5 research outputs found
Short- and long-term physiological effects of capture and handling on free-ranging brown bears (Ursus arctos)
PHD in Applied ecology, Evenstad 2017Brown bears (Ursus arctos) are captured and handled for conservation, research or management purposes. However, capture and handling have potential to cause injury and stress, thus, negatively impacting an animal’s health. The evaluation of behavioural and physiological effects of capture and handling can provide science-based information to better understand the impact of capture and handling on wildlife health, refine techniques and minimize adverse effects. The main goal of my thesis was to assess the short- and long-term physiological effects of capture and handling on free-ranging brown bears in association with two long-term research projects, one in Scandinavia, and the other in Alberta, Canada. For this, I conducted three studies to: i) evaluate the acute stress response to capture and handling by using a field-based technique called the leukocyte coping capacity (LCC), ii) compare two different anaesthetic protocols based on the behavioural and physiological short-term responses of captured bears and iii) assess the long-term effects of capture, handling and surgery on the body condition of independent male bears. In my first study, I found that LCC values measured in blood samples collected at 30 minutes following capture were significantly lower in solitary bears (n = 12) than in bears living in family groups (n = 12) which could suggest that mothers and their dependent offspring had greater capacity to cope with captureinduced stress. In addition, LCC values for blood samples collected at approximately 90 minutes following capture were directly correlated with an index used to estimate body condition which suggests the better a bear’s body condition, the better its capacity to cope with stress. I also found that the LCC values at 90 minutes following capture did not appear to differ between 19 bears that had abdominal surgery to implant or remove radio transmitters, physiological sensors and/or temperature loggers, and five bears that did no undergo surgery. Although further evaluation of this technique is required, my results from this preliminary study provide support for the use of the LCC technique as a field-based, quantitative measure of stress. In my second study, I found that intramuscular injection of either dexmedetomidine-tiletamine-zolazepam (DTZ), a new anaesthetic protocol, or medetomidine-tiletamine-zolazepam (MTZ), an established anaesthetic protocol, induced anaesthesia of free-ranging brown bears captured by helicopter (n = 34) or by culvert trap (n = 6) in a smooth and predictable manner with no difference in induction times between the two anaesthetic protocols. Both protocols also caused acidemia (pH of arterial blood < 7.35), hypoxaemia (partial pressure of arterial oxygen < 80 mmHg), and hypercapnia (partial pressure of arterial carbon dioxide ≥ 45 mmHg) to a similar degree. Based on the absence of significant differences in these measurements and in other behavioural and physiological measurements (i.e., the need for supplemental drugs to sustain anaesthesia, serum cortisol, heart and respiratory rates, rectal temperature), I concluded that DTZ offered no advantage over the use of MTZ in the anaesthesia of brown bears. In my third study, I found that the
body condition of independent male brown bears (n = 551), estimated as a body condition index (BCI) validated for ursids, was associated with the age of the bear, the day the capture occurred, and the area of study. BCI was positively associated with the age of the bear and the ordinal day of capture. Thus, older bears and bears captured later in the year had higher BCI values. I also found a weak difference in the bear’s BCI between study areas. BCI values tended to be higher for bears in Scandinavian than bears in Alberta irrespective of the annual timing of captures, the year of capture, or the age composition of captured animals. However, BCI values did not appear to be influenced by capture, handling, and surgery. Although no measureable long-term effect on BCI was found in independent male brown bears, future studies should be conducted to determine if the same holds true for other sex, age, and reproductive classes. Further, studies assessing long-term effects of capture and handling are needed to determine if research procedures are inadvertently biasing research results.
The findings of this thesis provide scientific evidence that capture and handling caused significant short-term physiological effects on the bears, although no long-term effect on their body condition was detected. I believe that this type of self-assessment of potential effects caused by capture and handling of wildlife is essential to fully understanding the overall impact of anthropogenic activities on wildlife health, and to better interpreting research results. By establishing the extent of the effects of research activities on an animals’ physiology, researchers can take measures to reduce their impact on the welfare and health of wildlife, and make better informed-decisions in relation to the use of capture and handling proceduresBrunbjørner (Ursus arctos) fanges for ulike forsknings- og forvaltningsformål. Dette kan imidlertid forårsake skader og stress og ha negative innvirkning på dyrenes helse. En vitenskapelig evaluering av konsekvenser av fangst og håndtering vil derfor gi grunnlag for forstå helsemessige effekter, forbedre metoder og minimere uheldig påvirkning. Avhandlingens hovedformål var å vurdere fysiologiske effekter av fangst og håndtering av viltlevende bjørner i to pågående forskningsprosjekter, henholdsvis i Skandinavia og i Alberta, Canada. Jeg utførte tre studier: i) evaluering av den akutte stressresponsen på fangst og håndtering med en feltbasert metode kalt “leukocyte coping capacity” (LCC), ii) sammenligning av to ulike anestesiprotokoller med hensyn på fysiologiske korttidseffekter, iii) vurdering av langtidseffekter av fangst og håndtering på kroppskondisjonen til enslige hannbjørner. I min første studie fant jeg at LCC-verdiene målt i blodprøver tatt 30 minutter etter fangst, var signifikant lavere hos enslige bjørner (n = 12) sammenlignet med bjørner i en en familiegruppe (n = 12), noe som kan indikere at binner og unger var bedre i stand til å håndtere fangst-relatert stress. I tillegg var LCC-verdier målt ca. 90 minutter etter fangst direkte korrelert med en indeks for kroppskondisjon, noe som indikerer at jo bedre
kroppskondisjonen er, jo bedre er bjørnen i stand til å håndtere stress. Jeg fant også at det ikke var noen forskjell på LCC-verdiene målt 90 minutter etter fangst hos 19 bjørner som ble operert for å implantere eller fjerne radiosendere eller biologgere sammenlignet med fem bjørner som ikke ble operert. Selv om dette krever flere undersøkelser, støtter mine resultater bruk av LCC-teknikken som en feltbasert, kvantitativ metode for måling av stress. I min andre studie fant jeg ingen forskjeller i induksjonstiden mellom en ny anestesikombinasjon, dexmedetomidine-tiletamine-zolazepam (DTZ), og en velprøvd anestesikombinasjon, medetomidine-tiletamine-zolazepam (MTZ); begge induserte anestesi hos bjørner anestesert fra helikopter (n = 34) eller i tunelfelle (n = 6) som forventet. Begge kombinasjoner forårsaket tilsvarende acidemi (pH i arterielt blod < 7.35), hypoksemi (partialtrykk av oksygen i arterielt blod < 80 mmHg), and hyperkapni (partialtrykk av karbondioksid i arterielt blod ≥ 45 mmHg) hos bjørnene. Basert på fravær av signifikante forskjeller for disse og andre fysiologiske målinger (f. eks. behov for ekstra medikamenter for å opprettholde anestesien, kortisol i serum, hjertfrekvens, rektalteperatur), konkluderte jeg med at DTZ ikke ga noen fordeler sammenlignet med MTZ for anestesi av bjørner. In min tredje studie fant jeg at kroppskondisjonen hos enslige hannbjørner (n = 551),, estimert som en indeks (BCI) validert for bjørner, var korrelert med alder, dato for fangsten og studieområde. BCI økte med alder og forløpet av fangstsesongen. BCI tenderte til å være høyere hos skandinaviske bjørner sammenlignet med bjørner i Alberta, uavhengig av fangstdato, fangstår og alder. BCI var tilsynelatende ikke påvirket av fangst, håndtering eller kirurgi. Selv om det ikke ble funnet noen målbare langtiseffekter på BCI hos enslige hannbjørner, bør det gjennomføres flere studier av andre grupper av bjørner med hensyn på alder, kjønn og reproduksjonsstatus. I tillegg er det viktig å avklare om mulige langtidseffekter av fangst og håndtering kan påvirke forskningsresultater. Selv om det ikke ble funnet langtidseffekter på kroppskondisjonen, viser
resultatene i denne avhandlingen at fangst og håndtering av bjørner forårsaker betydelige fysiologiske korttidseffekter. Jeg mener at denne formen for selvevaluering er essensiell for å forstå konsekvensen av menneskelig påvirkning av viltlevende dyr og for å kunne tolke forskningsresultater. På denne måten kan forskere gjøre kunnskapsbaserte valg når det gjelder metoder for fangst og håndtering
Chewing lice Trichodectes pinguis pinguis in Scandinavian brown bears ( Ursus arctos )
In April 2014 and 2015, we noted localized alopecia (neck, forelimbs, and chest) and hyperpigmentation
on two adult brown bears (Ursus arctos) captured in central-south Sweden for ecological studies under
the Scandinavian Brown Bear Research Project. In spring 2015, a brown bear was shot because of human-
wildlife conflict in the same region. This bear also had extensive alopecia and hyperpigmentation. Ec-
toparasites were collected from the affected skin areas in all three individuals and preserved in ethanol
for identification. Based on morphological characteristics, the lice were identified as Trichodectes spp. and
Trichodectes pinguis pinguis. To our knowledge, these are the first reported cases of chewing lice in free-
ranging brown bears in Scandinavia
Short- and long-term physiological effects of capture and handling on free-ranging brown bears (Ursus arctos)
Brown bears (Ursus arctos) are captured and handled for conservation, research or management purposes. However, capture and handling have potential to cause injury and stress, thus, negatively impacting an animal’s health. The evaluation of behavioural and physiological effects of capture and handling can provide science-based information to better understand the impact of capture and handling on wildlife health, refine techniques and minimize adverse effects. The main goal of my thesis was to assess the short- and long-term physiological effects of capture and handling on free-ranging brown bears in association with two long-term research projects, one in Scandinavia, and the other in Alberta, Canada. For this, I conducted three studies to: i) evaluate the acute stress response to capture and handling by using a field-based technique called the leukocyte coping capacity (LCC), ii) compare two different anaesthetic protocols based on the behavioural and physiological short-term responses of captured bears and iii) assess the long-term effects of capture, handling and surgery on the body condition of independent male bears. In my first study, I found that LCC values measured in blood samples collected at 30 minutes following capture were significantly lower in solitary bears (n = 12) than in bears living in family groups (n = 12) which could suggest that mothers and their dependent offspring had greater capacity to cope with captureinduced stress. In addition, LCC values for blood samples collected at approximately 90 minutes following capture were directly correlated with an index used to estimate body condition which suggests the better a bear’s body condition, the better its capacity to cope with stress. I also found that the LCC values at 90 minutes following capture did not appear to differ between 19 bears that had abdominal surgery to implant or remove radio transmitters, physiological sensors and/or temperature loggers, and five bears that did no undergo surgery. Although further evaluation of this technique is required, my results from this preliminary study provide support for the use of the LCC technique as a field-based, quantitative measure of stress. In my second study, I found that intramuscular injection of either dexmedetomidine-tiletamine-zolazepam (DTZ), a new anaesthetic protocol, or medetomidine-tiletamine-zolazepam (MTZ), an established anaesthetic protocol, induced anaesthesia of free-ranging brown bears captured by helicopter (n = 34) or by culvert trap (n = 6) in a smooth and predictable manner with no difference in induction times between the two anaesthetic protocols. Both protocols also caused acidemia (pH of arterial blood < 7.35), hypoxaemia (partial pressure of arterial oxygen < 80 mmHg), and hypercapnia (partial pressure of arterial carbon dioxide ≥ 45 mmHg) to a similar degree. Based on the absence of significant differences in these measurements and in other behavioural and physiological measurements (i.e., the need for supplemental drugs to sustain anaesthesia, serum cortisol, heart and respiratory rates, rectal temperature), I concluded that DTZ offered no advantage over the use of MTZ in the anaesthesia of brown bears. In my third study, I found that the
body condition of independent male brown bears (n = 551), estimated as a body condition index (BCI) validated for ursids, was associated with the age of the bear, the day the capture occurred, and the area of study. BCI was positively associated with the age of the bear and the ordinal day of capture. Thus, older bears and bears captured later in the year had higher BCI values. I also found a weak difference in the bear’s BCI between study areas. BCI values tended to be higher for bears in Scandinavian than bears in Alberta irrespective of the annual timing of captures, the year of capture, or the age composition of captured animals. However, BCI values did not appear to be influenced by capture, handling, and surgery. Although no measureable long-term effect on BCI was found in independent male brown bears, future studies should be conducted to determine if the same holds true for other sex, age, and reproductive classes. Further, studies assessing long-term effects of capture and handling are needed to determine if research procedures are inadvertently biasing research results.
The findings of this thesis provide scientific evidence that capture and handling caused significant short-term physiological effects on the bears, although no long-term effect on their body condition was detected. I believe that this type of self-assessment of potential effects caused by capture and handling of wildlife is essential to fully understanding the overall impact of anthropogenic activities on wildlife health, and to better interpreting research results. By establishing the extent of the effects of research activities on an animals’ physiology, researchers can take measures to reduce their impact on the welfare and health of wildlife, and make better informed-decisions in relation to the use of capture and handling procedure
Leukocyte coping capacity as a tool to assess capture- and handling-induced stress in Scandinavian brown bears (Ursus arctos)
Brown bears (Ursus arctos) are often captured and handled for research and management purposes. Although the techniques used are potentially stressful for the animals and might have detrimental and long-lasting consequences, it is difficult to assess their physiological impact. Here we report the use of the leukocyte coping capacity (LCC) technique to quantify the acute stress of capture and handling in brown bears in Scandinavia. In April and May 2012 and 2013, we collected venous blood samples and recorded a range of physiological variables to evaluate the effects of capture and the added impact of surgical implantation or removal of transmitters and sensors. We studied 24 brown bears, including 19 that had abdominal surgery. We found 1) LCC values following capture were lower in solitary bears than in bears in family groups suggesting capture caused relatively more stress in solitary bears, 2) ability to cope with handling stress was better (greater LCC values) in bears with good body condition, and 3) LCC values did not appear to be influenced by surgery. Although further evaluation of this technique is required, our preliminary results support the use of the LCC technique as a quantitative measure of stress
Chewing lice Trichodectes pinguis pinguis in Scandinavian brown bears ( Ursus arctos )
In April 2014 and 2015, we noted localized alopecia (neck, forelimbs, and chest) and hyperpigmentation
on two adult brown bears (Ursus arctos) captured in central-south Sweden for ecological studies under
the Scandinavian Brown Bear Research Project. In spring 2015, a brown bear was shot because of human-
wildlife conflict in the same region. This bear also had extensive alopecia and hyperpigmentation. Ec-
toparasites were collected from the affected skin areas in all three individuals and preserved in ethanol
for identification. Based on morphological characteristics, the lice were identified as Trichodectes spp. and
Trichodectes pinguis pinguis. To our knowledge, these are the first reported cases of chewing lice in free-
ranging brown bears in Scandinavia