Bettina Wachter

Dr. Bettina Wachter

orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 May 2022 in Science
Verified
Journal Article
Closed access
TBTimothée Bonnet
Timothée Bonnet
MMMichael B. Morrissey
Michael B. Morrissey
PVPierre de Villemereuil
Pierre de Villemereuil
SASusan C. Alberts
Susan C. Alberts
PAPeter Arcese
Peter Arcese
LKLoeske E. B. Kruuk
Loeske E. B. Kruuk
The rate of adaptive evolution, the contribution of selection to genetic changes that increase mean fitness, is determined by the additive genetic variance in individual relative fitness. To date, there are few robust estimates of this parameter for natural populations, and it is therefore unclear whether adaptive evolution can play a meaningful role in short-term population dynamics. We developed and applied quantitative genetic methods to long-term datasets from 19 wild bird and mammal populations and found that, while estimates vary between populations, additive genetic variance in relative fitness is often substantial and, on average, twice that of previous estimates. We show that these rates of contemporary adaptive evolution can affect population dynamics and hence that natural selection has the potential to partly mitigate effects of current environmental change.


9 June 2023 in Science
Verified
Journal Article
Closed access
MTMarlee A. Tucker
Marlee A. Tucker
ASAafke Schipper
Aafke Schipper
TATempe S. F. Adams
Tempe S. F. Adams
NANina Attias
Nina Attias
TATal Avgar
Tal Avgar
TMThomas Mueller
Thomas Mueller
COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals’ 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.

1 February 2010 in Clinical and Vaccine Immunology
Verified
Journal Article
Closed access
STSusanne Thalwitzer
Susanne Thalwitzer
BWBettina Wachter
Bettina Wachter
NRNadia Robert
Nadia Robert
GWGudrun Wibbelt
Gudrun Wibbelt
TMThomas MülLer
Thomas MülLer
HLHans Lutz
Hans Lutz
Cheetah populations are diminishing rapidly in their natural habitat. One reason for their decline is thought to be a high susceptibility to (infectious) diseases because cheetahs in zoos suffer from high disease-induced mortality. Data on the health status of free-ranging cheetahs are scarce, and little is known about their exposure and susceptibility to infectious diseases. We determined seroprevalences to nine key viruses (feline herpesvirus 1, feline calicivirus, feline parvovirus, feline coronavirus, canine distemper virus, feline immunodeficiency virus [FIV], puma lentivirus, feline leukemia virus, and rabies virus) in 68 free-ranging cheetahs on east-central Namibian farmland, 24 nonvaccinated Namibian captive cheetahs, and several other wild carnivore species and conducted necropsies of cheetahs and other wild carnivores. Eight of 11 other wild carnivores were seropositive for at least one of the viruses, including the first record of an FIV-like infection in a wild felid west of the Kalahari, the caracal (Felis caracal). Seroprevalences of the free-ranging cheetahs were below 5% for all nine viruses, which is significantly lower than seroprevalences in nonvaccinated captive cheetahs and those for five of seven viruses in previously studied free-ranging cheetahs from north-central Namibia (L. Munson, L. Marker, E. Dubovi, J. A. Spencer, J. F. Evermann, and S. J. O'Brien, J. Wildl. Dis.40:23-31, 2004). There was no clinical or pathological evidence of infectious diseases in living or dead cheetahs. The results suggest that while free-ranging wild carnivores may be a source of pathogens, the distribution of seroprevalences across studies mirrored local human population density and factors associated with human habitation, probably reflecting contact opportunities with (nonvaccinated) domestic and feral cats and dogs. They also suggest that Namibian cheetahs respond effectively to viral challenges, encouraging consistent and sustainable conservation efforts.

8 June 2012 in PLOS ONE
Verified
Journal Article
Open access
PDF file
BWBettina Wachter
Bettina Wachter
ABAnne-Sophie Blanc
Anne-Sophie Blanc
JMJörg Melzheimer
Jörg Melzheimer
OHOliver P. Höner
Oliver P. Höner
MJMark Jago
Mark Jago
HHHeribert Hofer
Heribert Hofer
The diet of free-ranging carnivores is an important part of their ecology. It is often determined from prey remains in scats. In many cases, scat analyses are the most efficient method but they require correction for potential biases. When the diet is expressed as proportions of consumed mass of each prey species, the consumed prey mass to excrete one scat needs to be determined and corrected for prey body mass because the proportion of digestible to indigestible matter increases with prey body mass. Prey body mass can be corrected for by conducting feeding experiments using prey of various body masses and fitting a regression between consumed prey mass to excrete one scat and prey body mass (correction factor 1). When the diet is expressed as proportions of consumed individuals of each prey species and includes prey animals not completely consumed, the actual mass of each prey consumed by the carnivore needs to be controlled for (correction factor 2). No previous study controlled for this second bias. Here we use an extended series of feeding experiments on a large carnivore, the cheetah (Acinonyx jubatus), to establish both correction factors. In contrast to previous studies which fitted a linear regression for correction factor 1, we fitted a biologically more meaningful exponential regression model where the consumed prey mass to excrete one scat reaches an asymptote at large prey sizes. Using our protocol, we also derive correction factor 1 and 2 for other carnivore species and apply them to published studies. We show that the new method increases the number and proportion of consumed individuals in the diet for large prey animals compared to the conventional method. Our results have important implications for the interpretation of scat-based studies in feeding ecology and the resolution of human-wildlife conflicts for the conservation of large carnivores.

7 December 2020 in Proceedings of the National Academy of Sciences
Verified
Journal Article
Open access
PDF file
JMJoerg Melzheimer
Joerg Melzheimer
SHSonja K. Heinrich
Sonja K. Heinrich
BWBernd Wasiolka
Bernd Wasiolka
RMRebekka Mueller
Rebekka Mueller
STSusanne Thalwitzer
Susanne Thalwitzer
BWBettina Wachter
Bettina Wachter
Human–wildlife conflicts occur worldwide. Although many nonlethal mitigation solutions are available, they rarely use the behavioral ecology of the conflict species to derive effective and long-lasting solutions. Here, we use a long-term study with 106 GPS-collared free-ranging cheetahs (Acinonyx jubatus) to demonstrate how new insights into the socio-spatial organization of this species provide the key for such a solution. GPS-collared territory holders marked and defended communication hubs (CHs) in the core area of their territories. The CHs/territories were distributed in a regular pattern across the landscape such that they were not contiguous with each other but separated by a surrounding matrix. They were kept in this way by successive territory holders, thus maintaining this overdispersed distribution. The CHs were also visited by nonterritorial cheetah males and females for information exchange, thus forming hotspots of cheetah activity and presence. We hypothesized that the CHs pose an increased predation risk to young calves for cattle farmers in Namibia. In an experimental approach, farmers shifted cattle herds away from the CHs during the calving season. This drastically reduced their calf losses by cheetahs because cheetahs did not follow the herds but instead preyed on naturally occurring local wildlife prey in the CHs. This implies that in the cheetah system, there are “problem areas,” the CHs, rather than “problem individuals.” The incorporation of the behavioral ecology of conflict species opens promising areas to search for solutions in other conflict species with nonhomogenous space use. Significance The cheetah is a prominent example for human–carnivore conflicts and mitigation challenges. Its global population suffered a substantial decline throughout its range. Here, we present an in-depth and new understanding of the socio-spatial organization of the cheetah. We show that cheetahs maintain a network of communication hubs distributed in a regular pattern across the landscape, not contiguous with each other and separated by a surrounding matrix. Cheetahs spend a substantial amount of their time in these hubs, resulting in high local cheetah activity, which represents a high local predation risk for livestock. Implementing this knowledge, farmers were able to reduce livestock losses by 86%.