Why does climate impact species distribution?5 answersClimate impacts species distribution due to its ability to alter habitats and environmental conditions, influencing the survival and range of various species. Climate change can lead to shifts in temperature, precipitation patterns, and other factors, affecting the availability of suitable habitats for different species. For example, studies on invasive plants and their biological control agents show how climate change can disrupt historical community assemblages and impact species interactions. Similarly, research on amphibians in West African savannahs demonstrates how future climate change can lead to the loss or gain of suitable habitats for different species. Understanding these impacts is crucial for conservation efforts and predicting how species distributions may change over time in response to climate fluctuations.
What are the key factors that influence species distribution modeling?4 answersKey factors influencing species distribution modeling include the choice of sampling type, resolution of environmental conditions, model transferability, incorporation of species interactions, and accuracy challenges. Sampling type, such as segment- or areal-based, significantly impacts model relevance. Model transferability is crucial, affected by geographical distance, degree of extrapolation, and species traits like distribution size and lifespan. Incorporating species interactions is challenging but essential for accurate predictions, requiring consideration of spatial scales and diverse training data. Accuracy challenges stem from various factors like environmental and species data, ecological differences, computational resources, model choice, and spatial resolution. These factors collectively emphasize the complexity and importance of making informed decisions in species distribution modeling.
The contraction of distribution range of mammals?4 answersThe contraction of mammal distribution ranges is influenced by a combination of factors including large body mass, increase in air temperature, loss of natural land, high human population density, small body size, generalist diet, and high reproductive rates. Environmental variables, such as mean annual precipitation, have a greater effect on species persistence and extinction compared to anthropogenic variables. The three main null models proposed for range contraction (demographic, contagion, and refuge) do not consistently conform to observed contraction patterns, suggesting the need for alternative models that account for both relative position and intensity of human impacts. Past climate change, particularly Quaternary range contractions and reduced suitability, predicts current mammal extinction risk, especially for threatened and small-bodied species. Habitat destruction from anthropogenic land use change is the main driver of range contraction, causing an average 23% loss of species ranges thus far, with tropical, small-ranged, and endangered species being particularly impacted.
How to do marine mammal species identification?5 answersMarine mammal species identification can be done using various methods. One approach is to use photo identification, where researchers analyze the shape and markings on marine animals' body parts to manually monitor them. Another method involves using convolutional neural networks (CNNs) to identify the calls of marine mammals based on their vocalizations. This one-step algorithm combines detection and classification, automatically learning the features of different marine mammal calls and positioning them with bounding boxes in a spectrogram. Acoustic signatures can also be used for classification, where features like 1D Local Binary Pattern (1D-LBP) and Mel Frequency Cepstral Coefficient (MFCC) are fused and a Support Vector Machines (SVM) classifier is employed. Additionally, genetic information can be used for species identification, such as the ISSR-HRM method, which offers a new approach for marine mammal species identification with high discrimination success rates. These methods provide valuable tools for researchers to accurately identify and classify marine mammal species.
What are species distribution models?5 answersSpecies distribution models (SDMs) are widely used methods in wildlife management, ecology, biogeography, and conservation. They involve the use of species data and environmental data to predict the distribution and abundance of species. SDMs rely on various techniques and the choice of technique depends on data availability and desired outcomes. Accuracy is a challenge in SDMs and can be affected by factors such as environmental data, species data, computational resources, and spatial resolution. SDMs are important for biodiversity studies and can be used to estimate species abundance, identify suitable habitats, and inform conservation planning. They can also be extended to integrate different data sources and improve model predictions.
What are the results of the two year sighting survey of marine mammals?5 answersThe two-year sighting survey of marine mammals yielded several important results. In the South Atlantic and Southern Ocean, the survey recorded sightings of various species, including dolphins and baleen whales, in the Exclusive Economic Zones of St Helena, Tristan da Cunha, and South Georgia and the South Sandwich Islands. In the deep-sea region off the coast of Luanda, Angola, the survey documented the occurrence of marine megafauna, such as humpback whales, sperm whales, and various dolphin species, including the first confirmed record of right whales in Angolan waters since the early 1900s. Additionally, a study conducted in Granite Canyon, California, used paired, independent searches to document inter-year changes in the offshore distribution of gray whales, providing valuable insights into their migration patterns. Lastly, a shipboard survey of the Northeast Atlantic estimated abundances of various non-target species, including fin whales, humpback whales, sperm whales, killer whales, harbour porpoises, and dolphins, revealing an increase in the abundance of humpback whales since the 1990s.