorn, vagrants could be cited or jailed under laws selectively enforced against anyone deemed undesirable. Although such laws have generally been struck down by courts as unconstitutionally vague, today’s “vagrants” are homeless people, who face growing harassment and punishment for their presence in public.More than one in five homeless people in the country lives in California, and two-thirds are unsheltered. The state legislature has done little to respond to this widespread problem, forcing municipal governments to address homelessness with local laws and resources. Cities have responded by enacting and enforcing new vagrancy laws — a wide range of municipal codes that target or disproportionately impact homeless people.Through extensive archival research and case studies of several cities, the report presents detailed evidence of the growing enactment and enforcement of municipal anti-homeless laws in recent decades as cities engage in a race to the bottom to push out homeless people. It concludes with a call for a state-level solution to end the expensive and inhumane treatment of some of California's most vulnerable residents.