An increasing trend in mass mortality events (MMEs) has been observed in recent years, leading to an increased study of these events and their causes. Still to be investigated are the immediate and long-term effects of these environmental disturbances. Microbial communities found on and within the carcass are a major contributor to decomposition. With an increased biomass from several carcasses, transfer of these microbes to secondary death events may be affected. For this project, several simulated MMEs were used in conjunction with a secondary death event to observe the effects of transfer between the microbial communities and changes in the communities over time. It was found that microbial diversity decreases over time as decomposition progresses, and that an initial difference which can be observed between skin and internal microbial communities homogenizes over time. This result will contribute to an understanding of microbial succession and the impact of increasing MMEs.

Mass mortality events (MMEs) are die-offs that result in increased carrion biomass and sometimes the impairment of functional roles. Concurrently, several vulture species are declining. Carrion is a basal resource in ecosystems and its recycling by vultures is considered an ecosystem service. However, the consequences of simultaneously increasing carrion loads and declining vulture populations are unknown. I developed a theoretical framework predicting that, with increasing carrion biomass, carrion food web diversity would increase horizontally and vertically, respectively increasing and decreasing carrion recycling efficiency. Using a manipulative experiment, I investigated the role of bottom-up and top-down forces affecting plant communities during an MME. I selected 5 sites to establish 6 treatments crossing different levels of carrion addition and nutrient addition, and control with vertebrate scavenger and herbivore access. I transplanted six cherrybark oak (Quercus pagoda) seedlings to each plot, protecting half of them from herbivory. Carrion biomass shifted dominance of plant functional groups to favor annual plants, an effect reduced by scavenger access. Herbivore access affected plant community response to carrion and limited growth and survival of transplanted seedlings regardless of treatment. Nutrient addition did not affect plant communities, growth, and survival suggesting that MME effects on plants are likely mediated primarily by top-down forces. To determine if behavioral plasticity of vultures affects carrion recycling efficiency, I monitored turkey (Cathartes aura) and black (Coragyps atratus) vulture behavior. Both species increased group size, but only black vultures increased individuals feeding per group and activity overlap between species increased with increasing carrion biomass. As a result, estimated carrion consumption by vultures increased with carrion biomass suggesting behavioral plasticity may alleviate some of the effects of vulture declines on carrion recycling. Finally, vultures compete with invertebrate scavengers so declining vultures may release their populations to compensate for the loss. However, in one of my experiments, variation in vulture visitation was negatively correlated with the abundance of blowflies parasitized by Entomophthora sp. Our observations may suggest that vultures were more likely mediating carrion decomposition affecting parasitism, which may limit blowflies from compensating for declining vultures.

Mass mortality events (MMEs) can affect communities through large amounts of carcass biomass and significant reductions in population sizes. I conducted laboratory experiments to compare effects of predator and herbivore MMEs on a community using a study system of convergent lady beetles (Hippodamia convergens), pea aphids (Acyrthosiphon pisum), and fava beans (Vicia faba). I used a factorial design crossing input (addition of carcasses) and mortality (removing 75% of the population) of aphids and lady beetles. Lady beetle mortality reduced the top-down pressure on the aphid population, which increased aphid abundance and decreased plant height. Input of aphid carcasses increased aphid abundance. Input and mortality of aphids caused the aphid population to diminish suggesting that top-down effects of mortality were more significant than bottom-up effects of carcasses. My results show that MMEs can have effects through both bottom-up and top-down processes, which is dependent upon who experiences the MME.

No description available.

No description available.

Além de sua importância ecológica para o ecossistema manguezal, o caranguejo-uçá (Ucides cordatus cordatus) é um importante recurso pesqueiro para comunidades de baixa renda do Brasil. Eventos de mortalidade em massa desta espécie têm sido registrados ao longo de vários manguezais da costa da Região Nordeste. A primeira etapa deste trabalho foi realizada de outubro/2003 a outubro/2004 e teve como objetivo estudar a dinâmica populacional do caranguejo-uçá em zonas de um manguezal do Município de Canavieiras/BA (afetado pela mortalidade em massa), comparando-o com zonas de um manguezal do Município de Caravelas/BA (não afetado pela mortalidade em massa). Após o término desta primeira etapa, a mortalidade em massa atingiu manguezais de Caravelas, iniciando-se então a segunda etapa, que teve como objetivo descrever e quantificar os efeitos deste fenômeno neste local em janeiro/2005 e julho/2005. Em Canavieiras e Caravelas, foram amostrados mensalmente 4 quadrados aleatórios de 5 X 5m em uma zona de L. racemosa (mangue branco ou manso) na margem do canal, 4 em uma zona intermediária de R. mangle (mangue vermelho) e 4 em uma zona de apicum, na transição entre o manguezal e a terra firme. Dentro dos quadrados, todas as aberturas de galerias de U. cordatus cordatus foram contadas e medidas, e um coletor de caranguejos removeu, quando possível, o caranguejo correspondente para biometria. Também foi registrada a presença de caranguejos em processo de ecdise, de fêmeas ovígeras, de galerias tapadas e galerias vazias. Adicionalmente, foram feitas estimativas da inundação dos quadrados amostrados, com base na faixa de algas nos troncos dos mangues. Através de uma regressão linear da variável menor diâmetro de abertura de galeria em função do comprimento do cefalotórax, chegou-se a uma equação de reta que permitiu a transformação de todas as medidas de galeria em medidas de comprimento de caranguejo. Foi observado que, quanto maior a inundação da zona, maior o comprimento dos caranguejos que nela habitam e que a maior freqüência de caranguejos de pequeno porte nas zonas menos x inundadas, deve-se ao fato do recrutamento ocorrer neste ambiente. Em Canavieiras, foram registrados, em campo, 113 recrutas (comprimento<0,9cm), todos dentro de galerias de outros caranguejos encontrados em áreas pouco inundadas, principalmente no limite inferior da zona de apicum. Os picos de recrutamento ocorreram de junho a outubro de 2004, indicando que os recrutas tinham cerca de 3 meses de idade. A confirmação de que o apicum funciona como um berçário para o caranguejo-uçá reforça a importância de preservação deste ambiente. A sub-população estudada em Canavieiras apresentou um aumento da densidade populacional e um deslocamento da moda para classes de comprimento maiores. Esta aparente recuperação pode estar ligada ao súbito aparecimento de caranguejos escondidos em suas galerias ou à migração de indivíduos vindos de zonas não afetadas. Canavieiras apresentou densidade populacional e comprimento médio de U. cordatus cordatus significativamente menores que Caravelas, indicando que, aparentemente, sua sub-população de caranguejos ainda não se recuperara totalmente da mortalidade em massa. Em Caravelas, registrou-se uma distribuição espacial diferenciada de machos, predominantes nas zonas mais inundadas de R. mangle, e de fêmeas, que predominaram nas zonas menos inundadas de L. racemosa, na margem do canal. Durante a ocorrência da mortalidade em massa de U. cordatus cordatus em Caravelas, observou-se que a maior parte dos caranguejos sai de suas galerias antes de morrer e que indivíduos de todos os tamanhos, nas três zonas, foram atingidos. A maior redução da densidade populacional, no entanto, foi registrada na zona de R. mangle, mais inundada, indicando que o agente causador da mortalidade em massa parece estar associado à água. Em julho/2005, seis meses após o início da mortalidade em massa, a amostragem em Caravelas registrou uma redução de 97,6% na densidade de caranguejos em tamanho comercial, valor que, extrapolado para os 11.000ha do sistema estuarino em questão, equivaleria à cerca de 45.000.000 de caranguejos mortos e um prejuízo de pelo menos R$18.000.000,00. A mortalidade em massa de U. cordatus cordatus não parece durar mais que seis meses em cada local afetado e, atualmente, está se expandindo rapidamente no sentido Norte Sul. / The mangrove crab (Ucides cordatus cordatus) is an important fishing resource for the low income communities in Brazil and also plays a role for the environment in the mangrove ecosystem. Massive mortality events of this specie have been registered in many mangrove areas in the Northeast Region of Brazil. The first step of this work was realized from October/2003 to October/2004 and had its main objective the study of the population dynamic of the mangrove crab in one particular mangrove area in Canavieiras/BA (affected by the massive mortality), compared to another mangrove area in Caravelas/BA (non-affected by the massive mortality). After the finishing of this first part of the work, the mass mortality had already reached the mangrove of Caravelas, henceforth the beginning of the second step, which the main objective was to quantify and describe the effects of this mortality in the periods of January/2005 and July/2005. In Canavieiras and Caravelas, four 5 X 5 random quadrats were monthly sampled in one L. racemosa (white mangrove) zone, in the channel bank, in one R. mangle (red mangrove) zone, in between, and in an apicum zone, in the transition for the dry land. Within the quadrats, all the apertures` burrows of U. cordatus cordatus were measured and counted. One crab gatherer removed, whenever possible, the correspondent crabs for biometry. It was also noted the presence of crabs in molting process, egg-bearing females, capped and empty burrows. Additionally, flooding of the quadrats was sampled based upon the algae height on the mangrove prop root. A simple linear regression of the aperture minimum diameter variable in function of the carapace length was done. With the obtained equation all the crab`s burrows measured were transformed in carapace length values. It was observed that the more the zone was flooded the larger size of crab was found and that smaller crabs prevailed in dryer zones in consequence of the recruitment in this habitat. In Canavieiras, 113 recruits (length<0.9cm) were registered on the field survey. All of them were found in burrows belonging to other crabs of less xii flooded areas, mainly on the inferior limit of the apicum zone. Recruitment peaks occurred from June/2004 to October/2004 indicating that the recruits had around three months age. Confirming that the apicum zone plays a role of nursery for the mangrove crab reinforces the importance of this particular environment preservation. The sub-population surveyed in Canavieiras presented an increased density and a shifting mode to higher length classes. This apparent recovery could be linked to sudden appearance of hidden crabs or migration of individuals coming from non-affected zones. Mean population density and carapace length were significantly lower in Canavieiras than in Caravelas, pointing out that apparently Canavieiras crab subpopulation didn`t recover completely from the mass mortality yet. The study in Caravelas showed a differential distribution of crabs with males predominating in flooded red mangrove zone and females preferring dryer zones of white mangrove near the channel banks. During the U. cordatus cordatus mass mortality in Caravelas most of the crabs got out of their burrows before they died. It was also proved that crabs of all sizes from the three zones were affected. Actually the greatest reduction in population density was found in the R. mangle zone, which is the most flooded, indicating that the mortality agent seems to be associated with the water. In July/2005, after 6 months from the beginning of the mass mortality, the Caravelas survey showed a 97.6% reduction of commercial sized crabs density, which means a mortality of 45.000.000 crabs within 11.000ha of mangroves, equal to at least R$18.000.000,00 loss. The mass mortality of U. cordatus cordatus seems to last not more than six months in each place, and presently it is expanding quickly on North to South direction.

Além de sua importância ecológica para o ecossistema manguezal, o caranguejo-uçá (Ucides cordatus cordatus) é um importante recurso pesqueiro para comunidades de baixa renda do Brasil. Eventos de mortalidade em massa desta espécie têm sido registrados ao longo de vários manguezais da costa da Região Nordeste. A primeira etapa deste trabalho foi realizada de outubro/2003 a outubro/2004 e teve como objetivo estudar a dinâmica populacional do caranguejo-uçá em zonas de um manguezal do Município de Canavieiras/BA (afetado pela mortalidade em massa), comparando-o com zonas de um manguezal do Município de Caravelas/BA (não afetado pela mortalidade em massa). Após o término desta primeira etapa, a mortalidade em massa atingiu manguezais de Caravelas, iniciando-se então a segunda etapa, que teve como objetivo descrever e quantificar os efeitos deste fenômeno neste local em janeiro/2005 e julho/2005. Em Canavieiras e Caravelas, foram amostrados mensalmente 4 quadrados aleatórios de 5 X 5m em uma zona de L. racemosa (mangue branco ou manso) na margem do canal, 4 em uma zona intermediária de R. mangle (mangue vermelho) e 4 em uma zona de apicum, na transição entre o manguezal e a terra firme. Dentro dos quadrados, todas as aberturas de galerias de U. cordatus cordatus foram contadas e medidas, e um coletor de caranguejos removeu, quando possível, o caranguejo correspondente para biometria. Também foi registrada a presença de caranguejos em processo de ecdise, de fêmeas ovígeras, de galerias tapadas e galerias vazias. Adicionalmente, foram feitas estimativas da inundação dos quadrados amostrados, com base na faixa de algas nos troncos dos mangues. Através de uma regressão linear da variável menor diâmetro de abertura de galeria em função do comprimento do cefalotórax, chegou-se a uma equação de reta que permitiu a transformação de todas as medidas de galeria em medidas de comprimento de caranguejo. Foi observado que, quanto maior a inundação da zona, maior o comprimento dos caranguejos que nela habitam e que a maior freqüência de caranguejos de pequeno porte nas zonas menos x inundadas, deve-se ao fato do recrutamento ocorrer neste ambiente. Em Canavieiras, foram registrados, em campo, 113 recrutas (comprimento<0,9cm), todos dentro de galerias de outros caranguejos encontrados em áreas pouco inundadas, principalmente no limite inferior da zona de apicum. Os picos de recrutamento ocorreram de junho a outubro de 2004, indicando que os recrutas tinham cerca de 3 meses de idade. A confirmação de que o apicum funciona como um berçário para o caranguejo-uçá reforça a importância de preservação deste ambiente. A sub-população estudada em Canavieiras apresentou um aumento da densidade populacional e um deslocamento da moda para classes de comprimento maiores. Esta aparente recuperação pode estar ligada ao súbito aparecimento de caranguejos escondidos em suas galerias ou à migração de indivíduos vindos de zonas não afetadas. Canavieiras apresentou densidade populacional e comprimento médio de U. cordatus cordatus significativamente menores que Caravelas, indicando que, aparentemente, sua sub-população de caranguejos ainda não se recuperara totalmente da mortalidade em massa. Em Caravelas, registrou-se uma distribuição espacial diferenciada de machos, predominantes nas zonas mais inundadas de R. mangle, e de fêmeas, que predominaram nas zonas menos inundadas de L. racemosa, na margem do canal. Durante a ocorrência da mortalidade em massa de U. cordatus cordatus em Caravelas, observou-se que a maior parte dos caranguejos sai de suas galerias antes de morrer e que indivíduos de todos os tamanhos, nas três zonas, foram atingidos. A maior redução da densidade populacional, no entanto, foi registrada na zona de R. mangle, mais inundada, indicando que o agente causador da mortalidade em massa parece estar associado à água. Em julho/2005, seis meses após o início da mortalidade em massa, a amostragem em Caravelas registrou uma redução de 97,6% na densidade de caranguejos em tamanho comercial, valor que, extrapolado para os 11.000ha do sistema estuarino em questão, equivaleria à cerca de 45.000.000 de caranguejos mortos e um prejuízo de pelo menos R$18.000.000,00. A mortalidade em massa de U. cordatus cordatus não parece durar mais que seis meses em cada local afetado e, atualmente, está se expandindo rapidamente no sentido Norte Sul. / The mangrove crab (Ucides cordatus cordatus) is an important fishing resource for the low income communities in Brazil and also plays a role for the environment in the mangrove ecosystem. Massive mortality events of this specie have been registered in many mangrove areas in the Northeast Region of Brazil. The first step of this work was realized from October/2003 to October/2004 and had its main objective the study of the population dynamic of the mangrove crab in one particular mangrove area in Canavieiras/BA (affected by the massive mortality), compared to another mangrove area in Caravelas/BA (non-affected by the massive mortality). After the finishing of this first part of the work, the mass mortality had already reached the mangrove of Caravelas, henceforth the beginning of the second step, which the main objective was to quantify and describe the effects of this mortality in the periods of January/2005 and July/2005. In Canavieiras and Caravelas, four 5 X 5 random quadrats were monthly sampled in one L. racemosa (white mangrove) zone, in the channel bank, in one R. mangle (red mangrove) zone, in between, and in an apicum zone, in the transition for the dry land. Within the quadrats, all the apertures` burrows of U. cordatus cordatus were measured and counted. One crab gatherer removed, whenever possible, the correspondent crabs for biometry. It was also noted the presence of crabs in molting process, egg-bearing females, capped and empty burrows. Additionally, flooding of the quadrats was sampled based upon the algae height on the mangrove prop root. A simple linear regression of the aperture minimum diameter variable in function of the carapace length was done. With the obtained equation all the crab`s burrows measured were transformed in carapace length values. It was observed that the more the zone was flooded the larger size of crab was found and that smaller crabs prevailed in dryer zones in consequence of the recruitment in this habitat. In Canavieiras, 113 recruits (length<0.9cm) were registered on the field survey. All of them were found in burrows belonging to other crabs of less xii flooded areas, mainly on the inferior limit of the apicum zone. Recruitment peaks occurred from June/2004 to October/2004 indicating that the recruits had around three months age. Confirming that the apicum zone plays a role of nursery for the mangrove crab reinforces the importance of this particular environment preservation. The sub-population surveyed in Canavieiras presented an increased density and a shifting mode to higher length classes. This apparent recovery could be linked to sudden appearance of hidden crabs or migration of individuals coming from non-affected zones. Mean population density and carapace length were significantly lower in Canavieiras than in Caravelas, pointing out that apparently Canavieiras crab subpopulation didn`t recover completely from the mass mortality yet. The study in Caravelas showed a differential distribution of crabs with males predominating in flooded red mangrove zone and females preferring dryer zones of white mangrove near the channel banks. During the U. cordatus cordatus mass mortality in Caravelas most of the crabs got out of their burrows before they died. It was also proved that crabs of all sizes from the three zones were affected. Actually the greatest reduction in population density was found in the R. mangle zone, which is the most flooded, indicating that the mortality agent seems to be associated with the water. In July/2005, after 6 months from the beginning of the mass mortality, the Caravelas survey showed a 97.6% reduction of commercial sized crabs density, which means a mortality of 45.000.000 crabs within 11.000ha of mangroves, equal to at least R$18.000.000,00 loss. The mass mortality of U. cordatus cordatus seems to last not more than six months in each place, and presently it is expanding quickly on North to South direction.

Yellow-eyed penguins have suffered major population declines and periodic mass mortality without an established cause. On Stewart Island a high incidence of regional chick mortality was associated with infection by a novel Leucocytozoon sp. The prevalence, structure and molecular characteristics of this leucocytozoon sp. were examined in the 2006-07 breeding season. In 2006-07, 100% of chicks (n=32) on the Anglem coast of Stewart Island died prior to fledging. Neonates showed poor growth and died acutely at approximately 10 days old. Clinical signs in older chicks up to 108 days included anaemia, loss of body condition, subcutaneous ecchymotic haemorrhages and sudden death. Infected adults on Stewart Island showed no clinical signs and were in good body condition, suggesting adequate food availability and a potential reservoir source of ongoing infections. A polymerase chain reaction (PCR) survey of blood samples from the South Island, Stewart and Codfish Island found Leucocytozoon infection exclusively on Stewart Island. The prevalence of Leucocytozoon infection in yellow-eyed penguin populations from each island ranged from 0-2.8% (South Island), to 0-21.25% (Codfish Island) and 51.6-97.9% (Stewart Island). The high prevalence on Stewart Island represented the infection of 100% of chicks and 83% of adult yellow-eyed penguins when tested by PCR. Sequencing of Leucocytozoon sp. DNA found similarities between infections in yellow-eyed penguin adults and chicks, but differences to Leucocytozoon sp. DNA obtained from Fiordland crested penguins. These findings support the suggestion of cross infection between adults and chicks, and indicate that endemic infection in yellow-eyed penguins is unrelated to that in Fiordland crested penguins. Examination by histology and electron microscopy showed tissue megaloschizonts and circulating round gametocytes. Megaloschizonts up to 440µm diameter showed an affinity for hepatic and splenic tissue and were observed releasing occasional intact cytomeres. Round gametocytes were observed within leucocytes in visceral sections, but not peripheral blood smears. The morphology of Leucocytozoon sp. in yellow-eyed penguins showed similarities to the pathogenic species L. simondi and L. sakharoffi but not L. tawaki. A successful treatment protocol for leucocytozoonosis has not been established, although treatment in a Fiordland crested penguin was able to suppress parasitaemia. The role of Leucocytozoon in yellow-eyed penguins as a cause of morbidity and mortality remains unclear. Further investigation into direct pathogenicity, and the interaction of concurrent disease and environmental influences is required. The findings of this thesis provide potential management recommendations and highlight areas requiring further investigation.

Les épizooties du passé, malgré leur impact économique, sanitaire et social sur les sociétés agro-pastorales anciennes, sont particulièrement mal documentées en archéologie, et leurs millions de victimes semblent n’avoir laissé aucune trace matérielle. Cette thèse s’attache donc à démontrer qu’il est non seulement possible de mettre en évidence des dépôts animaux consécutifs à des crises de mortalité, mais aussi d’identifier les causes spécifiques des décès. Elle adopte une démarche interdisciplinaire, mêlant méthodes et données de l’archéologie, de l’histoire et de la médecine vétérinaire. Deux outils méthodologiques y sont développés. Le premier est une grille d’analyse permettant l’identification des crises de mortalité animales parmi tous les dépôts de faune rencontrés en archéologie. Le second est une démarche de diagnostic différentiel de la nature des crises, reposant sur la confrontation entre les caractéristiques épidémiologiques des dépôts animaux et celles des principales causes de mortalité identifiées aux époques étudiées. Des examens complémentaires ciblés permettent alors la validation des hypothèses diagnostiques obtenues. Une cinquantaine de dépôts animaux témoignant vraisemblablement de crises de mortalité passées sont ainsi identifiés dans la bibliographie, corpus faisant l’objet d’une analyse multicritère diachronique et spécifique. Six assemblages ovins datés de l’Antiquité à la période Moderne font ensuite l’objet d’une étude archéologique et ostéologique approfondie. L’application du protocole d’analyse permet la formulation d’hypothèses diagnostiques dans cinq cas sur six, et dans un cas sa confirmation par la mise en évidence du pathogène incriminé. / Acute episodes of animal mortality had severe impacts on past societies, with lasting economical, sanitary and social consequences. They remain however largely undocumented, in particular in archaeology, where the millions of animal victims described in historical texts appear to have left no material evidence. This dissertation thus strives to explore this discrepancy and to demonstrate that not only is it possible to identify archaeological deposits of mass animal mortality, but that it is also possible to diagnose the specific cause of the deaths. Theses aims are addressed by an interdisciplinary approach, drawing on methods and data from the fields of archaeology, history and veterinary science, and leading to the development of two methodological tools. The first tool allows the identification of animal mass mortality deposits through a flow chart based on objective archaeological criteria. The second presents as a protocol allowing the differential diagnosis and those of the main causes for animal mortalities in that time and place. Selected diagnostic hypotheses are then tested by targeted analyses. This allows us to identify fifty-one archaeological animal deposits probably resulting from mass mortality events in the bibliographical record, and to carry out a multi-criteria analysis of the resulting corpus in a diachronic and a species-specific perspective. Six ovine assemblages dating from the Roman period to the Modern period are then selected for an in-depth archaeological and osteological study. Likely diagnostic hypotheses are identified through our protocol in five cases out of six, one of which is confirmed by the paleoparasitological identification of the suspected pathogen.

Death and decomposition are natural processes that are generally well-understood. However, large events of death, such as mass mortality events (MMEs) are increasing in frequency and their impacts on the ecosystem are largely unknown. These events may have both bottom-up effects from increased nutrient input as well as top-down effects from loss of an ecological functional group by the affected population. Different functional MMEs may result in different top-down effects, creating cascading effects. In Chapter 1, I test the hypothesis that scavenger and herbivore simulated MMEs generate novel bottom-up and top-down effects. Results indicate that MMEs have a significant effect on communities, including on soil chemistry, plant tissue, soil microbes, and soil arthropods. Carrion effects on the community were both a result of biomass (MMEs vs. single carcasses) as well as functional group exclusion (herbivores, scavengers). Further, MMEs may also generate long-lasting community effects due to the size and nature of the disturbance. In Chapter 3, I evaluated the potential long-term of effects of MMEs by sampling an experimental MME that was conducted four years earlier. I found that MMEs generated long-term asymmetrical effects on ecosystems, with some noticeable changes in increased soil nutrients as well as an unexpected effect of biomass on aboveground arthropod communities, with very little effect on belowground soil arthropods. However, studies of long-term decomposition from mass carcasses may expand beyond studying MMEs. Composting of carrion is a continuous disturbance event, with numerous carcasses being deposited in the same location over a longer period of time. In Chapter 2, I analyzed potential effects on the surrounding community at a unique instance of concentrated carcass disposal (5 years old). Significant differences were revealed between samples taken near the compost pit (0 m, 5 m) compared to further distances (10 m, 25 m, 50 m) with calcium being increased away from the pit, different soil microbial communities at the pit than farther distances and increased aboveground arthropod abundance at the pit. These experiments provide us with a greater, holistic understanding of previously understudied events of mass death on community structure and ecosystem function.