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Seabirds' Nesting Performance
in the Grenadines
Wayne Smart*, Natalia CollierƗ
, and Virginie Rolland*,
Environmental Pr...
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  1. 1. Seabirds' Nesting Performance in the Grenadines Wayne Smart*, Natalia CollierƗ , and Virginie Rolland*, Ɨ Environmental Protection in the Caribbean; *Department of Biological Sciences, Arkansas State University. Contact: Background Caribbean seabird populations have shown decreasing trends, particularly in the Southern Grenadines which harbours several regional and globally important bird areas3 . Previous studies have identified factors associated with declining trends including habitat loss/destruction, substantial human disturbance, and introduction of exotic predators (particularly rats). Further threats encountered in foraging habitat (marine environment) are risks of bycatch, contamination, and inadequate productivity of the marine environment possibly caused by climate change 2,3 . Throughout the Grenadines, locals use space that is shared with nesting seabirds. Already, people are noticing a decline in population size, and nesting activity throughout the islands. Fishermen periodically make camps in these areas, which can be a significant factor of poaching. Preliminary surveys in the Southern Grenadines suggest disturbance of seabird colonies by hunters, though protected under the ‘Birds and Other Wildlife Act’. Methods Site Description Six islands (Grenadines) were visited in the Caribbean Sea within the tri-island maritime territory of Grenada [12.0500° N, 61.7500°W]. These islands were accessed using fishing boats first to assess breeding colony location, nesting state and initial number of nesting pairs, and subsequently for nest monitoring. Predator Assessment Five methods1 were used to detect rodents including (1) visual search for evidence of possible predator presence using rodent scat, and tracks; (2) chew blocks, (3) tracking tunnels, (4) baited camera traps, and (5) interviews with locals that frequently visit the islands. Figure 5 Baited indicators used during 2015 nesting season. Left: corrugated plastic, and Right: chew block References 1.Collier, N. 2014. Invasive Predator Surveys of Important Bird Areas and Protected Areas in the Grenadines. Environmental Protection in the Caribbean report No. 48. Unpublished report. 2.Haynes, A.M. 1987. Human Exploitation of Seabirds in Jamaica. Biological Conservation 41: 99-124. 3.Lowrie, K., D. Lowrie, N. Collier. 2012. Seabird Atlas of the Lesser Antilles. Charleston, SC: Create space/ Environmental Protection in the Caribbean. 4.Smart, W. 2014. Grenadines Seabird Project: Nesting Productivity Report. Environmental Protection in the Caribbean report No. 49. Unpublished report. Preliminary Results Colony Count: Birds, both incubating and roosting individuals, were counted using binoculars and spotting scopes. In case birds cannot be easily detected, flush counts, and remote counts were used. Breeding Monitoring: Nests found will be marked using tying wire and flagging tape. The fate of previously marked eggs and chicks will be assessed on subsequent weekly visits. Figure 3. Brown Booby chick Figure 4. Surveyors performing regular counts from neighboring island Objectives To assess: (1) Nesting productivity of seven seabird species. (2) Presence of rats in the seabird breeding territories. Future Study & Perspectives  An on-going second field season will provide additional data on seabird nesting activities to estimate nest survival and perform comparisons among species and islands.  Interviews of locals who use the islands for harvest or other recreational activities are currently being conducted. These interviews will help clarify the extent of human disturbance–related nesting failure. If substantial, interviews will further help understand economic and cultural importance of such activities so that a community– based conservation plan can be proposed.  We will also compare past to present colony locations in terms of vegetation. Poster Presented at the 20th International Meeting of BirdsCaribbean, New Kingston, Jamaica, 25 July—29 July 2015 Acknowledgements Gratitude is extended to those who worked along with this project, both past and present. Special thanks is given to interns Matthew Basil (2014), and Ramon Williams (2015) for their assistance during this study. Figure 1: Sites for Seabird’s Nesting Performance surveys Figure 2. Scene taken from Les Tantes North  Six species were recorded nesting. 47 nests were observed with an over all success of 31% (Table 1).  More nest data are required to discuss the status of birds in the grenadines.  No invasive predators were detected at the bait stations, however, locals reported their presence. Table 1. Seabird Nesting productivity in 2014 (15 May—26 July) at four Grenadine Islands. No. Eggs No. Hatchlings No. Fledglings Success Les Tantes "east" Bridled Tern 5 0 0 0% Brown Noddy 4 0 0 0% Red-Billed Tropbicbird 1 1 1 100% Red-Footed Booby 3 1 0 0% Les Tantes "north" Bridled Tern 7 2 0 0% Brown Noddy 3 0 0 0% Diamond Rock Brown Booby 3 2 2 67% Brown Noddy 1 0 0 0% Laughing Gull 4 0 2 50% The Sisters Bridled Tern 2 0 0 0% Brown Booby 1 0 0 0% Brown Noddy 3 1 0 0% Laughing Gull 15 12 11 73% Total 52 19 16 31%