The Beauty Of Butterflies
Category: Butterflies, Shimoni Forest | Date: Oct 23 2009 | By: gvikenya
When I first came out here to GVI Kenya in July 2008, I never thought I would become an avid fan of butterflies. To be honest, I would have laughed at the thought (as would many of my friends back home in England!), but I now proud to say otherwise.
As part of our biodiversity research in Shimoni east forest, we monitor butterfly diversity and abundance. We are trying to put together a comprehensive species list, as well as record any changes in species presence, distribution, or changes in abundance. We do this for several reasons.
Charaxes brutus. Here you can see its proboscis very well (the curly red thing) which is used for feeding.
Firstly, butterflies are a very well studied taxon. They are also easily identifiable (they are 90% identifiable by external characteristics), and we can do it ourselves relatively accurately using a book (Larsen 2006). They are also excellent ecological indicators due to their very specific plant and habitat associations. So by monitoring them, we can indirectly monitor the health of the forest.
Charaxes brutus
And finally, they have a trait that plays straight into our hands. They can only take off upwards. This means they are very easy to trap! We use things called canopy traps, which comprise of a board with a pot of bait in the middle. A couple of inches above the board is a cylindrical tube of mosquito netting. So the butterflies fly onto the board to feed on the bait, then when they attempt to fly away, they fly straight into the net!
The face of Charaxes brutus
Once caught, we remove them from the net, and take photographs of the upperside and the underside for later identification. Getting them out of the trap is fairly easy. You grab them by the sides of the thorax, which is the middle section that houses all of the muscles for the legs and wings. You can then use your other hand to slide your finger between the wings and get a grip of the thorax from the top and bottom. The butterflies we catch in the traps tend to be the larger species, and they are very strong! It still surprises me how solid their thorax is, and the strength of their wings. By using this method, we can be sure not to touch their wings or harm the butterfly. Once photographed, we let them fly on their way. An example of the grip we get is shown below.
Papilio demodocus demodocus
I decided to write this blog because Andy (a new edition to GVI) has a camera with an amazing macro setting, allowing us to get some really cool photos of the butterflies. Enjoy the close ups!
Tags: , abundance, bait, biodiversity research, Butterflies, butterfly diversity, canopy traps, cylindical tube, distribution, ecological indicators, habitat association, health of the forest, identification, mosquito netting, papilio demodocus demodocus, plant association, Shimoni east forest, species list, species presence, taxon, thoraxcharaxes brutus, underside, upperside
Bottlenose Abundance In Kenyan Coastal Waters
Category: Cetacean research, Dolphins, Kenya Wildlife Service, Kisite Mpunguti MPA, bottlenose dolphins | Date: Oct 14 2009 | By: gvikenya
Kisite-Mpunguti Marine Protected Area (KMMPA) lies south of Wasini Island (south-coast of Kenya) and covers an area of 39 square kilometres. The KMMPA includes the National Park surrounding Kisite Island and the Marine Reserve surrounding the Mpunguti islands. The KMMPA and the marine wildlife it contains are an important tourist attraction and, as a result, an important resource for Shimoni and surrounding communities. The islands within the KMMPA are surrounded by coral reefs attracting divers and snorkelers to the area. Almost every day dolphin-watching companies operating from Shimoni travel through Wasini Channel to the KMMPA. These tourist dhows most frequently encounter Indo-Pacific bottlenose dolphins (Tursiops aduncus), and less frequently, Indo-Pacific humpback dolphins (Sousa chinensis).
Global Vision International (GVI) Kenya’s main working partner is the Kenya Wildlife Service (KWS). The research conducted by GVI is shaped to satisfy the objectives of KWS, so as to assist them towards better management of the area. All data collected thus far is made available to KWS to aid in management plans of the study area. The Marine Programme is supporting KWS to collate data by conducting vessel surveys, which was focus on assessing the bottlenose dolphin abundance on the area, during the initial phase.
After three years of cetacean research in Kisite-Mpunguti MPA, GVI has estimated the absolute abundance of bottlenose dolphins around 122 individuals, being the second biggest population of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in East Africa. The largest population of the species inhabits in Kizimkazi (south-coast of Zanzibar), and holds between 139 and 179 individuals (estimation made by University of Stockholm in 1999-2002).
Photo-id and mark-recapture methods were the methodology used on both studies to get the estimation. Photo-ID refers to the identification of individuals by distinctive features (shape, outline, natural markings and scarring) of their dorsal fins, flanks and flukes. Some scars will be retained through life, whereas others will be added and may fade through life. The depth and severity of the wound will determine the length of time this may be used for identification. These features allow known individuals to be re-sighted. The re-sighting rate can be plotted on a discovery curve, the plateau of which suggests population size. Photo-ID can also be used to determine residency and demographic data such as inter-birth intervals, patterns of ranging and mortality.
Mark-recapture methods are used to calculate population size from the proportion of known individuals re-sighted over the study period. Mark-recapture models estimate only the size of marked individuals in the population. Therefore, the total population size has been corrected by the correction factor.
Kenya Wildlife Service applied a code of conduct in 2007 for the tour operators to follow when manoeuvring around the cetacean species; unfortunately it is not being fully adhered to as it has only recently been implemented. The levels of interaction between cetaceans and the tour operators are not being monitored or regulated in any way. The impact these activities may be having is unknown. In particular, it’s not known whether current levels of dolphin tourism are sustainable for the area. The first estimation of Indo-Pacific bottlenose dolphins in KMMPA will allow GVI and KWS to measure the levels of tourism impacts, analysing the population dynamics of this species.
Tags: absolute abundance, coral reefs, correction factor, demographic data, depth, divers, dorsal fin, identification, Indo-Pacific bottlenose dolphins, inter-birth intervals, Kenya, Kenya Wildlife Service, kisite island, marine programme, marine reserve, mark-recapture, mpunguti island, national park, photo-ID, severity, shimoni, snorkellers, south coast, surveys, University of Stockholm, wasini channel, wasini island
-
100% of your donation, minus a small bank fee, will go to your intended purpose.
Donations made here are safe.
