One of the most intriguing things about studying animal populations over a long period is the emergence of stark differences in the fortunes of individuals. Some flames shine bright and long, while others flicker low or burn out almost immediately. What causes these differences? Well, they could be to do with environmental conditions at critical times, or the quality of parental care and inherited genes, or they could just be the result of plain, blind luck. The answer is probably a complex mixture of all these factors, but it is tempting to think that one characteristic, one incident, one decision, ultimately led to everything that followed. Think of our own lives. How often are we drawn to question and bemoan our destinies, agonising over what we should have done differently?
This Sunday I went looking for colour-ringed Peregrine Falcons in the suburbs of Cape Town. I’ve been monitoring the Peninsula Peregrines for nearly three decades, trying to follow the fortunes of as many uniquely marked individuals as I can. One of the falcons I spotted yesterday was a male, perched on a cell mast in the Fish Hoek area that has been used by a locally resident bird for some years. It turned out this was a different adult male, who has probably replaced the previous incumbent (who has probably died).
The old Fish Hoek bird saw 13 summers before his apparent demise, but only managed to raise five young in his time. Compare these numbers with those of another recent fatality: the male from the site on the Red Cross Children’s Hospital in Rondebosch lived just one year more than the Fish Hoek bird, but raised 37 young in his lifetime! Clearly something, or some combination of things, led to these two birds achieving markedly different levels of success in their lives. Hope springs eternal that my study will one day reveal how and why their paths became so divergent.
Another favourite perch of the Fish Hoek male was the cross on the steeple of his local church. I wonder if he ever sat there in the twilight of his life, pondering his fate, trying to figure out where it all went wrong…?