Aaaaaargh!!!
Sorry.
But it's been nice and sunny out today, and I've been stuck inside all damn day writing a project proposal for my Research Methods module. While I remain very enthusiastic about my upcoming research project in Peru, I can honestly think of better things to be doing than typing up an outline of it on a day like this.
Here's a (very brief) excerpt, so you guys have an idea of what I've been doing with my afternoon:
Rationale and Overview of Existing Work:
This project seeks to investigate the similarities and more importantly the differences in terms of relative species abundance and dietary ecology of two populations of South American Caimans: those in the Pacaya Samiria and Lago Preto regions of Peru.
Caimans are the most diverse and populous branch of the New World Crocodilians, and of the five Crocodilian species which are found in Peru (American Crocodile, Crocodylus acutus; Spectacled Caiman, Caiman crocodilus; Black Caiman Melanosuchus Niger; Smooth-Fronted Caiman Paleosuchus trigonatus; and the Dwarf Caiman, Paleosuchus palpebrosus), four of them belong to one of the three genera which make up the Caimans (Caiman, Melanosuchus and Paleosuchus) (Vasconcelos et al., 2008).
Like the majority of Crocodilian species, Caimans are often top predators in their habitats, and some (mainly M. niger and C. crocodilus) have been identified as keystone species (Leveque & Mounolou, 2004), which means that their removal from an area is likely to result in ecological imbalance (Primack, 2002; Leveque & Mounolou, 2004). The Black Caiman in particular is recognised as the largest Amazonian predator, with individuals reaching lengths of over 5 metres and a mean adult female length of 2.8 metres (Ross, 1998). The Black Caiman has been heavily exploited since the 1940s for both the leather and bushmeat trades, and has been more intensively hunted than other Caiman species (Britton, 2002). The decline in Black Caiman populations has resulted in degradation of local biodiversity in certain areas (Steel, 1989).
While hunting of Caimans for skins and meat has subsided to a degree in recent years, thanks in part due to increased legal protections of the species, illegal and clandestine harvesting of Caimans still occurs to this day (Da Silveira & Thorbjarnarson, 1999). While the Black and Spectacled Caimans have both endured heavy exploitation in the past, the Smooth-Fronted Caiman has suffered little pressure from the skin trade as a result of possessing highly ossified hides and therefore a low commercial value (Ross, 1998; Britton, 2002). The Spectacled Caiman is known to be the most opportunistic of these three species, with the highest reproductive ability (Ross, 1998; Guerrero et al., 2003) and has recovered more extensively from hunting pressure than the Black Caiman. It theorised that C. crocodilus has potential for sustainable exploitation (Da Silveira & Thorbjarnarson, 1999), which its larger relative, M. niger lacks. Spectacled and Black Caimans are known to fill similar ecological niches, and to exist in almost direct competition in some places. While no two species can exist in 100% competition for resources, it is known that in some areas the abundance of C. crocodilus has been a major hindrance to population recovery of M. niger (Ross, 1998; Britton, 2002)
As things stand, the three Caiman species on which this study centres exist under differing levels of long-term threat. C. crocodilus is listed under Appendix II of CITES as of year 2008, which currently regulates the trade in C. crocodilus and all derived products. The Spectacled Caiman has not been listed under the IUCN Red List since 1988, nor is it cited in the Peruvian Red List (2007), indicating a stable wild population.
M. niger is listed under Appendix I of CITES 2008, which makes any international trade illegal. It is also registered as Endangered on the 2007 IUCN Red List, although the IUCN website states that the species is “Reported to have undergone substantial recovery in several parts of its range. Recent surveys suggest that this species remains widespread and extinction is unlikely...” The Black Caiman is listed as Vulnerable on the Peruvian Red List (Perú Ecologico, 2007).
P. trigonatus is registered in Appendix II of CITES 2008, but there is no commercial exportation of P. trigonatus meat or skins from the area of study. The Smooth-Fronted Caiman is unlisted on the 2007 IUCN Red List, but is classed as Threatened on the Peruvian Red List. Previous studies have shown P. trigonatus to be the least common Caiman species in the Lago Preto and Pacaya Samiria reserves, despite the relatively little pressure it has received from human exploitation.
In exploring the ecological similarities and differences between the three Caiman species in the sites of study, this project seeks to understand how the different species are affected by one another’s presence (or lack thereof). By examining how the dietary habits of the different species overlap, I hope to be able to make predictions about the future feasibility of coexistence between Caiman species in areas where one or more species has suffered decline. By assessing the relative abundance of each species in the two sites, I also hope to be able to recommend future conservation measures in order to ensure the preservation of Caiman species which have suffered as a result of human activity.
References:
Britton, A. (2002). Accessed 2008:
http://www.flmnh.ufl.edu/natsci/herpetology/brittoncrocs/csp_ccro.htm
CITES (2008). Accessed 2008:
http://www.cites.org/
Da Silveira, R & Thorbjarnarson, John B.
1999. Conservation implications of commercial hunting of black and
spectacled caiman in the Mamiraua Sustainable Development
Reserve, Brazil. Biological Conservation 88: pp103-109.
Guerrero SM, Caldero´ ML, de Pe´rez GR & Ramı´rez-Pinilla MP.
2003. Annual Reproductive Activity of Caiman
crocodilus fuscus in Captivity. Zoo Biology 22: pp121-133
IUCN (2007). Accessed 2008:
http://www.redlist.org/
Leveque, C. & Mounolou, J.C.
2004. Biodiversity. Jon Wiley & Sons, Ltd Chichester, UK.
Peru Ecologico, (2007). Accessed 2008:
http://www.peruecologico.com.pe/extincion.htm
Primack, R.B.
2002. Essentials of conservation biology 3rd edition.
Ross, J.P. (ed.).
1998. Crocodiles. Status Survey and Conservation Action Plan [Online]. 2nd Edition.
IUCN/SSC Crocodile Specialist Group.
IUCN, Gland, Switzerland and Cambridge, UK. Accessed 2008:
http://www.flmnh.ufl.edu/natsci/herpetology/act-plan/plan1998a.htm
Steel, R.
1989. Crocodilians. Christopher Helm Ltd, Kent, UK
Vasconcelos WR, Hrbek T, Silveira RD, Thoisy BD, Ruffeil
LAADS, Farias IP.
2008. Phylogeographic and conservation genetic analysis of the black
caiman (Melanosuchus niger). Journal of Experimental Zoology 309A.
I hope you enjoyed that. You know what I have to look forward to now? Writing downtime feedbacks for a LARP game that I won't even be able to ST for, because I have an exam the very next day at 9:30 in the morning. I hope my ASTs can handle it on their own...I have every faith they can. Oh, and if you have read my IC journal recently (sword_of_sutekh) you'll be aware that Tuesday's Newcastle vampire game was a blast. Things could finally be looking up for my character...as in, for the first time since the game started my character might be on course for a victory which isn't a pyric one. Yeah, right.
But it's been nice and sunny out today, and I've been stuck inside all damn day writing a project proposal for my Research Methods module. While I remain very enthusiastic about my upcoming research project in Peru, I can honestly think of better things to be doing than typing up an outline of it on a day like this.
Here's a (very brief) excerpt, so you guys have an idea of what I've been doing with my afternoon:
Rationale and Overview of Existing Work:
This project seeks to investigate the similarities and more importantly the differences in terms of relative species abundance and dietary ecology of two populations of South American Caimans: those in the Pacaya Samiria and Lago Preto regions of Peru.
Caimans are the most diverse and populous branch of the New World Crocodilians, and of the five Crocodilian species which are found in Peru (American Crocodile, Crocodylus acutus; Spectacled Caiman, Caiman crocodilus; Black Caiman Melanosuchus Niger; Smooth-Fronted Caiman Paleosuchus trigonatus; and the Dwarf Caiman, Paleosuchus palpebrosus), four of them belong to one of the three genera which make up the Caimans (Caiman, Melanosuchus and Paleosuchus) (Vasconcelos et al., 2008).
Like the majority of Crocodilian species, Caimans are often top predators in their habitats, and some (mainly M. niger and C. crocodilus) have been identified as keystone species (Leveque & Mounolou, 2004), which means that their removal from an area is likely to result in ecological imbalance (Primack, 2002; Leveque & Mounolou, 2004). The Black Caiman in particular is recognised as the largest Amazonian predator, with individuals reaching lengths of over 5 metres and a mean adult female length of 2.8 metres (Ross, 1998). The Black Caiman has been heavily exploited since the 1940s for both the leather and bushmeat trades, and has been more intensively hunted than other Caiman species (Britton, 2002). The decline in Black Caiman populations has resulted in degradation of local biodiversity in certain areas (Steel, 1989).
While hunting of Caimans for skins and meat has subsided to a degree in recent years, thanks in part due to increased legal protections of the species, illegal and clandestine harvesting of Caimans still occurs to this day (Da Silveira & Thorbjarnarson, 1999). While the Black and Spectacled Caimans have both endured heavy exploitation in the past, the Smooth-Fronted Caiman has suffered little pressure from the skin trade as a result of possessing highly ossified hides and therefore a low commercial value (Ross, 1998; Britton, 2002). The Spectacled Caiman is known to be the most opportunistic of these three species, with the highest reproductive ability (Ross, 1998; Guerrero et al., 2003) and has recovered more extensively from hunting pressure than the Black Caiman. It theorised that C. crocodilus has potential for sustainable exploitation (Da Silveira & Thorbjarnarson, 1999), which its larger relative, M. niger lacks. Spectacled and Black Caimans are known to fill similar ecological niches, and to exist in almost direct competition in some places. While no two species can exist in 100% competition for resources, it is known that in some areas the abundance of C. crocodilus has been a major hindrance to population recovery of M. niger (Ross, 1998; Britton, 2002)
As things stand, the three Caiman species on which this study centres exist under differing levels of long-term threat. C. crocodilus is listed under Appendix II of CITES as of year 2008, which currently regulates the trade in C. crocodilus and all derived products. The Spectacled Caiman has not been listed under the IUCN Red List since 1988, nor is it cited in the Peruvian Red List (2007), indicating a stable wild population.
M. niger is listed under Appendix I of CITES 2008, which makes any international trade illegal. It is also registered as Endangered on the 2007 IUCN Red List, although the IUCN website states that the species is “Reported to have undergone substantial recovery in several parts of its range. Recent surveys suggest that this species remains widespread and extinction is unlikely...” The Black Caiman is listed as Vulnerable on the Peruvian Red List (Perú Ecologico, 2007).
P. trigonatus is registered in Appendix II of CITES 2008, but there is no commercial exportation of P. trigonatus meat or skins from the area of study. The Smooth-Fronted Caiman is unlisted on the 2007 IUCN Red List, but is classed as Threatened on the Peruvian Red List. Previous studies have shown P. trigonatus to be the least common Caiman species in the Lago Preto and Pacaya Samiria reserves, despite the relatively little pressure it has received from human exploitation.
In exploring the ecological similarities and differences between the three Caiman species in the sites of study, this project seeks to understand how the different species are affected by one another’s presence (or lack thereof). By examining how the dietary habits of the different species overlap, I hope to be able to make predictions about the future feasibility of coexistence between Caiman species in areas where one or more species has suffered decline. By assessing the relative abundance of each species in the two sites, I also hope to be able to recommend future conservation measures in order to ensure the preservation of Caiman species which have suffered as a result of human activity.
References:
Britton, A. (2002). Accessed 2008:
http://www.flmnh.ufl.edu/natsci/herpetology/brittoncrocs/csp_ccro.htm
CITES (2008). Accessed 2008:
http://www.cites.org/
Da Silveira, R & Thorbjarnarson, John B.
1999. Conservation implications of commercial hunting of black and
spectacled caiman in the Mamiraua Sustainable Development
Reserve, Brazil. Biological Conservation 88: pp103-109.
Guerrero SM, Caldero´ ML, de Pe´rez GR & Ramı´rez-Pinilla MP.
2003. Annual Reproductive Activity of Caiman
crocodilus fuscus in Captivity. Zoo Biology 22: pp121-133
IUCN (2007). Accessed 2008:
http://www.redlist.org/
Leveque, C. & Mounolou, J.C.
2004. Biodiversity. Jon Wiley & Sons, Ltd Chichester, UK.
Peru Ecologico, (2007). Accessed 2008:
http://www.peruecologico.com.pe/extincion.htm
Primack, R.B.
2002. Essentials of conservation biology 3rd edition.
Ross, J.P. (ed.).
1998. Crocodiles. Status Survey and Conservation Action Plan [Online]. 2nd Edition.
IUCN/SSC Crocodile Specialist Group.
IUCN, Gland, Switzerland and Cambridge, UK. Accessed 2008:
http://www.flmnh.ufl.edu/natsci/herpetology/act-plan/plan1998a.htm
Steel, R.
1989. Crocodilians. Christopher Helm Ltd, Kent, UK
Vasconcelos WR, Hrbek T, Silveira RD, Thoisy BD, Ruffeil
LAADS, Farias IP.
2008. Phylogeographic and conservation genetic analysis of the black
caiman (Melanosuchus niger). Journal of Experimental Zoology 309A.
I hope you enjoyed that. You know what I have to look forward to now? Writing downtime feedbacks for a LARP game that I won't even be able to ST for, because I have an exam the very next day at 9:30 in the morning. I hope my ASTs can handle it on their own...I have every faith they can. Oh, and if you have read my IC journal recently (sword_of_sutekh) you'll be aware that Tuesday's Newcastle vampire game was a blast. Things could finally be looking up for my character...as in, for the first time since the game started my character might be on course for a victory which isn't a pyric one. Yeah, right.
Click to view