ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)

[peter]

AMUR TIGER RESEARCH - THE CLAYTON S. MILLER THESIS - III


G - GLOBAL POSITIONING SYSTEM (GPS)

" ... From the tiger's perspective, the goal of allocating prey to tigers based on annual kill rates through management is to ensure that tigers maintain a consumption rate sufficient to survive and reproduce. While kill rate is an important ecological parameter, ultimately it is the consumption rate that matters most for tiger conservation. Recent advances in GPS collars gave enabled carnivore researchers to gather detailed location data that can be used to estimate kill rates ... " (pp. 9).

Miller and all others involved in his thesis, for the first time, develop " ... methods for estimating Amur tiger kill rates and consumption rates from GPS data to estimate annual kill rates on large ungulates in the Russian Far East ... " (pp. 10).    

To estimate tiger kill and consumtion rates with GPS data, Miller and those helping out " ... combined GPS data collection with field investigation of potential kill sites to estimate tiger kill rates as the number of days between kills and in terms of consumption rates. To estimate the number of kills, we processed GPS location data into clusters and ground-searched most of the largest clusters as putative kill sites ... " (pp. 12).  

Miller assumed that " ... tigers not disturbed by humans rarely leave edible portions of a carcass. As human disturbance in the backcountry of the SABZ is limited, we assumed tigers consumed 79% of each prey item ... " (pp. 16).

 
H - THE COLLARED TIGERS

From 2009 to 2010, two adult females, two adult males and one sub-adult female were collared. These five tigers were each monitored from 0 to 481 days, with a combined total of 697 days for all tigers. A bit meagre, one would think. The reason was " ... human-tiger conflicts and technology failures limited data collection ... " (pp. 16). Below is an overview of what happened. 

- The first collar malfunctioned soon after tigress Pt94 was released. This tigress was never seen again. 

- Adult male tiger Pt90 was captured in the fall of 2009, but data from his collar could not be downloaded " ... until the collar was retrieved after this tiger was killed during a human-tiger conflict in January 2010. Post-mortem analysis showed that Pt90 was infected with canine distemper virus when he was killed ... " (pp. 16-17).

- Pt97 was a sub-adult female captured in the fall of 2009. She was monitored for five weeks only before she died from unknown causes in the SABZ.

- Pt99 was a tigress captured in a human-tiger conflict situation in February 2010 (she was shot by a hunter, but survived). She was translocated into a remote forested area with healthy prey populations.

- Pt100 was a young adult male captured in the fall of 2010. His collar malfunctioned 99 days after capture.

So the collars malfunctioned in two tigers (Pt94 and Pt100), whereas pt99 was shot and relocated and adult male tiger Pt90 died as a result of a conflict that most probably was a result of the disease he had contracted. Sub-adult tigress Pt97 died of unknown causes. The only tiger not shot, diseased or injured was tigress Pt94. One can only conclude that Amur tigers face tough conditions.

Tigress Pt99, at 130 kg., is the heaviest weighed in the last two decades. The adult male was about average in weight, whereas the young adult male was quite heavy for his age.      
 

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