Pathways to paradise or highways of hell

If you travel overseas (especially to Australia) you are likely to hear a lot of sheep jokes about New Zealanders. This makes sense when you realise that nearly 40% of the total land area in New Zealand is sheep and beef farms (our conservation estate is 31% of the total land area) (see Jennifer Pannell’s super cool infographic below). These farms also contain 25% of the native vegetation in New Zealand. This means that farms provide an excellent opportunity for improving our native biodiversity.

I’m part of a National Science Challenge project that has been looking at just that; considering how the connectivity of bush patches on farms can help facilitate the movement of native species across the landscape. Connectivity can be thought of in two ways. Structural connectivity refers to how the vegetation is arranged, such as spacing between habitat patches or corridors of vegetation between them, while functional connectivity refers to species-specific needs and how species interact with landscape structures, such as how far birds can fly between bush patches and how large the patches need to be. So, if you are considering connectivity from the perspective of a robin, then patches of vegetation may need to be as close as 100m from each other, compared to a kereru which can fly 10s of kilometres between habitat patches.

It’s all well and good to enhance connectivity to help the robin, tūī or kōkako disperse and move throughout the landscape, but is this enhanced connectivity also facilitating the movement and populations of invasive mammalian predators? That would be a perverse outcome for bird species whose habitat we are aiming to improve. This is what I’m aiming to find out during my PhD. In particular I’ll be looking at feral cat movement on farms and how the distribution and arrangement of native vegetation influences their movement. Understanding cat movement on farms in relation to vegetation connectivity will help with both managing biodiversity and farmers hoping to minimise diseases, such as toxoplasmosis, on their farms.

Cathy is a PhD student in the Centre for Biodiversity & Biosecurity, School of Biological Sciences, University of Auckland. She is studing feral cat movement and landscape connectity in agroecosystems. She is supervised by Margaret Stanley, Hannah Buckley, Brad Case and Al Glen.

Just like time, intelligence is relative

By Juliane Gaviraghi Mussoi

Animal cognition can be defined as the mechanisms in which animals acquire, process, store and act on information of their environment (Shettleworth, 1998).

Figure 1. Simplified representation of the cognitive mechanism (1.Acquire, 2.Proccess, 3.Store, 4.Act)

As a research area, animal cognition is relatively new and full of unanswered questions. Testing for cognitive ability in animals can be challenging. Many experiments are human-centric and based on what humans are good at, e.g. tool use, language, numerical counting… It is also complex to measure something we don’t fully understand. For instance, how can we test the cognitive ability of a mosquito when we can barely grasp how they perceive the world? But it is still in our nature to try to differentiate “us” (humans) from “them” (other animals).

The more we learn about what animals can do, the less humans seem unique. For example, tool use, which was thought to be an ability exclusive to humans, is also present in monkeys, birds, elephants, dolphins and even invertebrates such as octopuses and ants. Some animals are also able to manufacture their own tools by shaping leaves and sticks.

Figure 2.  New Caledonian crow probing tree bark with a stick for insects. Image credit: James St Clair.

Further, there are some types of cognitive abilities that humans are very poor at and some animals excel. Spatial memory is one of them. Some species of birds and rodents , store food for times when resources are scarce and remember the exact location of their caches after weeks or months. Black-capped chickadees depend on stored food to survive during harsh winters and it is estimated that they can store up to 100 000 individual food items per year. Personally, I can’t relate to that. Every morning I forget where I put my keys and cell phone.

One of the biggest challenges in animal cognition research is to design tests that are relevant to the animal being studied, while still being comparable to other species. An animal that relies on smell to recognize peers, would be unlikely to pass a mirror self-recognition test. Not because it is not self-aware, but because the mirror does not provide the information needed for a species that relies on olfactory (smell) cues instead of visual cues.

Figure 3. This cartoon illustrates one of the issues when testing for cognitive ability. Artist unknown.

Another example are bees, which are faster than most animals when it comes to associating a colour with a food reward. However, that does not mean bees are “smarter”, it reflects their well-developed (and necessary) ability to find colourful flowers to get food in their natural environment.

Therefore, whenever you get the urge to compare a chimpanzee with a 3-year-old child or to say that a dog is smarter than a fish, try to remember that there are different types of “intelligence” and they are all relative.

Juliane Gaviraghi Mussoi is a Ph.D. student from the University of Auckland. Her research focuses on vocalization, ornamentation and cognition of New Zealand fantails and Australian magpies. She is supervised by Dr. Kristal Cain and Dr. Margaret Stanley.