在劉克襄的《野狗之丘》及《虎地貓》中，主要以臺北的野狗、香港的街貓為對象，觀察牠們的生態活動和行為習性。然而，牠們雖是不同物種，卻因為同是遭到遺棄，於是有著共同的身分―城市的廢棄物，宛如追求發展下的多餘，並被認為會破壞秩序及景觀而被迫驅離，甚至遭受捕捉與撲殺。實際上，「餘」的字義並非只有多出之意，而是也有殘剩跟無盡等意涵，端看語境脈絡而定，具有多重的詮釋可能。本文欲以此概念切入，探討二書中的地理空間及生命型態，了解動物的生存實與景觀變遷、人類行為相關。就前者而言，書中的野狗、街貓大多在城市的邊緣餘部求生，以期獲得一絲生機；不過，當為了追求發展導致環境劇烈變動之時，牠們的生存餘地便也常被剝奪。以後者來說，作者在字裡行間不時流露對動物依賴人類成性的擔憂，認為此會造成主體性喪失，有失能甚至死亡的危機；但是，牠們並非只能被動承受，而是具有能動性，以開創生命的嶄新可能，而這也是劉克襄的書寫動機，希望能藉此省察人類與動物之間的倫理、互動關係，並提升對動物的尊重與保護。

In Ka-Shiang Liu’s Hill of Stray Dogs and Fu Tei Cats, the discussions mainly focus on the behaviors and habits of stray dogs and street cats in Taipei and Hong Kong respectively. Although dogs and cats are different species, they have a common identity, that is “the remains of the city”, it means they are all abandoned animals by human. Because of this status, those which are seen as the breaker of order and landscape of the city are often driven away, trapped and caught, and this is the motivation of author`s writing and recording. Regarding the Chinese definition of “Yu”（餘）, there are many implications that rely on the context. In this article, we will discuss the Geographic Space and Life Concern in Ka-Shiang Liu’s works to realize the life dilemmas of animals. About the former, the stray dogs and street cats live in the edge of the city, but the environmental change and the pursuit of the development will cause their life crisis. As to the latter, the author concerns that these animals will lose their subjectivity and be disabled if depending on human deeply. But, as a matter of fact, they also have agency to create a new life after being abandoned or captured. All in all, Ka-Shiang Liu wants to prompt everyone to rethink the ethic and interaction lines between human beings and animals by writing these works, and promote the rights, protection and respect for animals.