Animal keepers use the term enrichment to describe the introduction of environmental stimuli into the surroundings of caged animals. In recent years, “environmental enrichment” also known as behavioral enrichment, providing animals with challenges, opportunities, and stimulation that are species-appropriate, has grown more popular in zoos and aquariums. A latest study does, however, identify potential to “diversify the enrichment types being supplied and the species being examined.”

The study conducted by the University of Exeter and Sparsholt College, Hampshire, looked into whether zoo enrichment is based on evidence of what each species requires. It was discovered that this was true for specific animals as well as certain forms of enrichment, but the quantities of both could be larger, especially the samples of certain species of animals. “Based on our findings, we would encourage zoos to continue enrichment, but with a stronger emphasis on using available knowledge on what works for each species. Keepers should also consider what behaviors are being taught and whether there is evidence that this behavior is normal and good in the long run.” stated University of Exeter’s Dr. Paul Rose.

The research looked at a database of peer-reviewed works as well as two magazines for zoo workers. Almost 77 percent of the enrichment articles identified focused on mammals, with 11 percent on birds, 6 percent on considerable species, 4 percent on reptiles, and only a few on some other species. This emphasis on popular species may result in greater and higher-quality enrichment for some species than others. What’s more, in the case of mammals, the application of biological evidence to inform this enrichment was inconsistent.

There are many ways to enrich an animal’s surroundings such as adjusting animal care, forming social groups, and enhancing sensory stimulation. The purpose of any enrichment program should be to generate ideas for providing a species-appropriate stimulating environment that encourages positive behaviors while keeping in mind that both species and individuals will have varied demands.

When prehistoric man arrived in new parts of the world, something strange happened to the large animals. They suddenly became extinct. Smaller species survived. The large, slow-growing animals were easy game, and were quickly hunted to extinction. Now something similar could be happening in the oceans.

That the seas are being overfished has been known for years. What researchers such as Ransom Myers and Boris Worm have shown is just how fast things are changing. They have looked at half a century of data from fisheries around the world. Their methods do not attempt to estimate the actual biomass (the amount of living biological matter) of fish species in particular parts of the ocean, but rather changes in that biomass over time. According to their latest paper published in Nature, the biomass of large predators (animals that kill and eat other animals) in a new fishery is reduced on average by 80% within 15 years of the start of exploitation. In some long-fished areas, it has halved again since then.

Dr. Worm acknowledges that the figures are conservative. One reason for this is that fishing technology has improved. Today's vessels (船)can find their prey using satellites and sonar, which were not available 50 years ago. That means a higher proportion of what is in the sea is being caught, so the real difference between present and past is likely to be worse than the one recorded by changes in catch sizes. In the early days, too, longlines (多钩长线) would have been more filled with fish. Some individuals would therefore not have been caught, since no baited hooks (带饵钩)would have been available to trap them, leading to an underestimate of fish stocks in the past. Furthermore, in the early days of longline fishing, a lot of fish were lost to sharks after they had been hooked. That is no longer a problem, because there are fewer sharks around now。

Dr. Myers and Dr. Worm argue that their work gives a correct baseline, which future management efforts must take into account. They believe the data support an idea current among marine biologists, that of the “shifting baseline". The idea is that people have failed to detect the massive changes which have happened in the ocean because they have been looking back only a relatively short time into the past. That matters because theory suggests that the maximum sustainable yield （产量）that can be cropped from a fishery comes when the biomass of a target species is about 50% of its original levels。. Most fisheries are well below that, which is a bad way to do business.

The word “soul” pops up everywhere. We may speak of a very polished performance, but without soul, or describe an athlete as the soul of his team. In each case, “soul” means deep feelings and core values. As neuroscientist Antonio Damasio wrote 20 years ago in his book Descartes’ Error. “Feelings form the basis for what humans have described for thousands of years as the soul or spirit.”

Today, studies increasingly show that many non-humans feel. Elephants appear to feel grief, while dolphins and whales express joy, or something much like it. Experiments have shown that rats become anxious when seeing surgery performed on other rats and that when presented with a trapped lab-mate and a piece of chocolate, they will free their trapped brother before eating.

None of the these will come as a surprise to pet owners or anyone who has observed virtually any kind of animal for any length of time. Science is rediscovering what Charles Darwin, in his book The Expression of the Emotions in Man and Animals (1872), concluded that the variations between humans and other species in their ability to feel and express their emotions are differences in degree rather than in kind.

It could even be argued that other creatures are more conscious of feelings than humans are, because they possess a primary form of consciousness: they are aware of themselves and their environment but are less burdened by complexities such as reflection and thoughts that typify (是……的典型) human consciousness. They live closer to the bone, so to speak. Jeffrey Masson, author of When Elephants Weep, has remarked that animals possess feelings of “undiluted (纯粹的) purity and clarity” compared to the “seeming opacity (费解) and inaccessibility of human feelings.” Furthermore, we should consider that humans may not experience the full range of feelings found in the animal kingdom. As Humane Society ethologist Jonathan Balcombe points out: “in light of their sometimes vastly different living circumstances and sensory abilities, other species may experience some emotional states that we do not.”

Sentience — the ability of an organism (有机体) to feel — is fundamental to being alive. What we feel deeply is what drives us, for good or ill. So if humans have souls, they must be more about sentience than consciousness. In his book Pleasure: A Creative Approach to Life, the late psychoanalyst Alexander Lowen reflected on these connections, proposing that “The soul of a man is in his body. Through his body a person is part of life and part of nature…If we are identified with our bodies, we have souls, for through our bodies we are identified with all creation.” As long as we are alive — and therefore feeling — we are connected to one another and to the natural world. We are, in a word, ensouled.

Thanks to the Internet, there’s a steady stream of examples of animals demonstrating sympathy, from an ape saving a bird to a gorilla protecting a three-year-old boy when he fell into her enclosure. A particularly striking case of animal gratitude occurred in 2005 off the California coast, where a female whale was found caught in nylon ropes used by fishermen. As narrated by Frans de Waal in The Age of Empathy: Nature’s Lessons for a Kinder Society, “The ropes were digging into the body. The only way to free the whale was to dive under the surface to cut away the ropes. The divers spent an hour on the task. The most remarkable part came when the whale realized it was free. Instead of leaving the scene, she hung around. The huge animal swam in a large circle, carefully approaching every diver separately. She nuzzled (用鼻子轻触) one, then moved on to the next, until she had touched them all.”

Soul may be a profound (深奥的) matter of fellow feeling. The stronger the capability of a given species for fellow feeling, the more that species can be said to exhibit soulfulness. To view things in this way offers an important step in humanity’s progression toward understanding its place in Creation — and toward appreciating the inheritance we hold in common with other sentient beings on this increasingly small and fragile planet.