Forest Disturbance and Occupancy Patterns of Carnivores: Results of a Large-scale Field Study in Maine, USA

Understanding trends in the abundance and distribution of carnivores is important at global, regional and local scales due to their ecological role, their aesthetic and economic value, and the numerous threats to their populations. Carnivores in Maine range from the American black bear (Ursus americanus), to numerous native mesocarnivore species, such as American marten (Martes americana), fisher (Pekania pennanti), coyote (Canis latrans), red fox (Vulpes vulpes), bobcat (Lynx rufus), Canada lynx (Lynx canadensis) and to two small weasel species (Mustela erminea and Neogale frenata). Though smaller than their apex carnivore cousins, Mesocarnivores are essential components of ecosystems and have complex impacts on prey species and intraguild dynamics. However, these species can vary in how they respond to human disturbances, from direct declines due to unregulated harvest and habitat loss, and their ability to adapt to land-use change. Maine is a working landscape which provides habitat for diverse wildlife species coincident with extensive forest harvest industries, as well as tourism and recreation. The intensity, timing, and configuration of harvest activities all interact to modify the landscape, with cascading impacts on the distribution of many animals. Forest management practices have changed through time (Maine Forest Service 2003) with potentially unpredictable outcomes (e.g. Simons 2009). However, the extent to which carnivore species adapt to land use change is a key knowledge gap that needs to be addressed to ensure proper management and conservation going forward. I investigated these patterns by designing a natural experiment across the forested landscape of Maine, and by collecting detection data on multiple species at camera trapping survey stations deployed along a gradient of forest disturbance. My dissertation aims to collect broad-scale, relevant information for carnivore management and conservation, and assess the efficacy of motion-triggered trail cameras for long-term monitoring. My work is divided into four sections, reflected by the four chapters included in the dissertation. My first goal was to determine the optimal number and configuration of camera-trap transects, to balance between reasonable effort expended and high-quality data collection. I used multi-method occupancy analyses to compare between one, two or three camera units spaced either 100 m or 150 m apart. We found that a design with three cameras spaced 100 m apart increased detection probabilities up to five-fold over a single camera trap, and thus used this configuration for the duration of the following research. Once the survey unit was selected, I established a large-scale, multi-year camera trapping regimen across the northern two-thirds of Maine. Survey sites were selected in compliance with a natural experimental design, replicating across all combinations of a) forest disturbance intensity, b) latitude, and c) fur trapping harvest reports for key furbearing species. In the second chapter I present this study design in more detail, and use the resulting data to investigate the interspecies dynamics of marten and fisher, two species of interest to the state of Maine that co-exist in several geographic areas and partition habitat in distinct ways. Both species are sensitive to habitat change resulting from timber harvest, which was a more important factor in occupancy patterns than intraguild dynamics. In chapter three, I took advantage of the large data set I collected to provide a landscape scale understanding of long-tailed and short-tailed weasel distribution patterns in the face of habitat change. Both of these species are poorly studied, and may be in decline in North American. My results indicate that short-tailed weasel are widespread in Maine and do not appear limited by forest harvest practices, while long-tailed weasel are rarer and more apt to be present in southern Maine. Finally in chapter four I ran models incorporating multiple states for species occupancy, beyond mere present or absent, to understand the dynamics of black bears and of black bear reproduction across managed forests in Maine. I found that generally disturbance at a small scale was positively associated with both occupancy and probability of reproduction, while the availability of hardwood trees (an important food source for bears) was also positively linked to the probability of female bears being with cubs. In addition to meeting our stake holder needs for informed management guidelines, I hope that many of my findings will be directly relevant to the broader research community—as camera trapping equipment becomes more affordable, it will become feasible to both monitor and rigorously study wildlife populations in remote locations and under many scenarios of human land-use

Steepmilk Deerdog: A Novel

Steepmilk Deerdog is an urban fantasy novel set in contemporary Ottawa and centering on the stories of three women. It opens as the protagonist, Kiki, receives an urgent phone call from her absent sister, Juliet, begging her to return to their hometown. Kiki rents a basement apartment from an elderly woman named Maureen who lives in the house above her. As Kiki attempts to make contact with her sister and uncover the secrets of her absence, Maureen’s developing dementia becomes more and more apparent. Maureen’s only regular visitor, a charming city councillor named Roger, offers Kiki work but may have ulterior motives for fostering his friendships with these women. Meanwhile, Kiki’s longtime online flirtation, a porn actor in Montreal, visits for the first time and they attempt to navigate their relationship. But something is off about reality, and only Kiki and Juliet seem to have noticed. Magical things begin to happen, and Maureen’s house upstairs seems to act as a gateway for them. Kiki is befriended by Maureen’s talking cat as the older woman begins to forget her pet, and the rest of the city is oddly concerned with tracking down a deer that has been sighted in the neighbourhood. However, the characters do not perceive the magical elements as unusual in any way, and Kiki continues to assert that nothing is different about this reality, despite it being a different reality. By the novel’s culmination, magic becomes metaphorical for power gained and power lost. As the centre of Canada’s federal political power, Ottawa is a unique and apt choice of setting. The integration of magical elements into an otherwise verisimilar world attempts to redress the underrepresentation of real-life Canadian urban spaces in works of fantasy. In doing so, Steepmilk Deerdog draws attention to the relativity of perspective, enabling the novel to explore the traps of the patriarchal and economic systems in which we live, the ways in which women resist these, and the ways in which Canadian cities continue to be sites of these struggles

Gender, relationship breakdown, and suicide risk: a review of research in western countries

An association between divorce and suicide risk has been noted in numerous studies, but the gender profile of this risk has not been clearly established. This article reviews the evidence on gender differentials in suicide risk following the breakdown of an intimate relationship (including divorce and separation). Nineteen published articles that included individuallevel data were identified. Twelve reported a greater risk of suicide in men following relationship breakdown, two indicated a greater risk in women, and a further five showed no clear gender differential. Although there are possible indications of increased risk for men, no definitive conclusion about gender differential can be drawn. Furthermore, research is required that directly compares men with women for suicide risk following relationship breakdown

Forest and snow rather than food or foe limit the distribution of a generalist mesocarnivore in winter

Investigating species responses to trophic interactions and abiotic factors is crucial to better understanding their ecology and creating effective management strategies. In carnivore communities, smaller species are often regulated by larger ones via top-down interference competition. Smaller subordinate carnivores can also be regulated by bottom-up and abiotic factors, such as the availability of important prey, habitat features, and climatic conditions. However, substantial ambiguity remains regarding the relative roles these complex factors play in shaping subordinate carnivore populations, especially during winter. To investigate this issue, we conducted a large-scale camera-trapping study (n = 197 sites distributed across a ~60,000 km2 landscape) using a balanced study design that sampled a gradient of forest disturbance and climatic conditions. We used dynamic occupancy modeling to examine the influences of top-down (interference competition), bottom-up (prey and habitat), and abiotic (climate) factors on a widespread, generalist subordinate carnivore, the red fox (Vulpes vulpes), in Maine, USA. Across three winters, we collected 107 red fox and 185 coyote (Canis latrans) daily detections, and 3875 snowshoe hare (Lepus americanus) detections. We found evidence for the top-down effects of coyotes on red fox detection probability and site colonization. However, contrary to theoretical expectations, the association between coyotes and red foxes was positive rather than negative. Snowshoe hares had a positive association with local extinction by red foxes, which also contrasts with prevailing theory given that snowshoe hares are an important winter prey of red foxes in this ecosystem. The intensity of forest disturbance and the proportion of conifer forest had negative effects on red fox occurrence and detection probability, while snow depth had a strong negative effect on site colonization. Together, these results suggest red foxes are limited more by abiotic and bottom-up factors related to habitat than by the top-down interference competition or primary prey availability in winter. Our study supports recent findings that bottom-up factors may shape carnivore distributions during less productive times of year. Our work also highlights how caution isneeded when extrapolating previous results from summer studies to winter, as the role of top-down and bottom-up factors may change seasonall

The recognizability and consequentiality of mistakes: Some notes on the article by Klemp et al.

In a documentary called Attrazione D’amore, the cinematographer Frank Scheffer provides footage from a lunch concert at Amsterdam’s Royal Concertgebouw. When the orchestra starts to play Mozart’s Piano Concerto No. 20 in D minor, it becomes apparent that the renowned pianist Maria João Pires had made a mistake. As the director of the concert, Riccardo Chailly, recounts in the film: “She was shocked because she was expecting us to play another concerto. So when I started the first bar of the D..

Why might men be more at risk of suicide after a relationship breakdown? Sociological insights

Relationship breakdown constitutes a major risk factor for suicide ideation and completion. Although no definitive conclusion can be reached about a gender differential in susceptibility to this factor, several studies have identified that there is an elevated risk factor in men following divorce and separation. This paper presents an overview of sociological explanations that may be employed to understand this phenomenon. There is discussion of: the changing nature of intimacy; men’s loss of honour; marriage as a more positive experience for men than for women; control in relationships; the increasing importance of the care of children for men; and men’s social networks. The paper concludes with possible implications for policy and practice

Differential habitat use between demographic states of black bears in managed timber forests

The long‐term effects of intensive forest harvest on sensitive demographic stages of the American black bear (Ursus americanus) have been often overlooked. Much of Maine, USA, is covered in forests that are hospitable to bears and commercial timber harvest. To investigate the potential effects of differing intensities of disturbance on black bears, and on females with cubs particularly, we designed a large‐scale natural experiment with 197 motion‐sensitive camera sites dispersed over representative forest stands in northern and central Maine. Using multi‐state occupancy models, we distinguished the overall trends in space use by females with young versus adult bears without young. Forest disturbance at large spatial scales was positively associated with the probability of use for both demographic groups and the availability of hardwood trees was an additional important factor for habitat use by females with young. Our study illustrates the use of motion‐sensitive cameras to monitor and understand habitat use by distinct life‐history stages of animals living in human‐modified landscapes, and results indicate that managers can maintain black bear habitat in areas of active forest harvest by ensuring the availability of hardwood specie

Spatial Density Dependence Scales up but Does Not Produce Temporal Density Dependence in a Reef Fish

Field experiments provide rigorous tests of ecological hypotheses but are typically of short duration and use small spatial replicates. We assessed empirically whether the results of experiments testing for density dependence applied at larger spatial domains and explained temporal population dynamics. We studied a small coral reef fish, the goldspot goby {Gnatholepis thompsoni), in the Bahamas. We assessed the effects of interactions with conspecifics and with an ecologically similar species, the bridled goby {Coryphopterus glaucofraenum). Two density manipulations on small reef patches revealed that goldspot goby mortality over one month increased as conspecifics became crowded. On five large natural reefs, we correlated the initial year-class density of both species (annual larval settlement) with the subsequent decline of goldspot goby year-classes for five years. Mortality was correlated with conspecific density among reefs for all years, but not among years for all reefs. Thus, spatial density dependence in mortality scaled up qualitatively from small patches to entire reefs but was not associated with temporal density dependence. Our results support the conclusion that field experiments may be extrapolated to larger spatial domains with care, but that using small spatial comparisons to predict temporal responses is difficult without knowing the underlying biological mechanisms