Moving in the anthropocene: global reductions in terrestrial mammalian movements

Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission

R code to analyze data

R code to read and analyze data to estimate band retention rat

Threading the needle: How humans influence predator–prey spatiotemporal interactions in a multiple-predator system

Perceived predation risk and the resulting antipredator behaviour varies across space, time and predator identity. Communities with multiple predators that interact and differ in their use of space, time of activity and hunting mode create a complex landscape for prey to avoid predation. Anthropogenic presence and disturbance have the potential to shift interactions among predators and prey and the where and when encounters occur. We examined how white-tailed deer Odocoileus virginianus fawn spatiotemporal antipredator behaviour differed along an anthropogenic disturbance gradient that had black bears Ursus americanus, coyotes Canis latrans, bobcats Lynx rufus and humans present. We quantified (a) spatial co-occurrence in species distributions, (b) temporal overlap across the diel cycle and (c) spatiotemporal associations between humans, bears, coyotes, bobcats, adult male deer and fawns. We also examined how deer vigilance behaviour changed across the anthropogenic disturbance gradient and survey duration. Anthropogenic disturbance influenced spatiotemporal co-occurrence across multiple scales, often increasing spatiotemporal overlap among species. In general, species’ spatial co-occurrence was neutral or positive in anthropogenically disturbed environments. Bears and fawns, coyotes and adult male deer, and bobcats and fawns all had higher temporal overlap in the agriculture-development matrix sites. In addition, factors that influenced deer vigilance (e.g. distance to forest edge and predator relative abundance) in the agriculture-development matrix sites did not in the forest matrix site. By taking into account the different antipredator behaviours that can be detected and the different scales these behaviours might occur, we were able to gain a more comprehensive picture of how humans reduce available niche space for wildlife, creating the neutral and positive spatiotemporal associations between species that studies have been seeing in more disturbed areas

Supplement 1. SAS/IML code used to perform aging-error analyses.

<h2>File List</h2><blockquote> <h3><i>All files at once </i></h3> <blockquote> <p><a href="ConnDiefenbach_SAS.zip">ConnDiefenbach_SAS.zip</a></p> </blockquote> <h3><i>Individual SAS files </i></h3> <blockquote> <p><a href="ConnDiefenbach_ModelSelection.SAS">ConnDiefenbach_ModelSelection.SAS</a><br> <a href="ConnDiefenbach_AgeError_1year.SAS">ConnDiefenbach_AgeError_1year.SAS</a></p> </blockquote> </blockquote><h2>Description</h2><blockquote> <p>The file ConnDiefenbach_ModelSelection.SAS includes requisite code to compute log likelihoods for different aging error models evaluated at their MLEs (maximum likelihood estimates). These are useful for calculating model selection criterion. The file ConnDiefenbach_AgeError_1year.SAS includes code for estimating the standing age distribution of female black bear harvests in Pennsylvania. Because of the potential for algorithm instability when these distributions are estimated simultaneously across all years, this code permits estimation of age distributions 1 year at a time (which year must be specified by the user).</p> </blockquote

Appendix A. Observed and estimated age distributions of harvested female black bears in Pennsylvania, 1983–2004.

Observed and estimated age distributions of harvested female black bears in Pennsylvania, 1983–2004

Data from: Retention of riveted aluminum leg bands by wild turkeys

No loss of marks is a critical assumption of mark-recapture models so they provide unbiased estimates of population parameters. We double-banded male and female wild turkeys with aluminum rivet bands and estimated the probability that a bird would be recovered with both bands &lt;1-225 weeks since banding ( = 51.2 weeks, SD = 44.0). We found that 100% of females (n = 37) were recovered with both bands. For males, we recovered 6 of 188 turkeys missing a rivet band for a retention probability of 0.984 (95% CI = 0.96-0.99). If male turkeys are double-banded with rivet bands the probability of recovering a turkey without any marks is &lt;0.001. We failed to detect a change in band retention over time or differences between adults and juveniles. Given the low cost and high retention rates of rivet aluminum bands, we believe they are an effective marking technique for wild turkeys and, for most studies, will minimize any concern about the assumption that marks are not lost

Evaluating Inter-Rater Reliability and Statistical Power of Vegetation Measures Assessing Deer Impact

Long-term vegetation monitoring projects are often used to evaluate how plant communities change through time in response to some external influence. Here, we evaluate the efficacy of vegetation monitoring to consistently detect changes in white-tailed deer browsing effects. Specifically, we compared inter-rater reliability (Cohen&#8217;s &#954; and Lin&#8217;s concordance correlation coefficient) between two identically trained field crews for several plant metrics used by Pennsylvania state agencies to monitor deer browsing impact. Additionally, we conducted a power analysis to determine the effect of sampling scale (1/2500th or 1/750th ha plots) on the ability to detect changes in tree seedling stem counts over time. Inter-rater reliability across sampling crews was substantial for most metrics based on direct measurements, while the observational based Deer Impact Index (DII) had only moderate inter-rater reliability. The smaller, 1/2500th ha sampling scale resulted in higher statistical power to detect changes in tree seedling stem counts due to reduced observer error. Overall, this study indicates that extensive training on plant identification, project protocols, and consistent data collection methods can result in reliable vegetation metrics useful for tracking understory responses to white-tailed deer browsing. Smaller sampling scales and objective plant measures (i.e., seedling counts, species richness) improve inter-rater reliability over subjective measures of deer impact (i.e., DII). However, considering objective plant measures when making a subjective assessment regarding deer browsing effects may also improve DII inter-rater reliability

Data from: Accounting for tagging-to-harvest mortality in a Brownie tag-recovery model by incorporating radio-telemetry data

The Brownie tag-recovery model is useful for estimating harvest rates but assumes all tagged individuals survive to the first hunting season; otherwise, mortality between time of tagging and the hunting season will cause the Brownie estimator to be negatively biased. Alternatively, fitting animals with radio transmitters can be used to accurately estimate harvest rate but may be more costly. We developed a joint model to estimate harvest and annual survival rates that combines known-fate data from animals fitted with transmitters to estimate the probability of surviving the period from capture to the first hunting season, and data from reward-tagged animals in a Brownie tag-recovery model. We evaluated bias and precision of the joint estimator, and how to optimally allocate effort between animals fitted with radio transmitters and inexpensive ear tags or leg bands. Tagging-to-harvest survival rates from >20 individuals with radio transmitters combined with 50–100 reward tags resulted in an unbiased and precise estimator of harvest rates. In addition, the joint model can test whether transmitters affect an individual's probability of being harvested. We illustrate application of the model using data from wild turkey, Meleagris gallapavo, to estimate harvest rates, and data from white-tailed deer, Odocoileus virginianus, to evaluate whether the presence of a visible radio transmitter is related to the probability of a deer being harvested. The joint known-fate tag-recovery model eliminates the requirement to capture and mark animals immediately prior to the hunting season to obtain accurate and precise estimates of harvest rate. In addition, the joint model can assess whether marking animals with radio transmitters affects the individual's probability of being harvested, caused by hunter selectivity or changes in a marked animal's behavior