28 February 2016

Up Close And Personal

Large-Spotted Genet (Grootkolmuskejaatkat - Genetta tigrina) in a small cave at the Woody Cape

This photograph was taken last year at the Woody Cape using the Birdcam 2.0. The Birdcam is a strange camera trap. Despite some major issues it still manages to come through with some wonderful surprises, like this photograph above.

The biggest advantage the Birdcam has is the fantastic white flash which works surprisingly well at close range.

Like most commercial camera traps the Birdcam has a fixed focus, but the focus can be manually adjusted. This can produce very sharp images when the animal is in the sweet spot.

Although I do like the benefits that IR cameras offer, I still think there is a place for a good white flash camera trap. I really wish that the recent advancements in mobile phone technology will start to filter through to camera traps and pave the way for a few good quality modern white flash commercial camera traps to enter the market. The color night photographs are particularly useful for identifying small mammals (something the IR models struggle with a bit).

30 January 2016

Getting Shrewed

A (likely) Greater Red Musk Shrew (Grootrooimuskusskeerbek - Crocidura flavescens) at Sonstraal Farm

2015 turned out to be a rough year.

It started out fine, but somewhere along the line it got derailed.

From about the middle of the year more and more of my energy was going towards dealing with some unfortunate changes that took place at work. It is always hard for me to deal with things outside of my control, especially when it effects things important to me. As a result I was left with little energy to spend on my camera trapping and other hobbies. I also didn't plan any vacation trips either and slowly things just kept on spiraling downwards.

A (suspected) Forest Shrew (Bosskeerbek - Myosorex varius) at Koeberg Nature Reserve

The energy I could muster was spent on upgrading the mapping functionality in WildLog. Progress has been slow, but it is finally starting to take shape. I'm really looking forward to wrapping it up and to start using it with my real dataset. I have a fun idea for a blog post about it when the programming side of things gets wrapped up.

Again the (probable) Forest Shrew

I had some Shrew photos lying around which I wanted to post. Identifying Shrews can be soooo hard. I really get the impression that not all species are well defined yet. Very little information is available for some species, and I'm sure that other listed species are most likely more than one real species grouped together.

The (plausible) Greater Red Musk Shrew in almost all its glory

Looking ahead, I have an exciting holiday trip planned for late April. I don't think I'll get to any camera trapping before then, but when I get back I would like to start a new camera trapping project.

Until then I'll most likely focus on wrapping up WildLog and maybe see if I can do an interesting day trip or two towards the end of summer when things cool down a bit (it's been a hot summer).

Is this (possible) Forest Shrew a stargazer?

08 August 2015

Camera Trap Photo Tricks 102

Cropping, one of the biggest enigmas of photography.

Cropping can have a huge effect on your photographs. It can either make or break a photograph. I have to admit that I'm definitely not an expert at cropping or framing pictures. Still, I don't let that prevent me from at least trying to find a good crop for the photos I upload to this blog.

Form my (limited) experience the following concepts come to mind when I think about cropping a camera trap photo:
  • What aspect ration will work best?
  • Will landscape or portrait work best?
  • What should be the focus point of the image?
  • How large do I want the animal to be in the final crop?
  • How should I crop the photo to "tell a story"?
  • What are the limiting factor? (For example resolution, border, obstructions, etc.)
There is a lot of information readily available that deals with cropping and framing in general, and I don't want to repeat it here. I would rather try to illustrate some of the common issues I encounter when cropping camera trap photos.

There is a bit of a love hate relationship between cropping and camera trapping. On the one hand you have very little control over the final image, especially where the animal will be in the photograph, as a result the initial (original) crop is usually rather bad. On the other hand you can use cropping to try and alleviate this problem by making a smaller but better crop of the original image.

However in some situations no amount of cropping can save the image...

[Original] Steenbok (Steenbok - Raphicerus campestris) at Koeberg Nature Reserve

Sometimes a little cropping can still make a meaningful improvement. For example, even thought the full animal isn't in the crop you might still be able to do the background scenery more justice with a good crop.

With some photographs the animal is simply too far away. In these situations cropping can be a very useful tool to bring the photograph to life.


[Original] Caracal (Rooikat - Caracal caracal) at Koeberg Nature Reserve

This slightly closer landscape crop still contains the essence of the original image

I think this much closer landscape crop starts to lose the essence of the original image

Sometimes it is worth playing around with the cropping orientation (landscape vs portrait) or even a square crop.

Square crops usually don't look very good, but can be practical, especially for small images

An important aspect of cropping is "telling a story". A good crop can really help to tell the story of the photograph. This is why the portrait crop (below) is my favourite. It tells the story of this Caracal walking across the expansive barren white dunes at Koeberg Nature Reserve.

My favourite crop, striking a balance between the animal, environment and atmosphere/story

Another size related issue is that the animal itself can be just too small.


[Original] Four-Striped Grass Mouse (Streepmuis - Rhabdomys pumilio) at Tygerberg Nature Reserve

An extremely close crop of the mouse

The image above illustrates another big problem frequently encountered while cropping: pixelation. When the crop becomes too small the pixels become more and more noticeable.

Or the reverse, the animal is just too big or close to the camera. In these situations there isn't much you can do to improve the image.

[Original] Bushpig (Bosvark - Potamochoerus larvatus) at Woody Cape section of Addo Elephant National Park

Another useful feature of cropping is that it can help when you need to rotate a photograph.

[Original] Blue Duiker (Blouduiker - Philantomba monticola) at Woody Cape

The rotated and cropped image

Cropping is often used to place the subject in the center of the image and can get rid of unnecessary, non-essential or undesirable parts of the image.

[Original] Black-Backed Jackal (Rooijakkals - Canis mesomelas) at Suikerbosrand Nature Reserve

Not perfect, but a potentially better crop

The photograph above illustrates another aspect of cropping very well, a too tight crop. The image would have been a lot beter if there was more space in front of the Jackal. When possible try to leave the animal enough space to interact with it's environment. This is closely related to "telling a story".

Instead of always centering on the animal's face, it might be better to allow some space to "follow the animal's gaze".

[Original] Grey/Common Duiker (Duiker - Sylvicapra grimmia) at Koeberg Nature Reserve

Not all crops are better, and I actually think the original (above) looks better than the crop below.

This crop didn't come out very well

Sometimes one is lucky and the original photograph "contains" a good crop. For example, the image below can be cropped to a more pleasing aspect ration and the focal point can be moved slightly to the Jackal's face, leaving enough space ahead of the animal to get the feeling of movement.

[Original] Black-Backed Jackal at Suikerbosrand

I feel that the final crop tells the story better than the original

Cropping is a vast area and I've only managed to scratch the surface of it, nonetheless I hope you will look with new eyes at the world of cropping.

[Original] Common Duiker at Koeberg Nature Reserve
"Oh oh, I'm being framed!"

20 June 2015

Porcupines Feetures

The Cape Porcupine is the largest rodent in this part of the world, and as a result also the largest rodent photographed earlier this year on the small farm near Paarl.

Porcupine (Ystervark - Hystrix africaeaustralis) amongst some denser vegetation

Porcupines can still, in this day and age, be found living close to human settlements in the more rural areas and along the urban edge. Given that there is enough natural cover, food and a place for them to rest underground during the day they can live happy lives.

The most intriguing camera trap photo I got was of this individual with a peculiar injury.

Porcupine with a strange injury on its right hip

I'm not sure what might have caused the injury. Maybe from fighting, or maybe it got injured by some of the old farm equipment? The property is also on the corner of a highway and a large road, but I think any collision with a vehicle would have been fatal. Porcupines are common victims of motor accidents, the scene of the crime usually marked by a plethora of broken quills scattered across the road. I'm sure that most of the casualties can be attributed to their nocturnal habits and tendency to not run away when threatened but instead rely on their formidable armour the deter attackers.

This photograph also nicely illustrates two interesting characteristics of Porcupines: their quills and feet.

Porcupines are covered by harsh think hair and spiky quills, but not all quills are the same. The quills have specialised into a range of spikes, from small short spikes to long thick strong spikes used for defence. The long thin wires on their heads give them that characteristic sleek hairstyle. They also have remarkable whiskers.

The other feature that can be seen very well in the photograph is the feet. They have a very human-like quality. This is because both primates (humans) and rodents (Porcupines) use plantigrade locomotion to get around. It can be difficult to see and appreciate the similarity in smaller rodents, but since Porcupines can grow over 80 cm long and weigh up to 30 kg it makes it easier to see the resemblance.

To wrap things up here is a video of the family a few weeks later visiting one of the small ponds at the farm.

Video: Porcupines at the pond

29 May 2015

The Data Pond

I've been camera trapping on a small farm just outside the town of Paarl (which is situated very close to Cape Town) from January to April this year.

Bushnell camera trap at the farm's pond

The camera trap at the small farm pond in the photograph above got some interesting results. The initial camera trap positioning was fairly good and I got a Cape Grysbok and Water Mongoose early on.

Cape Grysbok (Kaapse Grysbok - Raphicerus melanotis) getting a drink

However the mongoose decided that my camera placement could do with some adjustment.

Marsh Mongoose (Kommetjiegatmuishond - Atilax paludinosus) freelance camera trap adjuster

After the adjustment I didn't get a decent photograph of any more mammals, but the camera did focus on a small part of the bank and as a result captured many photographs of the resident water birds.

Black-Crowned Night Heron (Gewone Nagreier - Nycticorax nycticorax) sneaking past the camera

Many of the photographs had multiple species visible at once and as a result it took a while to capture the data. In the end I recorded 325 observations over the 3 week period. This is a sizable amount, and I was curious whether the reporting feature I recently added to WildLog might show some interesting trends.

First up is a chart showing the number of observations recorded compared to the duration of the observation (using 30 second intervals). The shape of the curve is fairly standard, with a very large amount of very short observations followed by a sharp drop. What I find interesting is that there is a high number of observations extending past 30 seconds and into the 3-4 minute mark. Clearly these water birds at the pond spend more time feeding in a small area, before moving on, compared to more conventional camera trap subjects and locations.

 
Another benefit of getting such a high number of observations over suck a short period of time is that you can compare the exact time the observations were made too each other, without having to worry too much about the change in season, sunrise, etc. In this case the data shows a huge spike in activity between 5:30am and 8:30am.


Looking at the bar chart that maps each time to a relative time of day category (based on season and sunrise) the same trend is visible. Sunrise and early morning is clearly the peek of activity at the pond.

 
The last chart I want to put in this blog post is one showing the number of observations recorded during each 24 hour period. Looking at the chart it seems like there might be a possible pattern: days with high activity are usually followed by days of low activity. I'm assuming this can be attributed to the birds' feeding behaviour. These species will be mostly feeding on plants, small animals, insect, invertebrates, etc. and it makes sense to allow the prey species some time to recover before feeding again in the same area.


Another interesting observation is that the birds would often feed together. There are many benefits to doing so, ranging from better protection from predators, to the fact that the disturbance caused by one bird feeding might make things easier for the other bird to catch its prey. The different species usually don't compete directly with each other for the same food.

The animated GIF below is somewhat on the large size (about 8 MB), but I'm going to try and include it in this blog post because I think it helps to illustrate life at the pond very well. The following species can be seen in the clip:
  • Yellow-Billed Duck (Geelbekeend - Anas undulata)
  • Common Moorhen (Grootwaterhoender - Gallinula chloropus)
  • Cape Wagtail (Gewone Kwikkie - Motacilla capensis)
  • Cape Weaver (Kaapse Wewer - Ploceus capensis)
  • Black Crake (Swartriethaan - Amaurornis flavirostra)
  • Little Grebe (Kleindobbertjie - Tachybaptus ruficollis)

About 20 minutes of bird activity at the pond condensed into a few seconds

For those wondering, in total this set recorded 19 species. The 6 species mentioned above was by far the most numerous visitors.

During my camera trapping excursions I came across a dead Yellow-Billed Duck and was able to get some close-up photos.

Close-up of the wings of a dead Yellow-Billed Duck

The Yellow-Billed Duck is a type of Dabbling Duck and has the grooves along the edge of the bill to help with feeding.

The duck's bill

I'm really enjoying the new reporting tools in WildLog. Even though these findings are nothing strange or ground-breaking I still learn a lot (first hand) from them. It is fun to see the data take shape after going through the hard work of capturing it.