Thursday, 23 April 2015

RIP: the cascades male

We knew there was something odd going on pretty early on. The radio telemetry signal was not coming from anywhere near the Cape Rockjumpers I could see on the other side of the valley by the predawn glow. One of the birds was the female we knew from the cascades territory, female blue, named after the blue ring on her right foot. I presumed the male with her was her mate, the cascades male, and that we were dealing with a case of a dropped telemetry tag. The birds foraged actively among the rocks, and engaged in a bit of what appeared to be playful socialization. All seemed well. I lost sight of them when they flew to the west facing slope, as they headed for the early morning sunshine which would add some warmth to the morning that had started at 5 degrees Celsius. Krista got a view on them and carried on the observations, while I headed back to trying to find the dropped tag, always a mission when the signal bounces around the rocks, crags and valleys.

After about an hour Krista let me know that she’d lost sight of the pair of rockjumpers close to where I was looking for the tag. I tried to locate them, and tried and tried. They were nowhere to be seen. Eventually, we started a sweep search of the territory. Two hours later, and still nothing. That was when I started to get worried. We knew these birds, they were always here. Where were they now? Come to think of it, had there been any rings on the male bird? Krista didn’t recall seeing any.

Maybe we weren’t just looking for a tag, maybe we were looking for a tag with a dead bird attached. I headed back to where I had been looking, and project volunteer Brian brought up another telemetry set. With this equipment within half an hour I was picking up a strong signal, and narrowed down my search to a boulder. Putting down the equipment, I peered around it. There were feathers, lots of feathers, the outcome of the search now seemed inevitable. A bit more searching, and the red and green rings that the cascades male had worn were found lying in the dirt, with more feathers and some bones. Finally, stretching and grabbing blindly under the rock I pulled out the chewed radio telemetry tag.

Judging by the location under the boulder, together with the feathers and damaged tag, the cascades male had been killed by a mongoose, and probably several weeks earlier. It was a sad moment – this was the first male that I had deployed a tag on, in November of last year. We had followed him and female blue twice a month for four months. He had become rather relaxed in our company, often foraging unconcerned within meters of us.

The male we had seen in the company of female blue was most likely the rival male with whom we had seen the cascades male tussling on most mornings. One tragedy, another’s opportunity it would appear. We spent the rest of the day looking out for female blue, but our guess is she’s made herself a new friend. No time for mourning in nature – you’ve got to get on with life.

So here’s to you cascades male, male 206. Thanks to you we now know so much more about the secret life of Cape Rockjumpers.  He represents the first ever recovery of a ringed Cape Rockjumper in the SAFRING database. 

The following photo of the cascades male was taken by project volunteer Dr Dean Portelli:

Monday, 6 April 2015

What makes a good blog post? An analytical approach applied to the Blue Hill Escape blog

When I first started blogging, I remember googling the question: what makes a good blog post? Back then I wanted to set up a blog that was part diary, part marketing tool for the guest house. Of course it has evolved along the way and I've posted on a variety of topics with nature and fynbos as the central themes. However, its all just been winging it and I've never really known what makes a good blog post except from a personal perspective; except now I have data to look at.

So, I've been blogging ad-hoc for four years now, accumulating around 200 posts along the way. Finally, using my blog as the data I can can try and answer the following questions:

  1. Do longer posts (those with more words) get more hits?
  2. Do posts with more pictures get more hits?
  3. Do posts written on a particular day get more hits (from my facebook feed I know we're more social on the weekend for instance)?
  4. Is hit rate a function of time: i.e. are older posts getting more hits just because they have been around longer, or am I getting more hits now because I have more followers?
  5. Finally, and perhaps of greatest interest: does the sentiment of a post have an influence on hit-rate? By sentiment I mean are posts that are positive or negative in their overall tone impacting hit rate. This is an important question to a conservation biologist, where the fear is that the bad news that we are continually surrounded by may be putting people off. Sentiment is a difficult thing to measure, and I use the sentiment analysis tool Semantria to find out.
The short answer: ALL of these are important, but some were important in ways I did not expect.

  1. Do longer posts get more hits?

Generally, longer posts do get more hits, but this is almost certainly because they are more searchable over time. i.e. more words does not equal a good post, but is good for long-term exposure. So that answers question 4: clearly I have not been making inroads into gaining more readers, but I don't blog regularly enough and I don't advertise, so I can't complain.

  1. Do posts with more pictures get more hits?

Definitely. The more photos the better. Picture paints a thousand words bla bla. Since I hardly ever uploaded more than 20 photos, I cannot advise if too many pictures is a bad thing, but I'd guess that 10 or so pics is a good rule of thumb.

  1. Do posts written on a particular day get more hits?

The results here surprised me. For me: Wednesday is a good post day (mid-week hump?), Thursday is very bad, and surprisingly, so is Saturday. Maybe too much competition from other digital media on a Saturday? Overall, my Saturday posts have been shorter, so perhaps that is a confounder using these measures given the influence of time on hit rate as Friday is a good day.

  1. Does the tone of an article influence hit-rate?

Anyone who works in the conservation field knows that there are many depressing stories around: climate change, species in endanger of extinction, pollution, over-population etc etc. We also know that going on about these things doesn't exactly make one the life of the party. So I try not focus on the negative when I write.

Quantifying tone is pretty difficult to do objectively. To do this I used a cool analytical tool developed by the company Semantria You can try it out – they have a live-demo on their website where you can post an article and it analyses words, phrases, names and themes to come out with an overall score.

So while I was encouraged to see that on balance my writing is neutral to positive overall, the trend is towards negative articles having higher hit-rate. Overall, the Semantria score was a poor predictor of hit-rate though.

In summary, there are many factors to take into account when writing up a good blog post, and of course here I have only looked at trends from my blog – factors could be very different for other blogs in other situations!

The technical bits (of interest to data analysts only):

I used the R package rvest to scrape and summarise my posts. I then used the MuMIn package and the dredge function to choose the best model from these two starting models:

model <- glm(views~charactercount+semantria_score+photos+blogageDays+day, data=blogdata, family=poisson)
lmmodel <- lm(log(views)~charactercount+semantria_score+photos+blogageDays+fday, data=blogdata)

I ran both because the data followed a poisson distribution, but log transformed data were gaussian and I find linear models easier to interpret.

The best poisson model contained all variables in the final model, while the log transformed data model dropped the Semantria score. Code and data available on request.

Tuesday, 17 March 2015

RIP: Butch the leopard

One of the first leopard photos our camera traps revealed was a male leopard that was collared by the Landmark Foundation deep in the Baviaanskloof. The collared fitted was a radio telemetry collar that stored gps points of the leopards movements. However, the data was never downloaded, partly because searches were being conducted in the Baviaanskloof and not on the periphery. Cape Mountain leopard territories are huge (some here are easily over 50 000ha) and so getting to the right place to download data can be an issue.

It became clear over time that he was the resident male leopard. Our last photo of him was obtained in 2013.

Earlier this year Landmark Foundation decided they would have another attempt at catching the leopard we had named Butch in order to remove the collar. However, just to the south of us it appears a leopard had been killed... and the remains were identified as Butch. The radio collar had been vandalized, suggesting human interference. This is the story from the Landmark Foundation perspective:

Our property forms just a very small part of a territory of any Cape Mountain Leopard, yet we are very sad to learn of his demise, its almost like loosing a friend. 

Friday, 27 February 2015

Van Stadens revisited

So far I have enjoyed every trip undertaken to the ever-in-bloom van Stadens Wildflower Nature Reserve, just outside Port Elizabeth. All the trips have been bird ringing trips, of which I've blogged about one visit before, and on each visit I've handled a new species of bird.

The last two nights I camped at Falcon Rock with Ruby and Dan (UK volunteers) and we headed to the reserve on two mornings to meet up with Ben and Jerry. Jerry is Ben's Master's student looking at differences in foraging strategy between male and female Cape Sugarbirds, to try and understand why females appear to be more stressed (they weigh less) in hot years.

Tuesday morning was cold and wet, but as it was overcast, we had a good haul for the morning, with over 50 birds dominated by sunbirds and sugarbirds. My new birds for the day were Yellow-eyed Canary and Green-spotted Wood-dove. We were assisted by Nick, another of Ben's students who will be starting a Master's on Rufous-eared Warbler (not found at Van Stadens but a bird of arid Karoo), and he was put to good use extracting birds from the widely dispersed nets.

Dan seeks shelter from the drizzle while Ruby and Jerry ring birds

Checking for wing molt and beautiful colours on this Emerald Spotted Wood-dove

Synchronized cataplexy tests (tonic immobility)

In their hands: A young Greater Double-collared Sunbird male doing tonic time before its release

Amethyst Sunbird males are gorgeous

as are King Proteas

Young Lesser Honey Guide

Wednesday dawned not much better, we'd been listening to rain from our tents all night, but it cleared enough to put up some nets. It was gratifying to get several recaptured Cape Sugarbirds during the morning – nice to know they are still around, and it gives a chance for Jerry to show he is getting independent samples for his research.

On each visit it has also been impressive to see the fruits of the labours of the Friend's of Van Stadens. This time recent work was very obvious: the large gum trees in the middle of the reserve had been felled. While raptorphiles might get uppity about this, I approve as exotic trees are the biggest current threat to Fynbos integrity. On a tangent, I don't believe that cutting down the large exotic trees that raptors like to nest in will impact raptor populations as the raptos are simply choosing the largest trees to nest, which happen to be exotics, but would then nest in the next best thing, albeit smaller stunted endemic tree species. I don't believe there is evidence they would simply not nest.

Also – I was very excited to see the first signs of a bird hide being built passing through the arboretum. Two thumbs up to Mr and Ms Goossens for their efforts! I for one can't wait to use the final product. If their energy and enthusiasm for the environment was virulently contagious we'd be living on a more beautiful and healthier planet.

Sunday, 15 February 2015

Fynbos Birds: Conservation Status and impacts of Climate Change

A summary paper focusing on our six main endemic birds of the Fynbos came out in the journal Bird Conservation International earlier this year. I calculated bird densities, population sizes, identified preferred fire successional preference and examined ranges from SABAP2 data. I also used the atlas data to identify trends for the Fynbos birds and a suite of other endemic birds (simply reporting rate changes and range changes).

A bit of a concern is that the group of Fynbos endemic birds is generally the worst off, with Cape Rockjumper and Protea Seedeater fairing particularly badly comparing between atlas projects. While the degree of population change that this really represents is still an item of discussion, it was worthy to note that these changes were well explained by the species tolerance (or intolerance) to warm temperatures as calculated from a physiology project conducted in 2013 by Robyn Milne. In fact, in the absence of any other explanatory variables, climate change (particularly warming) seems to be the best reason for these changes at this time. After all, Mountain Fynbos is little modified by the usual host of problems associated with human land conversion. For Cape Rockjumper in particular, which stresses out at just over 30 degrees (the lowest of 12 species tested), it appears from various angles that range is limited by temperature. With an increase of between 0.5 and 1 degree, this translates to a vertical loss of space of around 100 meters, which isn't a good thing if you're already a species that prefers mountain tops – there is no where left to go, and a temperature increase of 4 degrees will mean there will no more comfortable living space left for this species.

How exactly hotter temperatures may influence behaviour and breeding is now the focus of the research of the Hot Fynbos Birds project team. Krista Oswald is just starting a Masters project on the topic and we're hoping for some good news from this in the next year or two.

The official paper can be downloaded from the publisher website here
and a copy is available here

Too hot for his own good: A male Cape Rockjumper
Krista Oswald and Kate Beer monitoring Cape Rockjumpers. No easy task!

Related Posts Plugin for WordPress, Blogger...