Wednesday, March 27, 2013

postheadericon New paper: clouded leopard & prey activity patterns

Sunda clouded leopards terrestrial activity was shown to be mainly nocturnal
On the menu. A samba deer calf may be an important component of
Sunda clouded leopard's diet

At long last we are beginning to churn through the mountain of camera trapping data we have been accumulating over the last few years and to turn it into conservation science. Our most recent paper, available from here, explores the terrestrial activity patterns of the Sunda clouded leopard and those of their potential ungulate prey.

I say potential, because at this stage we really don’t know what these cats are eating – in fact, we know almost nothing about even the basic ecology of these elusive felids. We have a number of anecdotes and sightings of clouded leopards attacking this species, and eating that, which tend to suggest that the clouded leopard has a very varied diet, feasting on a diverse array of mammals from monkeys to muntjacs. But we really don’t have a good handle on what constitutes the most important prey. 

Ultimately, the only way to answer this important question is to collect scat, and poke around to quantitatively assess prey composition – and this is something we are attempting to do right now. Another, indirect approach is to explore overlaps in activity between the predator and their prey – by making use of camera trap data. We might expect predator activity to be often in phase with the periods when those potential prey species are most vulnerable to their method of predation. For some predators, this may result in their activity patterns mirroring those of their prey, as has been shown in several felid-prey systems, but this may not always be the case.
Saving their bacon? Bearded pigs were shown to have a more diurnal activity
pattern when clouded leopard were present - evidence of avoidance?

With this in mind we catalogued the tens of thousands of images for clouded leopard and prey from across our forest study sites, and used some clever wizardry to construct models of each species’ activity patterns. So what did we find? Firstly, Sunda clouded leopard’s terrestrial activity was found to be primarily nocturnal, although crepuscular peaks and some diurnal activity was also evident.  We found that of six potential ungulate prey species, Sunda clouded leopards' activity patterns overlapped most closely with those of sambar deer and greater mouse deer.

Interestingly, we also found that in one of our forest areas where clouded leopard were apparently absent, bearded pigs showed a greater level of nocturnal activity, whe compared to pig populations living alongside the predatory felid. This finding suggests that bearded pigs may be prey species for clouded leopards and they are capable of altering their activity pattern in response to this risk.

Tuesday, March 26, 2013

postheadericon Return to Danum Valley

A glimpse into the life of a clouded leopard. This was the first of
six males we recorded.
Male 2 wanders along a high ridgeline early in the morning

Well it’s been a fair while since I last wrote on here – so high time for another update on our progress with the clouded leopards of Borneo...  

Following directly on from our survey of the Crocker Range the team and I packed up and headed to an old stomping ground – the Danum Valley Conservation Area. 

The last time we were here, way back in 2006, we struggled to get sufficient numbers of photographic detections of clouded leopards to estimate their density. Armed with far more, and arguable much better, camera traps, and hopefully a little more wild cat savvy than in the past, we headed into the forest along once familiar trails and ridges, in search of Sabah’s elusive felids. Not wanting to make things too easy, we set ourselves the hardest task to date (yes, even harder than Crocker’s punishing mountains): 80 camera stations over 150 km2. This took the team a gruelling 6 months to complete, the vast majority of it spent camping at makeshift camp sites – but thankfully it was most definitely worth it.  

One of only two detections of the bay cat. In seven years we've only
recorded this cat  around 30 times
We photographed an amazing 9 nine different animals, six males and 3 females, on 93 distinct occasions, which is a record for us! Marbled cats were coming in thick and fast too, with a total of 53 independent photographic detections, yet we photographed surprisingly few bay cats, only two occasions. Whilst these reddish/grey cats appear to be rarer than chicken’s teeth, and so I wouldn’t expect to get many of them on camera, we actually fared much better back in 2006/7, despite a hugely greater effort. I suspect this is more a reflection of our heightened ability to place cameras in clouded leopard areas as opposed to there being less bay cats – but more on these thought later.  

A rather nice turn-up for the books was the Hose’s civet, which to my knowledge is the first confirmed record for this species in Danum.  Suffice to say, the second crack at Danum Valley has been a complete success, and I thank my team for putting in a huge effort!