The Beautiful Sea Creatures

Posted by Carolina Lara @carislaris

In the process of becoming half New Zealander, I have invariably found myself spending a lot of time at the beach. I grew up in a semi-deserted area of Mexico so the marine environment was unknown to me, particularly the vast seabird community. From this I’ve learnt two things, not all birds live in the forest and not all seabirds are seagulls. In New Zealand/Aotearoa, around a third of the ca. 80 species of seabirds are endemic. Among the most amazing ones we find the largest albatross in the world, the magnificent toroa; the tiny and unfortunately endangered dotterel/tūturiwhatu; the Chatham Island oystercatcher/tōrea; the Westland petrel/tāiko, and the fascinating  New Zealand storm petrel (believed extinct and re-discovered in 2003), to mention a few.

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New Zealand storm Petrel

Why are seabirds important? Well as explained by Moller et al (2000), seabirds often breed in dense colonies and their abundance, high guano loads and soil burrowing makes them a “keystone species”, species that play a large role in the prevalence and population levels of other species within their environment.  Any change in seabirds abundance would likely affect important soil processes (nitrification, plant regeneration) and therefore abundance of other animal species. Most importantly, seabirds shape the ecology of terrestrial communities by acting as a link between the sea and the land because they import marine-derived nutrients into terrestrial communities.

Despite the great value of seabirds in maintaining of ecosystems, their abundance has dramatically decrease worldwide, with an estimated 70% decline over the last 60 years, representing the deaths of 230 million birds. Some of the threats seabirds face are: plastic pollution (plastic rubbish is found in 90% of birds guts), overfishing, toxic pollution, nest predation by invasive species (e.g. rats) and the effects of rising sea temperatures on their food supply. New Zealand hasn’t escaped this trend with the dotterel/tūturiwhatu and yellow-eyed penguin/hoiho making it to the news recently, not many individuals of each species are left in the wild.

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Dotterel/tūturiwhatu at Martin’s Bay

Is there still hope for our seabirds? Yes, with adequate management programs to get rid of invasive species in seabird colonies, regulating fishing to avoid birds getting caught in fish nets, reducing our plastic consumption and the establishment of conservation areas we can expect a recovery in seabird abundance in the long run. For now, let’s go out and appreciate these beautiful sea creatures.

 

CalisCarolina Lara M. is a PhD Candidate within the Centre for Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland. Her research interests focus on seed dispersal networks within fragmented landscapes. She is supervised by Margaret StanleyJason Tylianakis, Karine David, and Anna Santure.

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Detecting drought with remote sensing – some preliminary results

Posted by Kshama Awasthi

Green vegetation growth is a useful indicator of drought events and vegetation indices such normalised difference vegetation index (NDVI) and enhanced vegetation index (EVI) are often used for the assessment of agricultural drought. I have been evaluating the sensitivity of these indices to detect the impact of drought on forest areas in various parts of Aotearoa New Zealand. In general, a higher NDVI or EVI value represents more healthy vegetation so I expected to see a decline in the vegetation indices during drought.

Picture1Right: NDVI values for the Hunua Ranges for the month of March

There was a slight decline in NDVI in 2013 during the drought. To confirm the role of drought in the decline in NDVI, I am using soil moisture deficit (SMD) data from NIWA. SMD is calculated using incoming daily rainfall (mm), outgoing daily potential evapotranspiration (mm) and fixed available water capacity that is the amount of water in the soil reservoir that plants can use.

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Above: Soil moisture deficit and vegetation health indices for summer months at Hunua Ranges.

As expected, the NDVI (r2=55%) and EVI (r2=65%) both show a strong relationships with SMD which indicates NDVI and EVI values are responsive to drought.

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Above: Relationships between soil moisture deficit and NDVI and EVI vegetation indices for summertime at Hunua Ranges, 2006-2017.

EVI values decreased more in response to drought conditions as compared to NDVI, indicating that EVI is more sensitive then NDVI on the onset of drought conditions.

Since the relationship between EVI and SMD is stronger than the correlation between NDVI and SMD, EVI can be the better indicator of drought detection in forest as compared to the NDVI as EVI provides improved sensitivity in high biomass regions while minimizing soil and atmosphere influences.

This is the result for the Hunua Ranges and calculations for other sites are still ongoing.

kshama Kshama Awasthi is an MSc student supervised by Cate Macinnis-Ng and Jay Gao

Microchipping: A force for good

Posted by Kathy Crewther @kat_crewz

Earlier this week, a Taranaki Regional Council hearings committee recommended that feral cats be defined as cats which are “unowned, unsocialised, and have no relationship with or dependence on humans” (Taranaki Regional Council, 2017). This will please some cat lovers since submissions had been made to define a feral cat as “any cat without a microchip, collar, or harness” with some owners fearing that this could equate to a ‘licence to kill’ their wandering, microchip-free pet moggie. But it does raise the question: Why haven’t you microchipped your cat?

According to the New Zealand Companion Animal Council, 44% of NZ households have a pet cat compared to 28% with dogs, making cats the most popular pet in the country. However, while 71% of dog owners had microchipped their pet, only 31% of cat owners had done so (New Zealand Companion Animal Council Inc., 2016).

Every day, websites like petsonthenet.co.nz and neighbourly.co.nz have listings of anxious owners desperate to find their missing cats and – yes – some of them are microchipped. However, the chances of being reunited with your furry family member are much higher if people know how to find you. This means not only microchipping your cat, but also making sure you keep your contact details up to date after you register the microchip.

I have had two recent experiences which illustrate the value of the microchip. Earlier in the year, one of my colleagues took in a distressed cat that looked like he had been wandering for some time. When she took him to the vet to check for a microchip, she discovered that the cat had been missing for 5 months and had somehow found his way from Botany to Takapuna! Thanks to an up-to-date microchip registration, kitty was reunited with a very happy and grateful owner.

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Distance is no object to cats who will sometimes secretly (or accidentally) hitch a lift

When a cat I had never seen before turned up repeatedly on my doorstep, the lack of a microchip did not mean a death sentence for this fluffy wanderer, but it did mean I was unable to reunite her with her owners, despite placing listings on various websites. Instead, Dorey (as she is now known) was able to be re-homed with a very caring family and no longer shows any desire to wander.

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In the absence of a microchip, Dorey was unable to be reunited with her owners, but fortunately a new family was found for her

Moral of the story: microchipping is there to help protect your beloved pets and to ensure that, in the event they go missing, you are reunited with them as quickly as possible. And, at around $45-80, microchipping is one of the most affordable aspects of pet ownership. So, please, if you haven’t already done it – microchip your cat.

 

twitter picKathy Crewther is a PhD candidate in the School of Biological Sciences at the University of Auckland. She is investigating the management of domestic cats and their impact on urban wildlife.

 

 

References:

Decision Report of Council in respect of submissions to the Proposed Regional Pest Management Plan and Taranaki Regional Council Biosecurity Strategy, Document number: 1952447. (October 31, 2017). Retrieved November 2, 2017, from https://www.trc.govt.nz/assets/Documents/Plans-policies/PestPlanReview/RPMP-TBS-DecisionReport2017-web.pdf

New Zealand Companion Animal Council Inc. (2016). Companion Animals in New Zealand 2016. Auckland, New Zealand.