Lab

David S. Jachowski's Lab

Institution: Clemson University

Featured projects (1)

Project
Exploring multiple aspects of scavenger community ecology (both avian and mammalian) across the eastern USA.

Featured research (5)

Species that respond to ecosystem change in a timely, measurable, and interpretable way can be used as sentinels of global change. Contrary to a pervasive view, we suggest that, among Carnivora, small carnivores are more appropriate sentinels than large carnivores. This reasoning is built around six key points: that, compared to large carnivores, small carnivores 1) are more species‐rich and diverse, providing more potential sentinels in many systems; 2) occupy a wider range of ecological niches, exhibiting a greater variety of sensitivities to change; 3) hold an intermediate trophic position that is more directly affected by changes at the producer, primary consumer, and tertiary consumer levels; 4) have shorter life spans and higher reproductive rates, exhibiting more rapid responses to change; 5) have smaller home ranges and are more abundant, making it easier to investigate fine‐scale management interventions; 6) are easier to monitor, manage, and manipulate. Therefore, we advocate for incorporating a middle‐out approach, in addition to the established top‐down and bottom‐up approaches, to assessing the responses of ecosystems to global change. Les espèces qui réagissent au changement de l'écosystème de manière opportune, mesurable et interprétable peuvent être utilisées comme sentinelles du changement global. Contrairement à une opinion répandue, nous suggérons que, parmi l'ordre des Carnivora, les petits carnivores sont des sentinelles plus appropriées que les grands carnivores. Ce raisonnement est construit autour de six points‐clés: que, comparés aux grands carnivores, les petits carnivores 1) sont plus riches en espèces et plus diversifiés, fournissant plus d'espèces sentinelles potentielles dans de nombreux systèmes; 2) occupent un plus large éventail de niches écologiques, présentant une plus grande variété de sensibilités au changement; 3) occupent une position trophique intermédiaire plus directement affectée par les changements au niveau du producteur, du consommateur primaire et du consommateur tertiaire; 4) ont des durées de vie plus courtes et des taux de reproduction plus élevés, présentant des réponses plus rapides au changement; 5) ont des domaines vitaux plus petits et sont plus abondants, ce qui facilite l'étude des interventions de gestion à petite échelle; 6) sont plus faciles à surveiller, gérer et manipuler. Par conséquent, nous préconisons l'intégration d'une approche intermédiaire, en plus des approches descendantes et ascendantes établies, pour évaluer les réponses des écosystèmes au changement global. Species that respond to ecosystem change in a timely, measurable, and interpretable way can be used as sentinels of global change. We suggest that, among Carnivora, small carnivores are more appropriate sentinels than large carnivores, and we support our view with six key points: that, compared to large carnivores, small carnivores 1) are more species‐rich and diverse, providing more potential sentinels in many systems; 2) occupy a wider range of ecological niches, exhibiting a greater variety of sensitivities to change; 3) hold an intermediate trophic position that is more directly affected by changes at the producer, primary consumer, and tertiary consumer levels; 4) have shorter life spans and higher reproductive rates, exhibiting more rapid responses to change; 5) have smaller home ranges and are more abundant, making it easier to investigate fine‐scale management interventions; 6) are easier to monitor, manage, and manipulate. We advocate for incorporating a middle‐out approach, in addition to the established top‐down and bottom‐up approaches, to assessing the responses of ecosystems to global change.
Eastern spotted skunks are of conservation concern, where competition and predation are possible causes of their decline. Using camera traps at a food subsidy, we investigated nocturnal temporal overlap of spotted skunks with co-occurring predators. Spotted skunks were more active during dark nights, when their activity overlapped with the largest predator (coyotes), but not with other mesopredators, thus possibly avoiding interspecific competition. Spotted skunk activity shifted during moonlit nights, where overlap with all predators was reduced, suggesting avoidance of both predators and competitors. This implies that both predation and interspecific competition could limit spotted skunk populations, and one mechanism they apply to coexist is nocturnal light-specific temporal partitioning.
We tracked a female eastern spotted skunk Spilogale putorius in North Carolina, USA, that gave birth to a litter of three kits in summer 2020. Using camera traps and radio-collars, we were able to monitor the movement and behaviors of the female and litter. We observed behaviors including food provisioning, play-fighting, and interspecific interactions. We tracked the movements of the kits past independence from their mother and documented dispersal events for two kits. This is the first known successful attempt to track eastern spotted skunk kits from birth to independence, providing new insights into the ecology of this cryptic species.
Small mammalian carnivores (Carnivora <16 kg) carry out important roles in ecosystems, such as influencing ecosystem structure and providing numerous ecosystem services. Despite their importance, there are contrasting views on the required conservation and management needs for species within this group. In a review of the IUCN Red List species-level assessments, we found that 53 small carnivore species were threatened (CR, EN, or VU) compared to 15 large. However, there were similar proportions of large (4%, 9%) and small (1%, 9%) carnivores endangered with extinction (CR or EN, respectively). We did not find support for small carnivores benefiting from mesopredator release in a global context; more than half of both large and small carnivore species decreasing, suggesting parallel declines. On average, large carnivores received their first IUCN assessment 10 years before small and, since their first assessment, small carnivores have received fewer assessments than large, highlighting the disparity in conservation attention within the guild. The leading threats for all carnivores include biological resource use and land use change. We review the major threats to threatened small carnivores and suggest areas for priority research and conservation. Collectively, we show that small carnivores are as endangered with extinction as are large carnivores, and that small carnivores should be of conservation concern globally, but particularly in species-rich regions of Southeast Asia, sub-Saharan Africa, and Madagascar. To inform conservation, we encourage more research into the basic ecology and demography of small carnivores, particularly regarding current and future threats in the face of global change.

Lab head

David S. Jachowski
Department
  • Forestry and Environmental Conservation

Members (7)

Courtney Marneweck
  • University of South Africa
Stephen N. Harris
  • Clemson University
Meghan P. Keating
  • Clemson University
Keifer L. Titus
  • Clemson University
Elizabeth A. Saldo
  • Clemson University
Amanda Williams
  • Clemson University
Alex Jensen
  • Clemson University
Alex J. Jensen
Alex J. Jensen
  • Not confirmed yet
Sze Wing Yu
Sze Wing Yu
  • Not confirmed yet