Arpat

Where can the wild things roam? Combining ecological suitability and human acceptance for the Swiss wolf.

About one third of the Swiss landscape offers suitable wolf habitat. Nonetheless, there is only a small fraction thereof where the wolf is tolerated by local communities. Those regions – characterized by both favourable environmental conditions and a positive attitude towards the wolf – are identified as candidate regions for the successful short to medium-term wolf expansion, according to a study conducted by the population ecology research group at the University of Zurich

©RamiroMarquezPhotos / iStock

The wolf was eradicated in Switzerland and from large parts of continental Europe including France and Germany by the end of the 19th century. Following legal protection, the wolf population started naturally increasing and expanding, and in 1995 its presence was confirmed in Switzerland. Sightings have increased since. Despite 13’800 km2 of Switzerland are characterized by favourable conditions such as large forests with little human pressure and have thus been identified as suitable wolf habitat, wolf expansion in Switzerland has been substantially slower than in other parts of continental Europe. As the wolf is more and more subject to human-dominated landscapes, scientist at the University of Zurich developed a novel method that integrated both ecological and human components to identify regions with favourable environmental conditions and where the wolf was tolerated.

Mapping human acceptance of the wolf to identify suitable socio-ecological areas

socio-ecological suitability model
Combining human acceptance (a, c) and habitat suitability (b, d)
helps identifying socio-ecologically suitable wolf habitats in Switzerland (e).

About one third of 10,000 randomly selected residents in Switzerland participated in the survey. Combining the response from questionnaires with geographical information, Dominik Behr and his team created a nationwide map of human acceptance. Acceptance decreased with increasing altitude of residency and even more so where high numbers of sheep and goats were held. Acceptance increased with increasing distance from confirmed wolf presence and in densely populated areas. People who perceived the wolf as dangerous to humans and harmful to livestock and wildlife mainly opposed the wolf. Younger people, and people who believe that the wolf had a positive influence on the ecosystem had a more positive attitude towards the predator.

“When we overlapped our human acceptance map with a habitat suitability map for the wolf, we realized that only about 6% of Switzerland was characterized by both a positive attitude and favourable environment conditions. This was in contrast to results from the habitat suitability map, which returned one third of the Swiss landscape as being suitable for the wolf” said Dominik Behr. “As wildlife biologists, we are good at understanding the ecological factors determining the suitability of a habitat for a wildlife species. Due to ever-increasing overlap between human and wildlife, however, we are obliged to take into consideration how human acceptance modifies our ecological description of habitat suitability. This study demonstrates one effective way to do this.” stressed Arpat Ozgul, professor of population ecology at the Department of Evolutionary Biology and Environmental Studies at the University of Zurich, and co-author of the study.

A novel framework to manage wolves and people
The socio-ecological map created by Dominik Behr and his co-authors appears to accurately represent the wolf situation in Switzerland of the past years, including identifications of areas of high, moderate or limited conflict. “By capturing areas characterized by both favourable environmental conditions and a positive acceptance towards the wolf, our approach is a valuable tool to identify overall socio-ecological suitable areas for the wolf. Under given conditions, those regions are good candidates for the successful short to medium-term expansion of the wolf. Additionally, this approach allows to identify key regions where proactive and targeted socio-ecological management plans and a constructive dialog among different stakeholders are needed” said Dr. Gabriele Cozzi, who coordinated the study.

Special thanks go to the 3142 people that returned the completed questionnaire – this study would not have been possible without their contribution.

Behr DM, Ozgul A, Cozzi G (2017) Combining human attitude and habitat suitability: a unified socio-ecological suitability model for the wolf in Switzerland. Journal of Applied Ecology

African wild dog dispersal and demography

Past and present African wild dog distribution
Past and present African wild dog distribution. The wide ranging African wild dog has been identified as flagship species for the Kavango Zambesi Transfrontier Conservation Area that spanning five countries including Angola, Botswana, Namibia, Zambia, Zimbabwe plays at home to the largest contiguous population of this endangered carnivore.

The African wild dog (Lycaon pictus) is Africa’s most endangered large carnivore and is listed as endangered in the IUCN Red List. The species was formerly distributed throughout sub-Sahara Africa but today it has disappeared from most of its former range. Less than 6’000 free-ranging individuals survive in the wild, and the species has been given very high conservation priority. One major threat to the survival of the species is the loss and fragmentation of suitable habitats due to expanding human population. As a result, wild dogs are forced to live in isolated small subpopulations, which are particularly vulnerable to extinction.

Dispersal of individuals is a fundamental process governing the dynamics of socially and spatially structured populations. Through emigration and immigration, dispersing individuals lead to the formation of new groups, can rescue small subpopulations, and recolonize unoccupied areas. There is, however, a mismatch between our understanding of the complexity of dispersal and our representation of dispersal in population dynamic models. This is particularly the case for species characterized by long-distance dispersal, such as the African wild dog, as the fate of dispersers is often unknown and consequently neglected.

The Okavango Delta in Botswana represents one of the last strongholds for this endangered carnivore in southern Africa and, through dispersing individuals, the resident population likely acts as a source population for the natural re-colonization of the surrounding regions. Under these circumstances, understanding how and where wild dogs disperse, and assessing connectivity between subpopulations is fundamental for the management and conservation of the species across large wildlife landscapes such as the Kavango Zambezi Transfrontier Conservation Area (KAZA/TFCA), for which wild dogs have been identified as a flagship species. Recent miniaturization of tracking devices finally allows us to follow dispersers in their whereabouts and collect information on dispersal movement patterns (e.g. travelled distance) and dispersal success (e.g. survival rate during dispersal), and to evaluate connectivity across the landscapes of KAZA/TFCA.

The aim of this project is to improve the long-term viability and connectivity of African wild dog subpopulations nationally and across the KAZA/TFCA landscapes by providing new empirical evidence and novel information on dispersal and its demographic consequences. To this end, we bring together novel information on dispersing individuals and 25 years of individual-based life-history data from resident groups to provide an explicit investigation of dispersal in African wild dogs. We deploy GPS/Satellite radio collars on sub-adult African wild dogs that disperse from their natal group, to collect information on dispersal patterns, habitat use and selection during dispersal, survival, settlement success in a new territory, and reproductive success of newly formed packs. This information on dispersing individuals will be merged with existing long-term demographic data on resident groups to inform a spatially explicit demographic model at an unprecedented level of detail. Our project will allow assessing population viability and extinction risks under changing environmental and anthropogenic scenarios and thus help identifying key conservation actions. Results from this project will be used to inform effective national and international management plans.

This project complies with one of the main objectives identified in the Regional conservation strategy for the cheetah and wild dog in southern Africa (IUCN/SSC 2009) in the “Strategic plan for African wild dogs in KAZA 2014 – 2018” (KAZA TFCA Secretariat, 2014) that aim to improve awareness and knowledge by “acquiring a better understanding of dispersal, habitat use and connectivity for wild dogs”.

 

A dispersing wild dog watches the sun setting over a lagoon in the Okavango Delta, northern Botswana (Photo: Dominik Behr)
A dispersing wild dog watches the sun setting over a lagoon in the Okavango Delta, northern Botswana (Photo: Dominik Behr)

By placing dispersal into a wider ecological and demographic context, this project will increase our fundamental biological understanding of dispersal and help improve our ability to predict and manage the responses of endangered carnivores to environmental and anthropogenic perturbations. This project will provide an important scientific insight for evidence-based conservation of the African wild dog, but also for other wide-ranging carnivores such as the cheetah and the lion.

This project has been developed in collaboration and coordination with the Botswana Predator Conservation Trust, the longest running conservation research study on African wild dogs. Financial support has been granted by Zurich University, Idea Wild, Jacot Foundation, Parrotia Foundation, Temperatio Foundation, and Wilderness Wildlife Trust.

 

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Arpat’s Antrittsvorlesung

Our Lab is proud to announce Arpat’s “Antrittsvorlesung” (inaugural lecture), which will be held Monday, 11 November 2013 at 5 pm at the University of Zurich.

I thought I post it on our blog to put some extra pressure on Arpat… 😉

inaugural lecture Ozgul

Do not miss that out… apparently the apèro afterwards is really nice! Oh, yeah and of course the lecture will be absolutely amazing

Moving forward – Animal Movement Ecology Summer School

The last week of August could not have been more hectic and inspiring for some of the people of our lab. The first Animal Movement Ecology Summer School held at the University of Zurich as part of the PhD Program in Ecology of the Life Science Zurich Graduate School has been a great success. We managed to bring together 30 highly dedicated and motivated participants from UZH/ETHZ and from overseas as well as seven top lecturers for what has been an intense and dynamic week.

Participants had the opportunity to alternate high-quality lectures – covering a wide range of topics, such as remote sensing, home-range and movement analysis, patch occupancy models, population dynamics – with some social activities, such has bbq and the long-sought-after jump in the Limmat, the local river. The scope of such activities was to quickly create a cohesive group and promote interactions among the participants and with the lecturers to establish future collaborations. A great success has been the day organised at the Tierpark Goldau, where we had the possibility to follow lectures in a natural and inspiring environment.

 

Participants interacting during one exercise in the suggestive class room at the Tierpark Goldau
Participants interacting during one exercise in the suggestive class room at the Tierpark Goldau

We, organizers, received very positive feedbacks from all participants, which is very encouraging, and we are therefore keen to offer a similar, and even more exciting, course during the summer 2014! Stay tuned on this blog if you do not want to miss-out and want to…keep moving forward!

Linking behavioural, physiological and demographic responses to climate change

WA
Wandering albatross in flight (Photo: Mike Double)

There is an increasing body of evidence highlighting ecological alterations induced by climate change across the globe. Recently, Henri Weimerskirch and his colleagues showed that the wandering albatross (Diomedea exulans), a wide-ranging Sub-Antarctic seabird responded behaviourally, physiologically and demographically to changing wind patterns. This bird, which takes advantage of winds to reduce the flying cost, benefited from stronger winds and could cover more distance during foraging trips. Consequently, individuals increased in mass and had a higher reproductive success. Taking into consideration the potential changes in the environment is crucial to efficiently manage wild populations. Changes in the environment can be linked to demographic rates using behavioural and physiological traits as state variables. Using a trait-based model, we aim to investigate the effects of changes in foraging patterns and physiology, whether directly or indirectly induced by environmental changes, on the population dynamics of the wandering albatross. Quantifying movement and foraging patterns as a trait adds a new dimension to the existing trait-based modeling approaches. This model will enable us to (1) determine the most critical life history processes or pathways governing the population  persistence,  and  (2)  predict  population,  behavioural  and  phenotypic dynamics  under alternative climate change scenarios.

 

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Eco-evolutionary Dynamics Workshop in Leiden

This week, Cindy and I participated in the “Eco-evolutionary Dynamics in a Changing World” workshop at Lorentz Center, Leiden.

The organisers, Stephanie Jenouvrier, Thomas Reed and Marcel Visser, brought together a select group of researchers working at the interface of ecology and evolution, from both theoretical and empirical backgrounds, to brainstorm on our current understanding of eco-evolutionary dynamics. Unlike most other workshops, this one had quite an interesting format. There were only a few plenary talks, and most of the time participants held smaller break-out sessions on their own research area. Although there were no final road-maps or even a clear definition of eco-evolutionary semantics, these break-out sessions, I think, worked very well for tossing around ideas and discussing more specialised topics among those with shared interests. For our part, we received great input on our two projects.

Arpat Ozgul | Team Leader

arpat

Research Interests

Population ecology, biodemography, life-history evolution, evolutionary demography, metapopulation dynamics, wildlife disease dynamics, quantitative methods in wildlife ecology, and conservation biology.

 

Google Scholar | Official UZH page | ORCID

 

CV

  • since 2017, Associate Professor of Population Ecology, University of Zurich
  • 2012-2017, Assistant Professor of Population Ecology, University of Zurich
  • 2011-2012, NERC Research Fellow, Imperial College London
  • 2010-2011, Postdoc, University of Cambridge / Darwin College Research Fellow
  • 2008-2010, Postdoc, Imperial College London
  • 2006-2008, Postdoc, University of Florida
  • 2001-2006, PhD in Wildlife Ecology & Conservation, University of Florida

Spatial ecology of large carnivores in human-dominated landscapes

sarikamisIt is widely accepted that habitat loss and habitat fragmentation are among the major causes responsible for the decline of animal and plant species worldwide. As suitable habitat patches become smaller and even more scattered, animal species are forced to seek the indispensable conditions to their survival in sub-optimal territories. This inevitably forces them to leave their natural, favourable environment and move into human dominated and modified landscapes. Where humans and animal species (particularly predators and crop riders) share the same territory, conflicts often arise. Direct persecution as a consequence of human-wildlife conflict thus adds an additional factor jeopardizing the survival of single individuals and entire populations, potentially leading to local extinctions. In few cases, however, animal species may profit from human activities. For instance, scavengers may benefit from human waste as an additional food resource and energy intake and predators may survive on landscapes where natural prey species have been depleted through predation on domestic stock. It thus appears that a complete understanding of the behaviour and ecology of animals living in a human altered landscape have to take into consideration both the negative and the positive effect of human activities.

bear-collaringThe overall aim of this project, which is a close collaboration with Kuzey Doğa Society, is to investigate the effect of human activities on a sub-population of brown bears Ursus arctus inhabiting rural north east Turkey. In particular we ask the following questions:

  • How does human induced habitat loss and fragmentation affect the movement patterns and ranging behaviour of brown bears? Do forest edges represent an obstacle to movements limiting connectivity between patches of forest?
  • How does the presence of a city garbage dump influence the diet and the foraging movement patterns of brown bears? Is the site used sporadically or it represents a central foraging place?
  • Does the garbage dump represent a substantial source of high energetic food resource?

by Gabriele Cozzi, Arpat Ozgul & in collaboration with:

Resurrecting population responses to past environmental changes from lake sediments

cores
Piero Guilizzoni from the Institute of Ecosystem Study during sediment sampling in 2012.

In this project, we investigate life-history responses of a freshwater rotifer, Brachionus calyciflorus, in retrospect. This is possible because brachionid rotifers produce dormant stages, so-called resting eggs, some of which remain viable in lake sediments for decades.

During the last century, Lake Orta – a deep, subalpine lake in northern Italy – was severely affected by industrial pollution. In 1926, a newly established textile factory began to discharge copper- and ammonium-sulphate contaminated sewage into the lake. The following acidification of the lake resulted in a dramatic decrease in rotifer diversity and an accumulation of resting eggs in the sediments. From the late 1950s onward, pre-treatment of the sewage prior to discharge gradually improved the quality of the lake water, and recovery was further accelerated by whole-lake liming in 1989 and 1990. Ten years after these liming efforts, the pH of Lake Orta had returned to pre-pollution levels, and copper was virtually absent from the water column.

In collaboration with the Institute of Ecosystem Study in Verbania, Italy, we collected sediment cores from different basins of Lake Orta. Back in the laboratory in Zürich, we screen these cores for brachionid resting eggs, which we try to hatch. Subsamples of rotifer lineages established from successfully hatched resting eggs are then subjected to a variety of treatments mimicking selected water parameters of historic lake conditions. Using such a ‘resurrection ecology’ approach allows us to investigate the adaptive value of life-history differences among rotifer lineages from different sediment layers, with each layer representing a distinct period in the well-documented pollution history of Lake Orta.

 

The video shows a B. calyciflorus female carrying five male eggs.

 

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