Die Beziehungen zwischen der Reproduktionsleistung und der Körperkondition wurde in zwei Experimenten mit Awassi Schafen im Libanon untersucht. Im ersten Experiment wurden 72 Schafe in drei Altersklassen (Zutreter, primipare und multipare Mutterschafe), in zwei Körpergewichtsklassen (leichte, schwere) eingeteilt und jeweils zwei Fütterungsgruppen (ohne und mit Zufüterung) zugeordnet. Primipare und multipare Mutterschafe der Zufütterungsgruppe wiesen höhere Körperkondition, gemessen als BCS (p / The relationship between reproductive performances and body condition has been studied in 2 experiments using Awassi sheep in Lebanon. In the first exp., 72 experimental animals were grouped according to age (ewe lamb A, primiparous P, multiparous M), to body weight into small weight (SW) and large weight (LW), and kept under two management systems: traditional and improved (barley supplement). Primiparous and multiparous ewes showed a higher BCS (p

Para avaliar a quantidade ótima de energia e recursos a ser investida em reprodução, um animal deve não só acessar informações sobre sua própria condição corporal, como acessar também informações sobre coespecíficos presentes no ambiente em que vive. Este trabalho investigou essas duas vias (endógena e exógena) de obtenção de informação. Utilizando como organismo modelo a aranha Paratrechalea ornata (Trechaleidae), uma espécie em que os machos produzem presentes nupciais, este estudo investigou: (a) se machos investem mais tempo de busca quando na presença de pistas químicas de fêmeas virgens; (b) se machos aumentam ou diminuem o investimento na produção do presente nupcial quando há pistas da presença de machos competidores; (c) se restrições alimentares impõem efeitos de curto e longo prazo sobre o comportamento de construção de presentes nupciais. Machos mostraram preferência por locais com pistas da presença de fêmeas, mas não diferenciaram pistas de fêmeas virgens e copuladas. Diante de pistas da presença de um macho competidor, machos produziram presentes de menor qualidade, com menos seda. Por fim, restrições alimentares provocam efeitos de curto e longo prazo no comportamento reprodutivo dos machos, diminuindo a frequência de produção do presente nupcial e o tamanho do presente construído. Conjuntamente, os três experimentos realizados mostram que machos de P. ornata utilizam tanto informações exógenas quanto endógenas para ajustar seu investimento em reprodução. A combinação das informações obtidas deve aumentar a eficiência no gasto de energia, maximizando o sucesso reprodutivo dos machos sem que isso prejudique a manutenção de seu organismo / To evaluate the optimal amount of energy and resources to be invested in reproduction, animals should not only obtain information about their own body condition, but they should also obtain information about conspecifics in the environment where they live. This study investigated these two ways (endogenous and exogenous) of acquiring information. Using as model organism the spider Paratrechalea ornata (Trechaleidae), a species in which males produce nuptial gifts, this study investigated: (a) if males invest more time searching for sexual partners in the presence of chemical cues of virgin females; (b) if males increase or decrease the investment in nuptial gift construction in the presence of chemical cues of competitor males; (c) if food deprivation imposes short- and long-term effects on nuptial gift construction. Males showed a preference for sites with cues of females, but they did not discriminate cues of virgin from cues of copulated females. When males detected cues of a male competitor, they produced lower quality gifts, with less silk. Finally, food deprivation imposed both short- and long-term negative effects on male reproductive behavior, decreasing the frequency of nuptial gift construction and also the size of the gift. Together, the three experiments show that males of P. ornata use both exogenous as endogenous information to adjust their investment in reproduction. The combination of information obtained may increase the efficiency in energy use, maximizing male reproductive success without compromising self maintenance

The alpaca is a small South American camelid (SAC) that is an important production animal in Peru, especially among the highly impoverished communities of the high Andes, and raised for its fiber and meat. Alpacas are highly reliant on the microbes within their digestive tracts to digest the plant material they consume; volatile fatty acids (VFAs) are released as a byproduct of this microbial fermentation and used as a major source of energy by the alpaca. To explore optimal parameters for alpaca microbiome analysis, performed 16S rRNA gene surveys on alpaca C1 and fecal samples that had been extracted using one of three different DNA extraction methods (PowerFecal® DNA Isolation Kit (MO BIO); ZR Fecal DNA MiniPrep™ (Zymo); and a non-commercial extraction method called salting out) and amplified using one of two different polymerase enzyme mixes (AccuPrime™ Pfx SuperMix and 5 PRIME HotMasterMix). We found that choice of polymerase enzyme had a profound effect on the recovered microbiome, with the majority of 5 PRIME-amplified fecal samples failing to amplify. Extraction method had an effect on the recovered microbiome of fecal samples (but not C1 samples), with samples extracted using the MO BIO kit and the salting out method recovering different communities. The Zymo extraction kit returned microbial communities comparable to each of the other extraction methods. These results suggested that the AccuPrime enzyme and either the MO BIO or Zymo kits were optimal for alpaca gut microbiome analysis. We also performed two 16S rRNA gene surveys, the first from alpacas fed either a grass hay (GH) or alfalfa hay (AH) diet, and the second a C1 survey of alpacas fed two-week periods of mixed grass hay plus one of four supplements. We discovered body site and diet effects on the microbiota of alpacas fed either the GH or AH diet, with samples grouping by general body site (C1, small intestine, and distal intestine) and diet. However, we found no significant effect on the C1 microbiome of alpacas administered grain supplements. To study how energy extraction related to the microbiome, we correlated OTUs from GH/AH-fed alpaca with C1 VFA abundances. We discovered no significant correlations, and a 16S survey of low body condition (LBC) and good body condition (GBC) alpacas showed no difference in C1 microbial communities. We concluded that the microbiota of the alpaca digestive tract follow trends seen in microbiome studies of ruminants, but found no evidence of a relationship between body condition, energy extraction, and the C1 microbiome in alpacas.

This thesis was written within the framework of a biomanipulation project where young-of-the-year (YOY) pikeperch (Sander lucioperca) were stocked to a Baltic Sea bay to improve water quality through a top-down trophic cascade. The aim of my doctorial studies was however focused on a broader ecological question, namely predation (the main driving force in a biomanipulation). Hence, this thesis consists of four papers where we study the interactions between predator and prey using fish and zooplankton and how these interactions can be measured. In paper I we evaluated the performance of different diet analysis methods by individual based modelling and found that when having a nutritional gain perspective, mass based methods described diets best. Paper II investigated how the explorative, foraging and anti-predator behaviour of the YOY pikeperch used for stocking were affected by their rearing environment (pond vs. tank rearing). The more complex and varied environment in the semi-natural ponds seemed to promote a more flexible and active behaviour, better equipping young fish for survival in the wild. For paper III we studied the diel vertical migration in the six copepodite stages of the zooplankton Acartia spp. and Eurytemora affinis in relation to fish biomass, phytoplankton abundance and temperature. Both species migrated and in addition showed increased migration range with size within species, indicating evasion from visual predators. Paper IV addressed the movement of littoral Eurasian perch (Perca fluviatilis) via stable isotope signatures (13C and 15N) and body condition. We found clear indications of sedentarity and intra-habitat dietary differences. Interactions between predators and prey are complex and affected by both physiological and environmental characteristics as well as behavioural traits. The results in this thesis suggest that different species and even different life stages pursue different strategies to survive. / At the time of doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Submitted.  Paper 2: In press.  Paper 4: Submitted.

<p>The principle objective of this investigation was to develop an understanding of the physiological response and ecological aspects of winter torpor of small carnivores, specifically striped skunks (<i>Mephitis mephitis</i>) in the northern environment. An experiment was undertaken to investigate the physiological response of skunks to solitary and communal over-winter strategies. Solitary skunks were able to undergo daily torpor to conserve energy to survive the winter, whereas communal skunks were able to use social huddling to reduce energy expenditure and rarely entered torpor. Due to seasonal changes in life requirements, den selection criteria change throughout the year. I examined the landscape metrics and habitat characteristics surrounding dens to evaluate the hierarchical selection and use of dens during winter (i.e., for torpor) and summer (i.e., for parturition). Den structures commonly used for winter dens were buildings, whereas den structures used for maternity dens were rockpiles and underground burrows. Habitat surrounding den sites influenced den use; animals chose den sites closer to roads, water sources, habitat edges, and crop fields. Seasonal movements of skunks from winter dens to the following summer home ranges were examined with respect to winter grouping (i.e., solitary or communal) and winter den structure (i.e., underground burrow or building) to investigate factors that influence spatial distribution of skunks. Male and female skunks moved similar distances (~1.5 km) from winter dens to the center of home ranges established in summer, irrespective of winter grouping status and winter den structure use. Due to limited movement in spring, skunks from communal winter dens had higher spatial overlap of summer home ranges than did skunks from solitary dens, producing spatial aggregation of skunk activities surrounding winter communal den sites. Consequently, winter communal dens represent localized hotspots in the landscape. The effects of extrinsic variables (i.e., environment and diseases) and intrinsic characteristics (i.e., age, gender, and body condition) on cumulative winter survival rate were examined. Winter survival rates were driven mostly by winter condition (i.e., low ambient temperature and snow depth), rabies, and body condition. These results suggest that winter severity probably poses a limit on the northern distribution of the species.</p>

Two closely-related, different-sized species of geese nest sympatrically south of the Queen Maud Gulf (QMG) in Canadas central arctic. Following a period of high population growth rate in both species within the QMG, the population growth rate of larger-bodied lesser snow geese (Chen caerulescens caerulescens; hereafter snow geese) has slowed most recently to roughly half that observed in smaller-bodied Rosss geese (Chen rossii). I focused on factors that influence productivity and recruitment in these two species, to improve our understanding of life history variation associated with interspecific differences in body size, and to test for density-dependent population responses. I used long-term data (1991 to 2008) to compare spring nutrient reserves, breeding strategies, clutch sizes, nest success, and juvenile survival in Rosss and snow geese breeding at Karrak Lake, Nunavut; a large breeding colony located within the QMG.<p> Long-term patterns of spring body condition (i.e., fat and protein reserves) diverged in prospective breeding female Rosss and snow geese implying that differences in food acquisition ability had become more acute. Snow geese displayed larger reductions in protein and fat reserves through time compared to Rosss geese thereby suggesting a differential density-dependent response in the ability to store nutrient reserves, a prerequisite for breeding in both species. Decreased per capita food availability influenced the timing of reproduction in both species. Nesting phenologies of Rosss and snow geese, adjusted for variation in phenology of local spring climate, have become later by 6.5 and 5.0 days, respectively, since 1991. Nutritional strategies (i.e., reliance on reserves versus local food) used for clutch formation differed between species. Rosss geese displayed greater reliance on stored reserves (i.e., capital breeding) than did snow geese, though both used endogenous reserves (> 62% of yolk protein, > 48% of albumen, and > 73% of yolk lipid) for clutch formation. Rosss and snow geese experienced declines of 28% and 23% in body masses from arrival to post-laying and also until hatch demonstrating that endogenous reserves are the main nutrient sources for incubation. Still, constraints of small size forced Rosss geese to use a mixture of local food plants and reserves for incubation metabolism.<p> I then examined differences in clutch size, nest success, and juvenile survival to understand of the role of recruitment in the interspecific divergence of population trajectories. I did not find strong interspecific differences in clutch size and nest success. Overall, snow geese had a larger mean clutch size, which was expected based on benefits of a larger-body size. Clutch sizes decreased with delays in breeding and decreasing protein reserves of arriving females, although Rosss geese displayed larger declines with decreasing protein reserves. Mean apparent nest success for Rosss geese was 4.5% higher compared to snow geese. Nest success showed large declines (11%) in both species with increasing population size at the breeding colony. However, nest success of snow geese decreased twice as fast with delays in breeding compared to Rosss geese. Last, I found no evidence of negative density dependence in juvenile survival over time. Juvenile survival was higher in snow geese (48%) compared to Rosss geese (38%), consistent with a life history prediction based on body size differences. Despite lower juvenile survival, recruitment by Rosss geese is likely greater than that of snow geese because of earlier sexual maturity, higher breeding probability and/or greater nest success.<p> Ultimately, small body size of Rosss geese may produce an ideal life history schedule under resource limitation at this colony i.e., one that maximizes fitness compared to larger snow geese. Life history characteristics of Rosss geese (e.g., absolutely lower energy requirement, have a flexible breeding strategy, higher reproductive effort, an earlier age of sexual maturity, a shorter breeding cycle allowing delayed arrival and nest initiation on arctic breeding areas, and shorter time required by goslings to attain adult size), in addition to their smaller bill morphology may allow exploitation of a wider niche space (i.e., one that includes marginal quality and low quantity vegetation) relative to snow geese. Because there were no large differences in components of recruitment considered here, other components of recruitment (age of sexual maturity, breeding probability) may be affected more strongly by diminished spring nutrition in snow geese and thus have a larger influence on local population dynamics.

<p>The principle objective of this investigation was to develop an understanding of the physiological response and ecological aspects of winter torpor of small carnivores, specifically striped skunks (<i>Mephitis mephitis</i>) in the northern environment. An experiment was undertaken to investigate the physiological response of skunks to solitary and communal over-winter strategies. Solitary skunks were able to undergo daily torpor to conserve energy to survive the winter, whereas communal skunks were able to use social huddling to reduce energy expenditure and rarely entered torpor. Due to seasonal changes in life requirements, den selection criteria change throughout the year. I examined the landscape metrics and habitat characteristics surrounding dens to evaluate the hierarchical selection and use of dens during winter (i.e., for torpor) and summer (i.e., for parturition). Den structures commonly used for winter dens were buildings, whereas den structures used for maternity dens were rockpiles and underground burrows. Habitat surrounding den sites influenced den use; animals chose den sites closer to roads, water sources, habitat edges, and crop fields. Seasonal movements of skunks from winter dens to the following summer home ranges were examined with respect to winter grouping (i.e., solitary or communal) and winter den structure (i.e., underground burrow or building) to investigate factors that influence spatial distribution of skunks. Male and female skunks moved similar distances (~1.5 km) from winter dens to the center of home ranges established in summer, irrespective of winter grouping status and winter den structure use. Due to limited movement in spring, skunks from communal winter dens had higher spatial overlap of summer home ranges than did skunks from solitary dens, producing spatial aggregation of skunk activities surrounding winter communal den sites. Consequently, winter communal dens represent localized hotspots in the landscape. The effects of extrinsic variables (i.e., environment and diseases) and intrinsic characteristics (i.e., age, gender, and body condition) on cumulative winter survival rate were examined. Winter survival rates were driven mostly by winter condition (i.e., low ambient temperature and snow depth), rabies, and body condition. These results suggest that winter severity probably poses a limit on the northern distribution of the species.</p>

Two closely-related, different-sized species of geese nest sympatrically south of the Queen Maud Gulf (QMG) in Canadas central arctic. Following a period of high population growth rate in both species within the QMG, the population growth rate of larger-bodied lesser snow geese (Chen caerulescens caerulescens; hereafter snow geese) has slowed most recently to roughly half that observed in smaller-bodied Rosss geese (Chen rossii). I focused on factors that influence productivity and recruitment in these two species, to improve our understanding of life history variation associated with interspecific differences in body size, and to test for density-dependent population responses. I used long-term data (1991 to 2008) to compare spring nutrient reserves, breeding strategies, clutch sizes, nest success, and juvenile survival in Rosss and snow geese breeding at Karrak Lake, Nunavut; a large breeding colony located within the QMG.<p> Long-term patterns of spring body condition (i.e., fat and protein reserves) diverged in prospective breeding female Rosss and snow geese implying that differences in food acquisition ability had become more acute. Snow geese displayed larger reductions in protein and fat reserves through time compared to Rosss geese thereby suggesting a differential density-dependent response in the ability to store nutrient reserves, a prerequisite for breeding in both species. Decreased per capita food availability influenced the timing of reproduction in both species. Nesting phenologies of Rosss and snow geese, adjusted for variation in phenology of local spring climate, have become later by 6.5 and 5.0 days, respectively, since 1991. Nutritional strategies (i.e., reliance on reserves versus local food) used for clutch formation differed between species. Rosss geese displayed greater reliance on stored reserves (i.e., capital breeding) than did snow geese, though both used endogenous reserves (> 62% of yolk protein, > 48% of albumen, and > 73% of yolk lipid) for clutch formation. Rosss and snow geese experienced declines of 28% and 23% in body masses from arrival to post-laying and also until hatch demonstrating that endogenous reserves are the main nutrient sources for incubation. Still, constraints of small size forced Rosss geese to use a mixture of local food plants and reserves for incubation metabolism.<p> I then examined differences in clutch size, nest success, and juvenile survival to understand of the role of recruitment in the interspecific divergence of population trajectories. I did not find strong interspecific differences in clutch size and nest success. Overall, snow geese had a larger mean clutch size, which was expected based on benefits of a larger-body size. Clutch sizes decreased with delays in breeding and decreasing protein reserves of arriving females, although Rosss geese displayed larger declines with decreasing protein reserves. Mean apparent nest success for Rosss geese was 4.5% higher compared to snow geese. Nest success showed large declines (11%) in both species with increasing population size at the breeding colony. However, nest success of snow geese decreased twice as fast with delays in breeding compared to Rosss geese. Last, I found no evidence of negative density dependence in juvenile survival over time. Juvenile survival was higher in snow geese (48%) compared to Rosss geese (38%), consistent with a life history prediction based on body size differences. Despite lower juvenile survival, recruitment by Rosss geese is likely greater than that of snow geese because of earlier sexual maturity, higher breeding probability and/or greater nest success.<p> Ultimately, small body size of Rosss geese may produce an ideal life history schedule under resource limitation at this colony i.e., one that maximizes fitness compared to larger snow geese. Life history characteristics of Rosss geese (e.g., absolutely lower energy requirement, have a flexible breeding strategy, higher reproductive effort, an earlier age of sexual maturity, a shorter breeding cycle allowing delayed arrival and nest initiation on arctic breeding areas, and shorter time required by goslings to attain adult size), in addition to their smaller bill morphology may allow exploitation of a wider niche space (i.e., one that includes marginal quality and low quantity vegetation) relative to snow geese. Because there were no large differences in components of recruitment considered here, other components of recruitment (age of sexual maturity, breeding probability) may be affected more strongly by diminished spring nutrition in snow geese and thus have a larger influence on local population dynamics.

Body size is an important determinant of reproduction in capital breeding animals, including large mammals. However, it is not always practical to hand-measure body size of free-ranging species. In recent years, parallel-laser photogrammetry has been used to obtain remote estimates of body size for some animals, though it remains unknown how well this technique might capture variation in curvilinear body features or if the distance between parallel-laser calipers is altered when projected onto a curved surface. In this thesis, I describe a photogrammetric system that may be useful for obtaining body-size measurements from unrestrained large mammals that permit approach, using domestic horses (Equus ferus caballus) as a model (Chapter 2). I then apply this technique in the field to a wild (feral) population of horses at Sable Island National Park Reserve, Nova Scotia, Canada, where I include body size measurements as variables in a detailed analysis of factors affecting reproduction in females (Chapter 3). Using my parallel-laser photogrammetric system, I show how curvilinear hand-measurements (e.g., across the barrel of a horse) are stongly correlated with their respective linear photogrammetric estimates (R2 ≥ 0.998), and most photogrammetric estimates using my system had high reliability. Using three variables of body size, photogrammetric estimates and hand-measurements explained 86.0% and 96.2%, respectively, of the variation in body weight of a sample of domestic Newfoundland ponies. On Sable Island, Nova Scotia, I examined the relationship of numerous variables (including skeletal body size and body condition) with the probability of yearly reproductive success for female Sable Island horses (years 2008–2012), where I define reproductive success as production of an offspring surviving to one year of age. Age class was a dominant factor predicting reproductive success, as expected from trends previously associated with body size or reproductive experience iii in other populations. Age-class specific energy budgets or social and sexual behaviour caused a more pronounced relationship with body condition at parturition in sub-adults, and body condition at conception and stability of consort relationships were associated with reproductive success in adults. In addition, relationships with local density suggested limited forage around the time of conception and limited water during lactation might also influence reproductive success in adult females. Although relationships were evident for age class, which is correlated with body size, reproductive success was not related to skeletal body size, past reproductive experience, age of primiparity, or band structure. The capital breeding strategy and year-round social associations seen in horses make their reproductive ecology a combination of patterns observed for large ungulates and social primates.

A primary focus of wildlife research is to understand how habitat conditions and human activities impact the health of wild animals. External factors, both natural and anthropogenic that impact the ability of an animal to acquire food and build energy reserves have important implications for reproductive success, avoidance of predators, and the ability to withstand disease, and periods of food scarcity. In the analyses presented here, I quantify the impacts of habitat quality and anthropogenic disturbance on indicators of health for individuals in a threatened grizzly bear population in Alberta, Canada. The first analysis relates spatial patterns of hair cortisol concentrations, a promising indicator of long-term stress in mammals, measured from 304 grizzly bears to a variety of continuous environmental variables representative of habitat quality (e.g., crown closure, landcover, and vegetation productivity), topographic conditions (e.g., elevation and terrain ruggedness), and anthropogenic disturbances (e.g., roads, forest harvest blocks, and oil and gas well-sites). Hair cortisol concentration point data were integrated with continuous variables by creating a stress surface for male and female bears using kernel density estimation validated through bootstrapping. The relationships between hair cortisol concentrations for males and females and environmental variables were quantified using random forests, and landscape scale stress levels for both genders was predicted based on observed relationships. Low female stress levels were found to correspond with regions with high levels of anthropogenic disturbance and activity. High female stress levels were associated primarily with high-elevation parks and protected areas. Conversely, low male stress levels were found to correspond with parks and protected areas and spatially limited moderate to high stress levels were found in regions with greater anthropogenic disturbance. Of particular concern for conservation is the observed relationship between low female stress and sink habitats which have high mortality rates and high energetic costs. Extending the first analysis, the second portion of this research examined the impacts of scale-specific habitat selection and relationships between biology, habitat quality, and anthropogenic disturbance on body condition in 85 grizzly bears represented using a body condition index. Habitat quality and anthropogenic variables were represented at multiple scales using isopleths of a utilization distribution calculated using kernel density estimation for each bear. Several hypotheses regarding the influence of biology, habitat quality, and anthropogenic disturbance on body condition quantified using linear mixed-effects models were evaluated at each habitat selection scale using the small sample Aikake Information Criterion. Biological factors were influential at all scales as males had higher body condition than females, and body condition increased with age for both genders. At the scale of most concentrated habitat selection, the biology and habitat quality hypothesis had the greatest support and had a positive effect on body condition. A component of biology, the influence of long-term stress, which had a negative impact on body condition, was most pronounced within the biology and habitat quality hypothesis at this scale. As the scale of habitat selection was represented more broadly, support for the biology and anthropogenic disturbance hypothesis increased. Anthropogenic variables of particular importance were distance decay to roads, density of secondary linear features, and density of forest harvest areas which had a negative relationship with body condition. Management efforts aimed to promote landscape conditions beneficial to grizzly bear health should focus on promoting habitat quality in core habitat and limiting anthropogenic disturbance within larger grizzly bear home ranges. / Graduate / 0768 / 0463 / 0478 / mathieub@uvic.ca