Table of Contents
Unlocking Partridge Breeding Success: A Scientific Look at How Rainfall Shapes Survival
Blog Post
Last Updated: July 26, 2025
Introduction
Have you ever wondered what makes the difference between a thriving bird population and one that struggles to survive? For many species, the answer lies hidden in plain sight: the weather. This is especially true for ground-nesting birds like partridges, whose entire life cycle is intimately tied to their environment. This article delves into a fascinating doctoral thesis by Waseem Ahmad Khan to uncover the secrets of partridge breeding success. We will explore how a single environmental factor—rainfall—directly influences the nesting habits, clutch size, and ultimate reproductive triumph of the Black and Grey Francolin partridges in Pakistan. The findings reveal a powerful connection between climate and conservation.
A Deep Dive into Partridge Breeding Success: Insights from Doctoral Research
The following analysis is extracted and adapted from the 2010 PhD thesis, “Studies on the Comparative Ecology of the South Persian Black Partridge, Francolinus francolinus henrici, and the Northern Grey Partridge, Francolinus pondicerianus interpositus, in Lal Suhanra National Park, Bahawalpur, Punjab, Pakistan” by Waseem Ahmad Khan, submitted to the Department of Zoology at Pir Mehr Ali Shah Arid Agriculture University.
The Critical Timing: Understanding the Francolin Breeding Season
The research revealed that the timing of breeding is a crucial component of partridge breeding success. The studies on the flock under the present study revealed that 67% of the Black Francolin females and 52% of the females of the Grey Francolin laid their clutches between mid-March and early May.
However, a low level of egg-laying continued between June and September as well. This suggests that the two species, though they continue laying eggs under the conditions of Lal Suhanra National Park (LSNP) between March and September, have a peak season where the majority of such activities occur.
The Black and Grey Francolins are long-day birds, where the reproductive activity initiates in January. The continuation of this activity is then controlled by the local conditions of temperature and the availability of food. LSNP is located in the middle latitude of the distribution range of these species and can be expected to allow the major part of breeding during spring, though some breeding may continue until September under the availability of food and cover through canal irrigation. (Khan, W. A., 2010, pp. 157, 159).
Building for the Future: Nest Construction Duration
The physical construction of the nest is the first major investment in the reproductive cycle. The data on the average duration of nest construction suggested that:
- The Black Francolin took 15.18 ± 2.45 days (range 12 – 17 days).
- The Grey Francolin took 12.68 ± 3.19 days (range 9 -13 days).
While the time taken is not significantly different between the two species, it was shorter in the Grey Francolin. This efficiency in nest building is an important factor in overall partridge breeding success, as it reduces the time the birds are exposed to predators before laying eggs. (Khan, W. A., 2010, p. 159).
Clutch Size and Egg Laying: A Numbers Game for Partridge Breeding Success
The present studies showed that the Black Francolin had an average clutch size of 6.56±1.47 eggs, while the average clutch size of Grey Francolin was 7.22±1.23 eggs. The clutch size ranged between 2 and 12 in the Black Francolin, and 59 percent of the clutches had 7 – 10 eggs. In the Grey Francolin the clutch ranged between 2 and 13, but in 65 percent of the clutches had 10 eggs.
The clutch size in a species is adjusted to the expected loss of eggs/chick expected by the species. The francolins are ground-nesting birds and are expected to face a high egg predation. A relatively larger clutch size in the Grey Francolin than the Black Francolin may indicate a higher egg predation in the former, which lives in more open places. (Khan, W. A., 2010, pp. 160-161). Optimizing clutch size is a key avian breeding strategy.
The Direct Link: How the Impact of Rainfall on Birds Dictates Survival
The most compelling finding from the research is the direct correlation between annual rainfall and reproductive outcomes. This demonstrates a clear environmental control over partridge breeding success.
During the initial part of the drought years (1993 – 1994), the clutch size remained larger but with an appreciably lower number of nestlings or fledglings produced. The average clutch size exhibited a decrease with the prolongation of the drought (1996).
With the onset of a higher rainfall period (1996 – 2000), the average clutch size, number of nestlings, and fledglings increased. This trend continued into the years with moderate rainfall (2000 – 2001). However, a prolongation of the moderate rainfall period (2002 – 2004) again resulted in an appreciable decrease in all breeding parameters.
This pattern appears understandable, as the level of rainfall increased the food and protection value of the habitat and hence the increased breeding efficiency and reproductive success. The rainfall has a direct effect on the vegetative cover, which may explain a higher breeding performance during high rainfall years. (Khan, W. A., 2010, p. 164). This highlights the profound impact of rainfall on birds and their ability to reproduce successfully.
From Hatching to Fledglings: Measuring Final Partridge Breeding Success
Ultimately, success is measured by how many young survive. The average breeding success was placed at 36.0 ± 3.18% in the Black Francolin and 37.0 ± 3.25% in the Grey Francolin.
No comparative figures for the Grey Partridge has suggested chick survival ratio of 31-35%, production of 1.6 – 2.8 young per adult bird and adult survival rate of 25 – 30%. This gives an indication that the francolin have adequately adapted their breeding strategies to achieve a good hatching success. The number of fledglings per brood was placed at 3.72±0.85 for the Grey Francolin and 3.97±0.58 for the Black Francolin. (Khan, W. A., 2010, p. 163).
These figures, directly influenced by factors like rainfall and habitat quality, are critical for wildlife conservation in Pakistan and beyond. For more on conservation efforts, see the IUCN Red List.
Conclusion
The doctoral research of Waseem Ahmad Khan provides undeniable evidence that environmental conditions, particularly annual rainfall, are a primary driver of partridge breeding success. From the timing of the Francolin breeding season to the final number of surviving fledglings, water availability shapes every step of the reproductive journey. These insights are vital for developing effective conservation strategies that for climate variability and habitat management.
Author Bio: This article is adapted from the PhD thesis of Waseem Ahmad Khan (2010), originally submitted to the Department of Zoology at Pir Mehr Ali Shah Arid Agriculture University. It has been reviewed and edited by the Professor of Zoology editorial team to ensure accuracy, readability, and adherence to E-E-A-T (Experience, Expertise, Authoritativeness, and Trustworthiness) standards.
Disclaimer: Some sentences have been lightly edited for SEO and readability. For the full, original research, please refer to the complete thesis PDF above.
What are your thoughts on how climate affects local wildlife? Share your observations in the comments below! If you found this analysis insightful, please share it with fellow nature enthusiasts and consider exploring our other articles on [avian breeding strategies].
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